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+/****************************************************************************
+
+ 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 $
+ *
+ * Modified for 386 by Jim Kingdon, Cygnus Support.
+ *
+ * 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.
+ *
+ * The external function exceptionHandler() is
+ * used to attach a specific handler to a specific 386 vector number.
+ * It should use the same privilege level it runs at. It should
+ * install it as an interrupt gate so that interrupts are masked
+ * while the handler runs.
+ * Also, need to assign exceptionHook and oldExceptionHook.
+ *
+ * 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>
+
+/************************************************************************
+ *
+ * external low-level support routines
+ */
+typedef void (*ExceptionHook)(int); /* pointer to function with int parm */
+typedef void (*Function)(); /* pointer to a function */
+
+extern void putDebugChar(); /* write a single character */
+extern int getDebugChar(); /* read and return a single char */
+
+extern Function exceptionHandler(); /* assign an exception handler */
+extern ExceptionHook exceptionHook; /* hook variable for errors/exceptions */
+
+/************************************************************************/
+/* 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 */
+
+void waitabit();
+
+static const char hexchars[]="0123456789abcdef";
+
+/* Number of registers. */
+#define NUMREGS 16
+
+/* Number of bytes of registers. */
+#define NUMREGBYTES (NUMREGS * 4)
+
+enum regnames {EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI,
+ PC /* also known as eip */,
+ PS /* also known as eflags */,
+ CS, SS, DS, ES, FS, GS};
+
+/*
+ * these should not be static cuz they can be used outside this module
+ */
+int registers[NUMREGS];
+
+#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;
+
+/*************************** ASSEMBLY CODE MACROS *************************/
+/* */
+
+extern void
+return_to_prog ();
+
+/* Restore the program's registers (including the stack pointer, which
+ means we get the right stack and don't have to worry about popping our
+ return address and any stack frames and so on) and return. */
+asm(".text");
+asm(".globl _return_to_prog");
+asm("_return_to_prog:");
+asm(" movw _registers+44, %ss");
+asm(" movl _registers+16, %esp");
+asm(" movl _registers+4, %ecx");
+asm(" movl _registers+8, %edx");
+asm(" movl _registers+12, %ebx");
+asm(" movl _registers+20, %ebp");
+asm(" movl _registers+24, %esi");
+asm(" movl _registers+28, %edi");
+asm(" movw _registers+48, %ds");
+asm(" movw _registers+52, %es");
+asm(" movw _registers+56, %fs");
+asm(" movw _registers+60, %gs");
+asm(" movl _registers+36, %eax");
+asm(" pushl %eax"); /* saved eflags */
+asm(" movl _registers+40, %eax");
+asm(" pushl %eax"); /* saved cs */
+asm(" movl _registers+32, %eax");
+asm(" pushl %eax"); /* saved eip */
+asm(" movl _registers, %eax");
+/* use iret to restore pc and flags together so
+ that trace flag works right. */
+asm(" iret");
+
+#define BREAKPOINT() asm(" int $3");
+
+/* Put the error code here just in case the user cares. */
+int gdb_i386errcode;
+/* Likewise, the vector number here (since GDB only gets the signal
+ number through the usual means, and that's not very specific). */
+int gdb_i386vector = -1;
+
+/* GDB stores segment registers in 32-bit words (that's just the way
+ m-i386v.h is written). So zero the appropriate areas in registers. */
+#define SAVE_REGISTERS1() \
+ asm ("movl %eax, _registers"); \
