/*> interp.c <*/ /* Simulator for the MIPS architecture. This file is part of the MIPS sim THIS SOFTWARE IS NOT COPYRIGHTED Cygnus offers the following for use in the public domain. Cygnus makes no warranty with regard to the software or it's performance and the user accepts the software "AS IS" with all faults. CYGNUS DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. $Revision$ $Author$ $Date$ NOTEs: We only need to take account of the target endianness when moving data between the simulator and the host. We do not need to worry about the endianness of the host, since this sim code and GDB are executing in the same process. The IDT monitor (found on the VR4300 board), seems to lie about register contents. It seems to treat the registers as sign-extended 32-bit values. This cause *REAL* problems when single-stepping 64-bit code on the hardware. */ /* The TRACE and PROFILE manifests enable the provision of extra features. If they are not defined then a simpler (quicker) simulator is constructed without the required run-time checks, etc. */ #if 1 /* 0 to allow user build selection, 1 to force inclusion */ #define TRACE (1) #define PROFILE (1) #endif #include "config.h" #include #include #include #include #include #include #include #ifdef HAVE_STDLIB_H #include #endif #ifdef HAVE_STRING_H #include #else #ifdef HAVE_STRINGS_H #include #endif #endif #include "getopt.h" #include "libiberty.h" #include "callback.h" /* GDB simulator callback interface */ #include "remote-sim.h" /* GDB simulator interface */ #include "support.h" /* internal support manifests */ #include "sysdep.h" #ifndef SIGBUS #define SIGBUS SIGSEGV #endif /* Get the simulator engine description, without including the code: */ #define SIM_MANIFESTS #include "engine.c" #undef SIM_MANIFESTS /* This variable holds the GDB view of the target endianness: */ extern int target_byte_order; /* The following reserved instruction value is used when a simulator trap is required. NOTE: Care must be taken, since this value may be used in later revisions of the MIPS ISA. */ #define RSVD_INSTRUCTION (0x7C000000) #define RSVD_INSTRUCTION_AMASK (0x03FFFFFF) /* NOTE: These numbers depend on the processor architecture being simulated: */ #define Interrupt (0) #define TLBModification (1) #define TLBLoad (2) #define TLBStore (3) #define AddressLoad (4) #define AddressStore (5) #define InstructionFetch (6) #define DataReference (7) #define SystemCall (8) #define BreakPoint (9) #define ReservedInstruction (10) #define CoProcessorUnusable (11) #define IntegerOverflow (12) /* Arithmetic overflow (IDT monitor raises SIGFPE) */ #define Trap (13) #define FPE (15) #define Watch (23) /* The following exception code is actually private to the simulator world. It is *NOT* a processor feature, and is used to signal run-time errors in the simulator. */ #define SimulatorFault (0xFFFFFFFF) /* The following are generic to all versions of the MIPS architecture to date: */ /* Memory Access Types (for CCA): */ #define Uncached (0) #define CachedNoncoherent (1) #define CachedCoherent (2) #define Cached (3) #define isINSTRUCTION (1 == 0) /* FALSE */ #define isDATA (1 == 1) /* TRUE */ #define isLOAD (1 == 0) /* FALSE */ #define isSTORE (1 == 1) /* TRUE */ #define isREAL (1 == 0) /* FALSE */ #define isRAW (1 == 1) /* TRUE */ #define isTARGET (1 == 0) /* FALSE */ #define isHOST (1 == 1) /* TRUE */ /* The "AccessLength" specifications for Loads and Stores. NOTE: This is the number of bytes minus 1. */ #define AccessLength_BYTE (0) #define AccessLength_HALFWORD (1) #define AccessLength_TRIPLEBYTE (2) #define AccessLength_WORD (3) #define AccessLength_QUINTIBYTE (4) #define AccessLength_SEXTIBYTE (5) #define AccessLength_SEPTIBYTE (6) #define AccessLength_DOUBLEWORD (7) #if defined(HASFPU) /* FPU registers must be one of the following types. All other values are reserved (and undefined). */ typedef enum { fmt_single = 0, fmt_double = 1, fmt_word = 4, fmt_long = 5, /* The following are well outside the normal acceptable format range, and are used in the register status vector. */ fmt_unknown = 0x10000000, fmt_uninterpreted = 0x20000000, } FP_formats; #endif /* HASFPU */ /* NOTE: We cannot avoid globals, since the GDB "sim_" interface does not allow a private variable to be passed around. This means that simulators under GDB can only be single-threaded. However, it would be possible for the simulators to be multi-threaded if GDB allowed for a private pointer to be maintained. i.e. a general "void **ptr" variable that GDB passed around in the argument list to all of sim_xxx() routines. It could be initialised to NULL by GDB, and then updated by sim_open() and used by the other sim_xxx() support functions. This would allow new features in the simulator world, like storing a context - continuing execution to gather a result, and then going back to the point where the context was saved and changing some state before continuing. i.e. the ability to perform UNDOs on simulations. It would also allow the simulation of shared-memory multi-processor systems. */ static host_callback *callback = NULL; /* handle onto the current callback structure */ /* This is nasty, since we have to rely on matching the register numbers used by GDB. Unfortunately, depending on the MIPS target GDB uses different register numbers. We cannot just include the relevant "gdb/tm.h" link, since GDB may not be configured before the sim world, and also the GDB header file requires too much other state. */ /* TODO: Sort out a scheme for *KNOWING* the mapping between real registers, and the numbers that GDB uses. At the moment due to the order that the tools are built, we cannot rely on a configured GDB world whilst constructing the simulator. This means we have to assume the GDB register number mapping. */ #ifndef TM_MIPS_H #define LAST_EMBED_REGNUM (89) #endif /* To keep this default simulator simple, and fast, we use a direct vector of registers. The internal simulator engine then uses manifests to access the correct slot. */ static ut_reg registers[LAST_EMBED_REGNUM + 1]; static int register_widths[LAST_EMBED_REGNUM + 1]; #define GPR (®isters[0]) #if defined(HASFPU) #define FGRIDX (38) #define FGR (®isters[FGRIDX]) #endif /* HASFPU */ #define LO (registers[33]) #define HI (registers[34]) #define PC (registers[37]) #define CAUSE (registers[36]) #define SRIDX (32) #define SR (registers[SRIDX]) /* CPU status register */ #define FCR0IDX (71) #define FCR0 (registers[FCR0IDX]) /* really a 32bit register */ #define FCR31IDX (70) #define FCR31 (registers[FCR31IDX]) /* really a 32bit register */ #define FCSR (FCR31) #define COCIDX (LAST_EMBED_REGNUM + 2) /* special case : outside the normal range */ /* The following are pseudonyms for standard registers */ #define ZERO (registers[0]) #define V0 (registers[2]) #define A0 (registers[4]) #define A1 (registers[5]) #define A2 (registers[6]) #define A3 (registers[7]) #define SP (registers[29]) #define RA (registers[31]) static ut_reg EPC = 0; /* Exception PC */ #if defined(HASFPU) /* Keep the current format state for each register: */ static FP_formats fpr_state[32]; #endif /* HASFPU */ /* The following are internal simulator state variables: */ static ut_reg IPC = 0; /* internal Instruction PC */ static ut_reg DSPC = 0; /* delay-slot PC */ /* TODO : these should be the bitmasks for these bits within the status register. At the moment the following are VR4300 bit-positions: */ #define status_KSU_mask (0x3) /* mask for KSU bits */ #define status_KSU_shift (3) /* shift for field */ #define ksu_kernel (0x0) #define ksu_supervisor (0x1) #define ksu_user (0x2) #define ksu_unknown (0x3) #define status_RE (1 << 25) /* Reverse Endian in user mode */ #define status_FR (1 << 26) /* enables MIPS III additional FP registers */ #define status_SR (1 << 20) /* soft reset or NMI */ #define status_BEV (1 << 22) /* Location of general exception vectors */ #define status_TS (1 << 21) /* TLB shutdown has occurred */ #define status_ERL (1 << 2) /* Error level */ #define status_RP (1 << 27) /* Reduced Power mode */ #define cause_BD ((unsigned)1 << 31) /* Exception in branch delay slot */ #if defined(HASFPU) /* Macro to update FPSR condition-code field. This is complicated by the fact that there is a hole in the index range of the bits within the FCSR register. Also, the number of bits visible depends on the MIPS ISA version being supported. */ #define SETFCC(cc,v) {\ int bit = ((cc == 0) ? 23 : (24 + (cc)));\ FCSR = ((FCSR & ~(1 << bit)) | ((v) << bit));\ } #define GETFCC(cc) (((((cc) == 0) ? (FCSR & (1 << 23)) : (FCSR & (1 << (24 + (cc))))) != 0) ? 1 : 0) /* This should be the COC1 value at the start of the preceding instruction: */ #define PREVCOC1() ((state & simPCOC1) ? 1 : 0) #endif /* HASFPU */ /* Standard FCRS bits: */ #define IR (0) /* Inexact Result */ #define UF (1) /* UnderFlow */ #define OF (2) /* OverFlow */ #define DZ (3) /* Division by Zero */ #define IO (4) /* Invalid Operation */ #define UO (5) /* Unimplemented Operation */ /* Get masks for individual flags: */ #if 1 /* SAFE version */ #define FP_FLAGS(b) (((unsigned)(b) < 5) ? (1 << ((b) + 2)) : 0) #define FP_ENABLE(b) (((unsigned)(b) < 5) ? (1 << ((b) + 7)) : 0) #define FP_CAUSE(b) (((unsigned)(b) < 6) ? (1 << ((b) + 12)) : 0) #else #define FP_FLAGS(b) (1 << ((b) + 2)) #define FP_ENABLE(b) (1 << ((b) + 7)) #define FP_CAUSE(b) (1 << ((b) + 12)) #endif #define FP_FS (1 << 24) /* MIPS III onwards : Flush to Zero */ #define FP_MASK_RM (0x3) #define FP_SH_RM (0) #define FP_RM_NEAREST (0) /* Round to nearest (Round) */ #define FP_RM_TOZERO (1) /* Round to zero (Trunc) */ #define FP_RM_TOPINF (2) /* Round to Plus infinity (Ceil) */ #define FP_RM_TOMINF (3) /* Round to Minus infinity (Floor) */ #define GETRM() (int)((FCSR >> FP_SH_RM) & FP_MASK_RM) /* Slots for delayed register updates. For the moment we just have a fixed number of slots (rather than a more generic, dynamic system). This keeps the simulator fast. However, we only allow for the register update to be delayed for a single instruction cycle. */ #define PSLOTS (5) /* Maximum number of instruction cycles */ static int pending_in; static int pending_out; static int pending_total; static int pending_slot_count[PSLOTS]; static int pending_slot_reg[PSLOTS]; static ut_reg pending_slot_value[PSLOTS]; /*---------------------------------------------------------------------------*/ /*-- GDB simulator interface ------------------------------------------------*/ /*---------------------------------------------------------------------------*/ static void dotrace PARAMS((FILE *tracefh,int type,SIM_ADDR address,int width,char *comment,...)); static void sim_warning PARAMS((char *fmt,...)); extern void sim_error PARAMS((char *fmt,...)); static void set_endianness PARAMS((void)); static void ColdReset PARAMS((void)); static int AddressTranslation PARAMS((uword64 vAddr,int IorD,int LorS,uword64 *pAddr,int *CCA,int host,int raw)); static void StoreMemory PARAMS((int CCA,int AccessLength,uword64 MemElem,uword64 pAddr,uword64 vAddr,int raw)); static uword64 LoadMemory PARAMS((int CCA,int AccessLength,uword64 pAddr,uword64 vAddr,int IorD,int raw)); static void SignalException PARAMS((int exception,...)); static void simulate PARAMS((void)); static long getnum PARAMS((char *value)); extern void sim_size PARAMS((unsigned int newsize)); extern void sim_set_profile PARAMS((int frequency)); static unsigned int power2 PARAMS((unsigned int value)); /*---------------------------------------------------------------------------*/ /* The following are not used for MIPS IV onwards: */ #define PENDING_FILL(r,v) {\ /* printf("DBG: FILL BEFORE pending_in = %d, pending_out = %d, pending_total = %d\n",pending_in,pending_out,pending_total); */\ if (pending_slot_reg[pending_in] != (LAST_EMBED_REGNUM + 1))\ sim_warning("Attempt to over-write pending value");\ pending_slot_count[pending_in] = 2;\ pending_slot_reg[pending_in] = (r);\ pending_slot_value[pending_in] = (uword64)(v);\ /*printf("DBG: FILL reg %d value = 0x%08X%08X\n",(r),WORD64HI(v),WORD64LO(v));*/\ pending_total++;\ pending_in++;\ if (pending_in == PSLOTS)\ pending_in = 0;\ /*printf("DBG: FILL AFTER pending_in = %d, pending_out = %d, pending_total = %d\n",pending_in,pending_out,pending_total);*/\ } static int LLBIT = 0; /* LLBIT = Load-Linked bit. A bit of "virtual" state used by atomic read-write instructions. It is set when a linked load occurs. It is tested and cleared by the conditional store. It is cleared (during other CPU operations) when a store to the location would no longer be atomic. In particular, it is cleared by exception return instructions. */ static int HIACCESS = 0; static int LOACCESS = 0; /* The HIACCESS and LOACCESS counts are used to ensure that corruptions caused by using the HI or LO register to close to a following operation are spotted. */ static ut_reg HLPC = 0; /* ??? The 4300 and a few other processors have interlocks on hi/lo register reads, and hence do not have this problem. To avoid spurious warnings, we just disable this always. */ #if 1 #define CHECKHILO(s) #else /* If either of the preceding two instructions have accessed the HI or LO registers, then the values they see should be undefined. However, to keep the simulator world simple, we just let them use the value read and raise a warning to notify the user: */ #define CHECKHILO(s) {\ if ((HIACCESS != 0) || (LOACCESS != 0))\ sim_warning("%s over-writing HI and LO registers values (PC = 0x%08X%08X HLPC = 0x%08X%08X)\n",(s),(unsigned int)(PC>>32),(unsigned int)(PC&0xFFFFFFFF),(unsigned int)(HLPC>>32),(unsigned int)(HLPC&0xFFFFFFFF));\ } #endif /* NOTE: We keep the following status flags as bit values (1 for true, 0 for false). This allows them to be used in binary boolean operations without worrying about what exactly the non-zero true value is. */ /* UserMode */ #define UserMode ((((SR & status_KSU_mask) >> status_KSU_shift) == ksu_user) ? 1 : 0) /* BigEndianMem */ /* Hardware configuration. Affects endianness of LoadMemory and StoreMemory and the endianness of Kernel and Supervisor mode execution. The value is 0 for little-endian; 1 for big-endian. */ #define BigEndianMem ((state & simBE) ? 1 : 0) /* ByteSwapMem */ /* This is true if the host and target have different endianness. */ #define ByteSwapMem (!(state & simHOSTBE) != !(state & simBE)) /* ReverseEndian */ /* This mode is selected if in User mode with the RE bit being set in SR (Status Register). It reverses the endianness of load and store instructions. */ #define ReverseEndian (((SR & status_RE) && UserMode) ? 