diff options
Diffstat (limited to 'gdb/sh-stub.c')
-rw-r--r-- | gdb/sh-stub.c | 1553 |
1 files changed, 1553 insertions, 0 deletions
diff --git a/gdb/sh-stub.c b/gdb/sh-stub.c new file mode 100644 index 0000000..86c3f0b --- /dev/null +++ b/gdb/sh-stub.c @@ -0,0 +1,1553 @@ +/* sh-stub.c -- debugging stub for the Hitachi-SH. + + NOTE!! This code has to be compiled with optimization, otherwise the + function inlining which generates the exception handlers won't work. + +*/ + +/* This is originally based on an m68k software stub written by Glenn + Engel at HP, but has changed quite a bit. + + Modifications for the SH by Ben Lee and Steve Chamberlain + +*/ + +/**************************************************************************** + + THIS SOFTWARE IS NOT COPYRIGHTED + + HP offers the following for use in the public domain. HP makes no + warranty with regard to the software or it's performance and the + user accepts the software "AS IS" with all faults. + + HP 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. + +****************************************************************************/ + + +/* Remote communication protocol. + + A debug packet whose contents are <data> + is encapsulated for transmission in the form: + + $ <data> # CSUM1 CSUM2 + + <data> must be ASCII alphanumeric and cannot include characters + '$' or '#'. If <data> starts with two characters followed by + ':', then the existing stubs interpret this as a sequence number. + + CSUM1 and CSUM2 are ascii hex representation of an 8-bit + checksum of <data>, the most significant nibble is sent first. + the hex digits 0-9,a-f are used. + + Receiver responds with: + + + - if CSUM is correct and ready for next packet + - - if CSUM is incorrect + + <data> is as follows: + All values are encoded in ascii hex digits. + + Request Packet + + read registers g + reply XX....X Each byte of register data + is described by two hex digits. + Registers are in the internal order + for GDB, and the bytes in a register + are in the same order the machine uses. + or ENN for an error. + + write regs GXX..XX Each byte of register data + is described by two hex digits. + reply OK for success + ENN for an error + + write reg Pn...=r... Write register n... with value r..., + which contains two hex digits for each + byte in the register (target byte + order). + reply OK for success + ENN for an error + (not supported by all stubs). + + read mem mAA..AA,LLLL AA..AA is address, LLLL is length. + reply XX..XX XX..XX is mem contents + Can be fewer bytes than requested + if able to read only part of the data. + or ENN NN is errno + + write mem MAA..AA,LLLL:XX..XX + AA..AA is address, + LLLL is number of bytes, + XX..XX is data + reply OK for success + ENN for an error (this includes the case + where only part of the data was + written). + + cont cAA..AA AA..AA is address to resume + If AA..AA is omitted, + resume at same address. + + step sAA..AA AA..AA is address to resume + If AA..AA is omitted, + resume at same address. + + last signal ? Reply the current reason for stopping. + This is the same reply as is generated + for step or cont : SAA where AA is the + signal number. + + There is no immediate reply to step or cont. + The reply comes when the machine stops. + It is SAA AA is the "signal number" + + or... TAAn...:r...;n:r...;n...:r...; + AA = signal number + n... = register number + r... = register contents + or... WAA The process exited, and AA is + the exit status. This is only + applicable for certains sorts of + targets. + kill request k + + toggle debug d toggle debug flag (see 386 & 68k stubs) + reset r reset -- see sparc stub. + reserved <other> On other requests, the stub should + ignore the request and send an empty + response ($#<checksum>). This way + we can extend the protocol and GDB + can tell whether the stub it is + talking to uses the old or the new. + search tAA:PP,MM Search backwards starting at address + AA for a match with pattern PP and + mask MM. PP and MM are 4 bytes. + Not supported by all stubs. + + general query qXXXX Request info about XXXX. + general set QXXXX=yyyy Set value of XXXX to yyyy. + query sect offs qOffsets Get section offsets. Reply is + Text=xxx;Data=yyy;Bss=zzz + console output Otext Send text to stdout. Only comes from + remote target. + + Responses can be run-length encoded to save space. A '*' means that + the next character is an ASCII encoding giving a repeat count which + stands for that many repititions of the character preceding the '*'. + The encoding is n+29, yielding a printable character where n >=3 + (which is where rle starts to win). Don't use an n > 126. + + So + "0* " means the same as "0000". */ + +#include <string.h> +#include <setjmp.h> + + + +#define COND_BR_MASK 0xff00 +#define UCOND_DBR_MASK 0xe000 +#define UCOND_RBR_MASK 0xf0df +#define TRAPA_MASK 0xff00 + +#define COND_DISP 0x00ff +#define UCOND_DISP 0x0fff +#define UCOND_REG 0x0f00 + +#define BF_INSTR 0x8b00 +#define BT_INSTR 0x8900 +#define BRA_INSTR 0xa000 +#define BSR_INSTR 0xb000 +#define JMP_INSTR 0x402b +#define JSR_INSTR 0x400b +#define RTS_INSTR 0x000b +#define RTE_INSTR 0x002b +#define TRAPA_INSTR 0xc300 + +#define SSTEP_INSTR 0xc3ff + +#define T_BIT_MASK 0x0001 +/* + * BUFMAX defines the maximum number of characters in inbound/outbound + * buffers at least NUMREGBYTES*2 are needed for register packets + */ +#define BUFMAX 1024 + +/* + * Number of bytes for registers + */ +#define NUMREGBYTES 112 /* 92 */ + +/* + * typedef + */ +typedef void (*Function) (); + +/* + * Forward declarations + */ + +static int hex (char); +static char *mem2hex (char *, char *, int); +static char *hex2mem (char *, char *, int); +static int hexToInt (char **, int *); +static void getpacket (char *); +static void putpacket (char *); +static void handle_buserror (void); +static int computeSignal (int exceptionVector); +static void handle_exception (int exceptionVector); +void init_serial(); + + +int putDebugChar (char); +char getDebugChar (void); + +/* These are in the file but in asm statements so the compiler can't see them */ +void catch_exception_4 (void); +void catch_exception_6 (void); +void catch_exception_9 (void); +void catch_exception_10 (void); +void catch_exception_11 (void); +void catch_exception_32 (void); +void catch_exception_33 (void); +void catch_exception_255 (void); + + + +#define catch_exception_random catch_exception_255 /* Treat all odd ones like 255 */ + +void breakpoint (void); + + +#define init_stack_size 8*1024 /* if you change this you should also modify BINIT */ +#define stub_stack_size 8*1024 + +int init_stack[init_stack_size] __attribute__ ((section ("stack"))) = {0}; +int stub_stack[stub_stack_size] __attribute__ ((section ("stack"))) = {0}; + +typedef struct + { + void (*func_cold) (); + int *stack_cold; + void (*func_warm) (); + int *stack_warm; + void (*(handler[256 - 4])) (); + } +vec_type; + + +void INIT (); +void BINIT (); + +/* When you link take care that this is at address 0 - + or wherever your vbr points */ + +#define CPU_BUS_ERROR_VEC 9 +#define DMA_BUS_ERROR_VEC 10 +#define NMI_VEC 11 +#define INVALID_INSN_VEC 4 +#define INVALID_SLOT_VEC 6 +#define TRAP_VEC 32 +#define IO_VEC 33 +#define USER_VEC 255 + + +#define BCR (*(volatile short *)(0x05FFFFA0)) /* Bus control register */ +#define BAS (0x800) /* Byte access select */ +#define WCR1 (*(volatile short *)(0x05ffffA2)) /* Wait state control register */ + +const vec_type vectable = +{ + &BINIT, /* 0: Power-on reset PC */ + init_stack + init_stack_size, /* 1: Power-on reset SP */ + &BINIT, /* 2: Manual reset PC */ + init_stack + init_stack_size, /* 3: Manual reset SP */ +{ + &catch_exception_4, /* 4: General invalid instruction */ + &catch_exception_random, /* 5: Reserved for system */ + &catch_exception_6, /* 6: Invalid slot instruction */ + &catch_exception_random, /* 7: Reserved for system */ + &catch_exception_random, /* 8: Reserved for system */ + &catch_exception_9, /* 9: CPU bus error */ + &catch_exception_10, /* 10: DMA bus error */ + &catch_exception_11, /* 11: NMI */ + &catch_exception_random, /* 12: User break */ + &catch_exception_random, /* 13: Reserved for system */ + &catch_exception_random, /* 14: Reserved for system */ + &catch_exception_random, /* 15: Reserved for system */ + &catch_exception_random, /* 16: Reserved for system */ + &catch_exception_random, /* 17: Reserved for system */ + &catch_exception_random, /* 