+ asm ("movl %ecx, _registers+4"); \
+ asm ("movl %edx, _registers+8"); \
+ asm ("movl %ebx, _registers+12"); \
+ asm ("movl %ebp, _registers+20"); \
+ asm ("movl %esi, _registers+24"); \
+ asm ("movl %edi, _registers+28"); \
+ asm ("movw $0, %ax"); \
+ asm ("movw %ds, _registers+48"); \
+ asm ("movw %ax, _registers+50"); \
+ asm ("movw %es, _registers+52"); \
+ asm ("movw %ax, _registers+54"); \
+ asm ("movw %fs, _registers+56"); \
+ asm ("movw %ax, _registers+58"); \
+ asm ("movw %gs, _registers+60"); \
+ asm ("movw %ax, _registers+62");
+#define SAVE_ERRCODE() \
+ asm ("popl %ebx"); \
+ asm ("movl %ebx, _gdb_i386errcode");
+#define SAVE_REGISTERS2() \
+ asm ("popl %ebx"); /* old eip */ \
+ asm ("movl %ebx, _registers+32"); \
+ asm ("popl %ebx"); /* old cs */ \
+ asm ("movl %ebx, _registers+40"); \
+ asm ("movw %ax, _registers+42"); \
+ asm ("popl %ebx"); /* old eflags */ \
+ asm ("movl %ebx, _registers+36"); \
+ /* Now that we've done the pops, we can save the stack pointer."); */ \
+ asm ("movw %ss, _registers+44"); \
+ asm ("movw %ax, _registers+46"); \
+ asm ("movl %esp, _registers+16");
+
+/* See if mem_fault_routine is set, if so just IRET to that address. */
+#define CHECK_FAULT() \
+ asm ("cmpl $0, _mem_fault_routine"); \
+ asm ("jne mem_fault");
+
+asm (".text");
+asm ("mem_fault:");
+/* OK to clobber temp registers; we're just going to end up in set_mem_err. */
+/* Pop error code from the stack and save it. */
+asm (" popl %eax");
+asm (" movl %eax, _gdb_i386errcode");
+
+asm (" popl %eax"); /* eip */
+/* We don't want to return there, we want to return to the function
+ pointed to by mem_fault_routine instead. */
+asm (" movl _mem_fault_routine, %eax");
+asm (" popl %ecx"); /* cs (low 16 bits; junk in hi 16 bits). */
+asm (" popl %edx"); /* eflags */
+
+/* Remove this stack frame; when we do the iret, we will be going to
+ the start of a function, so we want the stack to look just like it
+ would after a "call" instruction. */
+asm (" leave");
+
+/* Push the stuff that iret wants. */
+asm (" pushl %edx"); /* eflags */
+asm (" pushl %ecx"); /* cs */
+asm (" pushl %eax"); /* eip */
+
+/* Zero mem_fault_routine. */
+asm (" movl $0, %eax");
+asm (" movl %eax, _mem_fault_routine");
+
+asm ("iret");
+
+#define CALL_HOOK() asm("call _remcomHandler");
+
+/* This function is called when a i386 exception occurs. It saves
+ * all the cpu regs in the _registers array, munges the stack a bit,
+ * and invokes an exception handler (remcom_handler).
+ *
+ * stack on entry: stack on exit:
+ * old eflags vector number
+ * old cs (zero-filled to 32 bits)
+ * old eip
+ *
+ */
+extern void _catchException3();
+asm(".text");
+asm(".globl __catchException3");
+asm("__catchException3:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $3");
+CALL_HOOK();
+
+/* Same thing for exception 1. */
+extern void _catchException1();
+asm(".text");
+asm(".globl __catchException1");
+asm("__catchException1:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $1");
+CALL_HOOK();
+
+/* Same thing for exception 0. */
+extern void _catchException0();
+asm(".text");
+asm(".globl __catchException0");
+asm("__catchException0:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $0");
+CALL_HOOK();
+
+/* Same thing for exception 4. */
+extern void _catchException4();
+asm(".text");
+asm(".globl __catchException4");
+asm("__catchException4:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $4");
+CALL_HOOK();
+
+/* Same thing for exception 5. */
+extern void _catchException5();
+asm(".text");
+asm(".globl __catchException5");