1 : 0) /* BigEndianCPU */ /* The endianness for load and store instructions (0=little;1=big). In User mode this endianness may be switched by setting the state_RE bit in the SR register. Thus, BigEndianCPU may be computed as (BigEndianMem EOR ReverseEndian). */ #define BigEndianCPU (BigEndianMem ^ ReverseEndian) /* Already bits */ #if !defined(FASTSIM) || defined(PROFILE) /* At the moment these values will be the same, since we do not have access to the pipeline cycle count information from the simulator engine. */ static unsigned int instruction_fetches = 0; static unsigned int instruction_fetch_overflow = 0; static unsigned int pipeline_ticks = 0; #endif /* Flags in the "state" variable: */ #define simSTOP (1 << 0) /* 0 = execute; 1 = stop simulation */ #define simSTEP (1 << 1) /* 0 = run; 1 = single-step */ #define simHALTEX (1 << 2) /* 0 = run; 1 = halt on exception */ #define simHALTIN (1 << 3) /* 0 = run; 1 = halt on interrupt */ #define simTRACE (1 << 8) /* 0 = do nothing; 1 = trace address activity */ #define simPROFILE (1 << 9) /* 0 = do nothing; 1 = gather profiling samples */ #define simHOSTBE (1 << 10) /* 0 = little-endian; 1 = big-endian (host endianness) */ /* Whilst simSTOP is not set, the simulator control loop should just keep simulating instructions. The simSTEP flag is used to force single-step execution. */ #define simBE (1 << 16) /* 0 = little-endian; 1 = big-endian (target endianness) */ #define simPCOC0 (1 << 17) /* COC[1] from current */ #define simPCOC1 (1 << 18) /* COC[1] from previous */ #define simDELAYSLOT (1 << 24) /* 0 = do nothing; 1 = delay slot entry exists */ #define simSKIPNEXT (1 << 25) /* 0 = do nothing; 1 = skip instruction */ #define simEXCEPTION (1 << 26) /* 0 = no exception; 1 = exception has occurred */ #define simEXIT (1 << 27) /* 0 = do nothing; 1 = run-time exit() processing */ #define simSIGINT (1 << 28) /* 0 = do nothing; 1 = SIGINT has occured */ #define simJALDELAYSLOT (1 << 29) /* 1 = in jal delay slot */ static unsigned int state = 0; static unsigned int rcexit = 0; /* _exit() reason code holder */ #define DELAYSLOT() {\ if (state & simDELAYSLOT)\ sim_warning("Delay slot already activated (branch in delay slot?)");\ state |= simDELAYSLOT;\ } #define JALDELAYSLOT() {\ DELAYSLOT ();\ state |= simJALDELAYSLOT;\ } #define NULLIFY() {\ state &= ~simDELAYSLOT;\ state |= simSKIPNEXT;\ } #define INDELAYSLOT() ((state & simDELAYSLOT) != 0) #define INJALDELAYSLOT() ((state & simJALDELAYSLOT) != 0) #define K0BASE (0x80000000) #define K0SIZE (0x20000000) #define K1BASE (0xA0000000) #define K1SIZE (0x20000000) /* Very simple memory model to start with: */ static unsigned char *membank = NULL; static ut_reg membank_base = K1BASE; /* The ddb.ld linker script loads text at K1BASE+1MB, and the idt.ld linker script loads text at K1BASE+128KB. We allocate 2MB, so that we have a minimum of 1 MB available for the user process. We must have memory above _end in order for sbrk to work. */ static unsigned membank_size = (2 << 20); /* Simple run-time monitor support */ static unsigned char *monitor = NULL; static ut_reg monitor_base = 0xBFC00000; static unsigned monitor_size = (1 << 11); /* power-of-2 */ static char *logfile = NULL; /* logging disabled by default */ static FILE *logfh = NULL; #if defined(TRACE) static char *tracefile = "trace.din"; /* default filename for trace log */ static FILE *tracefh = NULL; static void open_trace PARAMS((void)); #endif /* TRACE */ #if defined(PROFILE) static unsigned profile_frequency = 256; static unsigned profile_nsamples = (128 << 10); static unsigned short *profile_hist = NULL; static ut_reg profile_minpc; static ut_reg profile_maxpc; static int profile_shift = 0; /* address shift amount */ #endif /* PROFILE */ /* The following are used to provide shortcuts to the required version of host<->target copying. This avoids run-time conditionals, which would slow the simulator throughput. */ typedef unsigned int (*fnptr_read_word) PARAMS((unsigned char *memory)); typedef unsigned int (*fnptr_swap_word) PARAMS((unsigned int data)); typedef uword64 (*fnptr_read_long) PARAMS((unsigned char *memory)); typedef uword64 (*fnptr_swap_long) PARAMS((uword64 data)); static fnptr_read_word host_read_word; static fnptr_read_long host_read_long; static fnptr_swap_word host_swap_word; static fnptr_swap_long host_swap_long; /*---------------------------------------------------------------------------*/ /*-- GDB simulator interface ------------------------------------------------*/ /*---------------------------------------------------------------------------*/ void sim_open (args) char *args; { if (callback == NULL) { fprintf(stderr,"SIM Error: sim_open() called without callbacks attached\n"); return; } /* The following ensures that the standard file handles for stdin, stdout and stderr are initialised: */ callback->init(callback); state = 0; CHECKSIM(); if (state & simEXCEPTION) { fprintf(stderr,"This simulator is not suitable for this host configuration\n"); exit(1); } { int data = 0x12; if (*((char *)&data) != 0x12) state |= simHOSTBE; /* big-endian host */ } set_endianness (); #if defined(HASFPU) /* Check that the host FPU conforms to IEEE 754-1985 for the SINGLE and DOUBLE binary formats. This is a bit nasty, requiring that we trust the explicit manifests held in the source: */ { unsigned int s[2]; s[state & simHOSTBE ? 0 : 1] = 0x40805A5A; s[state & simHOSTBE ? 1 : 0] = 0x00000000; /* TODO: We need to cope with the simulated target and the host not having the same endianness. This will require the high and low words of a (double) to be swapped when converting between the host and the simulated target. */ if (((float)4.01102924346923828125 != *(float *)(s + ((state & simHOSTBE) ? 0 : 1))) || ((double)523.2939453125 != *(double *)s)) { fprintf(stderr,"The host executing the simulator does not seem to have IEEE 754-1985 std FP\n"); fprintf(stderr,"*(float *)s = %.20f (4.01102924346923828125)\n",*(float *)s); fprintf(stderr,"*(double *)s = %.20f (523.2939453125)\n",*(double *)s); exit(1); } } #endif /* HASFPU */ /* This is NASTY, in that we are assuming the size of specific registers: */ { int rn; for (rn = 0; (rn < (LAST_EMBED_REGNUM + 1)); rn++) { if (rn < 32) register_widths[rn] = GPRLEN; else if ((rn >= FGRIDX) && (rn < (FGRIDX + 32))) register_widths[rn] = GPRLEN; else if ((rn >= 33) && (rn <= 37)) register_widths[rn] = GPRLEN; else if ((rn == SRIDX) || (rn == FCR0IDX) || (rn == FCR31IDX) || ((rn >= 72) && (rn <= 89))) register_widths[rn] = 32; else register_widths[rn] = 0; } } /* It would be good if we could select particular named MIPS architecture simulators. However, having a pre-built, fixed engine would mean including multiple engines. If the simulator is changed to a run-time conditional version, then the ability to select a particular architecture would be straightforward. */ if (args != NULL) { int c; char *cline; char **argv; int argc; static struct option cmdline[] = { {"help", 0,0,'h'}, {"log", 1,0,'l'}, {"name", 1,0,'n'}, {"profile", 0,0,'p'}, {"size", 1,0,'s'}, {"trace", 0,0,'t'}, {"tracefile",1,0,'z'}, {"frequency",1,0,'y'}, {"samples", 1,0,'x'}, {0, 0,0,0} }; /* Unfortunately, getopt_long() is designed to be used with vectors, where the first option is normally program name (and ignored). We cheat by creating a dummy first argument, so that we can use the standard argument processing. */ #define DUMMYARG "simulator " cline = (char *)malloc(strlen(args) + strlen(DUMMYARG) + 1); if (cline == NULL) { fprintf(stderr,"Failed to allocate memory for command line buffer\n"); exit(1); } sprintf(cline,"%s%s",DUMMYARG,args); argv = buildargv(cline); for (argc = 0; argv[argc]; argc++); /* Unfortunately, getopt_long() assumes that it is ignoring the first argument (normally the program name). This means it ignores the first option on our "args" line. */ optind = 0; /* Force reset of argument processing */ while (1) { int option_index = 0; c = getopt_long(argc,argv,"hn:s:tp",cmdline,&option_index); if (c == -1) break; switch (c) { case 'h': callback->printf_filtered(callback,"Usage:\n\t\ target sim [-h] [--log=] [--name=] [--size=]"); #if defined(TRACE) callback->printf_filtered(callback," [-t [--tracefile=]]"); #endif /* TRACE */ #if defined(PROFILE) callback->printf_filtered(callback," [-p [--frequency=] [--samples=]]"); #endif /* PROFILE */ callback->printf_filtered(callback,"\n"); break; case 'l': if (optarg != NULL) { char *tmp; tmp = (char *)malloc(strlen(optarg) + 1); if (tmp == NULL) callback->printf_filtered(callback,"Failed to allocate buffer for logfile name \"%s\"\n",optarg); else { strcpy(tmp,optarg); logfile = tmp; } } break; case 'n': callback->printf_filtered(callback,"Explicit model selection not yet available (Ignoring \"%s\")\n",optarg); break; case 's': membank_size = (unsigned)getnum(optarg); break; case 't': #if defined(TRACE) /* Eventually the simTRACE flag could be treated as a toggle, to allow external control of the program points being traced (i.e. only from main onwards, excluding the run-time setup, etc.). */ state |= simTRACE; #else /* !TRACE */ fprintf(stderr,"\ Simulator constructed without tracing support (for performance).\n\ Re-compile simulator with \"-DTRACE\" to enable this option.\n"); #endif /* !TRACE */ break; case 'z': #if defined(TRACE) if (optarg != NULL) { char *tmp; tmp = (char *)malloc(strlen(optarg) + 1); if (tmp == NULL) callback->printf_filtered(callback,"Failed to allocate buffer for tracefile name \"%s\"\n",optarg); else { strcpy(tmp,optarg); tracefile = tmp; callback->printf_filtered(callback,"Placing trace information into file \"%s\"\n",tracefile); } } #endif /* TRACE */ break; case 'p': #if defined(PROFILE) state |= simPROFILE; #else /* !PROFILE */ fprintf(stderr,"\ Simulator constructed without profiling support (for performance).\n\ Re-compile simulator with \"-DPROFILE\" to enable this option.\n"); #endif /* !PROFILE */ break; case 'x': #if defined(PROFILE) profile_nsamples = (unsigned)getnum(optarg); #endif /* PROFILE */ break; case 'y': #if defined(PROFILE) sim_set_profile((int)getnum(optarg)); #endif /* PROFILE */ break; default: callback->printf_filtered(callback,"Warning: Simulator getopt returned unrecognised code 0x%08X\n",c); case '?': break; } } #if 0 if (optind < argc) { callback->printf_filtered(callback,"Warning: Ignoring spurious non-option arguments "); while (optind < argc) callback->printf_filtered(callback,"\"%s\" ",argv[optind++]); callback->printf_filtered(callback,"\n"); } #endif freeargv(argv); } if (logfile != NULL) { if (strcmp(logfile,"-") == 0) logfh = stdout; else { logfh = fopen(logfile,"wb+"); if (logfh == NULL) { callback->printf_filtered(callback,"Failed to create file \"%s\", writing log information to stderr.\n",tracefile); logfh = stderr; } } } /* If the host has "mmap" available we could use it to provide a very large virtual address space for the simulator, since memory would only be allocated within the "mmap" space as it is accessed. This can also be linked to the architecture specific support, required to simulate the MMU. */ sim_size(membank_size); /* NOTE: The above will also have enabled any profiling state */ ColdReset(); /* If we were providing a more complete I/O, co-processor or memory simulation, we should perform any "device" initialisation at this point. This can include pre-loading memory areas with particular patterns (e.g. simulating ROM monitors). */ /* We can start writing to the memory, now that the processor has been reset: */ monitor = (unsigned char *)calloc(1,monitor_size); if (!monitor) { fprintf(stderr,"Not enough VM for monitor simulation (%d bytes)\n",monitor_size); } else { unsigned loop; /* Entry into the IDT monitor is via fixed address vectors, and not using machine instructions. To avoid clashing with use of the MIPS TRAP system, we place our own (simulator specific) "undefined" instructions into the relevant vector slots. */ for (loop = 0; (loop < monitor_size); loop += 4) { uword64 vaddr = (monitor_base + loop); uword64 paddr; int cca; if (AddressTranslation(vaddr,isDATA,isSTORE,&paddr,&cca,isTARGET,isRAW)) StoreMemory(cca,AccessLength_WORD,(RSVD_INSTRUCTION | ((loop >> 2) & RSVD_INSTRUCTION_AMASK)),paddr,vaddr,isRAW); } /* The PMON monitor uses the same address space, but rather than branching into it the address of a routine is loaded. We can cheat for the moment, and direct the PMON routine to IDT style instructions within the monitor space. This relies on the IDT monitor not using the locations from 0xBFC00500 onwards as its entry points.*/ for (loop = 0; (loop < 24); loop++) { uword64 vaddr = (monitor_base + 0x500 + (loop * 4)); uword64 paddr; int cca; unsigned int value = ((0x500 - 8) / 8); /* default UNDEFINED reason code */ switch (loop) { case 0: /* read */ value = 7; break; case 1: /* write */ value = 8; break; case 2: /* open */ value = 6; break; case 3: /* close */ value = 10; break; case 5: /* printf */ value = ((0x500 - 16) / 8); /* not an IDT reason code */ break; case 8: /* cliexit */ value = 17; break; case 11: /* flush_cache */ value = 28; break; } /* FIXME - should monitor_base be SIM_ADDR?? */ value = ((unsigned int)monitor_base + (value * 8)); if (AddressTranslation(vaddr,isDATA,isSTORE,&paddr,&cca,isTARGET,isRAW)) StoreMemory(cca,AccessLength_WORD,value,paddr,vaddr,isRAW); else sim_error("Failed to write to monitor space 0x%08X%08X",WORD64HI(vaddr),WORD64LO(vaddr)); } } #if defined(TRACE) if (state & simTRACE) open_trace(); #endif /* TRACE */ return; } #if defined(TRACE) static void open_trace() { tracefh = fopen(tracefile,"wb+"); if (tracefh == NULL) { sim_warning("Failed to create file \"%s\", writing trace information to stderr.",tracefile); tracefh = stderr; } } #endif /* TRACE */ /* For the profile writing, we write the data in the host endianness. This unfortunately means we are assuming that the profile file we create is processed on the same host executing the simulator. The gmon.out file format should either have an explicit endianness, or a method of encoding the endianness in the file header. */ static int writeout32(fh,val) FILE *fh; unsigned int val; { char buff[4]; int res = 1; if (state & simHOSTBE) { buff[3] = ((val >> 0) & 0xFF); buff[2] = ((val >> 8) & 0xFF); buff[1] = ((val >> 16) & 0xFF); buff[0] = ((val >> 24) & 0xFF); } else { buff[0] = ((val >> 0) & 0xFF); buff[1] = ((val >> 8) & 0xFF); buff[2] = ((val >> 16) & 0xFF); buff[3] = ((val >> 24) & 0xFF); } if (fwrite(buff,4,1,fh) != 1) { sim_warning("Failed to write 4bytes to the profile file"); res = 0; } return(res); } static int writeout16(fh,val) FILE *fh; unsigned short val; { char buff[2]; int res = 1; if (state & simHOSTBE) { buff[1] = ((val >> 0) & 0xFF); buff[0] = ((val >> 8) & 0xFF); } else { buff[0] = ((val >> 0) & 0xFF); buff[1] = ((val >> 8) & 0xFF); } if (fwrite(buff,2,1,fh) != 1) { sim_warning("Failed to write 2bytes to the profile file"); res = 0; } return(res); } void sim_close (quitting) int quitting; { #ifdef DEBUG printf("DBG: sim_close: entered (quitting = %d)\n",quitting); #endif /* Cannot assume sim_kill() has been called */ /* "quitting" is non-zero if we cannot hang on errors */ /* Ensure that any resources allocated through the callback mechanism are released: */ callback->shutdown(callback); #if defined(PROFILE) if ((state & simPROFILE) && (profile_hist != NULL)) { unsigned