--- /dev/null
+/****************************************************************************
+
+ 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.
+
+****************************************************************************/
+
+/****************************************************************************
+ * $Header$
+ *
+ * $Module name: remcom.c $
+ * $Revision$
+ * $Date$
+ * $Contributor: Lake Stevens Instrument Division$
+ *
+ * $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>
+
+/************************************************************************
+ *
+ * external low-level support routines
+ */
+typedef void (*ExceptionHook)(int); /* pointer to function with int parm */
+typedef void (*Function)(); /* pointer to a function */
+
+extern putDebugChar(); /* write a single character */
+extern getDebugChar(); /* read and return a single char */
+
+extern Function exceptionHandler(); /* assign an exception handler */
+extern ExceptionHook exceptionHook; /* hook variable for errors/exceptions */
+
+/************************/
+/* FORWARD DECLARATIONS */
+/************************/
+void initializeRemcomErrorFrame(void);
+
+/************************************************************************/
+/* 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;
+/* 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];
+static 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)];
+static 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;
+
+/*************************** ASSEMBLY CODE MACROS *************************/
+/* */
+
+#ifdef __HAVE_68881__
+/* do an fsave, then remember the address to begin a restore from */
+#define SAVE_FP_REGS() asm(" fsave a0@-"); \
+ asm(" fmovemx fp0-fp7,_registers+72"); \
+ asm(" fmoveml fpcr/fpsr/fpi,_registers+168");
+#define RESTORE_FP_REGS() \
+asm(" \n\
+ fmoveml _registers+168,fpcr/fpsr/fpi \n\
+ fmovemx _registers+72,fp0-fp7 \n\
+ cmpl #-1,a0@ | skip frestore flag set ? \n\
+ beq skip_frestore \n\
+ frestore a0@+ \n\
+skip_frestore: \n\
+");
+
+#else
+#define SAVE_FP_REGS()
+#define RESTORE_FP_REGS()
+#endif /* __HAVE_68881__ */
+
+void return_to_super(void);
+void return_to_user(void);
+
+asm("
+.text
+.globl _return_to_super
+_return_to_super:
+ movel _registers+60,sp /* get new stack pointer */
+ movel _lastFrame,a0 /* get last frame info */
+ bra return_to_any
+
+.globl _return_to_user
+_return_to_user:
+ movel _registers+60,a0 /* get usp */
+ movel a0,usp /* set usp */
+ movel _superStack,sp /* get original stack pointer */
+
+return_to_any:
+ movel _lastFrame,a0 /* get last frame info */
+ movel a0@+,_lastFrame /* link in previous frame */
+ addql #8,a0 /* skip over pc, vector#*/
+ movew a0@+,d0 /* get # of words in cpu frame */
+ addw d0,a0 /* point to end of data */
+ addw d0,a0 /* point to end of data */
+ movel a0,a1
+#
+# copy the stack frame
+ subql #1,d0
+copyUserLoop:
+ movew a1@-,sp@-
+ dbf d0,copyUserLoop
+");
+ RESTORE_FP_REGS()
+ asm(" moveml _registers,d0-d7/a0-a6");
+ asm(" rte"); /* pop and go! */
+
+#define DISABLE_INTERRUPTS() asm(" oriw #0x0700,sr");
+#define BREAKPOINT() asm(" trap #1");
+
+/* this function is called immediately when a level 7 interrupt occurs */
+/* if the previous interrupt level was 7 then we're already servicing */
+/* this interrupt and an rte is in order to return to the debugger. */
+/* For the 68000, the offset for sr is 6 due to the jsr return address */
+asm("
+.text
+.globl __debug_level7
+__debug_level7:
+ movew d0,sp@-");
+#ifdef mc68020
+asm(" movew sp@(2),d0");
+#else
+asm(" movew sp@(6),d0");
+#endif
+asm(" andiw #0x700,d0
+ cmpiw #0x700,d0
+ beq _already7
+ movew sp@+,d0
+ bra __catchException
+_already7:
+ movew sp@+,d0");
+#ifndef mc68020
+asm(" lea sp@(4),sp"); /* pull off 68000 return address */
+#endif
+asm(" rte");
+
+extern void _catchException();
+
+#ifdef mc68020
+/* This function is called when a 68020 exception occurs. It saves
+ * all the cpu and fpcp regs in the _registers array, creates a frame on a
+ * linked list of frames which has the cpu and fpcp stack frames needed
+ * to properly restore the context of these processors, and invokes
+ * an exception handler (remcom_handler).
