kgdb.c

优龙2410linux2.6.8内核源代码

				putpacket (remcomOutBuffer);
				return;
				
			case '?':
				/* The last signal which caused a stop. ?
				   Success: SAA, where AA is the signal number.
				   Failure: void. */
				remcomOutBuffer[0] = 'S';
				remcomOutBuffer[1] = highhex (sigval);
				remcomOutBuffer[2] = lowhex (sigval);
				remcomOutBuffer[3] = 0;
				break;
				
			case 'D':
				/* Detach from host. D
				   Success: OK, and return to the executing thread.
				   Failure: will never know */
				putpacket ("OK");
				return;
				
			case 'k':
			case 'r':
				/* kill request or reset request.
				   Success: restart of target.
				   Failure: will never know. */
				kill_restart ();
				break;
				
			case 'C':
			case 'S':
			case '!':
			case 'R':
			case 'd':
				/* Continue with signal sig. Csig;AA..AA
				   Step with signal sig. Ssig;AA..AA
				   Use the extended remote protocol. !
				   Restart the target system. R0
				   Toggle debug flag. d
				   Search backwards. tAA:PP,MM
				   Not supported: E04 */
				gdb_cris_strcpy (remcomOutBuffer, error_message[E04]);
				break;
#ifdef PROCESS_SUPPORT

			case 'T':
				/* Thread alive. TXX
				   Is thread XX alive?
				   Success: OK, thread XX is alive.
				   Failure: E03, thread XX is dead. */
				{
					int thread_id = (int)gdb_cris_strtol (&remcomInBuffer[1], 0, 16);
					/* Cannot tell whether it is alive or not. */
					if (thread_id >= 0 && thread_id < number_of_tasks)
						gdb_cris_strcpy (remcomOutBuffer, "OK");
				}
				break;
								
			case 'H':
				/* Set thread for subsequent operations: Hct
				   c = 'c' for thread used in step and continue;
				   t can be -1 for all threads.
				   c = 'g' for thread used in other  operations.
				   t = 0 means pick any thread.
				   Success: OK
				   Failure: E01 */
				{
					int thread_id = gdb_cris_strtol (&remcomInBuffer[2], 0, 16);
					if (remcomInBuffer[1] == 'c') {
						/* c = 'c' for thread used in step and continue */
						/* Do not change current_thread_c here. It would create a mess in
						   the scheduler. */
						gdb_cris_strcpy (remcomOutBuffer, "OK");
					}
					else if (remcomInBuffer[1] == 'g') {
						/* c = 'g' for thread used in other  operations.
						   t = 0 means pick any thread. Impossible since the scheduler does
						   not allow that. */
						if (thread_id >= 0 && thread_id < number_of_tasks) {
							current_thread_g = thread_id;
							gdb_cris_strcpy (remcomOutBuffer, "OK");
						}
						else {
							/* Not expected - send an error message. */
							gdb_cris_strcpy (remcomOutBuffer, error_message[E01]);
						}
					}
					else {
						/* Not expected - send an error message. */
						gdb_cris_strcpy (remcomOutBuffer, error_message[E01]);
					}
				}
				break;
				
			case 'q':
			case 'Q':
				/* Query of general interest. qXXXX
				   Set general value XXXX. QXXXX=yyyy */
				{
					int pos;
					int nextpos;
					int thread_id;
					