short *p = profile_hist; FILE *pf = fopen("gmon.out","wb"); unsigned loop; if (pf == NULL) sim_warning("Failed to open \"gmon.out\" profile file"); else { int ok; #ifdef DEBUG printf("DBG: minpc = 0x%08X\n",(unsigned int)profile_minpc); printf("DBG: maxpc = 0x%08X\n",(unsigned int)profile_maxpc); #endif /* DEBUG */ ok = writeout32(pf,(unsigned int)profile_minpc); if (ok) ok = writeout32(pf,(unsigned int)profile_maxpc); if (ok) ok = writeout32(pf,(profile_nsamples * 2) + 12); /* size of sample buffer (+ header) */ #ifdef DEBUG printf("DBG: nsamples = %d (size = 0x%08X)\n",profile_nsamples,((profile_nsamples * 2) + 12)); #endif /* DEBUG */ for (loop = 0; (ok && (loop < profile_nsamples)); loop++) { ok = writeout16(pf,profile_hist[loop]); if (!ok) break; } fclose(pf); } free(profile_hist); profile_hist = NULL; state &= ~simPROFILE; } #endif /* PROFILE */ #if defined(TRACE) if (tracefh != NULL && tracefh != stderr) fclose(tracefh); tracefh = NULL; state &= ~simTRACE; #endif /* TRACE */ if (logfh != NULL && logfh != stdout && logfh != stderr) fclose(logfh); logfh = NULL; if (membank) free(membank); /* cfree not available on all hosts */ membank = NULL; return; } void control_c (sig, code, scp, addr) int sig; int code; char *scp; char *addr; { state |= (simSTOP | simSIGINT); } void sim_resume (step,signal_number) int step, signal_number; { void (*prev) (); #ifdef DEBUG printf("DBG: sim_resume entered: step = %d, signal = %d (membank = 0x%08X)\n",step,signal_number,membank); #endif /* DEBUG */ if (step) state |= simSTEP; /* execute only a single instruction */ else state &= ~(simSTOP | simSTEP); /* execute until event */ state |= (simHALTEX | simHALTIN); /* treat interrupt event as exception */ /* Start executing instructions from the current state (set explicitly by register updates, or by sim_create_inferior): */ prev = signal (SIGINT, control_c); simulate(); signal (SIGINT, prev); return; } int sim_write (addr,buffer,size) SIM_ADDR addr; unsigned char *buffer; int size; { int index = size; uword64 vaddr = (uword64)addr; /* Return the number of bytes written, or zero if error. */ #ifdef DEBUG callback->printf_filtered(callback,"sim_write(0x%08X%08X,buffer,%d);\n",WORD64HI(addr),WORD64LO(addr),size); #endif /* We provide raw read and write routines, since we do not want to count the GDB memory accesses in our statistics gathering. */ /* There is a lot of code duplication in the individual blocks below, but the variables are declared locally to a block to give the optimiser the best chance of improving the code. We have to perform slow byte reads from the host memory, to ensure that we get the data into the correct endianness for the (simulated) target memory world. */ /* Mask count to get odd byte, odd halfword, and odd word out of the way. We can then perform doubleword transfers to and from the simulator memory for optimum performance. */ if (index && (index & 1)) { uword64 paddr; int cca; if (AddressTranslation(vaddr,isDATA,isSTORE,&paddr,&cca,isTARGET,isRAW)) { uword64 value = ((uword64)(*buffer++)); StoreMemory(cca,AccessLength_BYTE,value,paddr,vaddr,isRAW); } vaddr++; index &= ~1; /* logical operations usually quicker than arithmetic on RISC systems */ } if (index && (index & 2)) { uword64 paddr; int cca; if (AddressTranslation(vaddr,isDATA,isSTORE,&paddr,&cca,isTARGET,isRAW)) { uword64 value; /* We need to perform the following magic to ensure that that bytes are written into same byte positions in the target memory world, regardless of the endianness of the host. */ if (BigEndianMem) { value = ((uword64)(*buffer++) << 8); value |= ((uword64)(*buffer++) << 0); } else { value = ((uword64)(*buffer++) << 0); value |= ((uword64)(*buffer++) << 8); } StoreMemory(cca,AccessLength_HALFWORD,value,paddr,vaddr,isRAW); } vaddr += 2; index &= ~2; } if (index && (index & 4)) { uword64 paddr; int cca; if (AddressTranslation(vaddr,isDATA,isSTORE,&paddr,&cca,isTARGET,isRAW)) { uword64 value; if (BigEndianMem) { value = ((uword64)(*buffer++) << 24); value |= ((uword64)(*buffer++) << 16); value |= ((uword64)(*buffer++) << 8); value |= ((uword64)(*buffer++) << 0); } else { value = ((uword64)(*buffer++) << 0); value |= ((uword64)(*buffer++) << 8); value |= ((uword64)(*buffer++) << 16); value |= ((uword64)(*buffer++) << 24); } StoreMemory(cca,AccessLength_WORD,value,paddr,vaddr,isRAW); } vaddr += 4; index &= ~4; } for (;index; index -= 8) { uword64 paddr; int cca; if (AddressTranslation(vaddr,isDATA,isSTORE,&paddr,&cca,isTARGET,isRAW)) { uword64 value; if (BigEndianMem) { value = ((uword64)(*buffer++) << 56); value |= ((uword64)(*buffer++) << 48); value |= ((uword64)(*buffer++) << 40); value |= ((uword64)(*buffer++) << 32); value |= ((uword64)(*buffer++) << 24); value |= ((uword64)(*buffer++) << 16); value |= ((uword64)(*buffer++) << 8); value |= ((uword64)(*buffer++) << 0); } else { value = ((uword64)(*buffer++) << 0); value |= ((uword64)(*buffer++) << 8); value |= ((uword64)(*buffer++) << 16); value |= ((uword64)(*buffer++) << 24); value |= ((uword64)(*buffer++) << 32); value |= ((uword64)(*buffer++) << 40); value |= ((uword64)(*buffer++) << 48); value |= ((uword64)(*buffer++) << 56); } StoreMemory(cca,AccessLength_DOUBLEWORD,value,paddr,vaddr,isRAW); } vaddr += 8; } return(size); } int sim_read (addr,buffer,size) SIM_ADDR addr; unsigned char *buffer; int size; { int index; /* Return the number of bytes read, or zero if error. */ #ifdef DEBUG callback->printf_filtered(callback,"sim_read(0x%08X%08X,buffer,%d);\n",WORD64HI(addr),WORD64LO(addr),size); #endif /* DEBUG */ /* TODO: Perform same optimisation as the sim_write() code above. NOTE: This will require a bit more work since we will need to ensure that the source physical address is doubleword aligned before, and then deal with trailing bytes. */ for (index = 0; (index < size); index++) { uword64 vaddr,paddr,value; int cca; vaddr = (uword64)addr + index; if (AddressTranslation(vaddr,isDATA,isLOAD,&paddr,&cca,isTARGET,isRAW)) { value = LoadMemory(cca,AccessLength_BYTE,paddr,vaddr,isDATA,isRAW); buffer[index] = (unsigned char)(value&0xFF); } else break; } return(index); } void sim_store_register (rn,memory) int rn; unsigned char *memory; { #ifdef DEBUG callback->printf_filtered(callback,"sim_store_register(%d,*memory=0x%08X%08X);\n",rn,*((unsigned int *)memory),*((unsigned int *)(memory + 4))); #endif /* DEBUG */ /* Unfortunately this suffers from the same problem as the register numbering one. We need to know what the width of each logical register number is for the architecture being simulated. */ if (register_widths[rn] == 0) sim_warning("Invalid register width for %d (register store ignored)",rn); else { if (register_widths[rn] == 32) registers[rn] = host_read_word(memory); else registers[rn] = host_read_long(memory); } return; } void sim_fetch_register (rn,memory) int rn; unsigned char *memory; { #ifdef DEBUG callback->printf_filtered(callback,"sim_fetch_register(%d=0x%08X%08X,mem) : place simulator registers into memory\n",rn,WORD64HI(registers[rn]),WORD64LO(registers[rn])); #endif /* DEBUG */ if (register_widths[rn] == 0) sim_warning("Invalid register width for %d (register fetch ignored)",rn); else { if (register_widths[rn] == 32) *((unsigned int *)memory) = host_swap_word((unsigned int)(registers[rn] & 0xFFFFFFFF)); else /* 64bit register */ *((uword64 *)memory) = host_swap_long(registers[rn]); } return; } void sim_stop_reason (reason,sigrc) enum sim_stop *reason; int *sigrc; { /* We can have "*reason = {sim_exited, sim_stopped, sim_signalled}", so sim_exited *sigrc = argument to exit() sim_stopped *sigrc = exception number sim_signalled *sigrc = signal number */ if (state & simEXCEPTION) { /* If "sim_signalled" is used, GDB expects normal SIGNAL numbers, and not the MIPS specific exception codes. */ #if 1 /* For some reason, sending GDB a sim_signalled reason cause it to terminate out. */ *reason = sim_stopped; #else *reason = sim_signalled; #endif switch ((CAUSE >> 2) & 0x1F) { case Interrupt: *sigrc = SIGINT; /* wrong type of interrupt, but it will do for the moment */ break; case TLBModification: case TLBLoad: case TLBStore: case AddressLoad: case AddressStore: case InstructionFetch: case DataReference: *sigrc = SIGBUS; break; case ReservedInstruction: case CoProcessorUnusable: *sigrc = SIGILL; break; case IntegerOverflow: case FPE: *sigrc = SIGFPE; break; case Trap: case Watch: case SystemCall: case BreakPoint: *sigrc = SIGTRAP; break; default : /* Unknown internal exception */ *sigrc = SIGQUIT; break; } } else if (state & simEXIT) { #if 0 printf("DBG: simEXIT (%d)\n",rcexit); #endif *reason = sim_exited; *sigrc = rcexit; } else if (state & simSIGINT) { *reason = sim_stopped; *sigrc = SIGINT; } else { /* assume single-stepping */ *reason = sim_stopped; *sigrc = SIGTRAP; } state &= ~(simEXCEPTION | simEXIT | simSIGINT); return; } void sim_info (verbose) int verbose; { /* Accessed from the GDB "info files" command: */ callback->printf_filtered(callback,"MIPS %d-bit simulator\n",(PROCESSOR_64BIT ? 64 : 32)); callback->printf_filtered(callback,"%s endian memory model\n",(state & simBE ? "Big" : "Little")); callback->printf_filtered(callback,"0x%08X bytes of memory at 0x%08X%08X\n",(unsigned int)membank_size,WORD64HI(membank_base),WORD64LO(membank_base)); #if !defined(FASTSIM) if (instruction_fetch_overflow != 0) callback->printf_filtered(callback,"Instruction fetches = 0x%08X%08X\n",instruction_fetch_overflow,instruction_fetches); else callback->printf_filtered(callback,"Instruction fetches = %d\n",instruction_fetches); callback->printf_filtered(callback,"Pipeline ticks = %d\n",pipeline_ticks); /* It would be a useful feature, if when performing multi-cycle simulations (rather than single-stepping) we keep the start and end times of the execution, so that we can give a performance figure for the simulator. */ #endif /* !FASTSIM */ /* print information pertaining to MIPS ISA and architecture being simulated */ /* things that may be interesting */ /* instructions executed - if available */ /* cycles executed - if available */ /* pipeline stalls - if available */ /* virtual time taken */ /* profiling size */ /* profiling frequency */ /* profile minpc */ /* profile maxpc */ return; } int sim_load (prog,from_tty) char *prog; int from_tty; { /* Return non-zero if the caller should handle the load. Zero if we have loaded the image. */ return(-1); } void sim_create_inferior (start_address,argv,env) SIM_ADDR start_address; char **argv; char **env; { #ifdef DEBUG printf("DBG: sim_create_inferior entered: start_address = 0x%08X\n",start_address); #endif /* DEBUG */ /* Prepare to execute the program to be simulated */ /* argv and env are NULL terminated lists of pointers */ #if 1 PC = (uword64)start_address; #else /* TODO: Sort this properly. SIM_ADDR may already be a 64bit value: */ PC = SIGNEXTEND(start_address,32); #endif /* NOTE: GDB normally sets the PC explicitly. However, this call is used by other clients of the simulator. */ if (argv || env) { #if 0 /* def DEBUG */ callback->printf_filtered(callback,"sim_create_inferior() : passed arguments ignored\n"); { char **cptr; for (cptr = argv; (cptr && *cptr); cptr++) printf("DBG: arg \"%s\"\n",*cptr); } #endif /* DEBUG */ /* We should really place the argv slot values into the argument registers, and onto the stack as required. However, this assumes that we have a stack defined, which is not necessarily true at the moment. */ } return; } void sim_kill () { #if 1 /* This routine should be for terminating any existing simulation thread. Since we are single-threaded only at the moment, this is not an issue. It should *NOT* be used to terminate the simulator. */ #else /* do *NOT* call sim_close */ sim_close(1); /* Do not hang on errors */ /* This would also be the point where any memory mapped areas used by the simulator should be released. */ #endif return; } ut_reg sim_get_quit_code () { /* The standard MIPS PCS (Procedure Calling Standard) uses V0(r2) as the function return value. However, it may be more correct for this to return the argument to the exit() function (if called). */ return(V0); } void sim_set_callbacks (p) host_callback *p; { callback = p; return; } typedef enum {e_terminate,e_help,e_setmemsize,e_reset} e_cmds; static struct t_sim_command { e_cmds id; const char *name; const char *help; } sim_commands[] = { {e_help, "help", ": Show MIPS simulator private commands"}, {e_setmemsize,"set-memory-size"," : Specify amount of memory simulated"}, {e_reset, "reset-system", ": Reset the simulated processor"}, {e_terminate, NULL} }; void sim_do_command (cmd) char *cmd; { struct t_sim_command *cptr; if (callback == NULL) { fprintf(stderr,"Simulator not enabled: \"target sim\" should be used to activate\n"); return; } if (!(cmd && *cmd != '\0')) cmd = "help"; /* NOTE: Accessed from the GDB "sim" commmand: */ for (cptr = sim_commands; cptr && cptr->name; cptr++) if (strncmp(cmd,cptr->name,strlen(cptr->name)) == 0) { cmd += strlen(cptr->name); switch (cptr->id) { case e_help: /* no arguments */ { /* no arguments */ struct t_sim_command *lptr; callback->printf_filtered(callback,"List of MIPS simulator commands:\n"); for (lptr = sim_commands; lptr->name; lptr++) callback->printf_filtered(callback,"%s %s\n",lptr->name,lptr->help); } break; case e_setmemsize: /* memory size argument */ { unsigned int newsize = (unsigned int)getnum(cmd); sim_size(newsize); } break; case e_reset: /* no arguments */ ColdReset(); /* NOTE: See the comments in sim_open() relating to device initialisation. */ break; default: callback->printf_filtered(callback,"FATAL: Matched \"%s\", but failed to match command id %d.\n",cmd,cptr->id); break; } break; } if (!(cptr->name)) callback->printf_filtered(callback,"Error: \"%s\" is not a valid MIPS simulator command.