18: Reserved for system */ + &catch_exception_random, /* 19: Reserved for system */ + &catch_exception_random, /* 20: Reserved for system */ + &catch_exception_random, /* 21: Reserved for system */ + &catch_exception_random, /* 22: Reserved for system */ + &catch_exception_random, /* 23: Reserved for system */ + &catch_exception_random, /* 24: Reserved for system */ + &catch_exception_random, /* 25: Reserved for system */ + &catch_exception_random, /* 26: Reserved for system */ + &catch_exception_random, /* 27: Reserved for system */ + &catch_exception_random, /* 28: Reserved for system */ + &catch_exception_random, /* 29: Reserved for system */ + &catch_exception_random, /* 30: Reserved for system */ + &catch_exception_random, /* 31: Reserved for system */ + &catch_exception_32, /* 32: Trap instr (user vectors) */ + &catch_exception_33, /* 33: Trap instr (user vectors) */ + &catch_exception_random, /* 34: Trap instr (user vectors) */ + &catch_exception_random, /* 35: Trap instr (user vectors) */ + &catch_exception_random, /* 36: Trap instr (user vectors) */ + &catch_exception_random, /* 37: Trap instr (user vectors) */ + &catch_exception_random, /* 38: Trap instr (user vectors) */ + &catch_exception_random, /* 39: Trap instr (user vectors) */ + &catch_exception_random, /* 40: Trap instr (user vectors) */ + &catch_exception_random, /* 41: Trap instr (user vectors) */ + &catch_exception_random, /* 42: Trap instr (user vectors) */ + &catch_exception_random, /* 43: Trap instr (user vectors) */ + &catch_exception_random, /* 44: Trap instr (user vectors) */ + &catch_exception_random, /* 45: Trap instr (user vectors) */ + &catch_exception_random, /* 46: Trap instr (user vectors) */ + &catch_exception_random, /* 47: Trap instr (user vectors) */ + &catch_exception_random, /* 48: Trap instr (user vectors) */ + &catch_exception_random, /* 49: Trap instr (user vectors) */ + &catch_exception_random, /* 50: Trap instr (user vectors) */ + &catch_exception_random, /* 51: Trap instr (user vectors) */ + &catch_exception_random, /* 52: Trap instr (user vectors) */ + &catch_exception_random, /* 53: Trap instr (user vectors) */ + &catch_exception_random, /* 54: Trap instr (user vectors) */ + &catch_exception_random, /* 55: Trap instr (user vectors) */ + &catch_exception_random, /* 56: Trap instr (user vectors) */ + &catch_exception_random, /* 57: Trap instr (user vectors) */ + &catch_exception_random, /* 58: Trap instr (user vectors) */ + &catch_exception_random, /* 59: Trap instr (user vectors) */ + &catch_exception_random, /* 60: Trap instr (user vectors) */ + &catch_exception_random, /* 61: Trap instr (user vectors) */ + &catch_exception_random, /* 62: Trap instr (user vectors) */ + &catch_exception_random, /* 63: Trap instr (user vectors) */ + &catch_exception_random, /* 64: IRQ0 */ + &catch_exception_random, /* 65: IRQ1 */ + &catch_exception_random, /* 66: IRQ2 */ + &catch_exception_random, /* 67: IRQ3 */ + &catch_exception_random, /* 68: IRQ4 */ + &catch_exception_random, /* 69: IRQ5 */ + &catch_exception_random, /* 70: IRQ6 */ + &catch_exception_random, /* 71: IRQ7 */ + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_random, + &catch_exception_255}}; + + +char in_nmi; /* Set when handling an NMI, so we don't reenter */ +int dofault; /* Non zero, bus errors will raise exception */ + +int *stub_sp; + +/* debug > 0 prints ill-formed commands in valid packets & checksum errors */ +int remote_debug; + +/* jump buffer used for setjmp/longjmp */ +jmp_buf remcomEnv; + +enum regnames + { + R0, R1, R2, R3, R4, R5, R6, R7, + R8, R9, R10, R11, R12, R13, R14, + R15, PC, PR, GBR, VBR, MACH, MACL, SR, + TICKS, STALLS, CYCLES, INSTS, PLR + }; + +typedef struct + { + short *memAddr; + short oldInstr; + } +stepData; + +int registers[NUMREGBYTES / 4]; +stepData instrBuffer; +char stepped; +static const char hexchars[] = "0123456789abcdef"; +char remcomInBuffer[BUFMAX]; +char remcomOutBuffer[BUFMAX]; + +char highhex(int x) +{ + return hexchars[(x >> 4) & 0xf]; +} + +char lowhex(int x) +{ + return hexchars[x & 0xf]; +} + +/* + * Assembly macros + */ + +#define BREAKPOINT() asm("trapa #0x20"::); + + +/* + * Routines to handle hex data + */ + +static int +hex (char