gdb-stub.c

底层驱动开发

			for (loop = 1; loop <= 27; loop++)
				ptr = mem2hex((unsigned long *)__debug_frame + REG_GR(loop),
					      ptr, 4, 0);
			temp = (unsigned long) __frame;
			ptr = mem2hex(&temp, ptr, 4, 0);
			ptr = mem2hex((unsigned long *)__debug_frame + REG_GR(29), ptr, 4, 0);
			ptr = mem2hex((unsigned long *)__debug_frame + REG_GR(30), ptr, 4, 0);
#ifdef CONFIG_MMU
			ptr = mem2hex((unsigned long *)__debug_frame + REG_GR(31), ptr, 4, 0);
#else
			temp = (unsigned long) __debug_frame;
			ptr = mem2hex(&temp, ptr, 4, 0);
#endif

			for (loop = 32; loop <= 63; loop++)
				ptr = mem2hex((unsigned long *)__debug_frame + REG_GR(loop),
					      ptr, 4, 0);

			/* deal with FR0-FR63 */
			for (loop = 0; loop <= 63; loop++)
				ptr = mem2hex((unsigned long *)&__break_user_context +
					      __FPMEDIA_FR(loop),
					      ptr, 4, 0);

			/* deal with special registers */
			ptr = mem2hex(&__debug_frame->pc,    ptr, 4, 0);
			ptr = mem2hex(&__debug_frame->psr,   ptr, 4, 0);
			ptr = mem2hex(&__debug_frame->ccr,   ptr, 4, 0);
			ptr = mem2hex(&__debug_frame->cccr,  ptr, 4, 0);
			ptr = mem2hex(&zero, ptr, 4, 0);
			ptr = mem2hex(&zero, ptr, 4, 0);
			ptr = mem2hex(&zero, ptr, 4, 0);
			ptr = mem2hex(&__debug_frame->tbr,   ptr, 4, 0);
			ptr = mem2hex(&__debug_regs->brr ,   ptr, 4, 0);

			asm volatile("movsg dbar0,%0" : "=r"(dbar));
			ptr = mem2hex(&dbar, ptr, 4, 0);
			asm volatile("movsg dbar1,%0" : "=r"(dbar));
			ptr = mem2hex(&dbar, ptr, 4, 0);
			asm volatile("movsg dbar2,%0" : "=r"(dbar));
			ptr = mem2hex(&dbar, ptr, 4, 0);
			asm volatile("movsg dbar3,%0" : "=r"(dbar));
			ptr = mem2hex(&dbar, ptr, 4, 0);

			asm volatile("movsg scr0,%0" : "=r"(dbar));
			ptr = mem2hex(&dbar, ptr, 4, 0);
			asm volatile("movsg scr1,%0" : "=r"(dbar));
			ptr = mem2hex(&dbar, ptr, 4, 0);
			asm volatile("movsg scr2,%0" : "=r"(dbar));
			ptr = mem2hex(&dbar, ptr, 4, 0);
			asm volatile("movsg scr3,%0" : "=r"(dbar));
			ptr = mem2hex(&dbar, ptr, 4, 0);

			ptr = mem2hex(&__debug_frame->lr, ptr, 4, 0);
			ptr = mem2hex(&__debug_frame->lcr, ptr, 4, 0);

			ptr = mem2hex(&__debug_frame->iacc0, ptr, 8, 0);

			ptr = mem2hex(&__break_user_context.f.fsr[0], ptr, 4, 0);

			for (loop = 0; loop <= 7; loop++)
				ptr = mem2hex(&__break_user_context.f.acc[loop], ptr, 4, 0);

			ptr = mem2hex(&__break_user_context.f.accg, ptr, 8, 0);

			for (loop = 0; loop <= 1; loop++)
				ptr = mem2hex(&__break_user_context.f.msr[loop], ptr, 4, 0);

			ptr = mem2hex(&__debug_frame->gner0, ptr, 4, 0);
			ptr = mem2hex(&__debug_frame->gner1, ptr, 4, 0);

			ptr = mem2hex(&__break_user_context.f.fner[0], ptr, 4, 0);
			ptr = mem2hex(&__break_user_context.f.fner[1], ptr, 4, 0);

			break;

			/* set the values of the CPU registers */
		case 'G':
			ptr = &input_buffer[1];

