/* Parameters for target machine of AMD 29000, for GDB, the GNU debugger. Copyright 1990, 1991 Free Software Foundation, Inc. Contributed by Cygnus Support. Written by Jim Kingdon. This file is part of GDB. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* Parameters for an EB29K (a board which plugs into a PC and is accessed through EBMON software running on the PC, which we use as we'd use a remote stub (see remote-eb.c). If gdb is ported to other 29k machines/systems, the machine/system-specific parts should be removed from this file (a la tm-68k.h). */ /* Byte order is configurable, but this machine runs big-endian. */ #define TARGET_BYTE_ORDER BIG_ENDIAN /* Floating point uses IEEE representations. */ #define IEEE_FLOAT /* We can either use a.out, encapsulated, or can use COFF */ #ifndef COFF_ENCAPSULATE #define COFF_FORMAT /* This just has to do with what coff header files are in use. */ #define COFF_CHECK_X_ZEROES #endif /* Recognize our magic number. */ #define BADMAG(x) ((x)->f_magic != 0572) /* Define this if the C compiler puts an underscore at the front of external names before giving them to the linker. */ #define NAMES_HAVE_UNDERSCORE /* Offset from address of function to start of its code. Zero on most machines. */ #define FUNCTION_START_OFFSET 0 /* Advance PC across any function entry prologue instructions to reach some "real" code. */ #define SKIP_PROLOGUE(pc) \ { pc = skip_prologue (pc); } CORE_ADDR skip_prologue (); /* Immediately after a function call, return the saved pc. Can't go through the frames for this because on some machines the new frame is not set up until the new function executes some instructions. */ #define SAVED_PC_AFTER_CALL(frame) (read_register (LR0_REGNUM)) /* I'm not sure about the exact value of this, but based on looking at the stack pointer when we get to main this seems to be right. This is the register stack; We call it "CONTROL" in GDB for consistency with Pyramid. */ #define CONTROL_END_ADDR 0x80200000 /* Memory stack. This is for the default register stack size, which is only 0x800 bytes. Perhaps we should let the user specify stack sizes (and tell EBMON with the "ZS" command). */ #define STACK_END_ADDR 0x801ff800 /* Stack grows downward. */ #define INNER_THAN < /* Stack must be aligned on 32-bit word boundaries. */ #define STACK_ALIGN(ADDR) (((ADDR) + 3) & ~3) /* Sequence of bytes for breakpoint instruction. */ /* ASNEQ 0x50, gr1, gr1 The trap number 0x50 is chosen arbitrarily. */ #if TARGET_BYTE_ORDER == BIG_ENDIAN #define BREAKPOINT {0x72, 0x50, 0x01, 0x01} #else /* Target is little-endian. */ #define BREAKPOINT {0x01, 0x01, 0x50, 0x72} #endif /* Target is little-endian. */ /* Amount PC must be decremented by after a breakpoint. This is often the number of bytes in BREAKPOINT but not always. */ #define DECR_PC_AFTER_BREAK 4 /* Nonzero if instruction at PC is a return instruction. On the 29k, this is a "jmpi l0" instruction. */ #define ABOUT_TO_RETURN(pc) \ ((read_memory_integer (pc, 4) & 0xff0000ff) == 0xc0000080) /* Return 1 if P points to an invalid floating point value. */ #define INVALID_FLOAT(p, len) 0 /* Just a first guess; not checked */ /* Say how long (ordinary) registers are. */ #define REGISTER_TYPE long /* Number of machine registers */ #define NUM_REGS 205 /* Initializer for an array of names of registers. There should be NUM_REGS strings in this initializer. FIXME, add floating point registers and support here. Also note that this list does not attempt to deal with kernel