+asm("__catchException5:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $5");
+CALL_HOOK();
+
+/* Same thing for exception 6. */
+extern void _catchException6();
+asm(".text");
+asm(".globl __catchException6");
+asm("__catchException6:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $6");
+CALL_HOOK();
+
+/* Same thing for exception 7. */
+extern void _catchException7();
+asm(".text");
+asm(".globl __catchException7");
+asm("__catchException7:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $7");
+CALL_HOOK();
+
+/* Same thing for exception 8. */
+extern void _catchException8();
+asm(".text");
+asm(".globl __catchException8");
+asm("__catchException8:");
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $8");
+CALL_HOOK();
+
+/* Same thing for exception 9. */
+extern void _catchException9();
+asm(".text");
+asm(".globl __catchException9");
+asm("__catchException9:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $9");
+CALL_HOOK();
+
+/* Same thing for exception 10. */
+extern void _catchException10();
+asm(".text");
+asm(".globl __catchException10");
+asm("__catchException10:");
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $10");
+CALL_HOOK();
+
+/* Same thing for exception 12. */
+extern void _catchException12();
+asm(".text");
+asm(".globl __catchException12");
+asm("__catchException12:");
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $12");
+CALL_HOOK();
+
+/* Same thing for exception 16. */
+extern void _catchException16();
+asm(".text");
+asm(".globl __catchException16");
+asm("__catchException16:");
+SAVE_REGISTERS1();
+SAVE_REGISTERS2();
+asm ("pushl $16");
+CALL_HOOK();
+
+/* For 13, 11, and 14 we have to deal with the CHECK_FAULT stuff. */
+
+/* Same thing for exception 13. */
+extern void _catchException13 ();
+asm (".text");
+asm (".globl __catchException13");
+asm ("__catchException13:");
+CHECK_FAULT();
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $13");
+CALL_HOOK();
+
+/* Same thing for exception 11. */
+extern void _catchException11 ();
+asm (".text");
+asm (".globl __catchException11");
+asm ("__catchException11:");
+CHECK_FAULT();
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $11");
+CALL_HOOK();
+
+/* Same thing for exception 14. */
+extern void _catchException14 ();
+asm (".text");
+asm (".globl __catchException14");
+asm ("__catchException14:");
+CHECK_FAULT();
+SAVE_REGISTERS1();
+SAVE_ERRCODE();
+SAVE_REGISTERS2();
+asm ("pushl $14");
+CALL_HOOK();
+
+/*
+ * remcomHandler is a front end for handle_exception. It moves the
+ * stack pointer into an area reserved for debugger use.
+ */
+asm("_remcomHandler:");
+asm(" popl %eax"); /* pop off return address */
+asm(" popl %eax"); /* get the exception number */
+asm(" movl _stackPtr, %esp"); /* move to remcom stack area */
+asm(" pushl %eax"); /* push exception onto stack */
+asm(" call _handle_exception"); /* this never returns */
+
+void _returnFromException()
+{
+ return_to_prog ();
+}
+
+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 $<data>#<checksum> */
+void getpacket(buffer)
+char * buffer;
+{
+ unsigned char checksum;
+ unsigned char xmitcsum;
+ int i;
+ int count;
+ char ch;
+
+ do {
+ /* wait around for the start character, ignore all other characters */
+ while ((ch = (getDebugChar() & 0x7f)) != '$');
+ checksum = 0;
+ xmitcsum = -1;
+
+ count = 0;
+
+ /* now, read until a # or end of buffer is found */
+ while (count < BUFMAX) {
+ ch = getDebugChar() & 0x7f;
+ if (ch == '#') break;
+ checksum = checksum + ch;
+ buffer[count] = ch;
+ count = count + 1;
+ }