			/* deal with GR0, GR1-GR27, GR28-GR31, GR32-GR63 */
			ptr = hex2mem(ptr, &temp, 4);

			for (loop = 1; loop <= 27; loop++)
				ptr = hex2mem(ptr, (unsigned long *)__debug_frame + REG_GR(loop),
					      4);

			ptr = hex2mem(ptr, &temp, 4);
			__frame = (struct pt_regs *) temp;
			ptr = hex2mem(ptr, &__debug_frame->gr29, 4);
			ptr = hex2mem(ptr, &__debug_frame->gr30, 4);
#ifdef CONFIG_MMU
			ptr = hex2mem(ptr, &__debug_frame->gr31, 4);
#else
			ptr = hex2mem(ptr, &temp, 4);
#endif

			for (loop = 32; loop <= 63; loop++)
				ptr = hex2mem(ptr, (unsigned long *)__debug_frame + REG_GR(loop),
					      4);

			/* deal with FR0-FR63 */
			for (loop = 0; loop <= 63; loop++)
				ptr = mem2hex((unsigned long *)&__break_user_context +
					      __FPMEDIA_FR(loop),
					      ptr, 4, 0);

			/* deal with special registers */
			ptr = hex2mem(ptr, &__debug_frame->pc,  4);
			ptr = hex2mem(ptr, &__debug_frame->psr, 4);
			ptr = hex2mem(ptr, &__debug_frame->ccr, 4);
			ptr = hex2mem(ptr, &__debug_frame->cccr,4);

			for (loop = 132; loop <= 140; loop++)
				ptr = hex2mem(ptr, &temp, 4);

			ptr = hex2mem(ptr, &temp, 4);
			asm volatile("movgs %0,scr0" :: "r"(temp));
			ptr = hex2mem(ptr, &temp, 4);
			asm volatile("movgs %0,scr1" :: "r"(temp));
			ptr = hex2mem(ptr, &temp, 4);
			asm volatile("movgs %0,scr2" :: "r"(temp));
			ptr = hex2mem(ptr, &temp, 4);
			asm volatile("movgs %0,scr3" :: "r"(temp));

			ptr = hex2mem(ptr, &__debug_frame->lr,  4);
			ptr = hex2mem(ptr, &__debug_frame->lcr, 4);

			ptr = hex2mem(ptr, &__debug_frame->iacc0, 8);

			ptr = hex2mem(ptr, &__break_user_context.f.fsr[0], 4);

			for (loop = 0; loop <= 7; loop++)
				ptr = hex2mem(ptr, &__break_user_context.f.acc[loop], 4);

			ptr = hex2mem(ptr, &__break_user_context.f.accg, 8);

			for (loop = 0; loop <= 1; loop++)
				ptr = hex2mem(ptr, &__break_user_context.f.msr[loop], 4);

			ptr = hex2mem(ptr, &__debug_frame->gner0, 4);
			ptr = hex2mem(ptr, &__debug_frame->gner1, 4);

			ptr = hex2mem(ptr, &__break_user_context.f.fner[0], 4);
			ptr = hex2mem(ptr, &__break_user_context.f.fner[1], 4);

			gdbstub_strcpy(output_buffer,"OK");
			break;

			/* mAA..AA,LLLL  Read LLLL bytes at address AA..AA */
		case 'm':
			ptr = &input_buffer[1];

			if (hexToInt(&ptr, &addr) &&
			    *ptr++ == ',' &&
			    hexToInt(&ptr, &length)
			    ) {
				if (mem2hex((char *)addr, output_buffer, length, 1))
					break;
				gdbstub_strcpy (output_buffer, "E03");
			}
			else {
				gdbstub_strcpy(output_buffer,"E01");
			}
			break;

			/* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
		case 'M':
			ptr = &input_buffer[1];

			if (hexToInt(&ptr, &addr) &&
			    *ptr++ == ',' &&
			    hexToInt(&ptr, &length) &&
			    *ptr++ == ':'
			    ) {
				if (hex2mem(ptr, (char *)addr, length)) {
					gdbstub_strcpy(output_buffer, "OK");
				}
				else {
					gdbstub_strcpy(output_buffer, "E03");
				}
			}
			else
				gdbstub_strcpy(output_buffer, "E02");

			flush_cache = 1;
			break;

			/* PNN,=RRRRRRRR: Write value R to reg N return OK */
		case 'P':
			ptr = &input_buffer[1];

			if (!hexToInt(&ptr, &addr) ||
			    *ptr++ != '=' ||
			    !hexToInt(&ptr, &temp)
			    ) {
				gdbstub_strcpy(output_buffer, "E01");
				break;
			}