+ *
+ * stack on entry: stack on exit:
+ * N bytes of junk exception # MSWord
+ * Exception Format Word exception # MSWord
+ * Program counter LSWord
+ * Program counter MSWord
+ * Status Register
+ *
+ *
+ */
+asm("
+.text
+.globl __catchException
+__catchException:");
+DISABLE_INTERRUPTS();
+asm("
+ moveml d0-d7/a0-a6,_registers /* save registers */
+ movel _lastFrame,a0 /* last frame pointer */
+");
+SAVE_FP_REGS();
+asm("
+ lea _registers,a5 /* get address of registers */
+ movew sp@,d1 /* get status register */
+ movew d1,a5@(66) /* save sr */
+ movel sp@(2),a4 /* save pc in a4 for later use */
+ movel a4,a5@(68) /* save pc in _regisers[] */
+
+#
+# figure out how many bytes in the stack frame
+ movew sp@(6),d0 /* get '020 exception format */
+ movew d0,d2 /* make a copy of format word */
+ andiw #0xf000,d0 /* mask off format type */
+ rolw #5,d0 /* rotate into the low byte *2 */
+ lea _exceptionSize,a1
+ addw d0,a1 /* index into the table */
+ movew a1@,d0 /* get number of words in frame */
+ movew d0,d3 /* save it */
+ subw d0,a0 /* adjust save pointer */
+ subw d0,a0 /* adjust save pointer(bytes) */
+ movel a0,a1 /* copy save pointer */
+ subql #1,d0 /* predecrement loop counter */
+#
+# copy the frame
+saveFrameLoop:
+ movew sp@+,a1@+
+ dbf d0,saveFrameLoop
+#
+# now that the stack has been clenaed,
+# save the a7 in use at time of exception
+ movel sp,_superStack /* save supervisor sp */
+ andiw #0x2000,d1 /* were we in supervisor mode ? */
+ beq userMode
+ movel a7,a5@(60) /* save a7 */
+ bra a7saveDone
+userMode:
+ movel usp,a1
+ movel a1,a5@(60) /* save user stack pointer */
+a7saveDone:
+
+#
+# save size of frame
+ movew d3,a0@-
+
+#
+# compute exception number
+ andl #0xfff,d2 /* mask off vector offset */
+ lsrw #2,d2 /* divide by 4 to get vect num */
+ movel d2,a0@- /* save it */
+#
+# save pc causing exception
+ movel a4,a0@-
+#
+# save old frame link and set the new value
+ movel _lastFrame,a1 /* last frame pointer */
+ movel a1,a0@- /* save pointer to prev frame */
+ movel a0,_lastFrame
+
+ movel d2,sp@- /* push exception num */
+ movel _exceptionHook,a0 /* get address of handler */
+ jbsr a0@ /* and call it */
+ clrl sp@ /* replace exception num parm with frame ptr */
+ jbsr __returnFromException /* jbsr, but never returns */
+");
+#else /* mc68000 */
+/* This function is called when an exception occurs. It translates the
+ * return address found on the stack into an exception vector # which
+ * is then handled by either handle_exception or a system handler.
+ * _catchException provides a front end for both.
