diff options
Diffstat (limited to 'arch/ppc/kernel/ppc-stub.c')
| -rw-r--r-- | arch/ppc/kernel/ppc-stub.c | 866 |
1 files changed, 0 insertions, 866 deletions
diff --git a/arch/ppc/kernel/ppc-stub.c b/arch/ppc/kernel/ppc-stub.c deleted file mode 100644 index 5f9ee7bb67e..00000000000 --- a/arch/ppc/kernel/ppc-stub.c +++ /dev/null @@ -1,866 +0,0 @@ -/* - * ppc-stub.c: KGDB support for the Linux kernel. - * - * adapted from arch/sparc/kernel/sparc-stub.c for the PowerPC - * some stuff borrowed from Paul Mackerras' xmon - * Copyright (C) 1998 Michael AK Tesch (tesch@cs.wisc.edu) - * - * Modifications to run under Linux - * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) - * - * This file originally came from the gdb sources, and the - * copyright notices have been retained below. - */ - -/**************************************************************************** - - 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 its 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 SPARC by Stu Grossman, Cygnus Support. - * - * This code has been extensively tested on the Fujitsu SPARClite demo board. - * - * 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 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 - * qOffsets Get section offsets. Reply is Text=xxx;Data=yyy;Bss=zzz - * - * 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) - * - * bBB..BB Set baud rate to BB..BB OK or BNN, then sets - * baud rate - * - * 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 <linux/kernel.h> -#include <linux/string.h> -#include <linux/mm.h> -#include <linux/smp.h> -#include <linux/smp_lock.h> -#include <linux/init.h> -#include <linux/sysrq.h> - -#include <asm/cacheflush.h> -#include <asm/system.h> -#include <asm/signal.h> -#include <asm/kgdb.h> -#include <asm/pgtable.h> -#include <asm/ptrace.h> - -void breakinst(void); - -/* - * BUFMAX defines the maximum number of characters in inbound/outbound buffers - * at least NUMREGBYTES*2 are needed for register packets - */ -#define BUFMAX 2048 -static char remcomInBuffer[BUFMAX]; -static char remcomOutBuffer[BUFMAX]; - -static int initialized; -static int kgdb_active; -static int kgdb_started; -static u_int fault_jmp_buf[100]; -static int kdebug; - - -static const char hexchars[]="0123456789abcdef"; - -/* Place where we save old trap entries for restoration - sparc*/ -/* struct tt_entry kgdb_savettable[256]; */ -/* typedef void (*trapfunc_t)(void); */ - -static void kgdb_fault_handler(struct pt_regs *regs); -static int handle_exception (struct pt_regs *regs); - -#if 0 -/* Install an exception handler for kgdb */ -static void exceptionHandler(int tnum, unsigned int *tfunc) -{ - /* We are dorking with a live trap table, all irqs off */ -} -#endif - -int -kgdb_setjmp(long *buf) -{ - asm ("mflr 0; stw 0,0(%0);" - "stw 1,4(%0); stw 2,8(%0);" - "mfcr 0; stw 0,12(%0);" - "stmw 13,16(%0)" - : : "r" (buf)); - /* XXX should save fp regs as well */ - return 0; -} -void -kgdb_longjmp(long *buf, int val) -{ - if (val == 0) - val = 1; - asm ("lmw 13,16(%0);" - "lwz 0,12(%0); mtcrf 0x38,0;" - "lwz 0,0(%0); lwz 1,4(%0); lwz 2,8(%0);" - "mtlr 