			temp2 = 1;
			switch (addr) {
			case GDB_REG_GR(0):
				break;
			case GDB_REG_GR(1) ... GDB_REG_GR(63):
				__break_user_context.i.gr[addr - GDB_REG_GR(0)] = temp;
				break;
			case GDB_REG_FR(0) ... GDB_REG_FR(63):
				__break_user_context.f.fr[addr - GDB_REG_FR(0)] = temp;
				break;
			case GDB_REG_PC:
				__break_user_context.i.pc = temp;
				break;
			case GDB_REG_PSR:
				__break_user_context.i.psr = temp;
				break;
			case GDB_REG_CCR:
				__break_user_context.i.ccr = temp;
				break;
			case GDB_REG_CCCR:
				__break_user_context.i.cccr = temp;
				break;
			case GDB_REG_BRR:
				__debug_regs->brr = temp;
				break;
			case GDB_REG_LR:
				__break_user_context.i.lr = temp;
				break;
			case GDB_REG_LCR:
				__break_user_context.i.lcr = temp;
				break;
			case GDB_REG_FSR0:
				__break_user_context.f.fsr[0] = temp;
				break;
			case GDB_REG_ACC(0) ... GDB_REG_ACC(7):
				__break_user_context.f.acc[addr - GDB_REG_ACC(0)] = temp;
				break;
			case GDB_REG_ACCG(0):
				*(uint32_t *) &__break_user_context.f.accg[0] = temp;
				break;
			case GDB_REG_ACCG(4):
				*(uint32_t *) &__break_user_context.f.accg[4] = temp;
				break;
			case GDB_REG_MSR(0) ... GDB_REG_MSR(1):
				__break_user_context.f.msr[addr - GDB_REG_MSR(0)] = temp;
				break;
			case GDB_REG_GNER(0) ... GDB_REG_GNER(1):
				__break_user_context.i.gner[addr - GDB_REG_GNER(0)] = temp;
				break;
			case GDB_REG_FNER(0) ... GDB_REG_FNER(1):
				__break_user_context.f.fner[addr - GDB_REG_FNER(0)] = temp;
				break;
			default:
				temp2 = 0;
				break;
			}

			if (temp2) {
				gdbstub_strcpy(output_buffer, "OK");
			}
			else {
				gdbstub_strcpy(output_buffer, "E02");
			}
			break;

			/* cAA..AA    Continue at address AA..AA(optional) */
		case 'c':
			/* try to read optional parameter, pc unchanged if no parm */
			ptr = &input_buffer[1];
			if (hexToInt(&ptr, &addr))
				__debug_frame->pc = addr;
			goto done;

			/* kill the program */
		case 'k' :
			goto done;	/* just continue */


			/* reset the whole machine (FIXME: system dependent) */
		case 'r':
			break;


			/* step to next instruction */
		case 's':
			__debug_regs->dcr |= DCR_SE;
			goto done;

			/* set baud rate (bBB) */
		case 'b':
			ptr = &input_buffer[1];
			if (!hexToInt(&ptr, &temp)) {
				gdbstub_strcpy(output_buffer,"B01");
				break;
			}

			if (temp) {
				/* ack before changing speed */
				gdbstub_send_packet("OK");
				gdbstub_set_baud(temp);
			}
			break;

			/* set breakpoint */
		case 'Z':
			ptr = &input_buffer[1];

			if (!hexToInt(&ptr,&temp) || *ptr++ != ',' ||
			    !hexToInt(&ptr,&addr) || *ptr++ != ',' ||
			    !hexToInt(&ptr,&length)
			    ) {
				gdbstub_strcpy(output_buffer,"E01");
				break;
			}

			if (temp >= 5) {
				gdbstub_strcpy(output_buffer,"E03");
				break;
			}

			if (gdbstub_set_breakpoint(temp, addr, length) < 0) {
				gdbstub_strcpy(output_buffer,"E03");
				break;
			}

			if (temp == 0)
				flush_cache = 1; /* soft bkpt by modified memory */

			gdbstub_strcpy(output_buffer,"OK");
			break;

			/* clear breakpoint */
		case 'z':
			ptr = &input_buffer[1];

			if (!hexToInt(&ptr,&temp) || *ptr++ != ',' ||
			    !hexToInt(&ptr,&addr) || *ptr++ != ',' ||
			    !hexToInt(&ptr,&length)
			    ) {
				gdbstub_strcpy(output_buffer,"E01");
				break;
			}

			if (temp >= 5) {
				gdbstub_strcpy(output_buffer,"E03");
				break;
			}

			if (gdbstub_clear_breakpoint(temp, addr, length) < 0) {
				gdbstub_strcpy(output_buffer,"E03");
				break;
			}

			if (temp == 0)
				flush_cache = 1; /* soft bkpt by modified memory */

			gdbstub_strcpy(output_buffer,"OK");
			break;

		default:
			gdbstub_proto("### GDB Unsupported Cmd '%s'\n",input_buffer);
			break;
		}