debugging (in which the first 32 registers are gr64-gr95). */ #define REGISTER_NAMES \ {"gr96", "gr97", "gr98", "gr99", "gr100", "gr101", "gr102", "gr103", "gr104", \ "gr105", "gr106", "gr107", "gr108", "gr109", "gr110", "gr111", "gr112", \ "gr113", "gr114", "gr115", "gr116", "gr117", "gr118", "gr119", "gr120", \ "gr121", "gr122", "gr123", "gr124", "gr125", "gr126", "gr127", \ "lr0", "lr1", "lr2", "lr3", "lr4", "lr5", "lr6", "lr7", "lr8", "lr9", \ "lr10", "lr11", "lr12", "lr13", "lr14", "lr15", "lr16", "lr17", "lr18", \ "lr19", "lr20", "lr21", "lr22", "lr23", "lr24", "lr25", "lr26", "lr27", \ "lr28", "lr29", "lr30", "lr31", "lr32", "lr33", "lr34", "lr35", "lr36", \ "lr37", "lr38", "lr39", "lr40", "lr41", "lr42", "lr43", "lr44", "lr45", \ "lr46", "lr47", "lr48", "lr49", "lr50", "lr51", "lr52", "lr53", "lr54", \ "lr55", "lr56", "lr57", "lr58", "lr59", "lr60", "lr61", "lr62", "lr63", \ "lr64", "lr65", "lr66", "lr67", "lr68", "lr69", "lr70", "lr71", "lr72", \ "lr73", "lr74", "lr75", "lr76", "lr77", "lr78", "lr79", "lr80", "lr81", \ "lr82", "lr83", "lr84", "lr85", "lr86", "lr87", "lr88", "lr89", "lr90", \ "lr91", "lr92", "lr93", "lr94", "lr95", "lr96", "lr97", "lr98", "lr99", \ "lr100", "lr101", "lr102", "lr103", "lr104", "lr105", "lr106", "lr107", \ "lr108", "lr109", "lr110", "lr111", "lr112", "lr113", "lr114", "lr115", \ "lr116", "lr117", "lr118", "lr119", "lr120", "lr121", "lr122", "lr123", \ "lr124", "lr125", "lr126", "lr127", \ "AI0", "AI1", "AI2", "AI3", "AI4", "AI5", "AI6", "AI7", "AI8", "AI9", \ "AI10", "AI11", "AI12", "AI13", "AI14", "AI15", "FP", \ "bp", "fc", "cr", "q", \ "vab", "ops", "cps", "cfg", "cha", "chd", "chc", "rbp", "tmc", "tmr", \ "pc0", "pc1", "pc2", "mmu", "lru", "fpe", "int", "fps", "exo", "gr1", \ "alu", "ipc", "ipa", "ipb" } /* Special register #x. */ #define SR_REGNUM(x) \ ((x) < 15 ? VAB_REGNUM + (x) \ : (x) >= 128 && (x) < 131 ? IPC_REGNUM + (x) \ : (x) == 131 ? Q_REGNUM \ : (x) == 132 ? ALU_REGNUM \ : (x) >= 133 && (x) < 136 ? BP_REGNUM + (x) \ : (x) >= 160 && (x) < 163 ? FPE_REGNUM + (x) \ : (x) == 164 ? EXO_REGNUM \ : (error ("Internal error in SR_REGNUM"), 0)) #define GR96_REGNUM 0 #define GR1_REGNUM 200 /* This needs to be the memory stack pointer, not the register stack pointer, to make call_function work right. */ #define SP_REGNUM MSP_REGNUM #define FP_REGNUM 33 /* lr1 */ /* Large Return Pointer (gr123). */ #define LRP_REGNUM (123 - 96 + GR96_REGNUM) /* Static link pointer (gr124). */ #define SLP_REGNUM (124 - 96 + GR96_REGNUM) /* Memory Stack Pointer (gr125). */ #define MSP_REGNUM (125 - 96 + GR96_REGNUM) /* Register allocate bound (gr126). */ #define RAB_REGNUM (126 - 96 + GR96_REGNUM) /* Register Free Bound (gr127). */ #define RFB_REGNUM (127 - 96 + GR96_REGNUM) /* Register Stack Pointer. */ #define RSP_REGNUM GR1_REGNUM #define LR0_REGNUM 32 #define PC_REGNUM 192 /* pc1 */ #define NPC_REGNUM 191 /* pc0 */ #define PC2_REGNUM 193 #define BP_REGNUM 177 #define FC_REGNUM 178 #define CR_REGNUM 179 #define Q_REGNUM 180 #define VAB_REGNUM 181 #define LRU_REGNUM 195 #define FPE_REGNUM 196 #define INT_REGNUM 197 #define FPS_REGNUM 198 #define EXO_REGNUM 199 #define PS_REGNUM 201 #define ALU_REGNUM 201 #define IPC_REGNUM 202 #define IPB_REGNUM 204 /* Total amount of space needed to store our copies of the machine's register state, the array `registers'. */ #define REGISTER_BYTES (NUM_REGS * 4) /* Index within `registers' of the first byte of the space for register N. */ #define REGISTER_BYTE(N) ((N)*4) /* Number of