* 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
*
* 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 */
+extern void exceptionHandler(); /* assign an exception handler */
/************************************************************************/
/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
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 *************************/
/* */
return (-1);
}
+static char remcomInBuffer[BUFMAX];
+static char remcomOutBuffer[BUFMAX];
/* scan for the sequence $<data>#<checksum> */
-void getpacket(buffer)
-char * buffer;
+
+unsigned char *
+getpacket ()
{
+ unsigned char *buffer = &remcomInBuffer[0];
unsigned char checksum;
unsigned char xmitcsum;
- int i;
- int count;
+ int count;
char ch;
- do {
- /* wait around for the start character, ignore all other characters */
- while ((ch = (getDebugChar() & 0x7f)) != '$');
- 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 (1)
+ {
+ /* wait around for the start character, ignore all other characters */
+ while ((ch = getDebugChar ()) != '$')
+ ;
+
+retry:
+ checksum = 0;
+ xmitcsum = -1;
+ count = 0;
+
+ /* now, read until a # or end of buffer is found */
+ while (count < BUFMAX)
+ {
+ ch = getDebugChar ();
+ if (ch == '$')
+ goto retry;
+ if (ch == '#')
+ break;
+ checksum = checksum + ch;
+ buffer[count] = ch;
+ count = count + 1;
+ }
+ buffer[count] = 0;
+
+ if (ch == '#')
+ {
+ ch = getDebugChar ();
+ xmitcsum = hex (ch) << 4;
+ ch = getDebugChar ();
+ xmitcsum += hex (ch);
+
+ if (checksum != xmitcsum)
+ {
+ if (remote_debug)
+ {
+ fprintf (stderr,
+ "bad checksum. My count = 0x%x, sent=0x%x. buf=%s\n",
+ checksum, xmitcsum, buffer);
+ }
+ 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]);
+
+ return &buffer[3];
+ }
+
+ return &buffer[0];
+ }
+ }
}
- } while (checksum != xmitcsum);
-
}
/* send the packet in buffer. */
-
void putpacket(buffer)
-char * buffer;
+ unsigned char *buffer;
{
unsigned char checksum;
int count;
putDebugChar(hexchars[checksum >> 4]);
putDebugChar(hexchars[checksum % 16]);
- } while ((getDebugChar() & 0x7f) != '+');
+ } while (getDebugChar() != '+');
}
-char remcomInBuffer[BUFMAX];
-char remcomOutBuffer[BUFMAX];
-static short error;
-
-
void debug_error(format, parm)
char * format;
char * parm;
*/
void handle_exception(int exceptionVector)
{
- int sigval;
+ int sigval, stepping;
int addr, length;
char * ptr;
int newPC;
putpacket(remcomOutBuffer);
+ stepping = 0;
+
while (1==1) {
- error = 0;
remcomOutBuffer[0] = 0;
- getpacket(remcomInBuffer);
- switch (remcomInBuffer[0]) {
+ ptr = getpacket();
+
+ switch (*ptr++) {
case '?' : remcomOutBuffer[0] = 'S';
remcomOutBuffer[1] = hexchars[sigval >> 4];
remcomOutBuffer[2] = hexchars[sigval % 16];
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);
+ hex2mem(ptr, (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, ®no) && *ptr++ == '=')
if (regno >= 0 && regno < NUMREGS)
{
/* 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))
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)
{
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' :
+ stepping = 1;
+ case 'c' :
/* try to read optional parameter, pc unchanged if no parm */
- ptr = &remcomInBuffer[1];
if (hexToInt(&ptr,&addr))
registers[ PC ] = addr;
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 */
+ if (stepping) registers[ PS ] |= 0x100;
_returnFromException(); /* this is a jump */
-
break;
/* kill the program */
exceptionHandler (14, _catchException14);
exceptionHandler (16, _catchException16);
- if (exceptionHook != remcomHandler)
- {
- oldExceptionHook = exceptionHook;
- exceptionHook = remcomHandler;
- }
-
initialized = 1;
}