		/* reply to the request */
		LEDS(0x5009);
		gdbstub_send_packet(output_buffer);
	}

 done:
	restore_user_regs(&__break_user_context);

	//gdbstub_dump_debugregs();
	//gdbstub_printk("<-- gdbstub() %08x\n", __debug_frame->pc);

	/* need to flush the instruction cache before resuming, as we may have
	 * deposited a breakpoint, and the icache probably has no way of
	 * knowing that a data ref to some location may have changed something
	 * that is in the instruction cache.  NB: We flush both caches, just to
	 * be sure...
	 */

	/* note: flushing the icache will clobber EAR0 on the FR451 */
	if (flush_cache)
		gdbstub_purge_cache();

	LEDS(0x5666);

} /* end gdbstub() */

/*****************************************************************************/
/*
 * initialise the GDB stub
 */
void __init gdbstub_init(void)
{
#ifdef CONFIG_GDBSTUB_IMMEDIATE
	unsigned char ch;
	int ret;
#endif

	gdbstub_printk("%s", gdbstub_banner);
	gdbstub_printk("DCR: %x\n", __debug_regs->dcr);

	gdbstub_io_init();

	/* try to talk to GDB (or anyone insane enough to want to type GDB protocol by hand) */
	gdbstub_proto("### GDB Tx ACK\n");
	gdbstub_tx_char('+'); /* 'hello world' */

#ifdef CONFIG_GDBSTUB_IMMEDIATE
	gdbstub_printk("GDB Stub waiting for packet\n");

	/*
	 * In case GDB is started before us, ack any packets
	 * (presumably "$?#xx") sitting there.
	 */
	do { gdbstub_rx_char(&ch, 0); } while (ch != '$');
	do { gdbstub_rx_char(&ch, 0); } while (ch != '#');
	do { ret = gdbstub_rx_char(&ch, 0); } while (ret != 0); /* eat first csum byte */
	do { ret = gdbstub_rx_char(&ch, 0); } while (ret != 0); /* eat second csum byte */

	gdbstub_proto("### GDB Tx NAK\n");
	gdbstub_tx_char('-'); /* nak it */

#else
	gdbstub_printk("GDB Stub set\n");
#endif

#if 0
	/* send banner */
	ptr = output_buffer;
	*ptr++ = 'O';
	ptr = mem2hex(gdbstub_banner, ptr, sizeof(gdbstub_banner) - 1, 0);
	gdbstub_send_packet(output_buffer);
#endif
#if defined(CONFIG_GDBSTUB_CONSOLE) && defined(CONFIG_GDBSTUB_IMMEDIATE)
	register_console(&gdbstub_console);
#endif

} /* end gdbstub_init() */

/*****************************************************************************/
/*
 * register the console at a more appropriate time
 */
#if defined (CONFIG_GDBSTUB_CONSOLE) && !defined(CONFIG_GDBSTUB_IMMEDIATE)
static int __init gdbstub_postinit(void)
{
	printk("registering console\n");
	register_console(&gdbstub_console);
	return 0;
} /* end gdbstub_postinit() */

__initcall(gdbstub_postinit);
#endif

/*****************************************************************************/
/*
 * send an exit message to GDB
 */
void gdbstub_exit(int status)
{
	unsigned char checksum;
	int count;
	unsigned char ch;

	sprintf(output_buffer,"W%02x",status&0xff);

	gdbstub_tx_char('$');
	checksum = 0;
	count = 0;

	while ((ch = output_buffer[count]) != 0) {
		gdbstub_tx_char(ch);
		checksum += ch;
		count += 1;
	}

	gdbstub_tx_char('#');
	gdbstub_tx_char(hexchars[checksum >> 4]);
	gdbstub_tx_char(hexchars[checksum & 0xf]);

	/* make sure the output is flushed, or else RedBoot might clobber it */
	gdbstub_tx_char('-');
	gdbstub_tx_flush();

} /* end gdbstub_exit() */

/*****************************************************************************/
/*
 * GDB wants to call malloc() and free() to allocate memory for calling kernel
 * functions directly from its command line
 */
static void *malloc(size_t size) __attribute__((unused));
static void *malloc(size_t size)
{
	return kmalloc(size, GFP_ATOMIC);
}

static void free(void *p) __attribute__((unused));
static void free(void *p)
{
	kfree(p);
}

static uint32_t ___get_HSR0(void) __attribute__((unused));
static uint32_t ___get_HSR0(void)
{
	return __get_HSR(0);
}

static uint32_t ___set_HSR0(uint32_t x) __attribute__((unused));
static uint32_t ___set_HSR0(uint32_t x)
{
	__set_HSR(0, x);
	return __get_HSR(0);
}