					switch (remcomInBuffer[1]) {
						case 'C':
							/* Identify the remote current thread. */
							gdb_cris_strcpy (&remcomOutBuffer[0], "QC");
							remcomOutBuffer[2] = highhex (current_thread_c);
							remcomOutBuffer[3] = lowhex (current_thread_c);
							remcomOutBuffer[4] = '\0';
							break;
						case 'L':
							gdb_cris_strcpy (&remcomOutBuffer[0], "QM");
							/* Reply with number of threads. */
							if (os_is_started()) {
								remcomOutBuffer[2] = highhex (number_of_tasks);
								remcomOutBuffer[3] = lowhex (number_of_tasks);
							}
							else {
								remcomOutBuffer[2] = highhex (0);
								remcomOutBuffer[3] = lowhex (1);
							}
							/* Done with the reply. */
							remcomOutBuffer[4] = lowhex (1);
							pos = 5;
							/* Expects the argument thread id. */
							for (; pos < (5 + HEXCHARS_IN_THREAD_ID); pos++)
								remcomOutBuffer[pos] = remcomInBuffer[pos];
							/* Reply with the thread identifiers. */
							if (os_is_started()) {
								/* Store the thread identifiers of all tasks. */
								for (thread_id = 0; thread_id < number_of_tasks; thread_id++) {
									nextpos = pos + HEXCHARS_IN_THREAD_ID - 1;
									for (; pos < nextpos; pos ++)
										remcomOutBuffer[pos] = lowhex (0);
									remcomOutBuffer[pos++] = lowhex (thread_id);
								}
							}
							else {
								/* Store the thread identifier of the boot task. */
								nextpos = pos + HEXCHARS_IN_THREAD_ID - 1;
								for (; pos < nextpos; pos ++)
									remcomOutBuffer[pos] = lowhex (0);
								remcomOutBuffer[pos++] = lowhex (current_thread_c);
							}
							remcomOutBuffer[pos] = '\0';
							break;
						default:
							/* Not supported: "" */
							/* Request information about section offsets: qOffsets. */
							remcomOutBuffer[0] = 0;
							break;
					}
				}
				break;
#endif /* PROCESS_SUPPORT */
				
			default:
				/* The stub should ignore other request and send an empty
				   response ($#<checksum>). This way we can extend the protocol and GDB
				   can tell whether the stub it is talking to uses the old or the new. */
				remcomOutBuffer[0] = 0;
				break;
		}
		putpacket(remcomOutBuffer);
	}
}

/* The jump is to the address 0x00000002. Performs a complete re-start
   from scratch. */
static void
kill_restart ()
{
	__asm__ volatile ("jump 2");
}

/********************************** Breakpoint *******************************/
/* The hook for both a static (compiled) and a dynamic breakpoint set by GDB.
   An internal stack is used by the stub. The register image of the caller is
   stored in the structure register_image.
   Interactive communication with the host is handled by handle_exception and
   finally the register image is restored. */

void kgdb_handle_breakpoint(void);