+ buffer[count] = 0;
+
+ if (ch == '#') {
+ xmitcsum = hex(getDebugChar() & 0x7f) << 4;
+ xmitcsum += hex(getDebugChar() & 0x7f);
+ 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. */
+
+
+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]) {
+ putDebugChar(ch);
+ checksum += ch;
+ count += 1;
+ }
+
+ putDebugChar('#');
+ putDebugChar(hexchars[checksum >> 4]);
+ putDebugChar(hexchars[checksum % 16]);
+
+ } while ((getDebugChar() & 0x7f) != '+');
+
+}
+
+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);
+}
+
+/* Address of a routine to RTE to if we get a memory fault. */
+static void (*volatile mem_fault_routine)() = NULL;
+
+/* Indicate to caller of mem2hex or hex2mem that there has been an
+ error. */
+static volatile int mem_err = 0;
+
+void
+set_mem_err ()
+{
+ mem_err = 1;
+}
+
+/* These are separate functions so that they are so short and sweet
+ that the compiler won't save any registers (if there is a fault
+ to mem_fault, they won't get restored, so there better not be any
+ saved). */
+int
+get_char (addr)
+ char *addr;
+{
+ return *addr;
+}
+
+void
+set_char (addr, val)
+ char *addr;
+ int val;
+{
+ *addr = val;
+}
+
+/* convert the memory pointed to by mem into hex, placing result in buf */
+/* return a pointer to the last char put in buf (null) */
+/* If MAY_FAULT is non-zero, then we should set mem_err in response to
+ a fault; if zero treat a fault like any other fault in the stub. */
+char* mem2hex(mem, buf, count, may_fault)
+char* mem;
+char* buf;
+int count;
+int may_fault;
+{
+ int i;
+ unsigned char ch;
+
+ if (may_fault)
+ mem_fault_routine = set_mem_err;
+ for (i=0;i<count;i++) {
+ ch = get_char (mem++);
+ if (may_fault && mem_err)
+ return (buf);
+ *buf++ = hexchars[ch >> 4];
+ *buf++ = hexchars[ch % 16];
+ }
+ *buf = 0;
+ if (may_fault)
+ mem_fault_routine = NULL;
+ 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, may_fault)
+char* buf;
+char* mem;
+int count;
+int may_fault;
+{
+ int i;
+ unsigned char ch;
+
+ if (may_fault)
+ mem_fault_routine = set_mem_err;
+ for (i=0;i<count;i++) {
+ ch = hex(*buf++) << 4;
+ ch = ch + hex(*buf++);
+ set_char (mem++, ch);
+ if (may_fault && mem_err)
+ return (mem);
+ }
+ if (may_fault)
+ mem_fault_routine = NULL;
+ return(mem);
+}
+
+/* this function takes the 386 exception vector and attempts to
+ translate this number into a unix compatible signal value */
+int computeSignal( exceptionVector )
+int exceptionVector;
+{
+ int sigval;
+ switch (exceptionVector) {
+ case 0 : sigval = 8; break; /* divide by zero */
+ case 1 : sigval = 5; break; /* debug exception */
+ case 3 : sigval = 5; break; /* breakpoint */
+ case 4 : sigval = 16; break; /* into instruction (overflow) */
+ case 5 : sigval = 16; break; /* bound instruction */
+ case 6 : sigval = 4; break; /* Invalid opcode */
+ case 7 : sigval = 8; break; /* coprocessor not available */
+ case 8 : sigval = 7; break; /* double fault */
+ case 9 : sigval = 11; break; /* coprocessor segment overrun */
+ case 10 : sigval = 11; break; /* Invalid TSS */
+ case 11 : sigval = 11; break; /* Segment not present */
+ case 12 : sigval = 11; break; /* stack exception */
+ case 13 : sigval = 11; break; /* general protection */
+ case 14 : sigval = 11; break; /* page fault */
+ case 16 : sigval = 7; break; /* coprocessor error */
+ 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;
+
+ gdb_i386vector = exceptionVector;
+
+ 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, 0);
+ break;
+ case 'G' : /* set the value of the CPU registers - return OK */