\n",cmd); return; } /*---------------------------------------------------------------------------*/ /* NOTE: The following routines do not seem to be used by GDB at the moment. However, they may be useful to the standalone simulator world. */ /* The profiling format is described in the "gmon_out.h" header file */ void sim_set_profile (n) int n; { #if defined(PROFILE) profile_frequency = n; state |= simPROFILE; #endif /* PROFILE */ return; } void sim_set_profile_size (n) int n; { #if defined(PROFILE) if (state & simPROFILE) { int bsize; /* Since we KNOW that the memory banks are a power-of-2 in size: */ profile_nsamples = power2(n); profile_minpc = membank_base; profile_maxpc = (membank_base + membank_size); /* Just in-case we are sampling every address: NOTE: The shift right of 2 is because we only have word-aligned PC addresses. */ if (profile_nsamples > (membank_size >> 2)) profile_nsamples = (membank_size >> 2); /* Since we are dealing with power-of-2 values: */ profile_shift = (((membank_size >> 2) / profile_nsamples) - 1); bsize = (profile_nsamples * sizeof(unsigned short)); if (profile_hist == NULL) profile_hist = (unsigned short *)calloc(64,(bsize / 64)); else profile_hist = (unsigned short *)realloc(profile_hist,bsize); if (profile_hist == NULL) { sim_warning("Failed to allocate VM for profiling buffer (0x%08X bytes)",bsize); state &= ~simPROFILE; } } #endif /* PROFILE */ return; } void sim_size(newsize) unsigned int newsize; { char *new; /* Used by "run", and internally, to set the simulated memory size */ if (newsize == 0) { callback->printf_filtered(callback,"Zero not valid: Memory size still 0x%08X bytes\n",membank_size); return; } newsize = power2(newsize); if (membank == NULL) new = (char *)calloc(64,(membank_size / 64)); else new = (char *)realloc(membank,newsize); if (new == NULL) { if (membank == NULL) sim_error("Not enough VM for simulation memory of 0x%08X bytes",membank_size); else sim_warning("Failed to resize memory (still 0x%08X bytes)",membank_size); } else { membank_size = (unsigned)newsize; membank = new; #if defined(PROFILE) /* Ensure that we sample across the new memory range */ sim_set_profile_size(profile_nsamples); #endif /* PROFILE */ } return; } int sim_trace() { /* This routine is called by the "run" program, when detailed execution information is required. Rather than executing a single instruction, and looping around externally... we just start simulating, returning TRUE when the simulator stops (for whatever reason). */ #if defined(TRACE) /* Ensure tracing is enabled, if available */ if (tracefh == NULL) { open_trace(); state |= simTRACE; } #endif /* TRACE */ state &= ~(simSTOP | simSTEP); /* execute until event */ state |= (simHALTEX | simHALTIN); /* treat interrupt event as exception */ /* Start executing instructions from the current state (set explicitly by register updates, or by sim_create_inferior): */ simulate(); return(1); } /*---------------------------------------------------------------------------*/ /*-- Private simulator support interface ------------------------------------*/ /*---------------------------------------------------------------------------*/ /* Simple monitor interface (currently setup for the IDT and PMON monitors) */ static void sim_monitor(reason) unsigned int reason; { /* The IDT monitor actually allows two instructions per vector slot. However, the simulator currently causes a trap on each individual instruction. We cheat, and lose the bottom bit. */ reason >>= 1; /* The following callback functions are available, however the monitor we are simulating does not make use of them: get_errno, isatty, lseek, rename, system, time and unlink */ switch (reason) { case 6: /* int open(char *path,int flags) */ { uword64 paddr; int cca; if (AddressTranslation(A0,isDATA,isLOAD,&paddr,&cca,isHOST,isREAL)) V0 = callback->open(callback,(char *)((int)paddr),(int)A1); else sim_error("Attempt to pass pointer that does not reference simulated memory"); } break; case 7: /* int read(int file,char *ptr,int len) */ { uword64 paddr; int cca; if (AddressTranslation(A1,isDATA,isLOAD,&paddr,&cca,isHOST,isREAL)) V0 = callback->read(callback,(int)A0,(char *)((int)paddr),(int)A2); else sim_error("Attempt to pass pointer that does not reference simulated memory"); } break; case 8: /* int write(int file,char *ptr,int len) */ { uword64 paddr; int cca; if (AddressTranslation(A1,isDATA,isLOAD,&paddr,&cca,isHOST,isREAL)) { if (A0 == 1) V0 = callback->write_stdout(callback,(const char *)((int)paddr), (int)A2); else V0 = callback->write(callback,(int)A0,(const char *)((int)paddr), (int)A2); } else sim_error("Attempt to pass pointer that does not reference simulated memory"); } break; case 10: /* int close(int file) */ V0 = callback->close(callback,(int)A0); break; case 11: /* char inbyte(void) */ { char tmp; if (callback->read_stdin(callback,&tmp,sizeof(char)) != sizeof(char)) { sim_error("Invalid return from character read"); V0 = (ut_reg)-1; } else V0 = (ut_reg)tmp; } break; case 12: /* void outbyte(char chr) : write a byte to "stdout" */ { char tmp = (char)(A0 & 0xFF); callback->write_stdout(callback,&tmp,sizeof(char)); } break; case 17: /* void _exit() */ sim_warning("sim_monitor(17): _exit(int reason) to be coded"); state |= (simSTOP | simEXIT); /* stop executing code */ rcexit = (unsigned int)(A0 & 0xFFFFFFFF); break; case 28 : /* PMON flush_cache */ break; case 55: /* void get_mem_info(unsigned int *ptr) */ /* in: A0 = pointer to three word memory location */ /* out: [A0 + 0] = size */ /* [A0 + 4] = instruction cache size */ /* [A0 + 8] = data cache size */ { uword64 vaddr = A0; uword64 paddr, value; int cca; int failed = 0; /* NOTE: We use RAW memory writes here, but since we are not gathering statistics for the monitor calls we are simulating, it is not an issue. */ /* Memory size */ if (AddressTranslation(vaddr,isDATA,isSTORE,&paddr,&cca,isTARGET,isREAL)) { value = (uword64)membank_size; StoreMemory(cca,AccessLength_WORD,value,paddr,vaddr,isRAW); /* We re-do the address translations, in-case the block overlaps a memory boundary: */ value = 0; vaddr += (AccessLength_WORD + 1); if (AddressTranslation(vaddr,isDATA,isSTORE,&paddr,&cca,isTARGET,isREAL)) { StoreMemory(cca,AccessLength_WORD,value,paddr,vaddr,isRAW); vaddr += (AccessLength_WORD + 1); if (AddressTranslation(vaddr,isDATA,isSTORE,&paddr,&cca,isTARGET,isREAL)) StoreMemory(cca,AccessLength_WORD,value,paddr,vaddr,isRAW); else failed = -1; } else failed = -1; } else failed = -1; if (failed) sim_error("Invalid pointer passed into monitor call"); } break; case 158 : /* PMON printf */ /* in: A0 = pointer to format string */ /* A1 = optional argument 1 */ /* A2 = optional argument 2 */ /* A3 = optional argument 3 */ /* out: void */ /* The following is based on the PMON printf source */ { uword64 paddr; int cca; /* This isn't the quickest way, since we call the host print routine for every character almost. But it does avoid having to allocate and manage a temporary string buffer. */ if (AddressTranslation(A0,isDATA,isLOAD,&paddr,&cca,isHOST,isREAL)) { char *s = (char *)((int)paddr); ut_reg *ap = &A1; /* 1st argument */ /* TODO: Include check that we only use three arguments (A1, A2 and A3) */ for (; *s;) { if (*s == '%') { char tmp[40]; enum {FMT_RJUST, FMT_LJUST, FMT_RJUST0, FMT_CENTER} fmt = FMT_RJUST; int width = 0, trunc = 0, haddot = 0, longlong = 0; int base = 10; s++; for (; *s; s++) { if (strchr ("dobxXulscefg%", *s)) break; else if (*s == '-') fmt = FMT_LJUST; else if (*s == '0') fmt = FMT_RJUST0; else if (*s == '~') fmt = FMT_CENTER; else if (*s == '*') { if (haddot) trunc = (int)*ap++; else width = (int)*ap++; } else if (*s >= '1' && *s <= '9') { char *t; unsigned int n; for (t = s; isdigit (*s); s++); strncpy (tmp, t, s - t); tmp[s - t] = '\0'; n = (unsigned int)strtol(tmp,NULL,10); if (haddot) trunc = n; else width = n; s--; } else if (*s == '.') haddot = 1; } if (*s == '%') { callback->printf_filtered(callback,"%%"); } else if (*s == 's') { if ((int)*ap != 0) { if (AddressTranslation(*ap++,isDATA,isLOAD,&paddr,&cca,isHOST,isREAL)) { char *p = (char *)((int)paddr);; callback->printf_filtered(callback,p); } else { ap++; sim_error("Attempt to pass pointer that does not reference simulated memory"); } } else callback->printf_filtered(callback,"(null)"); } else if (*s == 'c') { int n = (int)*ap++; callback->printf_filtered(callback,"%c",n); } else { if (*s == 'l') { if (*++s == 'l') { longlong = 1; ++s; } } if (strchr ("dobxXu", *s)) { word64 lv = (word64) *ap++; if (*s == 'b') callback->printf_filtered(callback,""); else { sprintf(tmp,"%%%s%c",longlong ? "ll" : "",*s); if (longlong) callback->printf_filtered(callback,tmp,lv); else callback->printf_filtered(callback,tmp,(int)lv); } } else if (strchr ("eEfgG", *s)) { #ifdef _MSC_VER /* MSVC version 2.x can't convert from uword64 directly */ double dbl = (double)((word64)*ap++); #else double dbl = (double)*ap++; #endif sprintf(tmp,"%%%d.%d%c",width,trunc,*s); callback->printf_filtered(callback,tmp,dbl); trunc = 0; } } s++; } else callback->printf_filtered(callback,"%c",*s++); } } else sim_error("Attempt to pass pointer that does not reference simulated memory"); } break; default: sim_warning("TODO: sim_monitor(%d) : PC = 0x%08X%08X",reason,WORD64HI(IPC),WORD64LO(IPC)); sim_warning("(Arguments : A0 = 0x%08X%08X : A1 = 0x%08X%08X : A2 = 0x%08X%08X : A3 = 0x%08X%08X)",WORD64HI(A0),WORD64LO(A0),WORD64HI(A1),WORD64LO(A1),WORD64HI(A2),WORD64LO(A2),WORD64HI(A3),WORD64LO(A3)); break; } return; } /* Store a word into memory. */ static void store_word (vaddr, val) uword64 vaddr; t_reg val; { uword64 paddr; int uncached; if ((vaddr & 3) != 0) SignalException (AddressStore); else { if (AddressTranslation (vaddr, isDATA, isSTORE, &paddr, &uncached, isTARGET, isREAL)) { const uword64 mask = 7; uword64 memval; unsigned int byte; paddr = (paddr & ~mask) | ((paddr & mask) ^ (ReverseEndian << 2)); byte = (vaddr & mask) ^ (BigEndianCPU << 2); memval = ((uword64) val) << (8 * byte); StoreMemory (uncached, AccessLength_WORD, memval, paddr, vaddr, isREAL); } } } /* Load a word from memory. */ static t_reg load_word (vaddr) uword64 vaddr; { if ((vaddr & 3) != 0) SignalException (AddressLoad); else { uword64 paddr; int uncached; if (AddressTranslation (vaddr, isDATA, isLOAD, &paddr, &uncached, isTARGET, isREAL)) { const uword64 mask = 0x7; const unsigned int reverse = ReverseEndian ? 1 : 0; const unsigned int bigend = BigEndianCPU ? 1 : 0; uword64 memval; unsigned int byte; paddr = (paddr & ~mask) | ((paddr & mask) ^ (reverse << 2)); memval = LoadMemory (uncached, AccessLength_WORD, paddr, vaddr, isDATA, isREAL); byte = (vaddr & mask) ^ (bigend << 2); return SIGNEXTEND (((memval >> (8 * byte)) & 0xffffffff), 32); } } return 0; } /* Simulate the mips16 entry and exit pseudo-instructions. These would normally be handled by the reserved instruction exception code, but for ease of simulation we just handle them directly. */ static void mips16_entry (insn) unsigned int insn; { int aregs, sregs, rreg; aregs = (insn & 0x700) >> 8; sregs = (insn & 0x0c0) >> 6; rreg = (insn & 0x020) >> 5; /* This should be checked by the caller. */ if (sregs == 3) abort (); if (aregs < 5) { int i; t_reg tsp; /* This is the entry pseudo-instruction. */ for (i = 0; i < aregs; i++) store_word ((uword64) (SP + 4 * i), registers[i + 4]); tsp = SP; SP -= 32; if (rreg) { tsp -= 4; store_word ((uword64) tsp, RA); } for (i = 0; i < sregs; i++) { tsp -= 4; store_word ((uword64) tsp, registers[16 + i]); } } else { int i; t_reg tsp; /* This is the exit pseudo-instruction. */ tsp = SP + 32; if (rreg) { tsp -= 4; RA = load_word ((uword64) tsp); } for (i = 0; i < sregs; i++) { tsp -= 4; registers[i + 16] = load_word ((uword64) tsp); } SP += 32; if (aregs == 5) { FGR[0] = WORD64LO (GPR[4]); fpr_state[0] = fmt_uninterpreted; } else if (aregs == 6) { FGR[0] = WORD64LO (GPR[5]); FGR[1] = WORD64LO (GPR[4]); fpr_state[0] = fmt_uninterpreted; fpr_state[1] = fmt_uninterpreted; } PC = RA; } } void sim_warning(char *fmt,...) { char buf[256]; va_list ap; va_start (ap,fmt); vsprintf (buf, fmt, ap); va_end (ap); if (logfh != NULL) { fprintf(logfh,"SIM Warning: %s\n", buf); } else { callback->printf_filtered(callback,"SIM Warning: %s\n", buf); } /* This used to call SignalException with a SimulatorFault, but that causes the simulator to exit, and that is inappropriate for a warning. */ return; } void sim_error(char *fmt,...) { char buf[256]; va_list ap; va_start (ap,fmt); vsprintf (buf, fmt, ap); va_end (ap); callback->printf_filtered(callback,"SIM Error: %s", buf); SignalException (SimulatorFault, buf); return; } static unsigned int power2(value) unsigned int value; { int loop,tmp; /* Round *UP* to the nearest power-of-2 if not already one */ if (value != (value & ~(value - 1))) { for (tmp = value, loop = 0; (tmp != 0); loop++) tmp >>= 1; value = (1 << loop); } return(value); } static long getnum(value) char *value; { long num; char *end; num = strtol(value,&end,10); if (end == value) callback->printf_filtered(callback,"Warning: Invalid number \"%s\" ignored, using zero\n",value); else { if (*end && ((tolower(*end) == 'k') || (tolower(*end) == 'm'))) { if (tolower(*end) == 'k') num *= (1 << 10); else num *= (1 << 20); end++; } if (*end) callback->printf_filtered(callback,"Warning: Spurious characters \"%s\" at end of number ignored\n",end); } return(num); } /*-- trace support ----------------------------------------------------------*/ /* The TRACE support is provided (if required) in the memory accessing routines. Since we are also providing the architecture specific features, the architecture simulation code can also deal with notifying the TRACE world of cache flushes, etc. Similarly we do not need to provide profiling support in the simulator engine, since we can sample in the instruction fetch control loop. By defining the TRACE manifest, we add tracing as a run-time option. */ #if defined(TRACE) /* Tracing by default produces "din" format (as required by dineroIII). Each line of such a trace file *MUST* have a din label and address field. The rest of the line is ignored, so comments can be included if desired. The first field is the label which must be one of the following values: 0 read data 1 write data 2 instruction fetch 3 escape record (treated as unknown access type) 4 escape record (causes cache flush) The address field is a 32bit (lower-case) hexadecimal address value. The address should *NOT* be preceded by "0x". The size of the memory transfer is not important when dealing with cache lines (as long as no more than a cache line can be transferred in a single operation :-), however more information could be given following the dineroIII requirement to allow more complete memory and cache simulators to provide better results. i.e. the University of Pisa has a cache simulator that can also take bus size and speed as (variable) inputs to calculate complete system performance (a much more useful ability when trying to construct an end product, rather than a processor). They currently have an ARM version of their tool called ChARM. */ static void dotrace(FILE *tracefh,int type,SIM_ADDR address,int width,char *comment,...) { if (state & simTRACE) { va_list ap; fprintf(tracefh,"%d %08x%08x ; width %d ; ", type, sizeof (address) > 4 ? (unsigned long)(address>>32) : 0, (unsigned long)(address&0xffffffff),width); va_start(ap,comment); vfprintf(tracefh,comment,ap); va_end(ap); fprintf(tracefh,"\n"); } /* NOTE: Since the "din" format will only accept 32bit addresses, and we may be generating 64bit ones, we should put the hi-32bits of the address into the comment field. */ /* TODO: Provide a buffer for the trace lines. We can then avoid performing writes until the buffer is filled, or the file is being closed. */ /* NOTE: We could consider adding a comment field to the "din" file produced using type 3 markers (unknown access). This would then allow information about the program that the "din" is for, and the MIPs world that was being simulated, to be placed into the trace file. */ return; } #endif /* TRACE */ /*---------------------------------------------------------------------------*/ /*-- host<->target transfers ------------------------------------------------*/ /*---------------------------------------------------------------------------*/ /* The following routines allow conditionals to be avoided during the simulation, at the cost of increasing the image and source size. */ static unsigned int xfer_direct_word(unsigned char *memory) { return *((unsigned int *)memory); } static uword64 xfer_direct_long(unsigned char *memory) { return *((uword64 *)memory); } static unsigned int swap_direct_word(unsigned int data) { return data; } static uword64 swap_direct_long(uword64 data) { return data; } static unsigned int xfer_big_word(unsigned char *memory) { return ((memory[0] << 24) | (memory[1] << 16) | (memory[2] << 8) | memory[3]); } static uword64 xfer_big_long(unsigned char *memory) { return (((uword64)memory[0] << 56) | ((uword64)memory[1] << 48) | ((uword64)memory[2] << 40) | ((uword64)memory[3] << 32) | ((uword64)memory[4] << 24) | ((uword64)memory[5] << 16) | ((uword64)memory[6] << 8) | ((uword64)memory[7])); } static unsigned int xfer_little_word(unsigned char *memory) { return ((memory[3] << 24) | (memory[2] << 16) | (memory[1] << 8) | memory[0]); } static uword64 xfer_little_long(unsigned char *memory) { return (((uword64)memory[7] << 56) | ((uword64)memory[6] << 48) | ((uword64)memory[5] << 40) | ((uword64)memory[4] << 32) | ((uword64)memory[3] << 24) | ((uword64)memory[2] << 16) | ((uword64)memory[1] << 8) | (uword64)memory[0]); } static unsigned int swap_word(unsigned int data) { unsigned int result; result = (((data & 0xff) << 24) | ((data & 0xff00) << 8) | ((data >> 8) & 0xff00) | ((data >> 24) & 0xff)); return result; } static uword64 swap_long(uword64 data) { unsigned int tmphi = WORD64HI(data); unsigned int tmplo = WORD64LO(data); tmphi = swap_word(tmphi); tmplo = swap_word(tmplo); /* Now swap the HI and LO parts */ return SET64LO(tmphi) | SET64HI(tmplo); } /*---------------------------------------------------------------------------*/ /*-- simulator engine -------------------------------------------------------*/ /*---------------------------------------------------------------------------*/ static void set_endianness () { /* In reality this check should be performed at various points within the simulation, since it is possible to change the endianness of user programs. However, we perform the check here to ensure that the start-of-day values agree. */ if (target_byte_order == 4321) state |= simBE; /* ??? This is a lot more code than is necessary to solve the problem. It would be simpler to handle this like the SH simulator. */ if (!ByteSwapMem) { host_read_word = xfer_direct_word; host_read_long = xfer_direct_long; host_swap_word = swap_direct_word; host_swap_long = swap_direct_long; } else if (state & simHOSTBE) { host_read_word = xfer_little_word; host_read_long = xfer_little_long; host_swap_word = swap_word; host_swap_long = swap_long; } else { /* HOST little-endian */ host_read_word = xfer_big_word; host_read_long = xfer_big_long; host_swap_word = swap_word; host_swap_long = swap_long; } } static void ColdReset() { /* RESET: Fixed PC address: */ PC = (((uword64)0xFFFFFFFF<<32) | 0xBFC00000); /* The reset vector address is in the unmapped, uncached memory space. */ SR &= ~(status_SR | status_TS | status_RP); SR |= (status_ERL | status_BEV); #if defined(HASFPU) && (GPRLEN == (64)) /* Cheat and allow access to the complete register set immediately: */ SR |= status_FR; /* 64bit registers */ #endif /* HASFPU and 64bit FP registers */ /* Ensure that any instructions with pending register updates are cleared: */ { int loop; for (loop = 0; (loop < PSLOTS); loop++) pending_slot_reg[loop] = (LAST_EMBED_REGNUM + 1); pending_in = pending_out = pending_total = 0; } #if defined(HASFPU) /* Initialise the FPU registers to the unknown state */ { int rn; for (rn = 0; (rn < 32); rn++) fpr_state[rn] = fmt_uninterpreted; } #endif /* HASFPU */ return; } /* Description from page A-22 of the "MIPS IV Instruction Set" manual (revision 3.1) */ /* Translate a virtual address to a physical address and cache coherence algorithm describing the mechanism used to resolve the memory reference. Given the virtual address vAddr, and whether the reference is to Instructions ot Data (IorD), find the corresponding physical address (pAddr) and the cache coherence algorithm (CCA) used to resolve the reference. If the virtual address is in one of the unmapped address spaces the physical address and the CCA are determined directly by the virtual address. If the virtual address is in one of the mapped address spaces then the TLB is used to determine the physical address and access type; if the required translation is not present in the TLB or the desired access is not permitted the function fails and an exception is taken. NOTE: This function is extended to return an exception state. This, along with the exception generation is used to notify whether a valid address translation occured */ static int AddressTranslation(vAddr,IorD,LorS,pAddr,CCA,host,raw) uword64 vAddr; int IorD; int LorS; uword64 *pAddr; int *CCA; int host; int raw; { int res = -1; /* TRUE : Assume good return */ #ifdef DEBUG callback->printf_filtered(callback,"AddressTranslation(0x%08X%08X,%s,%s,...);\n",WORD64HI(vAddr),WORD64LO(vAddr),(IorD ? "isDATA" : "isINSTRUCTION"),(LorS ? "iSTORE" : "isLOAD")); #endif /* Check that the address is valid for this memory model */ /* For a simple (flat) memory model, we simply pass virtual addressess through (mostly) unchanged. */ vAddr &= 0xFFFFFFFF; /* Treat the kernel memory spaces identically for the moment: */ if ((membank_base == K1BASE) && (vAddr >= K0BASE) && (vAddr < (K0BASE + K0SIZE))) vAddr += (K1BASE - K0BASE); /* Also assume that the K1BASE memory wraps. This is required to allow the PMON run-time __sizemem() routine to function (without having to provide exception simulation). NOTE: A kludge to work around the fact that the monitor memory is currently held in the K1BASE space. */ if (((vAddr < monitor_base) || (vAddr >= (monitor_base + monitor_size))) && (vAddr >= K1BASE && vAddr < (K1BASE + K1SIZE))) vAddr = (K1BASE | (vAddr & (membank_size - 1))); *pAddr = vAddr; /* default for isTARGET */ *CCA = Uncached; /* not used for isHOST */ /* NOTE: This is a duplicate of the code that appears in the LoadMemory and StoreMemory functions. They should be merged into a single function (that can be in-lined if required). */ if ((vAddr >= membank_base) && (vAddr < (membank_base + membank_size))) { if (host) *pAddr = (int)&membank[((unsigned int)(vAddr - membank_base) & (membank_size - 1))]; } else if ((vAddr >= monitor_base) && (vAddr < (monitor_base + monitor_size))) { if (host) *pAddr = (int)&monitor[((unsigned int)(vAddr - monitor_base) & (monitor_size - 1))]; } else { #ifdef DEBUG sim_warning("Failed: AddressTranslation(0x%08X%08X,%s,%s,...) IPC = 0x%08X%08X",WORD64HI(vAddr),WORD64LO(vAddr),(IorD ? "isDATA" : "isINSTRUCTION"),(LorS ? "isSTORE" : "isLOAD"),WORD64HI(IPC),WORD64LO(IPC)); #endif /* DEBUG */ res = 0; /* AddressTranslation has failed */ *pAddr = (SIM_ADDR)-1; if (!raw) /* only generate exceptions on real memory transfers */ SignalException((LorS == isSTORE) ? AddressStore : AddressLoad); #ifdef DEBUG else /* This is a normal occurance during gdb operation, for instance trying to print parameters at function start before they have been setup, and hence we should not print a warning except when debugging the simulator. */ sim_warning("AddressTranslation for %s %s from 0x%08X%08X failed",(IorD ? "data" : "instruction"),(LorS ? "store" : "load"),WORD64HI(vAddr),WORD64LO(vAddr)); #endif } return(res); } /* Description from page A-23 of the "MIPS IV Instruction Set" manual (revision 3.1) */ /* Prefetch data from memory. Prefetch is an advisory instruction for which an implementation specific action is taken. The action taken may increase performance, but must not change the meaning of the program, or alter architecturally-visible state. */ static void Prefetch(CCA,pAddr,vAddr,DATA,hint) int CCA; uword64 pAddr; uword64 vAddr; int DATA; int hint; { #ifdef DEBUG callback->printf_filtered(callback,"Prefetch(%d,0x%08X%08X,0x%08X%08X,%d,%d);\n",CCA,WORD64HI(pAddr),WORD64LO(pAddr),WORD64HI(vAddr),WORD64LO(vAddr),DATA,hint); #endif /* DEBUG */ /* For our simple memory model we do nothing */ return; } /* Description from page A-22 of the "MIPS IV Instruction Set" manual (revision 3.1) */ /* Load a value from memory. Use the cache and main memory as specified in the Cache Coherence Algorithm (CCA) and the sort of access (IorD) to find the contents of AccessLength memory bytes starting at physical location pAddr. The data is returned in the fixed width naturally-aligned memory element (MemElem). The low-order two (or three) bits of the address and the AccessLength indicate which of the bytes within MemElem needs to be given to the processor. If the memory access type of the reference is uncached then only the referenced bytes are read from memory and valid within the memory element. If the access type is cached, and the data is not present in cache, an implementation specific size and alignment block of memory is read and loaded into the cache to satisfy a load reference. At a minimum, the block is the entire memory element. */ static uword64 LoadMemory(CCA,AccessLength,pAddr,vAddr,IorD,raw) int CCA; int AccessLength; uword64 pAddr; uword64 vAddr; int IorD; int raw; { uword64 value; #ifdef DEBUG if (membank == NULL) callback->printf_filtered(callback,"DBG: LoadMemory(%d,%d,0x%08X%08X,0x%08X%08X,%s,%s)\n",CCA,AccessLength,WORD64HI(pAddr),WORD64LO(pAddr),WORD64HI(vAddr),WORD64LO(vAddr),(IorD ? "isDATA" : "isINSTRUCTION"),(raw ? "isRAW" : "isREAL")); #endif /* DEBUG */ #if defined(WARN_MEM) if (CCA != uncached) sim_warning("LoadMemory CCA (%d) is not uncached (currently all accesses treated as cached)",CCA); if (((pAddr & LOADDRMASK) + AccessLength) > LOADDRMASK) { /* In reality this should be a Bus Error */ sim_error("AccessLength of %d would extend over %dbit aligned boundary for physical address 0x%08X%08X\n",AccessLength,(LOADDRMASK + 1)<<2,WORD64HI(pAddr),WORD64LO(pAddr)); } #endif /* WARN_MEM */ /* Decide which physical memory locations are being dealt with. At this point we should be able to split the pAddr bits into the relevant address map being simulated. If the "raw" variable is set, the memory read being performed should *NOT* update any I/O state or affect the CPU state. This also includes avoiding affecting statistics gathering. */ /* If instruction fetch then we need to check that the two lo-order bits are zero, otherwise raise a InstructionFetch exception: */ if ((IorD == isINSTRUCTION) && ((pAddr & 0x3) != 0) && (((pAddr & 0x1) != 0) || ((vAddr & 0x1) == 0))) SignalException(InstructionFetch); else { unsigned int index; unsigned char *mem = NULL; #if defined(TRACE) if (!raw) dotrace(tracefh,((IorD == isDATA) ? 0 : 2),(unsigned int)(pAddr&0xFFFFFFFF),(AccessLength + 1),"load%s",((IorD == isDATA) ? "" : " instruction")); #endif /* TRACE */ /* NOTE: Quicker methods of decoding the address space can be used when a real memory map is being simulated (i.e. using hi-order address bits to select device). */ if ((pAddr >= membank_base) && (pAddr < (membank_base + membank_size))) { index = ((unsigned int)(pAddr - membank_base) & (membank_size - 1)); mem = membank; } else if ((pAddr >= monitor_base) && (pAddr < (monitor_base + monitor_size))) { index = ((unsigned int)(pAddr - monitor_base) & (monitor_size - 1)); mem = monitor; } if (mem == NULL) sim_error("Simulator memory not found for physical address 0x%08X%08X\n",WORD64HI(pAddr),WORD64LO(pAddr)); else { /* If we obtained the endianness of the host, and it is the same as the target memory system we can optimise the memory accesses. However, without that information we must perform slow transfer, and hope that the compiler optimisation will merge successive loads. */ value = 0; /* no data loaded yet */ /* In reality we should always be loading a doubleword value (or word value in 32bit memory worlds). The external code then extracts the required bytes. However, to keep performance high we only load the required bytes into the relevant slots. */ if (BigEndianMem) switch (AccessLength) { /* big-endian memory */ case AccessLength_DOUBLEWORD : value |= ((uword64)mem[index++] << 56); case AccessLength_SEPTIBYTE : value |= ((uword64)mem[index++] << 48); case AccessLength_SEXTIBYTE : value |= ((uword64)mem[index++] << 40); case AccessLength_QUINTIBYTE : value |= ((uword64)mem[index++] << 32); case AccessLength_WORD : value |= ((unsigned int)mem[index++] << 24); case AccessLength_TRIPLEBYTE : value |= ((unsigned int)mem[index++] << 16); case AccessLength_HALFWORD : value |= ((unsigned int)mem[index++] << 8); case AccessLength_BYTE : value |= mem[index]; break; } else { index += (AccessLength + 1); switch (AccessLength) { /* little-endian memory */ case AccessLength_DOUBLEWORD : value |= ((uword64)mem[--index] << 56); case AccessLength_SEPTIBYTE : value |= ((uword64)mem[--index] << 48); case AccessLength_SEXTIBYTE : value |= ((uword64)mem[--index] << 40); case AccessLength_QUINTIBYTE : value |= ((uword64)mem[--index] << 32); case AccessLength_WORD : value |= ((uword64)mem[--index] << 24); case AccessLength_TRIPLEBYTE : value |= ((uword64)mem[--index] << 16); case AccessLength_HALFWORD : value |= ((uword64)mem[--index] << 8); case AccessLength_BYTE : value |= ((uword64)mem[--index] << 0); break; } } #ifdef DEBUG printf("DBG: LoadMemory() : (offset %d) : value = 0x%08X%08X\n",(int)(pAddr & LOADDRMASK),WORD64HI(value),WORD64LO(value)); #endif /* DEBUG */ /* TODO: We could try and avoid the shifts when dealing with raw memory accesses. This would mean updating the LoadMemory and StoreMemory routines to avoid shifting the data before returning or using it. */ if (!raw) { /* do nothing for raw accessess */ if (BigEndianMem) value <<= (((7 - (pAddr & LOADDRMASK)) - AccessLength) * 8); else /* little-endian only needs to be shifted up to the correct byte offset */ value <<= ((pAddr & LOADDRMASK) * 8); } #ifdef DEBUG printf("DBG: LoadMemory() : shifted value = 0x%08X%08X\n",WORD64HI(value),WORD64LO(value)); #endif /* DEBUG */ } } return(value); } /* Description from page A-23 of the "MIPS IV Instruction Set" manual (revision 3.1) */ /* Store a value to memory. The specified data is stored into the physical location pAddr using the memory hierarchy (data caches and main memory) as specified by the Cache Coherence Algorithm (CCA). The MemElem contains the data for an aligned, fixed-width memory element (word for 32-bit processors, doubleword for 64-bit processors), though only the bytes that will actually be stored to memory need to be valid. The low-order two (or three) bits of pAddr and the AccessLength field indicates which of the bytes within the MemElem data should actually be stored; only these bytes in memory will be changed. */ static void