bytes of storage in the actual machine representation for register N. */ /* All regs are 4 bytes. */ #define REGISTER_RAW_SIZE(N) (4) /* Number of bytes of storage in the program's representation for register N. */ /* All regs are 4 bytes. */ #define REGISTER_VIRTUAL_SIZE(N) (4) /* Largest value REGISTER_RAW_SIZE can have. */ #define MAX_REGISTER_RAW_SIZE (4) /* Largest value REGISTER_VIRTUAL_SIZE can have. */ #define MAX_REGISTER_VIRTUAL_SIZE (4) /* Nonzero if register N requires conversion from raw format to virtual format. */ #define REGISTER_CONVERTIBLE(N) (0) /* Convert data from raw format for register REGNUM to virtual format for register REGNUM. */ #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \ { bcopy ((FROM), (TO), 4); } /* Convert data from virtual format for register REGNUM to raw format for register REGNUM. */ #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \ { bcopy ((FROM), (TO), 4); } /* Return the GDB type object for the "standard" data type of data in register N. */ #define REGISTER_VIRTUAL_TYPE(N) \ (((N) == PC_REGNUM || (N) == LRP_REGNUM || (N) == SLP_REGNUM \ || (N) == MSP_REGNUM || (N) == RAB_REGNUM || (N) == RFB_REGNUM \ || (N) == GR1_REGNUM || (N) == FP_REGNUM || (N) == LR0_REGNUM \ || (N) == NPC_REGNUM || (N) == PC2_REGNUM) \ ? lookup_pointer_type (builtin_type_void) : builtin_type_int) /* Store the address of the place in which to copy the structure the subroutine will return. This is called from call_function. */ /* On the 29k the LRP points to the part of the structure beyond the first 16 words. */ #define STORE_STRUCT_RETURN(ADDR, SP) \ write_register (LRP_REGNUM, (ADDR) + 16 * 4); /* Should call_function allocate stack space for a struct return? */ /* On the 29k objects over 16 words require the caller to allocate space. */ #define USE_STRUCT_CONVENTION(gcc_p, type) (TYPE_LENGTH (type) > 16 * 4) /* Extract from an array REGBUF containing the (raw) register state a function return value of type TYPE, and copy that, in virtual format, into VALBUF. */ #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \ { \ int reg_length = TYPE_LENGTH (TYPE); \ if (reg_length > 16 * 4) \ { \ reg_length = 16 * 4; \ read_memory (*((int *)(REGBUF) + LRP_REGNUM), (VALBUF) + 16 * 4, \ TYPE_LENGTH (TYPE) - 16 * 4); \ } \ bcopy (((int *)(REGBUF))+GR96_REGNUM, (VALBUF), reg_length); \ } /* Write into appropriate registers a function return value of type TYPE, given in virtual format. */ #define STORE_RETURN_VALUE(TYPE,VALBUF) \ { \ int reg_length = TYPE_LENGTH (TYPE); \ if (reg_length > 16 * 4) \ { \ reg_length = 16 * 4; \ write_memory (read_register (LRP_REGNUM), \ (char *)(VALBUF) + 16 * 4, \ TYPE_LENGTH (TYPE) - 16 * 4); \ } \ write_register_bytes (REGISTER_BYTE (GR96_REGNUM), (char *)(VALBUF), \ TYPE_LENGTH (TYPE)); \ } /* The am29k user's guide documents well what the stacks look like. But what isn't so clear there is how this interracts with the symbols, or with GDB. In the following saved_msp, saved memory stack pointer (which functions as a memory frame pointer), means either a register containing the memory frame pointer or, in the case of functions with fixed size memory frames (i.e. those who don't use alloca()), the result of the calculation msp + msize. LOC_ARG, LOC_LOCAL - For GCC, these are relative to saved_msp. For high C, these are relative to msp (making alloca impossible). LOC_REGISTER, LOC_REGPARM - The register number is the number at the time the function is running (after the prologue), or in the case