asm ("
  .global kgdb_handle_breakpoint
kgdb_handle_breakpoint:
;;
;; Response to the break-instruction
;;
;; Create a register image of the caller
;;
  move     $dccr,[reg+0x5E] ; Save the flags in DCCR before disable interrupts
  di                        ; Disable interrupts
  move.d   $r0,[reg]        ; Save R0
  move.d   $r1,[reg+0x04]   ; Save R1
  move.d   $r2,[reg+0x08]   ; Save R2
  move.d   $r3,[reg+0x0C]   ; Save R3
  move.d   $r4,[reg+0x10]   ; Save R4
  move.d   $r5,[reg+0x14]   ; Save R5
  move.d   $r6,[reg+0x18]   ; Save R6
  move.d   $r7,[reg+0x1C]   ; Save R7
  move.d   $r8,[reg+0x20]   ; Save R8
  move.d   $r9,[reg+0x24]   ; Save R9
  move.d   $r10,[reg+0x28]  ; Save R10
  move.d   $r11,[reg+0x2C]  ; Save R11
  move.d   $r12,[reg+0x30]  ; Save R12
  move.d   $r13,[reg+0x34]  ; Save R13
  move.d   $sp,[reg+0x38]   ; Save SP (R14)
;; Due to the old assembler-versions BRP might not be recognized
  .word 0xE670              ; move brp,$r0
  subq     2,$r0             ; Set to address of previous instruction.
  move.d   $r0,[reg+0x3c]   ; Save the address in PC (R15)
  clear.b  [reg+0x40]      ; Clear P0
  move     $vr,[reg+0x41]   ; Save special register P1
  clear.w  [reg+0x42]      ; Clear P4
  move     $ccr,[reg+0x44]  ; Save special register CCR
  move     $mof,[reg+0x46]  ; P7
  clear.d  [reg+0x4A]      ; Clear P8
  move     $ibr,[reg+0x4E]  ; P9,
  move     $irp,[reg+0x52]  ; P10,
  move     $srp,[reg+0x56]  ; P11,
  move     $dtp0,[reg+0x5A] ; P12, register BAR, assembler might not know BAR
                            ; P13, register DCCR already saved
;; Due to the old assembler-versions BRP might not be recognized
  .word 0xE670              ; move brp,r0
;; Static (compiled) breakpoints must return to the next instruction in order
;; to avoid infinite loops. Dynamic (gdb-invoked) must restore the instruction
;; in order to execute it when execution is continued.
  test.b   [is_dyn_brkp]    ; Is this a dynamic breakpoint?
  beq      is_static         ; No, a static breakpoint
  nop
  subq     2,$r0              ; rerun the instruction the break replaced
is_static:
  moveq    1,$r1
  move.b   $r1,[is_dyn_brkp] ; Set the state variable to dynamic breakpoint
  move.d   $r0,[reg+0x62]    ; Save the return address in BRP
  move     $usp,[reg+0x66]   ; USP
;;
;; Handle the communication
;;
  move.d   internal_stack+1020,$sp ; Use the internal stack which grows upward
  moveq    5,$r10                   ; SIGTRAP
  jsr      handle_exception       ; Interactive routine
;;
;; Return to the caller
;;
   move.d  [reg],$r0         ; Restore R0
   move.d  [reg+0x04],$r1    ; Restore R1
   move.d  [reg+0x08],$r2    ; Restore R2
   move.d  [reg+0x0C],$r3    ; Restore R3
   move.d  [reg+0x10],$r4    ; Restore R4
   move.d  [reg+0x14],$r5    ; Restore R5
   move.d  [reg+0x18],$r6    ; Restore R6
   move.d  [reg+0x1C],$r7    ; Restore R7
   move.d  [reg+0x20],$r8    ; Restore R8
   move.d  [reg+0x24],$r9    ; Restore R9
   move.d  [reg+0x28],$r10   ; Restore R10
   move.d  [reg+0x2C],$r11   ; Restore R11
   move.d  [reg+0x30],$r12   ; Restore R12
   move.d  [reg+0x34],$r13   ; Restore R13
;;
;; FIXME: Which registers should be restored?
;;
   move.d  [reg+0x38],$sp    ; Restore SP (R14)
   move    [reg+0x56],$srp   ; Restore the subroutine return pointer.
   move    [reg+0x5E],$dccr  ; Restore DCCR
   move    [reg+0x66],$usp   ; Restore USP
   jump    [reg+0x62]       ; A jump to the content in register BRP works.
   nop                       ;
");

/* The hook for an interrupt generated by GDB. An internal stack is used
   by the stub. The register image of the caller is stored in the structure
   register_image. Interactive communication with the host is handled by
   handle_exception and finally the register image is restored. Due to the
   old assembler which does not recognise the break instruction and the
   breakpoint return pointer hex-code is used. */

void kgdb_handle_serial(void);

asm ("
  .global kgdb_handle_serial
kgdb_handle_serial:
;;
;; Response to a serial interrupt
;;