StoreMemory(CCA,AccessLength,MemElem,pAddr,vAddr,raw) int CCA; int AccessLength; uword64 MemElem; uword64 pAddr; uword64 vAddr; int raw; { #ifdef DEBUG callback->printf_filtered(callback,"DBG: StoreMemory(%d,%d,0x%08X%08X,0x%08X%08X,0x%08X%08X,%s)\n",CCA,AccessLength,WORD64HI(MemElem),WORD64LO(MemElem),WORD64HI(pAddr),WORD64LO(pAddr),WORD64HI(vAddr),WORD64LO(vAddr),(raw ? "isRAW" : "isREAL")); #endif /* DEBUG */ #if defined(WARN_MEM) if (CCA != uncached) sim_warning("StoreMemory CCA (%d) is not uncached (currently all accesses treated as cached)",CCA); if (((pAddr & LOADDRMASK) + AccessLength) > LOADDRMASK) sim_error("AccessLength of %d would extend over %dbit aligned boundary for physical address 0x%08X%08X\n",AccessLength,(LOADDRMASK + 1)<<2,WORD64HI(pAddr),WORD64LO(pAddr)); #endif /* WARN_MEM */ #if defined(TRACE) if (!raw) dotrace(tracefh,1,(unsigned int)(pAddr&0xFFFFFFFF),(AccessLength + 1),"store"); #endif /* TRACE */ /* See the comments in the LoadMemory routine about optimising memory accesses. Also if we wanted to make the simulator smaller, we could merge a lot of this code with the LoadMemory routine. However, this would slow the simulator down with run-time conditionals. */ { unsigned int index; unsigned char *mem = NULL; if ((pAddr >= membank_base) && (pAddr < (membank_base + membank_size))) { index = ((unsigned int)(pAddr - membank_base) & (membank_size - 1)); mem = membank; } else if ((pAddr >= monitor_base) && (pAddr < (monitor_base + monitor_size))) { index = ((unsigned int)(pAddr - monitor_base) & (monitor_size - 1)); mem = monitor; } if (mem == NULL) sim_error("Simulator memory not found for physical address 0x%08X%08X\n",WORD64HI(pAddr),WORD64LO(pAddr)); else { int shift = 0; #ifdef DEBUG printf("DBG: StoreMemory: offset = %d MemElem = 0x%08X%08X\n",(unsigned int)(pAddr & LOADDRMASK),WORD64HI(MemElem),WORD64LO(MemElem)); #endif /* DEBUG */ if (BigEndianMem) { if (raw) shift = ((7 - AccessLength) * 8); else /* real memory access */ shift = ((pAddr & LOADDRMASK) * 8); MemElem <<= shift; } else { /* no need to shift raw little-endian data */ if (!raw) MemElem >>= ((pAddr & LOADDRMASK) * 8); } #ifdef DEBUG printf("DBG: StoreMemory: shift = %d MemElem = 0x%08X%08X\n",shift,WORD64HI(MemElem),WORD64LO(MemElem)); #endif /* DEBUG */ if (BigEndianMem) { switch (AccessLength) { /* big-endian memory */ case AccessLength_DOUBLEWORD : mem[index++] = (unsigned char)(MemElem >> 56); MemElem <<= 8; case AccessLength_SEPTIBYTE : mem[index++] = (unsigned char)(MemElem >> 56); MemElem <<= 8; case AccessLength_SEXTIBYTE : mem[index++] = (unsigned char)(MemElem >> 56); MemElem <<= 8; case AccessLength_QUINTIBYTE : mem[index++] = (unsigned char)(MemElem >> 56); MemElem <<= 8; case AccessLength_WORD : mem[index++] = (unsigned char)(MemElem >> 56); MemElem <<= 8; case AccessLength_TRIPLEBYTE : mem[index++] = (unsigned char)(MemElem >> 56); MemElem <<= 8; case AccessLength_HALFWORD : mem[index++] = (unsigned char)(MemElem >> 56); MemElem <<= 8; case AccessLength_BYTE : mem[index++] = (unsigned char)(MemElem >> 56); break; } } else { index += (AccessLength + 1); switch (AccessLength) { /* little-endian memory */ case AccessLength_DOUBLEWORD : mem[--index] = (unsigned char)(MemElem >> 56); case AccessLength_SEPTIBYTE : mem[--index] = (unsigned char)(MemElem >> 48); case AccessLength_SEXTIBYTE : mem[--index] = (unsigned char)(MemElem >> 40); case AccessLength_QUINTIBYTE : mem[--index] = (unsigned char)(MemElem >> 32); case AccessLength_WORD : mem[--index] = (unsigned char)(MemElem >> 24); case AccessLength_TRIPLEBYTE : mem[--index] = (unsigned char)(MemElem >> 16); case AccessLength_HALFWORD : mem[--index] = (unsigned char)(MemElem >> 8); case AccessLength_BYTE : mem[--index] = (unsigned char)(MemElem >> 0); break; } } } } return; } /* Description from page A-26 of the "MIPS IV Instruction Set" manual (revision 3.1) */ /* Order loads and stores to synchronise shared memory. Perform the action necessary to make the effects of groups of synchronizable loads and stores indicated by stype occur in the same order for all processors. */ static void SyncOperation(stype) int stype; { #ifdef DEBUG callback->printf_filtered(callback,"SyncOperation(%d) : TODO\n",stype); #endif /* DEBUG */ return; } /* Description from page A-26 of the "MIPS IV Instruction Set" manual (revision 3.1) */ /* Signal an exception condition. This will result in an exception that aborts the instruction. The instruction operation pseudocode will never see a return from this function call. */ static void SignalException (int exception,...) { /* Ensure that any active atomic read/modify/write operation will fail: */ LLBIT = 0; switch (exception) { /* TODO: For testing purposes I have been ignoring TRAPs. In reality we should either simulate them, or allow the user to ignore them at run-time. */ case Trap : sim_warning("Ignoring instruction TRAP (PC 0x%08X%08X)",WORD64HI(IPC),WORD64LO(IPC)); break; case ReservedInstruction : { va_list ap; unsigned int instruction; va_start(ap,exception); instruction = va_arg(ap,unsigned int); va_end(ap); /* Provide simple monitor support using ReservedInstruction exceptions. The following code simulates the fixed vector entry points into the IDT monitor by causing a simulator trap, performing the monitor operation, and returning to the address held in the $ra register (standard PCS return address). This means we only need to pre-load the vector space with suitable instruction values. For systems were actual trap instructions are used, we would not need to perform this magic. */ if ((instruction & ~RSVD_INSTRUCTION_AMASK) == RSVD_INSTRUCTION) { sim_monitor(instruction & RSVD_INSTRUCTION_AMASK); PC = RA; /* simulate the return from the vector entry */ /* NOTE: This assumes that a branch-and-link style instruction was used to enter the vector (which is the case with the current IDT monitor). */ break; /* out of the switch statement */ } /* Look for the mips16 entry and exit instructions, and simulate a handler for them. */ else if ((IPC & 1) != 0 && (instruction & 0xf81f) == 0xe809 && (instruction & 0x0c0) != 0x0c0) { mips16_entry (instruction); break; } /* else fall through to normal exception processing */ sim_warning("ReservedInstruction 0x%08X at IPC = 0x%08X%08X",instruction,WORD64HI(IPC),WORD64LO(IPC)); } default: #ifdef DEBUG if (exception != BreakPoint) callback->printf_filtered(callback,"DBG: SignalException(%d) IPC = 0x%08X%08X\n",exception,WORD64HI(IPC),WORD64LO(IPC)); #endif /* DEBUG */ /* Store exception code into current exception id variable (used by exit code): */ /* TODO: If not simulating exceptions then stop the simulator execution. At the moment we always stop the simulation. */ state |= (simSTOP | simEXCEPTION); /* Keep a copy of the current A0 in-case this is the program exit breakpoint: */ if (exception == BreakPoint) { va_list ap; unsigned int instruction; va_start(ap,exception); instruction = va_arg(ap,unsigned int); va_end(ap); /* Check for our special terminating BREAK: */ if ((instruction & 0x03FFFFC0) == 0x03ff0000) { rcexit = (unsigned int)(A0 & 0xFFFFFFFF); state &= ~simEXCEPTION; state |= simEXIT; } } /* Store exception code into current exception id variable (used by exit code): */ CAUSE = (exception << 2); if (state & simDELAYSLOT) { CAUSE |= cause_BD; EPC = (IPC - 4); /* reference the branch instruction */ } else EPC = IPC; /* The following is so that the simulator will continue from the exception address on breakpoint operations. */ PC = EPC; break; case SimulatorFault: { va_list ap; char *msg; va_start(ap,exception); msg = va_arg(ap,char *); fprintf(stderr,"FATAL: Simulator error \"%s\"\n",msg); va_end(ap); } exit(1); } return; } #if defined(WARN_RESULT) /* Description from page A-26 of the "MIPS IV Instruction Set" manual (revision 3.1) */ /* This function indicates that the result of the operation is undefined. However, this should not affect the instruction stream. All that is meant to happen is that the destination register is set to an undefined result. To keep the simulator simple, we just don't bother updating the destination register, so the overall result will be undefined. If desired we can stop the simulator by raising a pseudo-exception. */ static void UndefinedResult() { sim_warning("UndefinedResult: IPC = 0x%08X%08X",WORD64HI(IPC),WORD64LO(IPC)); #if 0 /* Disabled for the moment, since it actually happens a lot at the moment. */ state |= simSTOP; #endif return; } #endif /* WARN_RESULT */ static void CacheOp(op,pAddr,vAddr,instruction) int op; uword64 pAddr; uword64 vAddr; unsigned int instruction; { #if 1 /* stop warning message being displayed (we should really just remove the code) */ static int icache_warning = 1; static int dcache_warning = 1; #else static int icache_warning = 0; static int dcache_warning = 0; #endif /* If CP0 is not useable (User or Supervisor mode) and the CP0 enable bit in the Status Register is clear - a coprocessor unusable exception is taken. */ #if 0 callback->printf_filtered(callback,"TODO: Cache availability checking (PC = 0x%08X%08X)\n",WORD64HI(IPC),WORD64LO(IPC)); #endif switch (op & 0x3) { case 0: /* instruction cache */ switch (op >> 2) { case 0: /* Index Invalidate */ case 1: /* Index Load Tag */ case 2: /* Index Store Tag */ case 4: /* Hit Invalidate */ case 5: /* Fill */ case 6: /* Hit Writeback */ if (!icache_warning) { sim_warning("Instruction CACHE operation %d to be coded",(op >> 2)); icache_warning = 1; } break; default: SignalException(ReservedInstruction,instruction); break; } break; case 1: /* data cache */ switch (op >> 2) { case 0: /* Index Writeback Invalidate */ case 1: /* Index Load Tag */ case 2: /* Index Store Tag */ case 3: /* Create Dirty */ case 4: /* Hit Invalidate */ case 5: /* Hit Writeback Invalidate */ case 6: /* Hit Writeback */ if (!dcache_warning) { sim_warning("Data CACHE operation %d to be coded",(op >> 2)); dcache_warning = 1; } break; default: SignalException(ReservedInstruction,instruction); break; } break; default: /* unrecognised cache ID */ SignalException(ReservedInstruction,instruction); break; } return; } /*-- FPU support routines ---------------------------------------------------*/ #if defined(HASFPU) /* Only needed when building FPU aware simulators */ #if 1 #define SizeFGR() (GPRLEN) #else /* They depend on the CPU being simulated */ #define SizeFGR() ((PROCESSOR_64BIT && ((SR & status_FR) == 1)) ? 64 : 32) #endif /* Numbers are held in normalized form. The SINGLE and DOUBLE binary formats conform to ANSI/IEEE Std 754-1985. */ /* SINGLE precision floating: * seeeeeeeefffffffffffffffffffffff * s = 1bit = sign * e = 8bits = exponent * f = 23bits = fraction */ /* SINGLE precision fixed: * siiiiiiiiiiiiiiiiiiiiiiiiiiiiiii * s = 1bit = sign * i = 31bits = integer */ /* DOUBLE precision floating: * seeeeeeeeeeeffffffffffffffffffffffffffffffffffffffffffffffffffff * s = 1bit = sign * e = 11bits = exponent * f = 52bits = fraction */ /* DOUBLE precision fixed: * siiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii * s = 1bit = sign * i = 63bits = integer */ /* Extract sign-bit: */ #define FP_S_s(v) (((v) & ((unsigned)1 << 31)) ? 1 : 0) #define FP_D_s(v) (((v) & ((uword64)1 << 63)) ? 1 : 0) /* Extract biased exponent: */ #define FP_S_be(v) (((v) >> 23) & 0xFF) #define FP_D_be(v) (((v) >> 52) & 0x7FF) /* Extract unbiased Exponent: */ #define FP_S_e(v) (FP_S_be(v) - 0x7F) #define FP_D_e(v) (FP_D_be(v) - 0x3FF) /* Extract complete fraction field: */ #define FP_S_f(v) ((v) & ~((unsigned)0x1FF << 23)) #define FP_D_f(v) ((v) & ~((uword64)0xFFF << 52)) /* Extract numbered fraction bit: */ #define FP_S_fb(b,v) (((v) & (1 << (23 - (b)))) ? 1 : 0) #define FP_D_fb(b,v) (((v) & (1 << (52 - (b)))) ? 1 : 0) /* Explicit QNaN values used when value required: */ #define FPQNaN_SINGLE (0x7FBFFFFF) #define FPQNaN_WORD (0x7FFFFFFF) #define FPQNaN_DOUBLE (((uword64)0x7FF7FFFF << 32) | 0xFFFFFFFF) #define FPQNaN_LONG (((uword64)0x7FFFFFFF << 32) | 0xFFFFFFFF) /* Explicit Infinity values used when required: */ #define FPINF_SINGLE (0x7F800000) #define FPINF_DOUBLE (((uword64)0x7FF00000 << 32) | 0x00000000) #if 1 /* def DEBUG */ #define RMMODE(v) (((v) == FP_RM_NEAREST) ? "Round" : (((v) == FP_RM_TOZERO) ? "Trunc" : (((v) == FP_RM_TOPINF) ? "Ceil" : "Floor"))) #define DOFMT(v) (((v) == fmt_single) ? "single" : (((v) == fmt_double) ? "double" : (((v) == fmt_word) ? "word" : (((v) == fmt_long) ? "long" : (((v) == fmt_unknown) ? "" : (((v) == fmt_uninterpreted) ? "" : "")))))) #endif /* DEBUG */ static uword64 ValueFPR(fpr,fmt) int fpr; FP_formats fmt; { uword64 value; int err = 0; /* Treat unused register values, as fixed-point 64bit values: */ if ((fmt == fmt_uninterpreted) || (fmt == fmt_unknown)) #if 1 /* If request to read data as "uninterpreted", then use the current encoding: */ fmt = fpr_state[fpr]; #else fmt = fmt_long; #endif /* For values not yet accessed, set to the desired format: */ if (fpr_state[fpr] == fmt_uninterpreted) { fpr_state[fpr] = fmt; #ifdef DEBUG printf("DBG: Register %d was fmt_uninterpreted. Now %s\n",fpr,DOFMT(fmt)); #endif /* DEBUG */ } if (fmt != fpr_state[fpr]) { sim_warning("FPR %d (format %s) being accessed with format %s - setting to unknown (PC = 0x%08X%08X)",fpr,DOFMT(fpr_state[fpr]),DOFMT(fmt),WORD64HI(IPC),WORD64LO(IPC)); fpr_state[fpr] = fmt_unknown; } if (fpr_state[fpr] == fmt_unknown) { /* Set QNaN value: */ switch (fmt) { case fmt_single: value = FPQNaN_SINGLE; break; case fmt_double: value = FPQNaN_DOUBLE; break; case fmt_word: value = FPQNaN_WORD; break; case fmt_long: value = FPQNaN_LONG; break; default: err = -1; break; } } else if (SizeFGR() == 64) { switch (fmt) { case fmt_single: case fmt_word: value = (FGR[fpr] & 0xFFFFFFFF); break; case fmt_uninterpreted: case fmt_double: case fmt_long: value = FGR[fpr]; break; default : err = -1; break; } } else { switch (fmt) { case fmt_single: case fmt_word: value = (FGR[fpr] & 0xFFFFFFFF); break; case fmt_uninterpreted: case fmt_double: case fmt_long: if ((fpr & 1) == 0) { /* even registers only */ value = ((((uword64)FGR[fpr+1]) << 32) | (FGR[fpr] & 0xFFFFFFFF)); } else { SignalException (ReservedInstruction, 0); } break; default : err = -1; break; } } if (err) SignalException(SimulatorFault,"Unrecognised FP format in ValueFPR()"); #ifdef DEBUG printf("DBG: ValueFPR: fpr = %d, fmt = %s, value = 0x%08X%08X : PC = 0x%08X%08X : SizeFGR() = %d\n",fpr,DOFMT(fmt),WORD64HI(value),WORD64LO(value),WORD64HI(IPC),WORD64LO(IPC),SizeFGR()); #endif /* DEBUG */ return(value); } static void StoreFPR(fpr,fmt,value) int fpr; FP_formats fmt; uword64 value; { int err = 0; #ifdef DEBUG printf("DBG: StoreFPR: fpr = %d, fmt = %s, value = 0x%08X%08X : PC = 0x%08X%08X : SizeFGR() = %d\n",fpr,DOFMT(fmt),WORD64HI(value),WORD64LO(value),WORD64HI(IPC),WORD64LO(IPC),SizeFGR()); #endif /* DEBUG */ if (SizeFGR() == 64) { switch (fmt) { case fmt_single : case fmt_word : FGR[fpr] = (((uword64)0xDEADC0DE << 32) | (value & 0xFFFFFFFF)); fpr_state[fpr] = fmt; break; case