/*
* This function does all command procesing for interfacing to gdb.
*/
void handle_exception (int exceptionVector)
{
int sigval, stepping;
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);
stepping = 0;
while (1 == 1)
{
remcomOutBuffer[0] = 0;
ptr = getpacket ();
switch (*ptr++)
{
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 (ptr, (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 */
if (hexToInt (&ptr, &addr))
if (*(ptr++) == ',')
if (hexToInt (&ptr, &length))
{
ptr = 0;
mem2hex ((char *) addr, remcomOutBuffer, length);
}
if (ptr)
{
strcpy (remcomOutBuffer, "E01");
}
}
else
{
exceptionHandler (2, _catchException);
strcpy (remcomOutBuffer, "E03");
debug_error ("%s","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 */
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
{
exceptionHandler (2, _catchException);
strcpy (remcomOutBuffer, "E03");
debug_error ("%s","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 's':
stepping = 1;
case 'c':
/* try to read optional parameter, pc unchanged if no parm */
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 (stepping)
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);
}
}
/*
* This function does all command procesing for interfacing to gdb.
*/
void
handle_exception (int exceptionVector)
{
int sigval;
int addr, length, reg;
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. Always return the
PC, SP, and FP, since gdb always wants them. */
ptr = remcomOutBuffer;
*ptr++ = 'T';
sigval = computeSignal (exceptionVector);
*ptr++ = hexchars[sigval >> 4];
*ptr++ = hexchars[sigval % 16];
*ptr++ = hexchars[ESP];
*ptr++ = ':';
mem2hex ((char *) ®isters[ESP], ptr, REGBYTES, 0);
ptr += REGBYTES * 2;
*ptr++ = ';';
*ptr++ = hexchars[EBP];
*ptr++ = ':';
mem2hex ((char *) ®isters[EBP], ptr, REGBYTES, 0);
ptr += REGBYTES * 2;
*ptr++ = ';';
*ptr++ = hexchars[PC];
*ptr++ = ':';
mem2hex ((char *) ®isters[PC], ptr, REGBYTES, 0);
ptr += REGBYTES * 2;
*ptr++ = ';';
*ptr = '\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 specific register */
ptr = &remcomInBuffer[1];
if (hexToInt (&ptr, ®)
&& *ptr++ == '=')
{
hex2mem (ptr, (char *) ®isters[reg], REGBYTES, 0);
strcpy (remcomOutBuffer, "OK");
}
else
{
strcpy (remcomOutBuffer, "E01");
debug_error ("malformed register set command; %s",
remcomInBuffer);
}
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", 0);
}
}
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", 0);
}
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;
_returnFromException (); /* this is a jump */
break;
/* Detach. */
case 'D':
putpacket (remcomOutBuffer);
registers[PS] &= 0xfffffeff;
_returnFromException (); /* this is a jump */
break;
/* kill the program */
case 'k': /* do nothing */
break;
} /* switch */
/* reply to the request */
putpacket (remcomOutBuffer);
}
}