ch) +{ + if ((ch >= 'a') && (ch <= 'f')) + return (ch - 'a' + 10); + if ((ch >= '0') && (ch <= '9')) + return (ch - '0'); + if ((ch >= 'A') && (ch <= 'F')) + return (ch - 'A' + 10); + return (-1); +} + +/* convert the memory, pointed to by mem into hex, placing result in buf */ +/* return a pointer to the last char put in buf (null) */ +static char * +mem2hex (char *mem, char *buf, int count) +{ + int i; + int ch; + for (i = 0; i < count; i++) + { + ch = *mem++; + *buf++ = highhex (ch); + *buf++ = lowhex (ch); + } + *buf = 0; + return (buf); +} + +/* convert the hex array pointed to by buf into binary, to be placed in mem */ +/* return a pointer to the character after the last byte written */ + +static char * +hex2mem (char *buf, char *mem, int count) +{ + int i; + unsigned char ch; + for (i = 0; i < count; i++) + { + ch = hex (*buf++) << 4; + ch = ch + hex (*buf++); + *mem++ = ch; + } + return (mem); +} + +/**********************************************/ +/* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */ +/* RETURN NUMBER OF CHARS PROCESSED */ +/**********************************************/ +static int +hexToInt (char **ptr, int *intValue) +{ + int numChars = 0; + int hexValue; + + *intValue = 0; + + while (**ptr) + { + hexValue = hex (**ptr); + if (hexValue >= 0) + { + *intValue = (*intValue << 4) | hexValue; + numChars++; + } + else + break; + + (*ptr)++; + } + + return (numChars); +} + +/* + * Routines to get and put packets + */ + +/* scan for the sequence $<data>#<checksum> */ + +static +void +getpacket (char *buffer) +{ + unsigned char checksum; + unsigned char xmitcsum; + int i; + int count; + char ch; + do + { + /* wait around for the start character, ignore all other characters */ + while ((ch = getDebugChar ()) != '$'); + checksum = 0; + xmitcsum = -1; + + count = 0; + + /* now, read until a # or end of buffer is found */ + while (count < BUFMAX) + { + ch = getDebugChar (); + if (ch == '#') + break; + checksum = checksum + ch; + buffer[count] = ch; + count = count + 1; + } + buffer[count] = 0; + + if (ch == '#') + { + xmitcsum = hex (getDebugChar ()) << 4; + xmitcsum += hex (getDebugChar ()); + if (checksum != xmitcsum) + putDebugChar ('-'); /* failed checksum */ + else + { + putDebugChar ('+'); /* successful transfer */ + /* if a sequence char is present, reply the sequence ID */ + if (buffer[2] == ':') + { + putDebugChar (buffer[0]); + putDebugChar (buffer[1]); + /* remove sequence chars from buffer */ + count = strlen (buffer); + for (i = 3; i <= count; i++) + buffer[i - 3] = buffer[i]; + } + } + } + } + while (checksum != xmitcsum); + +} + + +/* send the packet in buffer. The host get's one chance to read it. + This routine does not wait for a positive acknowledge. */ + +static void +putpacket (register char *buffer) +{ + register int checksum; + register int count; + + /* $<packet info>#<checksum>. */ + do + { + char *src = buffer; + putDebugChar ('$'); + checksum = 0; + + while (*src) + { + int runlen; + + /* Do run length encoding */ + for (runlen = 0; runlen < 100; runlen ++) + { + if (src[0] != src[runlen]) + { + if (runlen > 3) + { + int encode; + /* Got a useful amount */ + putDebugChar (*src); + checksum += *src; + putDebugChar ('*'); + checksum += '*'; + checksum += (encode = runlen + ' ' - 4); + putDebugChar (encode); + src += runlen; + } + else + { + putDebugChar (*src); + checksum += *src; + src++; + } + break; + } + } + } + + + putDebugChar ('#'); + putDebugChar (highhex(checksum)); + putDebugChar (lowhex(checksum)); + } + while (getDebugChar() != '+'); + +} + + +/* a bus error has occurred, perform a longjmp + to return execution and allow handling of the error */ + +void +handle_buserror (void) +{ + longjmp (remcomEnv, 1); +} + +/* + * this function takes the SH-1 exception number and attempts to + * translate this number into a unix compatible signal value + */ +static int +computeSignal (int exceptionVector) +{ + int sigval; + switch (exceptionVector) + { + case INVALID_INSN_VEC: + sigval = 4; + break; + case INVALID_SLOT_VEC: + sigval = 4; + break; + case CPU_BUS_ERROR_VEC: + sigval = 10; + break; + case DMA_BUS_ERROR_VEC: + sigval = 10; + break; + case NMI_VEC: + sigval = 2; + break; + + case