fmt_uninterpreted: case fmt_double : case fmt_long : FGR[fpr] = value; fpr_state[fpr] = fmt; break; default : fpr_state[fpr] = fmt_unknown; err = -1; break; } } else { switch (fmt) { case fmt_single : case fmt_word : FGR[fpr] = (value & 0xFFFFFFFF); fpr_state[fpr] = fmt; break; case fmt_uninterpreted: case fmt_double : case fmt_long : if ((fpr & 1) == 0) { /* even register number only */ FGR[fpr+1] = (value >> 32); FGR[fpr] = (value & 0xFFFFFFFF); fpr_state[fpr + 1] = fmt; fpr_state[fpr] = fmt; } else { fpr_state[fpr] = fmt_unknown; fpr_state[fpr + 1] = fmt_unknown; SignalException (ReservedInstruction, 0); } break; default : fpr_state[fpr] = fmt_unknown; err = -1; break; } } #if defined(WARN_RESULT) else UndefinedResult(); #endif /* WARN_RESULT */ if (err) SignalException(SimulatorFault,"Unrecognised FP format in StoreFPR()"); #ifdef DEBUG printf("DBG: StoreFPR: fpr[%d] = 0x%08X%08X (format %s)\n",fpr,WORD64HI(FGR[fpr]),WORD64LO(FGR[fpr]),DOFMT(fmt)); #endif /* DEBUG */ return; } static int NaN(op,fmt) uword64 op; FP_formats fmt; { int boolean = 0; /* Check if (((E - bias) == (E_max + 1)) && (fraction != 0)). We know that the exponent field is biased... we we cheat and avoid removing the bias value. */ switch (fmt) { case fmt_single: boolean = ((FP_S_be(op) == 0xFF) && (FP_S_f(op) != 0)); /* We could use "FP_S_fb(1,op)" to ascertain whether we are dealing with a SNaN or QNaN */ break; case fmt_double: boolean = ((FP_D_be(op) == 0x7FF) && (FP_D_f(op) != 0)); /* We could use "FP_S_fb(1,op)" to ascertain whether we are dealing with a SNaN or QNaN */ break; case fmt_word: boolean = (op == FPQNaN_WORD); break; case fmt_long: boolean = (op == FPQNaN_LONG); break; } #ifdef DEBUG printf("DBG: NaN: returning %d for 0x%08X%08X (format = %s)\n",boolean,WORD64HI(op),WORD64LO(op),DOFMT(fmt)); #endif /* DEBUG */ return(boolean); } static int Infinity(op,fmt) uword64 op; FP_formats fmt; { int boolean = 0; #ifdef DEBUG printf("DBG: Infinity: format %s 0x%08X%08X (PC = 0x%08X%08X)\n",DOFMT(fmt),WORD64HI(op),WORD64LO(op),WORD64HI(IPC),WORD64LO(IPC)); #endif /* DEBUG */ /* Check if (((E - bias) == (E_max + 1)) && (fraction == 0)). We know that the exponent field is biased... we we cheat and avoid removing the bias value. */ switch (fmt) { case fmt_single: boolean = ((FP_S_be(op) == 0xFF) && (FP_S_f(op) == 0)); break; case fmt_double: boolean = ((FP_D_be(op) == 0x7FF) && (FP_D_f(op) == 0)); break; default: printf("DBG: TODO: unrecognised format (%s) for Infinity check\n",DOFMT(fmt)); break; } #ifdef DEBUG printf("DBG: Infinity: returning %d for 0x%08X%08X (format = %s)\n",boolean,WORD64HI(op),WORD64LO(op),DOFMT(fmt)); #endif /* DEBUG */ return(boolean); } static int Less(op1,op2,fmt) uword64 op1; uword64 op2; FP_formats fmt; { int boolean = 0; /* Argument checking already performed by the FPCOMPARE code */ #ifdef DEBUG printf("DBG: Less: %s: op1 = 0x%08X%08X : op2 = 0x%08X%08X\n",DOFMT(fmt),WORD64HI(op1),WORD64LO(op1),WORD64HI(op2),WORD64LO(op2)); #endif /* DEBUG */ /* The format type should already have been checked: */ switch (fmt) { case fmt_single: { unsigned int wop1 = (unsigned int)op1; unsigned int wop2 = (unsigned int)op2; boolean = (*(float *)&wop1 < *(float *)&wop2); } break; case fmt_double: boolean = (*(double *)&op1 < *(double *)&op2); break; } #ifdef DEBUG printf("DBG: Less: returning %d (format = %s)\n",boolean,DOFMT(fmt)); #endif /* DEBUG */ return(boolean); } static int Equal(op1,op2,fmt) uword64 op1; uword64 op2; FP_formats fmt; { int boolean = 0; /* Argument checking already performed by the FPCOMPARE code */ #ifdef DEBUG printf("DBG: Equal: %s: op1 = 0x%08X%08X : op2 = 0x%08X%08X\n",DOFMT(fmt),WORD64HI(op1),WORD64LO(op1),WORD64HI(op2),WORD64LO(op2)); #endif /* DEBUG */ /* The format type should already have been checked: */ switch (fmt) { case fmt_single: boolean = ((op1 & 0xFFFFFFFF) == (op2 & 0xFFFFFFFF)); break; case fmt_double: boolean = (op1 == op2); break; } #ifdef DEBUG printf("DBG: Equal: returning %d (format = %s)\n",boolean,DOFMT(fmt)); #endif /* DEBUG */ return(boolean); } static uword64 AbsoluteValue(op,fmt) uword64 op; FP_formats fmt; { uword64 result; #ifdef DEBUG printf("DBG: AbsoluteValue: %s: op = 0x%08X%08X\n",DOFMT(fmt),WORD64HI(op),WORD64LO(op)); #endif /* DEBUG */ /* The format type should already have been checked: */ switch (fmt) { case fmt_single: { unsigned int wop = (unsigned int)op; float tmp = ((float)fabs((double)*(float *)&wop)); result = (uword64)*(unsigned int *)&tmp; } break; case fmt_double: { double tmp = (fabs(*(double *)&op)); result = *(uword64 *)&tmp; } } return(result); } static uword64 Negate(op,fmt) uword64 op; FP_formats fmt; { uword64 result; #ifdef DEBUG printf("DBG: Negate: %s: op = 0x%08X%08X\n",DOFMT(fmt),WORD64HI(op),WORD64LO(op)); #endif /* DEBUG */ /* The format type should already have been checked: */ switch (fmt) { case fmt_single: { unsigned int wop = (unsigned int)op; float tmp = ((float)0.0 - *(float *)&wop); result = (uword64)*(unsigned int *)&tmp; } break; case fmt_double: { double tmp = ((double)0.0 - *(double *)&op); result = *(uword64 *)&tmp; } break; } return(result); } static uword64 Add(op1,op2,fmt) uword64 op1; uword64 op2; FP_formats fmt; { uword64 result; #ifdef DEBUG printf("DBG: Add: %s: op1 = 0x%08X%08X : op2 = 0x%08X%08X\n",DOFMT(fmt),WORD64HI(op1),WORD64LO(op1),WORD64HI(op2),WORD64LO(op2)); #endif /* DEBUG */ /* The registers must specify FPRs valid for operands of type "fmt". If they are not valid, the result is undefined. */ /* The format type should already have been checked: */ switch (fmt) { case fmt_single: { unsigned int wop1 = (unsigned int)op1; unsigned int wop2 = (unsigned int)op2; float tmp = (*(float *)&wop1 + *(float *)&wop2); result = (uword64)*(unsigned int *)&tmp; } break; case fmt_double: { double tmp = (*(double *)&op1 + *(double *)&op2); result = *(uword64 *)&tmp; } break; } #ifdef DEBUG printf("DBG: Add: returning 0x%08X%08X (format = %s)\n",WORD64HI(result),WORD64LO(result),DOFMT(fmt)); #endif /* DEBUG */ return(result); } static uword64 Sub(op1,op2,fmt) uword64 op1; uword64 op2; FP_formats fmt; { uword64 result; #ifdef DEBUG printf("DBG: Sub: %s: op1 = 0x%08X%08X : op2 = 0x%08X%08X\n",DOFMT(fmt),WORD64HI(op1),WORD64LO(op1),WORD64HI(op2),WORD64LO(op2)); #endif /* DEBUG */ /* The registers must specify FPRs valid for operands of type "fmt". If they are not valid, the result is undefined. */ /* The format type should already have been checked: */ switch (fmt) { case fmt_single: { unsigned int wop1 = (unsigned int)op1; unsigned int wop2 = (unsigned int)op2; float tmp = (*(float *)&wop1 - *(float *)&wop2); result = (uword64)*(unsigned int *)&tmp; } break; case fmt_double: { double tmp = (*(double *)&op1 - *(double *)&op2); result = *(uword64 *)&tmp; } break; } #ifdef DEBUG printf("DBG: Sub: returning 0x%08X%08X (format = %s)\n",WORD64HI(result),WORD64LO(result),DOFMT(fmt)); #endif /* DEBUG */ return(result); } static uword64 Multiply(op1,op2,fmt) uword64 op1; uword64 op2; FP_formats fmt; { uword64 result; #ifdef DEBUG printf("DBG: Multiply: %s: op1 = 0x%08X%08X : op2 = 0x%08X%08X\n",DOFMT(fmt),WORD64HI(op1),WORD64LO(op1),WORD64HI(op2),WORD64LO(op2)); #endif /* DEBUG */ /* The registers must specify FPRs valid for operands of type "fmt". If they are not valid, the result is undefined. */ /* The format type should already have been checked: */ switch (fmt) { case fmt_single: { unsigned int wop1 = (unsigned int)op1; unsigned int wop2 = (unsigned int)op2; float tmp = (*(float *)&wop1 * *(float *)&wop2); result = (uword64)*(unsigned int *)&tmp; } break; case fmt_double: { double tmp = (*(double *)&op1 * *(double *)&op2); result = *(uword64 *)&tmp; } break; } #ifdef DEBUG printf("DBG: Multiply: returning 0x%08X%08X (format = %s)\n",WORD64HI(result),WORD64LO(result),DOFMT(fmt)); #endif /* DEBUG */ return(result); } static uword64 Divide(op1,op2,fmt) uword64 op1; uword64 op2; FP_formats fmt; { uword64 result; #ifdef DEBUG printf("DBG: Divide: %s: op1 = 0x%08X%08X : op2 = 0x%08X%08X\n",DOFMT(fmt),WORD64HI(op1),WORD64LO(op1),WORD64HI(op2),WORD64LO(op2)); #endif /* DEBUG */ /* The registers must specify FPRs valid for operands of type "fmt". If they are not valid, the result is undefined. */ /* The format type should already have been checked: */ switch (fmt) { case fmt_single: { unsigned int wop1 = (unsigned int)op1; unsigned int wop2 = (unsigned int)op2; float tmp = (*(float *)&wop1 / *(float *)&wop2); result = (uword64)*(unsigned int *)&tmp; } break; case fmt_double: { double tmp = (*(double *)&op1 / *(double *)&op2); result = *(uword64 *)&tmp; } break; } #ifdef DEBUG printf("DBG: Divide: returning 0x%08X%08X (format = %s)\n",WORD64HI(result),WORD64LO(result),DOFMT(fmt)); #endif /* DEBUG */ return(result); } static uword64 Recip(op,fmt) uword64 op; FP_formats fmt; { uword64 result; #ifdef DEBUG printf("DBG: Recip: %s: op = 0x%08X%08X\n",DOFMT(fmt),WORD64HI(op),WORD64LO(op)); #endif /* DEBUG */ /* The registers must specify FPRs valid for operands of type "fmt". If they are not valid, the result is undefined. */ /* The format type should already have been checked: */ switch (fmt) { case fmt_single: { unsigned int wop = (unsigned int)op; float tmp = ((float)1.0 / *(float *)&wop); result = (uword64)*(unsigned int *)&tmp; } break; case fmt_double: { double tmp = ((double)1.0 / *(double *)&op); result = *(uword64 *)&tmp; } break; } #ifdef DEBUG printf("DBG: Recip: returning 0x%08X%08X (format = %s)\n",WORD64HI(result),WORD64LO(result),DOFMT(fmt)); #endif /* DEBUG */ return(result); } static uword64 SquareRoot(op,fmt) uword64 op; FP_formats fmt; { uword64 result; #ifdef DEBUG printf("DBG: SquareRoot: %s: op = 0x%08X%08X\n",DOFMT(fmt),WORD64HI(op),WORD64LO(op)); #endif /* DEBUG */ /* The registers must specify FPRs valid for operands of type "fmt". If they are not valid, the result is undefined. */ /* The format type should already have been checked: */ switch (fmt) { case fmt_single: { unsigned int wop = (unsigned int)op; #ifdef HAVE_SQRT float tmp = ((float)sqrt((double)*(float *)&wop)); result = (uword64)*(unsigned int *)&tmp; #else /* TODO: Provide square-root */ result = (uword64)0; #endif } break; case fmt_double: { #ifdef HAVE_SQRT double tmp = (sqrt(*(double *)&op)); result = *(uword64 *)&tmp; #else /* TODO: Provide square-root */ result = (uword64)0; #endif } break; } #ifdef DEBUG printf("DBG: SquareRoot: returning 0x%08X%08X (format = %s)\n",WORD64HI(result),WORD64LO(result),DOFMT(fmt)); #endif /* DEBUG */ return(result); } static uword64 Convert(rm,op,from,to) int rm; uword64 op; FP_formats from; FP_formats to; { uword64 result; #ifdef DEBUG printf("DBG: Convert: mode %s : op 0x%08X%08X : from %s : to %s : (PC = 0x%08X%08X)\n",RMMODE(rm),WORD64HI(op),WORD64LO(op),DOFMT(from),DOFMT(to),WORD64HI(IPC),WORD64LO(IPC)); #endif /* DEBUG */ /* The value "op" is converted to the destination format, rounding using mode "rm". When the destination is a fixed-point format, then a source value of Infinity, NaN or one which would round to an integer outside the fixed point range then an IEEE Invalid Operation condition is raised. */ switch (to) { case fmt_single: { float tmp; switch (from) { case fmt_double: tmp = (float)(*(double *)&op); break; case fmt_word: tmp = (float)((int)(op & 0xFFFFFFFF)); break; case fmt_long: tmp = (float)((word64)op); break; } #if 0 /* FIXME: This code is incorrect. The rounding mode does not round to integral values; it rounds to the nearest representable value in the format. */ switch (rm) { case FP_RM_NEAREST: /* Round result to nearest representable value. When two representable values are equally near, round to the value that has a least significant bit of zero (i.e. is even). */ #ifdef HAVE_ANINT tmp = (float)anint((double)tmp); #else /* TODO: Provide round-to-nearest */ #endif break; case FP_RM_TOZERO: /* Round result to the value closest to, and not greater in magnitude than, the result. */ #ifdef HAVE_AINT tmp = (float)aint((double)tmp); #else /* TODO: Provide round-to-zero */ #endif break; case FP_RM_TOPINF: /* Round result to the value closest to, and not less than, the result. */ tmp = (float)ceil((double)tmp); break; case FP_RM_TOMINF: /* Round result to the value closest to, and not greater than, the result. */ tmp = (float)floor((double)tmp); break; } #endif /* 0 */ result = (uword64)*(unsigned int *)&tmp; } break; case fmt_double: { double tmp; word64 xxx; switch (from) { case fmt_single: { unsigned int wop = (unsigned int)op; tmp = (double)(*(float *)&wop); } break; case fmt_word: xxx = SIGNEXTEND((op & 0xFFFFFFFF),32); tmp = (double)xxx; break; case fmt_long: tmp = (double)((word64)op); break; } #if 0 /* FIXME: This code is incorrect. The rounding mode does not round to integral values; it rounds to the nearest representable value in the format. */ switch (rm) { case FP_RM_NEAREST: #ifdef HAVE_ANINT tmp = anint(*(double *)&tmp); #else /* TODO: Provide round-to-nearest */ #endif break; case FP_RM_TOZERO: #ifdef HAVE_AINT tmp = aint(*(double *)&tmp); #else /* TODO: Provide round-to-zero */ #endif break; case FP_RM_TOPINF: tmp = ceil(*(double *)&tmp); break; case FP_RM_TOMINF: tmp = floor(*(double *)&tmp); break; } #endif /* 0 */ result = *(uword64 *)&tmp; } break; case fmt_word: case fmt_long: if (Infinity(op,from) || NaN(op,from) || (1 == 0/*TODO: check range */)) { printf("DBG: TODO: update FCSR\n"); SignalException(FPE); } else { if (to == fmt_word) { int tmp; switch (from) { case fmt_single: { unsigned int wop = (unsigned int)op; tmp = (int)*((float *)&wop); } break; case fmt_double: tmp = (int)*((double *)&op); #ifdef DEBUG printf("DBG: from double %.30f (0x%08X%08X) to word: 0x%08X\n",*((double *)&op),WORD64HI(op),WORD64LO(op),tmp); #endif /* DEBUG */ break; } result = (uword64)tmp; } else { /* fmt_long */ word64 tmp; switch (from) { case fmt_single: { unsigned int wop = (unsigned int)op; tmp = (word64)*((float *)&wop); } break; case fmt_double: tmp = (word64)*((double *)&op); break; } result = (uword64)tmp; } } break; } #ifdef DEBUG printf("DBG: Convert: returning 0x%08X%08X (to format = %s)\n",WORD64HI(result),WORD64LO(result),DOFMT(to)); #endif /* DEBUG */ return(result); } #endif /* HASFPU */ /*-- co-processor support routines ------------------------------------------*/ static int CoProcPresent(coproc_number) unsigned int coproc_number; { /* Return TRUE if simulator provides a model for the given co-processor number */ return(0); } static void COP_LW(coproc_num,coproc_reg,memword) int coproc_num, coproc_reg; unsigned int memword; { switch (coproc_num) { #if defined(HASFPU) case 1: #ifdef DEBUG printf("DBG: COP_LW: memword = 0x%08X (uword64)memword = 0x%08X%08X\n",memword,WORD64HI(memword),WORD64LO(memword)); #endif StoreFPR(coproc_reg,fmt_word,(uword64)memword); fpr_state[coproc_reg] = fmt_uninterpreted; break; #endif /* HASFPU */ default: #if 0 /* this should be controlled by a configuration option */ callback->printf_filtered(callback,"COP_LW(%d,%d,0x%08X) at