0; mr 3,%1" - : : "r" (buf), "r" (val)); -} -/* Convert ch from a hex digit to an int */ -static int -hex(unsigned 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; -} - -/* Convert the memory pointed to by mem into hex, placing result in buf. - * Return a pointer to the last char put in buf (null), in case of mem fault, - * return 0. - */ -static unsigned char * -mem2hex(const char *mem, char *buf, int count) -{ - unsigned char ch; - unsigned short tmp_s; - unsigned long tmp_l; - - if (kgdb_setjmp((long*)fault_jmp_buf) == 0) { - debugger_fault_handler = kgdb_fault_handler; - - /* Accessing 16 bit and 32 bit objects in a single - ** load instruction is required to avoid bad side - ** effects for some IO registers. - */ - - if ((count == 2) && (((long)mem & 1) == 0)) { - tmp_s = *(unsigned short *)mem; - mem += 2; - *buf++ = hexchars[(tmp_s >> 12) & 0xf]; - *buf++ = hexchars[(tmp_s >> 8) & 0xf]; - *buf++ = hexchars[(tmp_s >> 4) & 0xf]; - *buf++ = hexchars[tmp_s & 0xf]; - - } else if ((count == 4) && (((long)mem & 3) == 0)) { - tmp_l = *(unsigned int *)mem; - mem += 4; - *buf++ = hexchars[(tmp_l >> 28) & 0xf]; - *buf++ = hexchars[(tmp_l >> 24) & 0xf]; - *buf++ = hexchars[(tmp_l >> 20) & 0xf]; - *buf++ = hexchars[(tmp_l >> 16) & 0xf]; - *buf++ = hexchars[(tmp_l >> 12) & 0xf]; - *buf++ = hexchars[(tmp_l >> 8) & 0xf]; - *buf++ = hexchars[(tmp_l >> 4) & 0xf]; - *buf++ = hexchars[tmp_l & 0xf]; - - } else { - while (count-- > 0) { - ch = *mem++; - *buf++ = hexchars[ch >> 4]; - *buf++ = hexchars[ch & 0xf]; - } - } - - } else { - /* error condition */ - } - debugger_fault_handler = NULL; - *buf = 0; - 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. -*/ -static char * -hex2mem(char *buf, char *mem, int count) -{ - unsigned char ch; - int i; - char *orig_mem; - unsigned short tmp_s; - unsigned long tmp_l; - - orig_mem = mem; - - if (kgdb_setjmp((long*)fault_jmp_buf) == 0) { - debugger_fault_handler = kgdb_fault_handler; - - /* Accessing 16 bit and 32 bit objects in a single - ** store instruction is required to avoid bad side - ** effects for some IO registers. - */ - - if ((count == 2) && (((long)mem & 1) == 0)) { - tmp_s = hex(*buf++) << 12; - tmp_s |= hex(*buf++) << 8; - tmp_s |= hex(*buf++) << 4; - tmp_s |= hex(*buf++); - - *(unsigned short *)mem = tmp_s; - mem += 2; - - } else if ((count == 4) && (((long)mem & 3) == 0)) { - tmp_l = hex(*buf++) << 28; - tmp_l |= hex(*buf++) << 24; - tmp_l |= hex(*buf++) << 20; - tmp_l |= hex(*buf++) << 16; - tmp_l |= hex(*buf++) << 12; - tmp_l |= hex(*buf++) << 8; - tmp_l |= hex(*buf++) << 4; - tmp_l |= hex(*buf++); - - *(unsigned long *)mem = tmp_l; - mem += 4; - - } else { - for (i=0; i<count; i++) { - ch = hex(*buf++) << 4; - ch |= hex(*buf++); - *mem++ = ch; - } - } - - - /* - ** Flush the data cache, invalidate the instruction cache. - */ - flush_icache_range((int)orig_mem, (int)orig_mem + count - 1); - - } else { - /* error condition */ - } - debugger_fault_handler = NULL; - return mem; -} - -/* - * While we find nice hex chars, build an int. - * Return number of chars processed. - */ -static int -hexToInt(char **ptr, int *intValue) -{ - int numChars = 0; - int hexValue; - - *intValue = 0; - - if (kgdb_setjmp((long*)fault_jmp_buf) == 0) { - debugger_fault_handler = kgdb_fault_handler; - while (**ptr) { - hexValue = hex(**ptr); - if (hexValue < 0) - break; - - *intValue = (*intValue << 4) | hexValue; - numChars ++; - - (*ptr)++; - } - } else { - /* error condition */ - } - debugger_fault_handler = NULL; - - return (numChars); -} - -/* scan for the sequence $<data>#<checksum> */ -static void -getpacket(char *buffer) -{ - unsigned char checksum; - unsigned char xmitcsum; - int i; - int count; - unsigned char ch; - - do { - /* wait around for the start character, ignore all other - * characters */ - while ((ch = (getDebugChar() & 0x7f)) != '$') ; - - 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; - } - - if (count >= BUFMAX) - continue; - - buffer[count] = 0; - - if (ch == '#') { - xmitcsum = hex(getDebugChar() & 0x7f) << 4; - xmitcsum |= hex(getDebugChar() & 0x7f); - if (checksum != xmitcsum) - putDebugChar('-'); /* failed checksum */ - else { - putDebugChar('+'); /* successful transfer */ - /* if a sequence char is present, reply the 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. */ -static void putpacket(unsigned char *buffer) -{ - unsigned char checksum; - int count; - unsigned char ch, recv; - - /* $<packet info>#<checksum>. */ - do { - putDebugChar('$'); - checksum = 0; - count = 0; - - while ((ch = buffer[count])) { - putDebugChar(ch); - checksum += ch; - count += 1; - } - - putDebugChar('#'); - putDebugChar(hexchars[checksum >> 4]); - putDebugChar(hexchars[checksum & 0xf]); - recv = getDebugChar(); - } while ((recv & 0x7f) != '+'); -} - -static void kgdb_flush_cache_all(void) -{ - flush_instruction_cache(); -} - -/* Set up exception handlers for tracing and breakpoints - * [could be called kgdb_init()] - */ -void set_debug_traps(void) -{ -#if 0 - unsigned char c; - - save_and_cli(flags); - - /* In case GDB is started before us, ack any packets (presumably - * "$?#xx") sitting there. - * - * I've found this code causes more problems than it solves, - * so that's why it's commented out. GDB seems to work fine - * now starting either before or after the kernel -bwb - */ - - while((c = getDebugChar()) != '$'); - while((c = getDebugChar()) != '#'); - c = getDebugChar(); /* eat first csum byte */ - c = getDebugChar(); /* eat second csum byte */ - putDebugChar('+'); /* ack it */ -#endif - debugger = kgdb; - debugger_bpt = kgdb_bpt; - debugger_sstep = kgdb_sstep; - debugger_iabr_match = kgdb_iabr_match; - debugger_dabr_match = kgdb_dabr_match; - - initialized = 1; -} - -static void kgdb_fault_handler(struct pt_regs *regs) -{ - kgdb_longjmp((long*)fault_jmp_buf, 1); -} - -int kgdb_bpt(struct pt_regs *regs) -{ - return handle_exception(regs); -} - -int kgdb_sstep(struct pt_regs *regs) -{ - return handle_exception(regs); -} - -void kgdb(struct pt_regs *regs) -{ - handle_exception(regs); -} - -int kgdb_iabr_match(struct pt_regs *regs) -{ - printk(KERN_ERR "kgdb doesn't support iabr, what?!?\n"); - return handle_exception(regs); -} - -int kgdb_dabr_match(struct pt_regs *regs) -{ - printk(KERN_ERR "kgdb doesn't support dabr, what?!?