+ hex2mem(&remcomInBuffer[1], (char*) registers, NUMREGBYTES, 0);
+ strcpy(remcomOutBuffer,"OK");
+ break;
+ case 'P' : /* set the value of a single CPU register - return OK */
+ {
+ int regno;
+
+ ptr = &remcomInBuffer[1];
+ if (hexToInt (&ptr, &regno) && *ptr++ == '=')
+ if (regno >= 0 && regno < NUMREGS)
+ {
+ hex2mem (ptr, (char *)&registers[regno], 4, 0);
+ strcpy(remcomOutBuffer,"OK");
+ break;
+ }
+
+ strcpy (remcomOutBuffer, "E01");
+ break;
+ }
+
+ /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
+ case 'm' :
+ /* 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;
+ mem_err = 0;
+ mem2hex((char*) addr, remcomOutBuffer, length, 1);
+ if (mem_err) {
+ strcpy (remcomOutBuffer, "E03");
+ debug_error ("memory fault");
+ }
+ }
+
+ if (ptr)
+ {
+ strcpy(remcomOutBuffer,"E01");
+ debug_error("malformed read memory command: %s",remcomInBuffer);
+ }
+ break;
+
+ /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
+ case 'M' :
+ /* 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++) == ':')
+ {
+ mem_err = 0;
+ hex2mem(ptr, (char*) addr, length, 1);
+
+ if (mem_err) {
+ strcpy (remcomOutBuffer, "E03");
+ debug_error ("memory fault");
+ } else {
+ strcpy(remcomOutBuffer,"OK");
+ }
+
+ ptr = 0;
+ }
+ if (ptr)
+ {
+ strcpy(remcomOutBuffer,"E02");
+ debug_error("malformed write memory command: %s",remcomInBuffer);
+ }
+ 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 ] &= 0xfffffeff;
+
+ /* set the trace bit if we're stepping */
+ if (remcomInBuffer[0] == 's') registers[ PS ] |= 0x100;
+
+ /*
+ * 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 0
+ /* Don't really think we need this, except maybe for protection
+ exceptions. */
+ /*
+ * invoke the previous handler.
+ */
+ if (oldExceptionHook)
+ (*oldExceptionHook) (frame->exceptionVector);
+ newPC = registers[ PC ]; /* pc may have changed */
+#endif /* 0 */
+
+ _returnFromException(); /* this is a jump */
+
+ break;
+
+ /* kill the program */
+ case 'k' : /* do nothing */
+#if 0
+ /* Huh? This doesn't look like "nothing".
+ m68k-stub.c and sparc-stub.c don't have it. */
+ BREAKPOINT();
+#endif
+ break;
+ } /* switch */
+
+ /* reply to the request */
+ putpacket(remcomOutBuffer);
+ }
+}
+
+/* this function is used to set up exception handlers for tracing and
+ breakpoints */
+void set_debug_traps()
+{
+extern void remcomHandler();
+int exception;
+
+ stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1];
+
+ exceptionHandler (0, _catchException0);
+ exceptionHandler (1, _catchException1);
+ exceptionHandler (3, _catchException3);
+ exceptionHandler (4, _catchException4);
+ exceptionHandler (5, _catchException5);
+ exceptionHandler (6, _catchException6);
+ exceptionHandler (7, _catchException7);
+ exceptionHandler (8, _catchException8);
+ exceptionHandler (9, _catchException9);
+ exceptionHandler (10, _catchException10);
+ exceptionHandler (11, _catchException11);
+ exceptionHandler (12, _catchException12);
+ exceptionHandler (13, _catchException13);
+ exceptionHandler (14, _catchException14);
+ exceptionHandler (16, _catchException16);
+
+ if (exceptionHook != remcomHandler)
+ {
+ oldExceptionHook = exceptionHook;
+ exceptionHook = remcomHandler;
+ }
+
+ /* In case GDB is started before us, ack any packets (presumably
+ "$?#xx") sitting there. */
+ putDebugChar ('+');
+
+ 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)
+#if 0
+ handle_exception(3);
+#else
+ BREAKPOINT();
+#endif
+ waitabit();
+}
+
+int waitlimit = 1000000;
+
+void
+waitabit()
+{
+ int i;
+ for (i = 0; i < waitlimit; i++) ;
+}
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