of LOC_REGPARM, may be a register number in the range 160-175. The compilers do things like store an argument into memory, and then put out a LOC_ARG for it, or put it into global registers and put out a LOC_REGPARM. Thus is it important to execute the first line of code (i.e. the line of the open brace, i.e. the prologue) of a function before trying to print arguments or anything. The following diagram attempts to depict what is going on in memory (see also the _am29k user's guide_) and also how that interacts with GDB frames. We arbitrarily pick fci->frame to point the same place as the register stack pointer; since we set it ourself in INIT_EXTRA_FRAME_INFO, and access it only through the FRAME_* macros, it doesn't really matter exactly how we do it. However, note that FRAME_FP is used in two ways in GDB: (1) as a "magic cookie" which uniquely identifies frames (even over calls to the inferior), (2) (in PC_IN_CALL_DUMMY [!CANNOT_EXECUTE_STACK]) as the value of SP_REGNUM before the dummy frame was pushed. These two meanings would be incompatible for the 29k if we didn't define CANNOT_EXECUTE_STACK (but we do, so don't worry about it). Also note that "lr1" below, while called a frame pointer in the user's guide, has only one function: To determine whether registers need to be filled in the function epilogue. Consider the code: < call bar> loc1: . . . bar: sub gr1,gr1,rsize_b . . . add mfp,msp,0 sub msp,msp,msize_b . . . < call foo > loc2: . . . foo: sub gr1,gr1,rsize_f . . . add mfp,msp,0 sub msp,msp,msize_f . . . loc3: < suppose the inferior stops here > memory stack register stack | | |____________| | | |____loc1____| +------->|___________| | | ^ | | ^ | | locals_b | | | | | | |____________| | | | | | | | | rsize_b | | | msize_b | | args_to_f | | | | | | |____________| | | | | | |____lr1_____| V | | V | |____loc2____|<----------------+ | +--->|___________|<---------mfp | ^ | | | | ^ | | locals_f | | | | | | | msize_f | |____________| | | | | | | | | | | rsize_f | | | | V | | args | | | | | |___________|pc and ->frame, but all the extra stuff, when called from get_prev_frame_info, that is. */ #define INIT_EXTRA_FRAME_INFO(fci) \ init_extra_frame_info(fci); void init_extra_frame_info (); #define INIT_FRAME_PC(fromleaf, fci) \ init_frame_pc(fromleaf, fci); void init_frame_pc (); /* FRAME_CHAIN takes a FRAME and produces the frame's chain-pointer. FRAME_CHAIN_COMBINE takes the chain pointer and the frame's nominal address and produces the nominal address of the caller frame. However, if FRAME_CHAIN_VALID returns zero, it means the given frame is the outermost one and has no caller. In that case, FRAME_CHAIN_COMBINE is not used. */ /* On the 29k, the nominal address of a frame is the address on the register stack of the return address (the one next to the incoming arguments, not down at the bottom so nominal address == stack pointer). GDB expects "nominal address" to equal contents of FP_REGNUM, at least when it comes time to create the innermost frame. However, that doesn't work for us, so when creating the innermost frame we set ->frame ourselves in INIT_EXTRA_FRAME_INFO. */ /* These are mostly dummies for the 29k because INIT_FRAME_PC sets prev->frame instead. */ #define FRAME_CHAIN(thisframe) (0) /* Not sure how to figure out where the bottom frame is. There is no frame for start. In my tests so far the pc has been outside the text segment, though, so check for that. However, allow a pc in a call dummy. */ #define FRAME_CHAIN_VALID(chain, thisframe) \ (outside_startup_file (FRAME_SAVED_PC (thisframe)) \ && FRAME_SAVED_PC (thisframe) >= text_start \ && FRAME_SAVED_PC (thisframe) < text_end + CALL_DUMMY_LENGTH) #define FRAME_CHAIN_COMBINE(chain, thisframe) (0) /* Define other aspects of the stack frame. */ /* A macro that tells us whether the function invocation represented by FI does not have a frame on the stack associated with it. If it does not, FRAMELESS is set to 1, else 0. */ #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \ (FRAMELESS) = frameless_look_for_prologue(FI) /* Saved pc (i.e. return address). */ #define FRAME_SAVED_PC(fraim) \ (read_register_stack_integer ((fraim)->frame + (fraim)->rsize, 4)) /* Local variables (i.e. LOC_LOCAL) are on the memory stack, with their offsets being relative to the memory stack pointer (high C) or saved_msp (gcc). */ #define FRAME_LOCALS_ADDRESS(fi) frame_locals_address (fi) extern CORE_ADDR frame_locals_address (); /* Return number of args passed to a frame. Can return -1, meaning no way to tell. */ /* While we could go the effort of finding the tags word and getting the argcount field from it, (1) It only counts arguments in registers, i.e. the first 16 words of arguments (2) It gives the number of arguments the function was declared with not how many it was called with (or some variation, like all 16 words for varadic functions). This makes argcount pretty much redundant with -g info, even for varadic functions. So don't bother. */ #define FRAME_NUM_ARGS(numargs, fi) ((numargs) = -1) #define FRAME_ARGS_ADDRESS(fi) FRAME_LOCALS_ADDRESS (fi) /* Return number of bytes at start of arglist that are not really args. */ #define FRAME_ARGS_SKIP 0 /* Provide our own get_saved_register. HAVE_REGISTER_WINDOWS is insufficient because registers get renumbered on the 29k without getting saved. */ #define GET_SAVED_REGISTER /* Call function stuff. */ /* The dummy frame looks like this (see also the general frame picture above): register stack | | frame for function | locals_sproc | executing at time |________________| of call_function. | | We must not disturb | args_out_sproc | it. memory stack |________________| |____lr1_sproc___| | | |__retaddr_sproc_| <- gr1 (at start) |____________|<-msp 0 <-----------mfp_dummy_____| | | (at start) | | | arg_slop | | saved regs | | (16 words) | | gr96-gr124 | |____________|<-msp 1--after | sr128-sr135 | | | PUSH_DUMMY_FRAME| | | struct ret | |________________| | 17+ | | | |____________|<- lrp | args_out_dummy | | struct ret | | (16 words) | | 16 | |________________| | (16 words) | |____lr1_dummy___| |____________|<- msp 2--after |_retaddr_dummy__|<- gr1 after | | struct ret | | PUSH_DUMMY_FRAME | margs17+ | area allocated | locals_inf | | | |________________| called |____________|<- msp 4--when | | function's | | inf called | args_out_inf | frame (set up | margs16 | |________________| by called | (16 words) | |_____lr1_inf____| function). |____________|<- msp 3--after | . | | | args pushed | . | | | | . | | | arg_slop: This area is so that when the call dummy adds 16 words to the msp, it won't end up larger than mfp_dummy (it is needed in the case where margs and struct_ret do not add up to at least 16 words). struct ret: This area is allocated by GDB if the return value is more than 16 words. struct ret_16 is not used on the 29k. margs: Pushed by GDB. The call dummy copies the first 16 words to args_out_dummy. retaddr_sproc: Contains the PC at the time we call the function. set by PUSH_DUMMY_FRAME and