\n"); - return handle_exception(regs); -} - -/* Convert the hardware trap type code to a unix signal number. */ -/* - * This table contains the mapping between PowerPC hardware trap types, and - * signals, which are primarily what GDB understands. - */ -static struct hard_trap_info -{ - unsigned int tt; /* Trap type code for powerpc */ - unsigned char signo; /* Signal that we map this trap into */ -} hard_trap_info[] = { -#if defined(CONFIG_40x) || defined(CONFIG_BOOKE) - { 0x100, SIGINT }, /* critical input interrupt */ - { 0x200, SIGSEGV }, /* machine check */ - { 0x300, SIGSEGV }, /* data storage */ - { 0x400, SIGBUS }, /* instruction storage */ - { 0x500, SIGINT }, /* interrupt */ - { 0x600, SIGBUS }, /* alignment */ - { 0x700, SIGILL }, /* program */ - { 0x800, SIGILL }, /* reserved */ - { 0x900, SIGILL }, /* reserved */ - { 0xa00, SIGILL }, /* reserved */ - { 0xb00, SIGILL }, /* reserved */ - { 0xc00, SIGCHLD }, /* syscall */ - { 0xd00, SIGILL }, /* reserved */ - { 0xe00, SIGILL }, /* reserved */ - { 0xf00, SIGILL }, /* reserved */ - /* - ** 0x1000 PIT - ** 0x1010 FIT - ** 0x1020 watchdog - ** 0x1100 data TLB miss - ** 0x1200 instruction TLB miss - */ - { 0x2002, SIGTRAP}, /* debug */ -#else - { 0x200, SIGSEGV }, /* machine check */ - { 0x300, SIGSEGV }, /* address error (store) */ - { 0x400, SIGBUS }, /* instruction bus error */ - { 0x500, SIGINT }, /* interrupt */ - { 0x600, SIGBUS }, /* alingment */ - { 0x700, SIGTRAP }, /* breakpoint trap */ - { 0x800, SIGFPE }, /* fpu unavail */ - { 0x900, SIGALRM }, /* decrementer */ - { 0xa00, SIGILL }, /* reserved */ - { 0xb00, SIGILL }, /* reserved */ - { 0xc00, SIGCHLD }, /* syscall */ - { 0xd00, SIGTRAP }, /* single-step/watch */ - { 0xe00, SIGFPE }, /* fp assist */ -#endif - { 0, 0} /* Must be last */ - -}; - -static int computeSignal(unsigned int tt) -{ - struct hard_trap_info *ht; - - for (ht = hard_trap_info; ht->tt && ht->signo; ht++) - if (ht->tt == tt) - return ht->signo; - - return SIGHUP; /* default for things we don't know about */ -} - -#define PC_REGNUM 64 -#define SP_REGNUM 1 - -/* - * This function does all command processing for interfacing to gdb. - */ -static int -handle_exception (struct pt_regs *regs) -{ - int sigval; - int addr; - int length; - char *ptr; - unsigned int msr; - - /* We don't handle user-mode breakpoints. */ - if (user_mode(regs)) - return 0; - - if (debugger_fault_handler) { - debugger_fault_handler(regs); - panic("kgdb longjump failed!\n"); - } - if (kgdb_active) { - printk(KERN_ERR "interrupt while in kgdb, returning\n"); - return 0; - } - - kgdb_active = 1; - kgdb_started = 1; - -#ifdef KGDB_DEBUG - printk("kgdb: entering handle_exception; trap [0x%x]\n", - (unsigned int)regs->trap); -#endif - - kgdb_interruptible(0); - lock_kernel(); - msr = mfmsr(); - mtmsr(msr & ~MSR_EE); /* disable interrupts */ - - if (regs->nip == (unsigned long)breakinst) { - /* Skip over breakpoint trap insn */ - regs->nip += 4; - } - - /* reply to host that an exception has occurred */ - sigval = computeSignal(regs->trap); - ptr = remcomOutBuffer; - - *ptr++ = 'T'; - *ptr++ = hexchars[sigval >> 4]; - *ptr++ = hexchars[sigval & 0xf]; - *ptr++ = hexchars[PC_REGNUM >> 4]; - *ptr++ = hexchars[PC_REGNUM & 0xf]; - *ptr++ = ':'; - ptr = mem2hex((char *)®s->nip, ptr, 4); - *ptr++ = ';'; - *ptr++ = hexchars[SP_REGNUM >> 4]; - *ptr++ = hexchars[SP_REGNUM & 0xf]; - *ptr++ = ':'; - ptr = mem2hex(((char *)regs) + SP_REGNUM*4, ptr, 4); - *ptr++ = ';'; - *ptr++ = 0; - - putpacket(remcomOutBuffer); - if (kdebug) - printk("remcomOutBuffer: %s\n", remcomOutBuffer); - - /* XXX We may want to add some features dealing with poking the - * XXX page tables, ... (look at sparc-stub.c for more info) - * XXX also required hacking to the gdb sources directly... - */ - - while (1) { - remcomOutBuffer[0] = 0; - - getpacket(remcomInBuffer); - switch (remcomInBuffer[0]) { - case '?': /* report most recent signal */ - remcomOutBuffer[0] = 'S'; - remcomOutBuffer[1] = hexchars[sigval >> 4]; - remcomOutBuffer[2] = hexchars[sigval & 0xf]; - remcomOutBuffer[3] = 0; - break; -#if 0 - case 'q': /* this screws up gdb for some reason...*/ - { - extern long _start, sdata, __bss_start; - - ptr = &remcomInBuffer[1]; - if (strncmp(ptr, "Offsets", 7) != 0) - break; - - ptr = remcomOutBuffer; - sprintf(ptr, "Text=%8.8x;Data=%8.8x;Bss=%8.8x", - &_start, &sdata, &__bss_start); - break; - } -#endif - case 'd': - /* toggle debug flag */ - kdebug ^= 1; - break; - - case 'g': /* return the value of the CPU registers. - * some of them are non-PowerPC names :( - * they are stored in gdb like: - * struct { - * u32 gpr[32]; - * f64 fpr[32]; - * u32 pc, ps, cnd, lr; (ps=msr) - * u32 cnt, xer, mq; - * } - */ - { - int i; - ptr = remcomOutBuffer; - /* General Purpose Regs */ - ptr = mem2hex((char *)regs, ptr, 32 * 4); - /* Floating Point Regs - FIXME */ - /*ptr = mem2hex((char *), ptr, 32 * 8);*/ - for(i=0; i<(32*8*2); i++) { /* 2chars/byte */ - ptr[i] = '0'; - } - ptr += 32*8*2; - /* pc, msr, cr, lr, ctr, xer, (mq is unused) */ - ptr = mem2hex((char *)®s->nip, ptr, 4); - ptr = mem2hex((char *)®s->msr, ptr, 4); - ptr = mem2hex((char *)®s->ccr, ptr, 4); - ptr = mem2hex((char *)®s->link, ptr, 4); - ptr = mem2hex((char *)®s->ctr, ptr, 4); - ptr = mem2hex((char *)®s->xer, ptr, 4); - } - break; - - case 'G': /* set the value of the CPU registers */ - { - ptr = &remcomInBuffer[1]; - - /* - * If the stack pointer has moved, you should pray. - * (cause only god can help you). - */ - - /* General Purpose Regs */ - hex2mem(ptr, (char *)regs, 32 * 4); - - /* Floating Point Regs - FIXME?? */ - /*ptr = hex2mem(ptr, ??, 32 * 8);*/ - ptr += 32*8*2; - - /* pc, msr, cr, lr, ctr, xer, (mq is unused) */ - ptr = hex2mem(ptr, (char *)®s->nip, 4); - ptr = hex2mem(ptr, (char *)®s->msr, 4); - ptr = hex2mem(ptr, (char *)®s->ccr, 4); - ptr = hex2mem(ptr, (char *)®s->link, 4); - ptr = hex2mem(ptr, (char *)®s->ctr, 4); - ptr = hex2mem(ptr, (char *)®s->xer, 4); - - strcpy(remcomOutBuffer,"OK"); - } - break; - case 'H': - /* don't do anything, yet, just acknowledge */ - hexToInt(&ptr, &addr); - strcpy(remcomOutBuffer,"OK"); - break; - - case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ - /* Try to read %x,%x. */ - - ptr = &remcomInBuffer[1]; - - if (hexToInt(&ptr, &addr) && *ptr++ == ',' - && hexToInt(&ptr, &length)) { - if (mem2hex((char *)addr, remcomOutBuffer, - length)) - break; - strcpy(remcomOutBuffer, "E03"); - } else - strcpy(remcomOutBuffer, "E01"); - break; - - case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ - /* Try to read '%x,%x:'. */ - - ptr = &remcomInBuffer[1]; - - if (hexToInt(&ptr, &addr) && *ptr++ == ',' - && hexToInt(&ptr, &length) - && *ptr++ == ':') { - if (hex2mem(ptr, (char *)addr, length)) - strcpy(remcomOutBuffer, "OK"); - else - strcpy(remcomOutBuffer, "E03"); - flush_icache_range(addr, addr+length); - } else - strcpy(remcomOutBuffer, "E02"); - break; - - - case 'k': /* kill the program, actually just continue */ - case 'c': /* cAA..AA Continue; address AA..AA optional */ - /* try to read optional parameter, pc unchanged if no parm */ - - ptr = &remcomInBuffer[1]; - if (hexToInt(&ptr, &addr)) - regs->nip = addr; - -/* Need to flush the instruction cache here, 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. - */ - kgdb_flush_cache_all(); - mtmsr(msr); - - kgdb_interruptible(1); - unlock_kernel(); - kgdb_active = 0; - if (kdebug) { - printk("remcomInBuffer: %s\n", remcomInBuffer); - printk("remcomOutBuffer: %s\n", remcomOutBuffer); - } - return 1; - - case 's': - kgdb_flush_cache_all(); -#if defined(CONFIG_40x) || defined(CONFIG_BOOKE) - mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC); - regs->msr |= MSR_DE; -#else - regs->msr |= MSR_SE; -#endif - unlock_kernel(); - kgdb_active = 0; - if (kdebug) { - printk("remcomInBuffer: %s\n", remcomInBuffer); - printk("remcomOutBuffer: %s\n", remcomOutBuffer); - } - return 1; - - case 'r': /* Reset (if user process..exit ???)*/ - panic("kgdb reset."); - break; - } /* switch */ - if (remcomOutBuffer[0] && kdebug) { - printk("remcomInBuffer: %s\n", remcomInBuffer); - printk("remcomOutBuffer: %s\n", remcomOutBuffer); - } - /* reply to the request */ - putpacket(remcomOutBuffer); - } /* while(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(void) -{ - if (!initialized) { - printk("breakpoint() called b4 kgdb init\n"); - return; - } - - asm(" .globl breakinst \n\ - breakinst: .long 0x7d821008"); -} - -#ifdef CONFIG_KGDB_CONSOLE -/* Output string in GDB O-packet format if GDB has connected. If nothing - output, returns 0 (caller must then handle output). */ -int -kgdb_output_string (const char* s, unsigned int count) -{ - char buffer[512]; - - if (!kgdb_started) - return 0; - - count = (count <= (sizeof(buffer) / 2 - 2)) - ? count : (sizeof(buffer) / 2 - 2); - - buffer[0] = 'O'; - mem2hex (s, &buffer[1], count); - putpacket(buffer); - - return 1; -} -#endif - -static void sysrq_handle_gdb(int key, struct pt_regs *pt_regs, - struct tty_struct *tty) -{ - printk("Entering GDB stub\n"); - breakpoint(); -} -static struct sysrq_key_op sysrq_gdb_op = { - .handler = sysrq_handle_gdb, - .help_msg = "Gdb", - .action_msg = "GDB", -}; - -static int gdb_register_sysrq(void) -{ - printk("Registering GDB sysrq handler\n"); - register_sysrq_key('g', &sysrq_gdb_op); - return 0; -} -module_init(gdb_register_sysrq); |