diff options
Diffstat (limited to 'libgloss/m68k/mvme-stub.c')
| -rw-r--r-- | libgloss/m68k/mvme-stub.c | 734 |
1 files changed, 0 insertions, 734 deletions
diff --git a/libgloss/m68k/mvme-stub.c b/libgloss/m68k/mvme-stub.c deleted file mode 100644 index fbc4c61b5..000000000 --- a/libgloss/m68k/mvme-stub.c +++ /dev/null @@ -1,734 +0,0 @@ -unsigned long sp_ptr; -unsigned long pc_ptr; -int cnt; -#define UNWIND asm ("movel %/sp, %0" : "=g" (sp_ptr));\ - printf ("\n\t\t== Starting at 0x%x ==\n", sp_ptr);\ - for (cnt=4; cnt <=32; cnt+=4) {\ - printf ("+%d(0x%x): 0x%x\t\t-%d(0x%x): 0x%x\n",\ - cnt, (sp_ptr + cnt), *(unsigned long *)(sp_ptr + cnt),\ - cnt, (sp_ptr - cnt), *(unsigned long *)(sp_ptr - cnt)\ - ); }; fflush (stdout); - -/**************************************************************************** - - 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. - -****************************************************************************/ - -/**************************************************************************** - * Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $ - * - * Module name: remcom.c $ - * Revision: 1.34 $ - * Date: 91/03/09 12:29:49 $ - * Contributor: Lake Stevens Instrument Division$ - * - * Description: low level support for gdb debugger. $ - * - * Considerations: only works on target hardware $ - * - * Written by: Glenn Engel $ - * ModuleState: Experimental $ - * - * NOTES: See Below $ - * - * To enable debugger support, two things need to happen. One, a - * call to set_debug_traps() is necessary in order to allow any breakpoints - * or error conditions to be properly intercepted and reported to gdb. - * Two, a breakpoint needs to be generated to begin communication. This - * is most easily accomplished by a call to breakpoint(). Breakpoint() - * simulates a breakpoint by executing a trap #1. - * - * Some explanation is probably necessary to explain how exceptions are - * handled. When an exception is encountered the 68000 pushes the current - * program counter and status register onto the supervisor stack and then - * transfers execution to a location specified in it's vector table. - * The handlers for the exception vectors are hardwired to jmp to an address - * given by the relation: (exception - 256) * 6. These are decending - * addresses starting from -6, -12, -18, ... By allowing 6 bytes for - * each entry, a jsr, jmp, bsr, ... can be used to enter the exception - * handler. Using a jsr to handle an exception has an added benefit of - * allowing a single handler to service several exceptions and use the - * return address as the key differentiation. The vector number can be - * computed from the return address by [ exception = (addr + 1530) / 6 ]. - * The sole purpose of the routine _catchException is to compute the - * exception number and push it on the stack in place of the return address. - * The external function exceptionHandler() is - * used to attach a specific handler to a specific 68k exception. - * For 68020 machines, the ability to have a return address around just - * so the vector can be determined is not necessary because the '020 pushes an - * extra word onto the stack containing the vector offset - * - * Because gdb will sometimes write to the stack area to execute function - * calls, this program cannot rely on using the supervisor stack so it - * uses it's own stack area reserved in the int array remcomStack. - * - ************* - * - * The following gdb commands are supported: - * - * command function Return value - * - * g return the value of the CPU registers hex data or ENN - * G set the value of the CPU registers OK or ENN - * - * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN - * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN - * - * c Resume at current address SNN ( signal NN) - * cAA..AA Continue at address AA..AA SNN - * - * s Step one instruction SNN - * sAA..AA Step one instruction from AA..AA SNN - * - * k kill - * - * ? What was the last sigval ? SNN (signal NN) - * - * All commands and responses are sent with a packet which includes a - * checksum. A packet consists of - * - * $<packet info>#<checksum>. - * - * where - * <packet info> :: <characters representing the command or response> - * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>> - * - * When a packet is received, it is first acknowledged with either '+' or '-'. - * '+' indicates a successful