read by POP_FRAME. retaddr_dummy: This points to a breakpoint instruction in the dummy. */ /* Rsize for dummy frame, in bytes. */ /* Bytes for outgoing args, lr1, and retaddr. */ #define DUMMY_ARG (2 * 4 + 16 * 4) /* Number of special registers (sr128-) to save. */ #define DUMMY_SAVE_SR128 8 /* Number of general (gr96-) registers to save. */ #define DUMMY_SAVE_GR96 29 #define DUMMY_FRAME_RSIZE \ (4 /* mfp_dummy */ \ + DUMMY_SAVE_GR96 * 4 \ + DUMMY_SAVE_SR128 * 4 \ + DUMMY_ARG \ ) /* Push an empty stack frame, to record the current PC, etc. */ #define PUSH_DUMMY_FRAME push_dummy_frame(); extern void push_dummy_frame (); /* Discard from the stack the innermost frame, restoring all saved registers. */ #define POP_FRAME pop_frame (); extern void pop_frame (); /* This sequence of words is the instructions mtsrim cr, 15 loadm 0, 0, lr2, msp ; load first 16 words of arguments into registers add msp, msp, 16 * 4 ; point to the remaining arguments CONST_INSN: const gr96,inf consth gr96,inf calli lr0, gr96 aseq 0x40,gr1,gr1 ; nop asneq 0x50,gr1,gr1 ; breakpoint */ /* Position of the "const" instruction within CALL_DUMMY in bytes. */ #define CONST_INSN (3 * 4) #if TARGET_BYTE_ORDER == HOST_BYTE_ORDER #define CALL_DUMMY {0x0400870f, 0x3600827d, 0x157d7d40, 0x03ff60ff, \ 0x02ff60ff, 0xc8008060, 0x70400101, 0x72500101} #else /* Byte order differs. */ you lose #endif /* Byte order differs. */ #define CALL_DUMMY_LENGTH (8 * 4) #define CALL_DUMMY_START_OFFSET 0 /* Start execution at beginning of dummy */ /* Helper macro for FIX_CALL_DUMMY. WORDP is a long * which points to a word in target byte order; bits 0-7 and 16-23 of *WORDP are replaced with bits 0-7 and 8-15 of DATA (which is in host byte order). */ #if TARGET_BYTE_ORDER == BIG_ENDIAN #define STUFF_I16(WORDP, DATA) \ { \ *((char *)(WORDP) + 3) = ((DATA) & 0xff);\ *((char *)(WORDP) + 1) = (((DATA) >> 8) & 0xff);\ } #else /* Target is little endian. */ #define STUFF_I16(WORDP, DATA) \ { *(char *)(WORDP) = ((DATA) & 0xff); *((char *)(WORDP) + 2) = (((DATA) >> 8) & 0xff); } #endif /* Target is little endian. */ /* Insert the specified number of args and function address into a call sequence of the above form stored at DUMMYNAME. */ /* Currently this stuffs in the address of the function that we are calling. If different 29k systems use different breakpoint instructions, it could also stuff BREAKPOINT in the right place (to avoid having to duplicate CALL_DUMMY in each tm-*.h file). */ #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \ {\ STUFF_I16((char *)dummyname + CONST_INSN, fun);\ STUFF_I16((char *)dummyname + CONST_INSN + 4, fun >> 16);\ } /* At least our 29k board has separate data & instruction memories and can't execute the data memory. Also, there should be space after text_end; we won't get a SIGSEGV or scribble on data space. */ #define CALL_DUMMY_LOCATION AFTER_TEXT_END /* How to translate register numbers in the .stab's into gdb's internal register numbers. We don't translate them, but we warn if an invalid register number is seen. Note that FIXME, we use the value "sym" as an implicit argument in printing the error message. It happens to be available where this macro is used. (This macro definition appeared in a late revision of gdb-3.91.6 and is not well tested. Also, it should be a "complaint".) */ #define STAB_REG_TO_REGNUM(num) \ (((num) > LR0_REGNUM + 127) \ ? fprintf(stderr, \ "Invalid register number %d in symbol table entry for %s\n", \ (num), SYMBOL_NAME (sym)), (num) \ : (num))