  move     $dccr,[reg+0x5E] ; Save the flags in DCCR
  di                        ; Disable interrupts
  move.d   $r0,[reg]        ; Save R0
  move.d   $r1,[reg+0x04]   ; Save R1
  move.d   $r2,[reg+0x08]   ; Save R2
  move.d   $r3,[reg+0x0C]   ; Save R3
  move.d   $r4,[reg+0x10]   ; Save R4
  move.d   $r5,[reg+0x14]   ; Save R5
  move.d   $r6,[reg+0x18]   ; Save R6
  move.d   $r7,[reg+0x1C]   ; Save R7
  move.d   $r8,[reg+0x20]   ; Save R8
  move.d   $r9,[reg+0x24]   ; Save R9
  move.d   $r10,[reg+0x28]  ; Save R10
  move.d   $r11,[reg+0x2C]  ; Save R11
  move.d   $r12,[reg+0x30]  ; Save R12
  move.d   $r13,[reg+0x34]  ; Save R13
  move.d   $sp,[reg+0x38]   ; Save SP (R14)
  move     $irp,[reg+0x3c]  ; Save the address in PC (R15)
  clear.b  [reg+0x40]      ; Clear P0
  move     $vr,[reg+0x41]   ; Save special register P1,
  clear.w  [reg+0x42]      ; Clear P4
  move     $ccr,[reg+0x44]  ; Save special register CCR
  move     $mof,[reg+0x46]  ; P7
  clear.d  [reg+0x4A]      ; Clear P8
  move     $ibr,[reg+0x4E]  ; P9,
  move     $irp,[reg+0x52]  ; P10,
  move     $srp,[reg+0x56]  ; P11,
  move     $dtp0,[reg+0x5A] ; P12, register BAR, assembler might not know BAR
                            ; P13, register DCCR already saved
;; Due to the old assembler-versions BRP might not be recognized
  .word 0xE670              ; move brp,r0
  move.d   $r0,[reg+0x62]   ; Save the return address in BRP
  move     $usp,[reg+0x66]  ; USP

;; get the serial character (from debugport.c) and check if it is a ctrl-c

  jsr getDebugChar
  cmp.b 3, $r10
  bne goback
  nop

;;
;; Handle the communication
;;
  move.d   internal_stack+1020,$sp ; Use the internal stack
  moveq    2,$r10                   ; SIGINT
  jsr      handle_exception       ; Interactive routine

goback:
;;
;; Return to the caller
;;
   move.d  [reg],$r0         ; Restore R0
   move.d  [reg+0x04],$r1    ; Restore R1
   move.d  [reg+0x08],$r2    ; Restore R2
   move.d  [reg+0x0C],$r3    ; Restore R3
   move.d  [reg+0x10],$r4    ; Restore R4
   move.d  [reg+0x14],$r5    ; Restore R5
   move.d  [reg+0x18],$r6    ; Restore R6
   move.d  [reg+0x1C],$r7    ; Restore R7
   move.d  [reg+0x20],$r8    ; Restore R8
   move.d  [reg+0x24],$r9    ; Restore R9
   move.d  [reg+0x28],$r10   ; Restore R10
   move.d  [reg+0x2C],$r11   ; Restore R11
   move.d  [reg+0x30],$r12   ; Restore R12
   move.d  [reg+0x34],$r13   ; Restore R13
;;
;; FIXME: Which registers should be restored?
;;
   move.d  [reg+0x38],$sp    ; Restore SP (R14)
   move    [reg+0x56],$srp   ; Restore the subroutine return pointer.
   move    [reg+0x5E],$dccr  ; Restore DCCR
   move    [reg+0x66],$usp   ; Restore USP
   reti                      ; Return from the interrupt routine
   nop
");

/* Use this static breakpoint in the start-up only. */

void
breakpoint(void)
{
	kgdb_started = 1;
	is_dyn_brkp = 0;     /* This is a static, not a dynamic breakpoint. */
	__asm__ volatile ("break 8"); /* Jump to handle_breakpoint. */
}

/* initialize kgdb. doesn't break into the debugger, but sets up irq and ports */

void
kgdb_init(void)
{
	/* could initialize debug port as well but it's done in head.S already... */

        /* breakpoint handler is now set in irq.c */
	set_int_vector(8, kgdb_handle_serial, 0);
	
	enableDebugIRQ();
}

/****************************** End of file **********************************/