transfer. '-' indicates a failed transfer. - * - * Example: - * - * Host: Reply: - * $m0,10#2a +$00010203040506070809101112131415#42 - * - ****************************************************************************/ - -#include <stdio.h> -#include <string.h> -#include <setjmp.h> -#include <_ansi.h> - -/************************************************************************ - * - * external low-level support routines - */ -typedef void (*ExceptionHook)(int); /* pointer to function with int parm */ -typedef void (*Function)(); /* pointer to a function */ - -extern int putDebugChar(); /* write a single character */ -extern char getDebugChar(); /* read and return a single char */ - -ExceptionHook exceptionHook; /* hook variable for errors/exceptions */ - -/************************/ -/* FORWARD DECLARATIONS */ -/************************/ -/** static void initializeRemcomErrorFrame PARAMS ((void)); **/ -static void _DEFUN_VOID (initializeRemcomErrorFrame); - -/************************************************************************/ -/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/ -/* at least NUMREGBYTES*2 are needed for register packets */ -#define BUFMAX 400 - -static char initialized; /* boolean flag. != 0 means we've been initialized */ - -int remote_debug = 0; /*** Robs Thu Sep 24 22:18:51 PDT 1992 ***/ -/* debug > 0 prints ill-formed commands in valid packets & checksum errors */ - -static const char hexchars[]="0123456789abcdef"; - -/* there are 180 bytes of registers on a 68020 w/68881 */ -/* many of the fpa registers are 12 byte (96 bit) registers */ -#define NUMREGBYTES 180 -enum regnames {D0,D1,D2,D3,D4,D5,D6,D7, - A0,A1,A2,A3,A4,A5,A6,A7, - PS,PC, - FP0,FP1,FP2,FP3,FP4,FP5,FP6,FP7, - FPCONTROL,FPSTATUS,FPIADDR - }; - -typedef struct FrameStruct -{ - struct FrameStruct *previous; - int exceptionPC; /* pc value when this frame created */ - int exceptionVector; /* cpu vector causing exception */ - short frameSize; /* size of cpu frame in words */ - short sr; /* for 68000, this not always sr */ - int pc; - short format; - int fsaveHeader; - int morejunk[0]; /* exception frame, fp save... */ -} Frame; - -#define FRAMESIZE 500 -int gdbFrameStack[FRAMESIZE]; -Frame *lastFrame; - -/* - * these should not be static cuz they can be used outside this module - */ -int registers[NUMREGBYTES/4]; -int superStack; - -#define STACKSIZE 10000 -int remcomStack[STACKSIZE/sizeof(int)]; -int* stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; - -/* - * In many cases, the system will want to continue exception processing - * when a continue command is given. - * oldExceptionHook is a function to invoke in this case. - */ - -static ExceptionHook oldExceptionHook; - -/* the size of the exception stack on the 68020 varies with the type of - * exception. The following table is the number of WORDS used - * for each exception format. - */ -const short exceptionSize[] = { 4,4,6,4,4,4,4,4,29,10,16,46,12,4,4,4 }; - -/************* jump buffer used for setjmp/longjmp **************************/ -jmp_buf remcomEnv; - -#define BREAKPOINT() asm(" trap #1"); - -extern void _DEFUN_VOID (return_to_super); -extern void _DEFUN_VOID (return_to_user); -extern void _DEFUN_VOID (_catchException); - -void _returnFromException( Frame *frame ) -{ - /* if no passed in frame, use the last one */ - if (! frame) - { - frame = lastFrame; - frame->frameSize = 4; - frame->format = 0; - frame->fsaveHeader = -1; /* restore regs, but we dont have fsave info*/ - } - -#ifndef mc68020 - /* a 68000 cannot use the internal info pushed onto a bus error - * or address error frame when doing an RTE so don't put this info - * onto the stack or the stack will creep every time this happens. - */ - frame->frameSize=3; -#endif - - /* throw away any frames in the list after this frame */ - lastFrame = frame; - - frame->sr = registers[(int) PS]; - frame->pc = registers[(int) PC]; - - if (registers[(int) PS] & 0x2000) - { - /* return to supervisor mode... */ - return_to_super(); - } - else - { /* return to user mode */ - return_to_user(); - } -} - -int hex(ch) -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); -} - - -/* scan for the sequence $<data>#<checksum> */ -void getpacket(buffer) -char * buffer; -{ - unsigned char checksum; - unsigned char xmitcsum; - int i; - int count; - char ch; - - if (remote_debug) { - printf("\nGETPACKET: sr=0x%x, pc=0x%x, sp=0x%x\n", - registers[ PS ], - registers[ PC ], - registers[ A7 ] - ); fflush (stdout); - UNWIND - } - - do { - /* wait around for the start character, ignore all other characters */ - while ((ch = getDebugChar()) != '$'); - 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 ((remote_debug ) && (checksum != xmitcsum)) { - fprintf(stderr,"bad checksum. My count = 0x%x, sent=0x%x. buf=%s\n", - checksum,xmitcsum,buffer); - } - - 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. */ - -void putpacket(buffer) -char * buffer; -{ - unsigned char checksum; - int count; - char ch; - - /* $<packet info>#<checksum>. */ - /*** do {***/ - putDebugChar('$'); - checksum = 0; - count = 0; - - while (ch=buffer[count]) { - if (! putDebugChar(ch)) return; - checksum += ch; - count += 1; - } - - putDebugChar('#'); - putDebugChar(hexchars[checksum >> 4]); - putDebugChar(hexchars[checksum % 16]); - - if (remote_debug) { - printf("\nPUTPACKET: sr=0x%x, pc=0x%x, sp=0x%x\n", - registers[ PS ], - registers[ PC ], - registers[ A7 ] - ); fflush (stdout); - UNWIND - } - -/*** } while (getDebugChar() != '+'); ***/ -/** } while (1 == 0); (getDebugChar() != '+'); **/ - -} - -char remcomInBuffer[BUFMAX]; -char remcomOutBuffer[BUFMAX]; -static short error; - - -void debug_error(format, parm) -char * format; -char * parm; -{ - if (remote_debug) fprintf(stderr,format,parm); -} - -/* convert the memory pointed to by mem into hex, placing result in buf */ -/* return a pointer to the last char put in buf (null) */ -char* mem2hex(mem, buf, count) -char* mem; -char* buf; -int count; -{ - int i; - unsigned char ch; - for (i=0;i<count;i++) { - ch = *mem++; - *buf++ = hexchars[ch >> 4]; - *buf++ = hexchars[ch % 16]; - } - *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 */ -char* hex2mem(buf, mem, count) -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); -} - -/* a bus error has occurred, perform a longjmp - to return execution and allow handling of the error */ - -void handle_buserror() -{ - longjmp(remcomEnv,1); -} - -/* this function takes the 68000 exception number and attempts to - translate this number into a unix compatible signal value */ -int computeSignal( exceptionVector ) -int exceptionVector; -{ - int sigval; - switch (exceptionVector) { - case 2 : sigval = 10; break; /* bus error */ - case 3 : sigval = 10; break; /* address error */ - case 4 : sigval = 4; break; /* illegal instruction */ - case 5 : sigval = 8; break; /* zero divide */ - case 6 : sigval = 16; break; /* chk instruction */ - case 7 : sigval = 16; break; /* trapv instruction */ - case 8 : sigval = 11; break; /* privilege violation */ - case 9 : sigval = 5; break; /* trace trap */ - case 10: sigval = 4; break; /* line 1010 emulator */ - case 11: sigval = 4; break; /* line 1111 emulator */ - case 13: sigval = 8; break; /* floating point err */ - case 31: sigval = 2; break; /* interrupt */ - case 33: sigval = 5; break; /* breakpoint */ - case 40: sigval = 8; break; /* floating point err */ - case 48: sigval = 8; break; /* floating point err */ - case 49: sigval = 8; break; /* floating point err */ - case 50: sigval = 8; break; /* zero divide */ - case 51: sigval = 8; break; /* underflow */ - case 52: sigval = 8; break; /* operand error */ - case 53: sigval = 8; break; /* overflow */ - case 54: sigval = 8; break; /* NAN */ - default: - sigval = 7; /* "software generated"*/ - } - return (sigval); -} - -/**********************************************/ -/* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */ -/* RETURN NUMBER OF CHARS PROCESSED */ -/**********************************************/ -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); -} - -/* - * This function does all command procesing for interfacing to gdb. - */ -void handle_exception(int exceptionVector) -{ - int sigval; - int addr, length; - char * ptr; - int newPC; - Frame *frame; - - if (remote_debug) printf("\nHANDLE_EXCEPTION: vector=%d, sr=0x%x, pc=0x%x, sp=0x%x\n", - exceptionVector, - registers[ PS ], - registers[ PC ], - registers[ A7 ] - ); fflush (stdout); - - /* reply to host that an exception has occurred */ - sigval = computeSignal( exceptionVector ); - remcomOutBuffer[0] = 'S'; - remcomOutBuffer[1] = hexchars[sigval >> 4]; - remcomOutBuffer[2] = hexchars[sigval % 16]; - remcomOutBuffer[3] = 0; - - putpacket(remcomOutBuffer); - - while (1==1) { - error = 0; - remcomOutBuffer[0] = 0; - getpacket(remcomInBuffer); - switch (remcomInBuffer[0]) { - case '?' : remcomOutBuffer[0] = 'S'; - remcomOutBuffer[1] = hexchars[sigval >> 4]; - remcomOutBuffer[2] = hexchars[sigval % 16]; - 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) - { - exceptionHandler(2,handle_buserror); - - /* 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"); - debug_error("malformed read memory command: %s",remcomInBuffer); - } - } - else { - exceptionHandler(2,_catchException); - strcpy(remcomOutBuffer,"E03"); - debug_error("bus error"); - } - - /* restore handler for bus error */ - exceptionHandler(2,_catchException); - break; - - /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ - case 'M' : - if (setjmp(remcomEnv) == 0) { - exceptionHandler(2,handle_buserror); - - /* 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"); - debug_error("malformed write memory command: %s",remcomInBuffer); - } - } - else { - exceptionHandler(2,_catchException); - strcpy(remcomOutBuffer,"E03"); - debug_error("bus error"); - } - - /* restore handler for bus error */ - exceptionHandler(2,_catchException); - 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; - - newPC = registers[ PC]; - - /* clear the trace bit */ - registers[ PS ] &= 0x7fff; - - /* set the trace bit if we're stepping */ - if (remcomInBuffer[0] == 's') registers[ PS ] |= 0x8000; - - /* - * look for newPC in the linked list of exception frames. - * if it is found, use the old frame it. otherwise, - * fake up a dummy frame in returnFromException(). - */ - if (remote_debug) printf("new pc = 0x%x\n",newPC); - frame = lastFrame; - while (frame) - { - if (remote_debug) - printf("frame at 0x%x has pc=0x%x, except#=%d\n", - frame,frame->exceptionPC, - frame->exceptionVector); - if (frame->exceptionPC == newPC) break; /* bingo! a match */ - /* - * for a breakpoint instruction, the saved pc may - * be off by two due to re-executing the instruction - * replaced by the trap instruction. Check for this. - */ - if ((frame->exceptionVector == 33) && - (frame->exceptionPC == (newPC+2))) break; - if (frame == frame->previous) - { - frame = 0; /* no match found */ - break; - } - frame = frame->previous; - } - - /* - * If we found a match for the PC AND we are not returning - * as a result of a breakpoint (33), - * trace exception (9), nmi (31), jmp to - * the old exception handler as if this code never ran. - */ - if (frame) - { - if ((frame->exceptionVector != 9) && - (frame->exceptionVector != 31) && - (frame->exceptionVector != 33)) - { - /* - * invoke the previous handler. - */ - if (oldExceptionHook) - (*oldExceptionHook) (frame->exceptionVector); - newPC = registers[ PC ]; /* pc may have changed */ - if (newPC != frame->exceptionPC) - { - if (remote_debug) - printf("frame at 0x%x has pc=0x%x, except#=%d\n", - frame,frame->exceptionPC, - frame->exceptionVector); - /* re-use the last frame, we're skipping it (longjump?)*/ - frame = (Frame *) 0; - _returnFromException( frame ); /* this is a jump */ - } - } - } - - /* if we couldn't find a frame, create one */ - if (frame == 0) - { - frame = lastFrame -1 ; - - /* by using a bunch of print commands with breakpoints, - it's possible for the frame stack to creep down. If it creeps - too far, give up and reset it to the top. Normal use should - not see this happen. - */ - if ((unsigned int) (frame-2) < (unsigned int) &gdbFrameStack) - { - initializeRemcomErrorFrame(); - frame = lastFrame; - } - frame->previous = lastFrame; - lastFrame = frame; - frame = 0; /* null so _return... will properly initialize it */ - } - - _returnFromException( frame ); /* this is a jump */ - - break; - - /* kill the program */ - case 'k' : /* do nothing */ - break; - } /* switch */ - - /* reply to the request */ - putpacket(remcomOutBuffer); - } -} - - -void initializeRemcomErrorFrame() -{ - lastFrame = ((Frame *) &gdbFrameStack[FRAMESIZE-1]) - 1; - lastFrame->previous = lastFrame; -} - -/* this function is used to set up exception handlers for tracing and - breakpoints */ -void set_debug_traps() -{ -extern void _debug_level7(); -extern void remcomHandler(); -int exception; - - initializeRemcomErrorFrame(); - stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; - - setup_vectors(); - - if (oldExceptionHook != remcomHandler) - { - oldExceptionHook = exceptionHook; - exceptionHook = remcomHandler; - } - - initialized = 1; - -} -/* 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() -{ - if (initialized) BREAKPOINT(); -} |