TRAP_VEC: + case USER_VEC: + sigval = 5; + break; + + default: + sigval = 7; /* "software generated"*/ + break; + } + return (sigval); +} + +void +doSStep (void) +{ + short *instrMem; + int displacement; + int reg; + unsigned short opcode; + + instrMem = (short *) registers[PC]; + + opcode = *instrMem; + stepped = 1; + + if ((opcode & COND_BR_MASK) == BT_INSTR) + { + if (registers[SR] & T_BIT_MASK) + { + displacement = (opcode & COND_DISP) << 1; + if (displacement & 0x80) + displacement |= 0xffffff00; + /* + * Remember PC points to second instr. + * after PC of branch ... so add 4 + */ + instrMem = (short *) (registers[PC] + displacement + 4); + } + else + instrMem += 1; + } + else if ((opcode & COND_BR_MASK) == BF_INSTR) + { + if (registers[SR] & T_BIT_MASK) + instrMem += 1; + else + { + displacement = (opcode & COND_DISP) << 1; + if (displacement & 0x80) + displacement |= 0xffffff00; + /* + * Remember PC points to second instr. + * after PC of branch ... so add 4 + */ + instrMem = (short *) (registers[PC] + displacement + 4); + } + } + else if ((opcode & UCOND_DBR_MASK) == BRA_INSTR) + { + displacement = (opcode & UCOND_DISP) << 1; + if (displacement & 0x0800) + displacement |= 0xfffff000; + + /* + * Remember PC points to second instr. + * after PC of branch ... so add 4 + */ + instrMem = (short *) (registers[PC] + displacement + 4); + } + else if ((opcode & UCOND_RBR_MASK) == JSR_INSTR) + { + reg = (char) ((opcode & UCOND_REG) >> 8); + + instrMem = (short *) registers[reg]; + } + else if (opcode == RTS_INSTR) + instrMem = (short *) registers[PR]; + else if (opcode == RTE_INSTR) + instrMem = (short *) registers[15]; + else if ((opcode & TRAPA_MASK) == TRAPA_INSTR) + instrMem = (short *) ((opcode & ~TRAPA_MASK) << 2); + else + instrMem += 1; + + instrBuffer.memAddr = instrMem; + instrBuffer.oldInstr = *instrMem; + *instrMem = SSTEP_INSTR; +} + +void +undoSStep (void) +{ + /* + If we single stepped, + restore the old instruction! +*/ + if (stepped) + { short *instrMem; + instrMem = instrBuffer.memAddr; + *instrMem = instrBuffer.oldInstr; + } + stepped = 0; +} + +/* +This function does all exception handling. It only does two things - +it figures out why it was called and tells gdb, and then it reacts +to gdb's requests. + +When in the monitor mode we talk a human on the serial line rather than gdb. + +*/ + + +void +gdb_handle_exception (int exceptionVector) +{ + int sigval; + int addr, length; + char *ptr; + + /* reply to host that an exception has occurred */ + sigval = computeSignal (exceptionVector); + remcomOutBuffer[0] = 'S'; + remcomOutBuffer[1] = highhex(sigval); + remcomOutBuffer[2] = lowhex (sigval); + remcomOutBuffer[3] = 0; + + putpacket (remcomOutBuffer); + + /* + * exception 255 indicates a software trap + * inserted in place of code ... so back up + * PC by one instruction, since this instruction + * will later be replaced by its original one! + */ + if (exceptionVector == 0xff + || exceptionVector == 0x20) + registers[PC] -= 2; + + /* + * Do the thangs needed to undo + * any stepping we may have done! + */ + undoSStep (); + + while (1) + { + remcomOutBuffer[0] = 0; + getpacket (remcomInBuffer); + + switch (remcomInBuffer[0]) + { + case '?': + remcomOutBuffer[0] = 'S'; + remcomOutBuffer[1] = highhex (sigval); + remcomOutBuffer[2] = lowhex (sigval); + remcomOutBuffer[3] = 0; + break; + case 'd': + remote_debug = !(remote_debug); /* toggle debug flag */ + break; + case 'g': /* return the value of the CPU registers */ + mem2hex ((char *) registers, remcomOutBuffer, NUMREGBYTES); + break; + case 'G': /* set the value of the CPU registers - return OK */ + hex2mem (&remcomInBuffer[1], (char *) registers, NUMREGBYTES); + strcpy (remcomOutBuffer, "OK"); + break; + + /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ + case 'm': + if (setjmp (remcomEnv) == 0) + { + dofault = 0; + /* TRY, TO READ %x,%x. IF SUCCEED, SET PTR = 0 */ + ptr = &remcomInBuffer[1]; + if (hexToInt (&ptr, &addr)) + if (*(ptr++) == ',') + if (hexToInt (&ptr, &length)) + { + ptr = 0; + mem2hex ((char *) addr, remcomOutBuffer, length); + } + if (ptr) + strcpy (remcomOutBuffer, "E01"); + } + else + strcpy (remcomOutBuffer, "E03"); + + /* restore handler for bus