IPC = 0x%08X%08X : TODO (architecture specific)\n",coproc_num,coproc_reg,memword,WORD64HI(IPC),WORD64LO(IPC)); #endif break; } return; } static void COP_LD(coproc_num,coproc_reg,memword) int coproc_num, coproc_reg; uword64 memword; { switch (coproc_num) { #if defined(HASFPU) case 1: StoreFPR(coproc_reg,fmt_uninterpreted,memword); break; #endif /* HASFPU */ default: #if 0 /* this message should be controlled by a configuration option */ callback->printf_filtered(callback,"COP_LD(%d,%d,0x%08X%08X) at IPC = 0x%08X%08X : TODO (architecture specific)\n",coproc_num,coproc_reg,WORD64HI(memword),WORD64LO(memword),WORD64HI(IPC),WORD64LO(IPC)); #endif break; } return; } static unsigned int COP_SW(coproc_num,coproc_reg) int coproc_num, coproc_reg; { unsigned int value = 0; FP_formats hold; switch (coproc_num) { #if defined(HASFPU) case 1: #if 1 hold = fpr_state[coproc_reg]; fpr_state[coproc_reg] = fmt_word; value = (unsigned int)ValueFPR(coproc_reg,fmt_uninterpreted); fpr_state[coproc_reg] = hold; #else #if 1 value = (unsigned int)ValueFPR(coproc_reg,fpr_state[coproc_reg]); #else #ifdef DEBUG printf("DBG: COP_SW: reg in format %s (will be accessing as single)\n",DOFMT(fpr_state[coproc_reg])); #endif /* DEBUG */ value = (unsigned int)ValueFPR(coproc_reg,fmt_single); #endif #endif break; #endif /* HASFPU */ default: #if 0 /* should be controlled by configuration option */ callback->printf_filtered(callback,"COP_SW(%d,%d) at IPC = 0x%08X%08X : TODO (architecture specific)\n",coproc_num,coproc_reg,WORD64HI(IPC),WORD64LO(IPC)); #endif break; } return(value); } static uword64 COP_SD(coproc_num,coproc_reg) int coproc_num, coproc_reg; { uword64 value = 0; switch (coproc_num) { #if defined(HASFPU) case 1: #if 1 value = ValueFPR(coproc_reg,fmt_uninterpreted); #else #if 1 value = ValueFPR(coproc_reg,fpr_state[coproc_reg]); #else #ifdef DEBUG printf("DBG: COP_SD: reg in format %s (will be accessing as double)\n",DOFMT(fpr_state[coproc_reg])); #endif /* DEBUG */ value = ValueFPR(coproc_reg,fmt_double); #endif #endif break; #endif /* HASFPU */ default: #if 0 /* should be controlled by configuration option */ callback->printf_filtered(callback,"COP_SD(%d,%d) at IPC = 0x%08X%08X : TODO (architecture specific)\n",coproc_num,coproc_reg,WORD64HI(IPC),WORD64LO(IPC)); #endif break; } return(value); } static void decode_coproc(instruction) unsigned int instruction; { int coprocnum = ((instruction >> 26) & 3); switch (coprocnum) { case 0: /* standard CPU control and cache registers */ { /* NOTEs: Standard CP0 registers 0 = Index R4000 VR4100 VR4300 1 = Random R4000 VR4100 VR4300 2 = EntryLo0 R4000 VR4100 VR4300 3 = EntryLo1 R4000 VR4100 VR4300 4 = Context R4000 VR4100 VR4300 5 = PageMask R4000 VR4100 VR4300 6 = Wired R4000 VR4100 VR4300 8 = BadVAddr R4000 VR4100 VR4300 9 = Count R4000 VR4100 VR4300 10 = EntryHi R4000 VR4100 VR4300 11 = Compare R4000 VR4100 VR4300 12 = SR R4000 VR4100 VR4300 13 = Cause R4000 VR4100 VR4300 14 = EPC R4000 VR4100 VR4300 15 = PRId R4000 VR4100 VR4300 16 = Config R4000 VR4100 VR4300 17 = LLAddr R4000 VR4100 VR4300 18 = WatchLo R4000 VR4100 VR4300 19 = WatchHi R4000 VR4100 VR4300 20 = XContext R4000 VR4100 VR4300 26 = PErr or ECC R4000 VR4100 VR4300 27 = CacheErr R4000 VR4100 28 = TagLo R4000 VR4100 VR4300 29 = TagHi R4000 VR4100 VR4300 30 = ErrorEPC R4000 VR4100 VR4300 */ int code = ((instruction >> 21) & 0x1F); /* R4000 Users Manual (second edition) lists the following CP0 instructions: DMFC0 Doubleword Move From CP0 (VR4100 = 01000000001tttttddddd00000000000) DMTC0 Doubleword Move To CP0 (VR4100 = 01000000101tttttddddd00000000000) MFC0 word Move From CP0 (VR4100 = 01000000000tttttddddd00000000000) MTC0 word Move To CP0 (VR4100 = 01000000100tttttddddd00000000000) TLBR Read Indexed TLB Entry (VR4100 = 01000010000000000000000000000001) TLBWI Write Indexed TLB Entry (VR4100 = 01000010000000000000000000000010) TLBWR Write Random TLB Entry (VR4100 = 01000010000000000000000000000110) TLBP Probe TLB for Matching Entry (VR4100 = 01000010000000000000000000001000) CACHE Cache operation (VR4100 = 101111bbbbbpppppiiiiiiiiiiiiiiii) ERET Exception return (VR4100 = 01000010000000000000000000011000) */ if (((code == 0x00) || (code == 0x04)) && ((instruction & 0x7FF) == 0)) { int rt = ((instruction >> 16) & 0x1F); int rd = ((instruction >> 11) & 0x1F); if (code == 0x00) { /* MF : move from */ #if 0 /* message should be controlled by configuration option */ callback->printf_filtered(callback,"Warning: MFC0 %d,%d not handled yet (architecture specific)\n",rt,rd); #endif GPR[rt] = 0xDEADC0DE; /* CPR[0,rd] */ } else { /* MT : move to */ /* CPR[0,rd] = GPR[rt]; */ #if 0 /* should be controlled by configuration option */ callback->printf_filtered(callback,"Warning: MTC0 %d,%d not handled yet (architecture specific)\n",rt,rd); #endif } } else sim_warning("Unrecognised COP0 instruction 0x%08X at IPC = 0x%08X%08X : No handler present",instruction,WORD64HI(IPC),WORD64LO(IPC)); /* TODO: When executing an ERET or RFE instruction we should clear LLBIT, to ensure that any out-standing atomic read/modify/write sequence fails. */ } break; case 2: /* undefined co-processor */ sim_warning("COP2 instruction 0x%08X at IPC = 0x%08X%08X : No handler present",instruction,WORD64HI(IPC),WORD64LO(IPC)); break; case 1: /* should not occur (FPU co-processor) */ case 3: /* should not occur (FPU co-processor) */ SignalException(ReservedInstruction,instruction); break; } return; } /*-- instruction simulation -------------------------------------------------*/ static void simulate () { unsigned int pipeline_count = 1; #ifdef DEBUG if (membank == NULL) { printf("DBG: simulate() entered with no memory\n"); exit(1); } #endif /* DEBUG */ #if 0 /* Disabled to check that everything works OK */ /* The VR4300 seems to sign-extend the PC on its first access. However, this may just be because it is currently configured in 32bit mode. However... */ PC = SIGNEXTEND(PC,32); #endif /* main controlling loop */ do { /* Fetch the next instruction from the simulator memory: */ uword64 vaddr = (uword64)PC; uword64 paddr; int cca; unsigned int instruction; int dsstate = (state & simDELAYSLOT); #ifdef DEBUG { printf("DBG: state = 0x%08X :",state); if (state & simSTOP) printf(" simSTOP"); if (state & simSTEP) printf(" simSTEP"); if (state & simHALTEX) printf(" simHALTEX"); if (state & simHALTIN) printf(" simHALTIN"); if (state & simBE) printf(" simBE"); } #endif /* DEBUG */ #ifdef DEBUG if (dsstate) callback->printf_filtered(callback,"DBG: DSPC = 0x%08X%08X\n",WORD64HI(DSPC),WORD64LO(DSPC)); #endif /* DEBUG */ if (AddressTranslation(PC,isINSTRUCTION,isLOAD,&paddr,&cca,isTARGET,isREAL)) { if ((vaddr & 1) == 0) { /* Copy the action of the LW instruction */ unsigned int reverse = (ReverseEndian ? (LOADDRMASK >> 2) : 0); unsigned int bigend = (BigEndianCPU ? (LOADDRMASK >> 2) : 0); uword64 value; unsigned int byte; paddr = ((paddr & ~LOADDRMASK) | ((paddr & LOADDRMASK) ^ (reverse << 2))); value = LoadMemory(cca,AccessLength_WORD,paddr,vaddr,isINSTRUCTION,isREAL); byte = ((vaddr & LOADDRMASK) ^ (bigend << 2)); instruction = ((value >> (8 * byte)) & 0xFFFFFFFF); } else { /* Copy the action of the LH instruction */ unsigned int reverse = (ReverseEndian ? (LOADDRMASK >> 1) : 0); unsigned int bigend = (BigEndianCPU ? (LOADDRMASK >> 1) : 0); uword64 value; unsigned int byte; paddr = (((paddr & ~ (uword64) 1) & ~LOADDRMASK) | (((paddr & ~ (uword64) 1) & LOADDRMASK) ^ (reverse << 1))); value = LoadMemory(cca, AccessLength_HALFWORD, paddr & ~ (uword64) 1, vaddr, isINSTRUCTION, isREAL); byte = (((vaddr &~ (uword64) 1) & LOADDRMASK) ^ (bigend << 1)); instruction = ((value >> (8 * byte)) & 0xFFFF); } } else { fprintf(stderr,"Cannot translate address for PC = 0x%08X%08X failed\n",WORD64HI(PC),WORD64LO(PC)); exit(1); } #ifdef DEBUG callback->printf_filtered(callback,"DBG: fetched 0x%08X from PC = 0x%08X%08X\n",instruction,WORD64HI(PC),WORD64LO(PC)); #endif /* DEBUG */ #if !defined(FASTSIM) || defined(PROFILE) instruction_fetches++; /* Since we increment above, the value should only ever be zero if we have just overflowed: */ if (instruction_fetches == 0) instruction_fetch_overflow++; #if defined(PROFILE) if ((state & simPROFILE) && ((instruction_fetches % profile_frequency) == 0) && profile_hist) { unsigned n = ((unsigned int)(PC - profile_minpc) >> (profile_shift + 2)); if (n < profile_nsamples) { /* NOTE: The counts for the profiling bins are only 16bits wide */ if (profile_hist[n] != USHRT_MAX) (profile_hist[n])++; } } #endif /* PROFILE */ #endif /* !FASTSIM && PROFILE */ IPC = PC; /* copy PC for this instruction */ /* This is required by exception processing, to ensure that we can cope with exceptions in the delay slots of branches that may already have changed the PC. */ if ((vaddr & 1) == 0) PC += 4; /* increment ready for the next fetch */ else PC += 2; /* NOTE: If we perform a delay slot change to the PC, this increment is not requuired. However, it would make the simulator more complicated to try and avoid this small hit. */ /* Currently this code provides a simple model. For more complicated models we could perform exception status checks at this point, and set the simSTOP state as required. This could also include processing any hardware interrupts raised by any I/O model attached to the simulator context. Support for "asynchronous" I/O events within the simulated world could be providing by managing a counter, and calling a I/O specific handler when a particular threshold is reached. On most architectures a decrement and check for zero operation is usually quicker than an increment and compare. However, the process of managing a known value decrement to zero, is higher than the cost of using an explicit value UINT_MAX into the future. Which system is used will depend on how complicated the I/O model is, and how much it is likely to affect the simulator bandwidth. If events need to be scheduled further in the future than UINT_MAX event ticks, then the I/O model should just provide its own counter, triggered from the event system. */ /* MIPS pipeline ticks. To allow for future support where the pipeline hit of individual instructions is known, this control loop manages a "pipeline_count" variable. It is initialised to 1 (one), and will only be changed by the simulator engine when executing an instruction. If the engine does not have access to pipeline cycle count information then all instructions will be treated as using a single cycle. NOTE: A standard system is not provided by the default simulator because different MIPS architectures have different cycle counts for the same instructions. */ #if defined(HASFPU) /* Set previous flag, depending on current: */ if (state & simPCOC0) state |= simPCOC1; else state &= ~simPCOC1; /* and update the current value: */ if (GETFCC(0)) state |= simPCOC0; else state &= ~simPCOC0; #endif /* HASFPU */ /* NOTE: For multi-context simulation environments the "instruction" variable should be local to this routine. */ /* Shorthand accesses for engine. Note: If we wanted to use global variables (and a single-threaded simulator engine), then we can create the actual variables with these names. */ if (!(state & simSKIPNEXT)) { /* Include the simulator engine */ #include "engine.c" #if ((GPRLEN == 64) && !PROCESSOR_64BIT) || ((GPRLEN == 32) && PROCESSOR_64BIT) #error "Mismatch between run-time simulator code and simulation engine" #endif #if defined(WARN_LOHI) /* Decrement the HI/LO validity ticks */ if (HIACCESS > 0) HIACCESS--; if (LOACCESS > 0) LOACCESS--; #endif /* WARN_LOHI */ #if defined(WARN_ZERO) /* For certain MIPS architectures, GPR[0] is hardwired to zero. We should check for it being changed. It is better doing it here, than within the simulator, since it will help keep the simulator small. */ if (ZERO != 0) { sim_warning("The ZERO register has been updated with 0x%08X%08X (PC = 0x%08X%08X) (reset back to zero)",WORD64HI(ZERO),WORD64LO(ZERO),WORD64HI(IPC),WORD64LO(IPC)); ZERO = 0; /* reset back to zero before next instruction */ } #endif /* WARN_ZERO */ } else /* simSKIPNEXT check */ state &= ~simSKIPNEXT; /* If the delay slot was active before the instruction is executed, then update the PC to its new value: */ if (dsstate) { #ifdef DEBUG printf("DBG: dsstate set before instruction execution - updating PC to 0x%08X%08X\n",WORD64HI(DSPC),WORD64LO(DSPC)); #endif /* DEBUG */ PC = DSPC; state &= ~(simDELAYSLOT | simJALDELAYSLOT); } if (MIPSISA < 4) { /* The following is only required on pre MIPS IV processors: */ /* Deal with pending register updates: */ #ifdef DEBUG printf("DBG: EMPTY BEFORE pending_in = %d, pending_out = %d, pending_total = %d\n",pending_in,pending_out,pending_total); #endif /* DEBUG */ if (pending_out != pending_in) { int loop; int index = pending_out; int total = pending_total; if (pending_total == 0) { fprintf(stderr,"FATAL: Mis-match on pending update pointers\n"); exit(1); } for (loop = 0; (loop < total); loop++) { #ifdef DEBUG printf("DBG: BEFORE index = %d, loop = %d\n",index,loop); #endif /* DEBUG */ if (pending_slot_reg[index] != (LAST_EMBED_REGNUM + 1)) { #ifdef DEBUG printf("pending_slot_count[%d] = %d\n",index,pending_slot_count[index]); #endif /* DEBUG */ if (--(pending_slot_count[index]) == 0) { #ifdef DEBUG printf("pending_slot_reg[%d] = %d\n",index,pending_slot_reg[index]); printf("pending_slot_value[%d] = 0x%08X%08X\n",index,WORD64HI(pending_slot_value[index]),WORD64LO(pending_slot_value[index])); #endif /* DEBUG */ if (pending_slot_reg[index] == COCIDX) { SETFCC(0,((FCR31 & (1 << 23)) ? 1 : 0)); } else { registers[pending_slot_reg[index]] = pending_slot_value[index]; #if defined(HASFPU) /* The only time we have PENDING updates to FPU registers, is when performing binary transfers. This means we should update the register type field. */ if ((pending_slot_reg[index] >= FGRIDX) && (pending_slot_reg[index] < (FGRIDX + 32))) fpr_state[pending_slot_reg[index] - FGRIDX] = fmt_uninterpreted; #endif /* HASFPU */ } #ifdef DEBUG printf("registers[%d] = 0x%08X%08X\n",pending_slot_reg[index],WORD64HI(registers[pending_slot_reg[index]]),WORD64LO(registers[pending_slot_reg[index]])); #endif /* DEBUG */ pending_slot_reg[index] = (LAST_EMBED_REGNUM + 1); pending_out++; if (pending_out == PSLOTS) pending_out = 0; pending_total--; } } #ifdef DEBUG printf("DBG: AFTER index = %d, loop = %d\n",index,loop); #endif /* DEBUG */ index++; if (index == PSLOTS) index = 0; } } #ifdef DEBUG printf("DBG: EMPTY AFTER pending_in = %d, pending_out = %d, pending_total = %d\n",pending_in,pending_out,pending_total); #endif /* DEBUG */ } #if !defined(FASTSIM) pipeline_ticks += pipeline_count; #endif /* FASTSIM */ if (state & simSTEP) state |= simSTOP; } while (!(state & simSTOP)); #ifdef DEBUG if (membank == NULL) { printf("DBG: simulate() LEAVING with no memory\n"); exit(1); } #endif /* DEBUG */ return; } /*---------------------------------------------------------------------------*/ /*> EOF interp.c <*/