+ *
+ * stack on entry: stack on exit:
+ * Program counter MSWord exception # MSWord
+ * Program counter LSWord exception # MSWord
+ * Status Register
+ * Return Address MSWord
+ * Return Address LSWord
+ */
+asm("
+.text
+.globl __catchException
+__catchException:");
+DISABLE_INTERRUPTS();
+asm("
+ moveml d0-d7/a0-a6,_registers /* save registers */
+ movel _lastFrame,a0 /* last frame pointer */
+");
+SAVE_FP_REGS();
+asm("
+ lea _registers,a5 /* get address of registers */
+ movel sp@+,d2 /* pop return address */
+ addl #1530,d2 /* convert return addr to */
+ divs #6,d2 /* exception number */
+ extl d2
+
+ moveql #3,d3 /* assume a three word frame */
+
+ cmpiw #3,d2 /* bus error or address error ? */
+ bgt normal /* if >3 then normal error */
+ movel sp@+,a0@- /* copy error info to frame buff*/
+ movel sp@+,a0@- /* these are never used */
+ moveql #7,d3 /* this is a 7 word frame */
+
+normal:
+ movew sp@+,d1 /* pop status register */
+ movel sp@+,a4 /* pop program counter */
+ movew d1,a5@(66) /* save sr */
+ movel a4,a5@(68) /* save pc in _regisers[] */
+ movel a4,a0@- /* copy pc to frame buffer */
+ movew d1,a0@- /* copy sr to frame buffer */
+
+ movel sp,_superStack /* save supervisor sp */
+
+ andiw #0x2000,d1 /* were we in supervisor mode ? */
+ beq userMode
+ movel a7,a5@(60) /* save a7 */
+ bra saveDone
+userMode:
+ movel usp,a1 /* save user stack pointer */
+ movel a1,a5@(60) /* save user stack pointer */
+saveDone:
+
+ movew d3,a0@- /* push frame size in words */
+ movel d2,a0@- /* push vector number */
+ movel a4,a0@- /* push exception pc */
+
+#
+# save old frame link and set the new value
+ movel _lastFrame,a1 /* last frame pointer */
+ movel a1,a0@- /* save pointer to prev frame */
+ movel a0,_lastFrame
+
+ movel d2,sp@- /* push exception num */
+ movel _exceptionHook,a0 /* get address of handler */
+ jbsr a0@ /* and call it */
+ clrl sp@ /* replace exception num parm with frame ptr */
+ jbsr __returnFromException /* jbsr, but never returns */
+");
+#endif
+
+
+/*
+ * remcomHandler is a front end for handle_exception. It moves the
+ * stack pointer into an area reserved for debugger use in case the
+ * breakpoint happened in supervisor mode.
+ */
+asm("_remcomHandler:");
+asm(" addl #4,sp"); /* pop off return address */
+asm(" movel sp@+,d0"); /* get the exception number */
+asm(" movel _stackPtr,sp"); /* move to remcom stack area */
+asm(" movel d0,sp@-"); /* push exception onto stack */
+asm(" jbsr _handle_exception"); /* this never returns */
+asm(" rts"); /* return */
+
+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 $<data>#<checksum> */
+void getpacket(buffer)
+char * buffer;
+{
+ unsigned char checksum;
+ unsigned char xmitcsum;
+ int i;
+ int count;
+ char ch;
+
+ do {
+ /* wait around for the start character, ignore all other characters */
+ while ((ch = getDebugChar()) != '$');
+ 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]);
+
+ } 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("vector=%d, sr=0x%x, pc=0x%x\n",
+ exceptionVector,
+ registers[ PS ],
+ registers[ PC ]);
+
+ /* 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(void)
+{
+ 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];
+
+ for (exception = 2; exception <= 23; exception++)
+ exceptionHandler(exception,_catchException);
+
+ /* level 7 interrupt */
+ exceptionHandler(31,_debug_level7);
+
+ /* breakpoint exception (trap #1) */
+ exceptionHandler(33,_catchException);
+
+ /* floating point error (trap #8) */
+ exceptionHandler(40,_catchException);
+
+ /* 48 to 54 are floating point coprocessor errors */
+ for (exception = 48; exception <= 54; exception++)
+ exceptionHandler(exception,_catchException);
+
+ 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();
+}
+
projects / binutils-gdb.git / commitdiff