error */ + dofault = 1; + break; + + /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ + case 'M': + if (setjmp (remcomEnv) == 0) + { + dofault = 0; + + /* TRY, TO READ '%x,%x:'. IF SUCCEED, SET PTR = 0 */ + ptr = &remcomInBuffer[1]; + if (hexToInt (&ptr, &addr)) + if (*(ptr++) == ',') + if (hexToInt (&ptr, &length)) + if (*(ptr++) == ':') + { + hex2mem (ptr, (char *) addr, length); + ptr = 0; + strcpy (remcomOutBuffer, "OK"); + } + if (ptr) + strcpy (remcomOutBuffer, "E02"); + } + else + strcpy (remcomOutBuffer, "E03"); + + /* restore handler for bus error */ + dofault = 1; + break; + + /* cAA..AA Continue at address AA..AA(optional) */ + /* sAA..AA Step one instruction from AA..AA(optional) */ + case 'c': + case 's': + { + /* tRY, to read optional parameter, pc unchanged if no parm */ + ptr = &remcomInBuffer[1]; + if (hexToInt (&ptr, &addr)) + registers[PC] = addr; + + if (remcomInBuffer[0] == 's') + doSStep (); + } + return; + break; + + /* kill the program */ + case 'k': /* do nothing */ + break; + } /* switch */ + + /* reply to the request */ + putpacket (remcomOutBuffer); + } +} + + +#define GDBCOOKIE 0x5ac +static int ingdbmode; +/* We've had an exception - choose to go into the monitor or + the gdb stub */ +void handle_exception(int exceptionVector) +{ +#ifdef MONITOR + if (ingdbmode != GDBCOOKIE) + monitor_handle_exception (exceptionVector); + else +#endif + gdb_handle_exception (exceptionVector); + +} + +void +gdb_mode() +{ + ingdbmode = GDBCOOKIE; + breakpoint(); +} +/* This function will generate a breakpoint exception. It is used at the + beginning of a program to sync up with a debugger and can be used + otherwise as a quick means to stop program execution and "break" into + the debugger. */ + +void +breakpoint (void) +{ + BREAKPOINT (); +} + +asm ("_BINIT: mov.l L1,r15"); +asm ("bra _INIT"); +asm ("nop"); +asm ("L1: .long _init_stack + 8*1024*4"); +void +INIT (void) +{ + /* First turn on the ram */ + WCR1 = 0; /* Never sample wait */ + BCR = BAS; /* use lowbyte/high byte */ + + init_serial(); + +#ifdef MONITOR + reset_hook (); +#endif + + + in_nmi = 0; + dofault = 1; + stepped = 0; + + stub_sp = stub_stack + stub_stack_size; + breakpoint (); + + while (1) + ; +} + + +static void sr() +{ + + + /* Calling Reset does the same as pressing the button */ + asm (".global _Reset + .global _WarmReset +_Reset: +_WarmReset: + mov.l L_sp,r15 + bra _INIT + nop + .align 2 +L_sp: .long _init_stack + 8000"); + + asm("saveRegisters: + mov.l @(L_reg, pc), r0 + mov.l @r15+, r1 ! pop R0 + mov.l r2, @(0x08, r0) ! save R2 + mov.l r1, @r0 ! save R0 + mov.l @r15+, r1 ! pop R1 + mov.l r3, @(0x0c, r0) ! save R3 + mov.l r1, @(0x04, r0) ! save R1 + mov.l r4, @(0x10, r0) ! save R4 + mov.l r5, @(0x14, r0) ! save R5 + mov.l r6, @(0x18, r0) ! save R6 + mov.l r7, @(0x1c, r0) ! save R7 + mov.l r8, @(0x20, r0) ! save R8 + mov.l r9, @(0x24, r0) ! save R9 + mov.l r10, @(0x28, r0) ! save R10 + mov.l r11, @(0x2c, r0) ! save R11 + mov.l r12, @(0x30, r0) ! save R12 + mov.l r13, @(0x34, r0) ! save R13 + mov.l r14, @(0x38, r0) ! save R14 + mov.l @r15+, r4 ! save arg to handleException + add #8, r15 ! hide PC/SR values on stack + mov.l r15, @(0x3c, r0) ! save R15 + add #-8, r15 ! save still needs old SP value + add #92, r0 ! readjust register pointer + mov r15, r2 + add #4, r2 + mov.l @r2, r2 ! R2 has SR + mov.l @r15, r1 ! R1 has PC + mov.l r2, @-r0 ! save SR + sts.l macl, @-r0 ! save MACL + sts.l mach, @-r0 ! save MACH + stc.l vbr, @-r0 ! save VBR + stc.l gbr, @-r0 ! save GBR + sts.l pr, @-r0 ! save PR + mov.l @(L_stubstack, pc), r2 + mov.l @(L_hdl_except, pc), r3 + mov.l @r2, r15 + jsr @r3 + mov.l r1, @-r0 ! save PC + mov.l @(L_stubstack, pc), r0 + mov.l @(L_reg, pc), r1 + bra restoreRegisters + mov.l r15, @r0 ! save __stub_stack + + .align 2 +L_reg: + .long _registers +L_stubstack: + .long _stub_sp +L_hdl_except: + .long _handle_exception"); + +} + +static void rr() +{ +asm(" + .align 2 + .global _resume +_resume: + mov r4,r1 +restoreRegisters: + add #8, r1 ! skip to R2 + mov.l @r1+, r2 ! restore R2 + mov.l @r1+, r3 ! restore R3 + mov.l @r1+, r4 ! restore R4 + mov.l @r1+, r5 ! restore R5 + mov.l @r1+, r6 ! restore R6 + mov.l @r1+, r7 ! restore R7 + mov.l @r1+, r8 ! restore R8 + mov.l @r1+, r9 ! restore R9 + mov.l @r1+, r10 ! restore R10 + mov.l @r1+, r11 ! restore R11 + mov.l @r1+, r12 ! restore R12 + mov.l @r1+, r13 ! restore R13 + mov.l @r1+, r14 ! restore R14 + mov.l @r1+, r15 ! restore programs stack + mov.l @r1+, r0 + add #-8, r15 ! uncover PC/SR on stack + mov.l r0, @r15 ! restore PC onto stack + lds.l @r1+, pr ! restore PR + ldc.l @r1+, gbr ! restore GBR + ldc.l @r1+, vbr ! restore VBR + lds.l @r1+, mach ! restore MACH + lds.l @r1+, macl ! restore MACL + mov.l @r1, r0 + add #-88, r1 ! readjust reg pointer to R1 + mov.l r0, @(4, r15) ! restore SR onto stack+4 + mov.l r2, @-r15 + mov.l L_in_nmi, r0 + mov #0, r2 + mov.b r2, @r0 + mov.l @r15+, r2 + mov.l @r1+, r0 ! restore R0 + rte + mov.l @r1, r1 ! restore R1 + +"); +} + + +static __inline__ void code_for_catch_exception(int n) +{ + asm(" .globl _catch_exception_%O0" : : "i" (n) ); + asm(" _catch_exception_%O0:" :: "i" (n) ); + + asm(" add #-4, r15 ! reserve spot on stack "); + asm(" mov.l r1, @-r15 ! push R1 "); + + if (n == NMI_VEC) + { + /* Special case for NMI - make sure that they don't nest */ + asm(" mov.l r0, @-r15 ! push R0"); + asm(" mov.l L_in_nmi, r0"); + asm(" tas.b @r0 ! Fend off against addtnl NMIs"); + asm(" bt noNMI"); + asm(" mov.l @r15+, r0"); + asm(" mov.l @r15+, r1"); + asm(" add #4, r15"); + asm(" rte"); + asm(" nop"); + asm(".align 2"); + asm("L_in_nmi: .long _in_nmi"); + asm("noNMI:"); + } + else + { + + if (n == CPU_BUS_ERROR_VEC) + { + /* Exception 9 (bus errors) are disasbleable - so that you + can probe memory and get zero instead of a fault. + Because the vector table may be in ROM we don't revector + the interrupt like all the other stubs, we check in here + */ + asm("mov.l L_dofault,r1"); + asm("mov.l @r1,r1"); + asm("tst r1,r1"); + asm("bf faultaway"); + asm("bsr _handle_buserror"); + asm(".align 2"); + asm("L_dofault: .long _dofault"); + asm("faultaway:"); + } + asm(" mov #15<<4, r1 "); + asm(" ldc r1, sr ! disable interrupts "); + asm(" mov.l r0, @-r15 ! push R0 "); + } + + /* Prepare for saving context, we've already pushed r0 and r1, stick exception number + into the frame */ + asm(" mov r15, r0 "); + asm(" add #8, r0 "); + asm(" mov %0,r1" :: "i" (n) ); + asm(" extu.b r1,r1 "); + asm(" bra saveRegisters ! save register values "); + asm(" mov.l r1, @r0 ! save exception # "); +} + + +static void +exceptions() +{ + code_for_catch_exception (CPU_BUS_ERROR_VEC); + code_for_catch_exception (DMA_BUS_ERROR_VEC); + code_for_catch_exception (INVALID_INSN_VEC); + code_for_catch_exception (INVALID_SLOT_VEC); + code_for_catch_exception (NMI_VEC); + code_for_catch_exception (TRAP_VEC); + code_for_catch_exception (USER_VEC); + code_for_catch_exception (IO_VEC); +} + + + + + + +/* Support for Serial I/O using on chip uart */ + +#define SMR0 (*(volatile char *)(0x05FFFEC0)) /* Channel 0 serial mode register */ +#define BRR0 (*(volatile char *)(0x05FFFEC1)) /* Channel 0 bit rate register */ +#define SCR0 (*(volatile char *)(0x05FFFEC2)) /* Channel 0 serial control register */ +#define TDR0 (*(volatile char *)(0x05FFFEC3)) /* Channel 0 transmit data register */ +#define SSR0 (*(volatile char *)(0x05FFFEC4)) /* Channel 0 serial status register */ +#define RDR0 (*(volatile char *)(0x05FFFEC5)) /* Channel 0 receive data register */ + +#define SMR1 (*(volatile char *)(0x05FFFEC8)) /* Channel 1 serial mode register */ +#define BRR1 (*(volatile char *)(0x05FFFEC9)) /* Channel 1 bit rate register */ +#define SCR1 (*(volatile char *)(0x05FFFECA)) /* Channel 1 serial control register */ +#define TDR1 (*(volatile char *)(0x05FFFECB)) /* Channel 1 transmit data register */ +#define SSR1 (*(volatile char *)(0x05FFFECC)) /* Channel 1 serial status register */ +#define RDR1 (*(volatile char *)(0x05FFFECD)) /* Channel 1 receive data register */ + +/* + * Serial mode register bits + */ + +#define SYNC_MODE 0x80 +#define SEVEN_BIT_DATA 0x40 +#define PARITY_ON 0x20 +#define ODD_PARITY 0x10 +#define STOP_BITS_2 0x08 +#define ENABLE_MULTIP 0x04 +#define PHI_64 0x03 +#define PHI_16 0x02 +#define PHI_4 0x01 + +/* + * Serial control register bits + */ +#define SCI_TIE 0x80 /* Transmit interrupt enable */ +#define SCI_RIE 0x40 /* Receive interrupt enable */ +#define SCI_TE 0x20 /* Transmit enable */ +#define SCI_RE 0x10 /* Receive enable */ +#define SCI_MPIE 0x08 /* Multiprocessor interrupt enable */ +#define SCI_TEIE 0x04 /* Transmit end interrupt enable */ +#define SCI_CKE1 0x02 /* Clock enable 1 */ +#define SCI_CKE0 0x01 /* Clock enable 0 */ + +/* + * Serial status register bits + */ +#define SCI_TDRE 0x80 /* Transmit data register empty */ +#define SCI_RDRF 0x40 /* Receive data register full */ +#define SCI_ORER 0x20 /* Overrun error */ +#define SCI_FER 0x10 /* Framing error */ +#define SCI_PER 0x08 /* Parity error */ +#define SCI_TEND 0x04 /* Transmit end */ +#define SCI_MPB 0x02 /* Multiprocessor bit */ +#define SCI_MPBT 0x01 /* Multiprocessor bit transfer */ + + +/* + * Port B IO Register (PBIOR) + */ +#define PBIOR (*(volatile char *)(0x05FFFFC6)) +#define PB15IOR 0x8000 +#define PB14IOR 0x4000 +#define PB13IOR 0x2000 +#define PB12IOR 0x1000 +#define PB11IOR 0x0800 +#define PB10IOR 0x0400 +#define PB9IOR 0x0200 +#define PB8IOR 0x0100 +#define PB7IOR 0x0080 +#define PB6IOR 0x0040 +#define PB5IOR 0x0020 +#define PB4IOR 0x0010 +#define PB3IOR 0x0008 +#define PB2IOR 0x0004 +#define PB1IOR 0x0002 +#define PB0IOR 0x0001 + +/* + * Port B Control Register (PBCR1) + */ +#define PBCR1 (*(volatile short *)(0x05FFFFCC)) +#define PB15MD1 0x8000 +#define PB15MD0 0x4000 +#define PB14MD1 0x2000 +#define PB14MD0 0x1000 +#define PB13MD1 0x0800 +#define PB13MD0 0x0400 +#define PB12MD1 0x0200 +#define PB12MD0 0x0100 +#define PB11MD1 0x0080 +#define PB11MD0 0x0040 +#define PB10MD1 0x0020 +#define PB10MD0 0x0010 +#define PB9MD1 0x0008 +#define PB9MD0 0x0004 +#define PB8MD1 0x0002 +#define PB8MD0 0x0001 + +#define PB15MD PB15MD1|PB14MD0 +#define PB14MD PB14MD1|PB14MD0 +#define PB13MD PB13MD1|PB13MD0 +#define PB12MD PB12MD1|PB12MD0 +#define PB11MD PB11MD1|PB11MD0 +#define PB10MD PB10MD1|PB10MD0 +#define PB9MD PB9MD1|PB9MD0 +#define PB8MD PB8MD1|PB8MD0 + +#define PB_TXD1 PB11MD1 +#define PB_RXD1 PB10MD1 +#define PB_TXD0 PB9MD1 +#define PB_RXD0 PB8MD1 + +/* + * Port B Control Register (PBCR2) + */ +#define PBCR2 0x05FFFFCE +#define PB7MD1 0x8000 +#define PB7MD0 0x4000 +#define PB6MD1 0x2000 +#define PB6MD0 0x1000 +#define PB5MD1 0x0800 +#define PB5MD0 0x0400 +#define PB4MD1 0x0200 +#define PB4MD0 0x0100 +#define PB3MD1 0x0080 +#define PB3MD0 0x0040 +#define PB2MD1 0x0020 +#define PB2MD0 0x0010 +#define PB1MD1 0x0008 +#define PB1MD0 0x0004 +#define PB0MD1 0x0002 +#define PB0MD0 0x0001 + +#define PB7MD PB7MD1|PB7MD0 +#define PB6MD PB6MD1|PB6MD0 +#define PB5MD PB5MD1|PB5MD0 +#define PB4MD PB4MD1|PB4MD0 +#define PB3MD PB3MD1|PB3MD0 +#define PB2MD PB2MD1|PB2MD0 +#define PB1MD PB1MD1|PB1MD0 +#define PB0MD PB0MD1|PB0MD0 + + +#ifdef MHZ +#define BPS 32 * 9600 * MHZ / ( BAUD * 10) +#else +#define BPS 32 /* 9600 for 10 Mhz */ +#endif + +char getDebugChar (void); +int putDebugChar (char); +void handleError (char theSSR); + +void +nop () +{ + +} +void +init_serial() +{ + int i; + + /* Clear TE and RE in Channel 1's SCR */ + SCR1 &= ~(SCI_TE | SCI_RE); + + /* Set communication to be async, 8-bit data, no parity, 1 stop bit and use internal clock */ + + SMR1 = 0; + BRR1 = BPS; + + SCR1 &= ~(SCI_CKE1 | SCI_CKE0); + + /* let the hardware settle */ + + for (i = 0; i < 1000; i++) + nop (); + + /* Turn on in and out */ + SCR1 |= SCI_RE | SCI_TE; + + /* Set the PFC to make RXD1 (pin PB8) an input pin and TXD1 (pin PB9) an output pin */ + PBCR1 &= ~(PB_TXD1 | PB_RXD1); + PBCR1 |= PB_TXD1 | PB_RXD1; +} + + +int +getDebugCharReady (void) +{ + char mySSR; + mySSR = SSR1 & ( SCI_PER | SCI_FER | SCI_ORER ); + if ( mySSR ) + handleError ( mySSR ); + return SSR1 & SCI_RDRF ; +} + +char +getDebugChar (void) +{ + char ch; + char mySSR; + + while ( ! getDebugCharReady()) + ; + + ch = RDR1; + SSR1 &= ~SCI_RDRF; + + mySSR = SSR1 & (SCI_PER | SCI_FER | SCI_ORER); + + if (mySSR) + handleError (mySSR); + + return ch; +} + +int +putDebugCharReady() +{ + return (SSR1 & SCI_TDRE); +} + +int +putDebugChar (char ch) +{ + while (!putDebugCharReady()) + ; + + /* + * Write data into TDR and clear TDRE + */ + TDR1 = ch; + SSR1 &= ~SCI_TDRE; + return 1; +} + +void +handleError (char theSSR) +{ + SSR1 &= ~(SCI_ORER | SCI_PER | SCI_FER); +} + |