868 lines
22 KiB
C
868 lines
22 KiB
C
|
/*
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* ppc-stub.c: KGDB support for the Linux kernel.
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*
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* adapted from arch/sparc/kernel/sparc-stub.c for the PowerPC
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* some stuff borrowed from Paul Mackerras' xmon
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* Copyright (C) 1998 Michael AK Tesch (tesch@cs.wisc.edu)
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*
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* Modifications to run under Linux
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* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
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*
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* This file originally came from the gdb sources, and the
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* copyright notices have been retained below.
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*/
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/****************************************************************************
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THIS SOFTWARE IS NOT COPYRIGHTED
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HP offers the following for use in the public domain. HP makes no
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warranty with regard to the software or its performance and the
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user accepts the software "AS IS" with all faults.
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HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
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TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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****************************************************************************/
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/****************************************************************************
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* Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $
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*
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* Module name: remcom.c $
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* Revision: 1.34 $
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* Date: 91/03/09 12:29:49 $
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* Contributor: Lake Stevens Instrument Division$
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*
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* Description: low level support for gdb debugger. $
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*
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* Considerations: only works on target hardware $
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*
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* Written by: Glenn Engel $
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* ModuleState: Experimental $
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*
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* NOTES: See Below $
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*
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* Modified for SPARC by Stu Grossman, Cygnus Support.
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*
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* This code has been extensively tested on the Fujitsu SPARClite demo board.
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*
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* To enable debugger support, two things need to happen. One, a
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* call to set_debug_traps() is necessary in order to allow any breakpoints
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* or error conditions to be properly intercepted and reported to gdb.
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* Two, a breakpoint needs to be generated to begin communication. This
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* is most easily accomplished by a call to breakpoint(). Breakpoint()
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* simulates a breakpoint by executing a trap #1.
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*
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*************
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*
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* The following gdb commands are supported:
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*
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* command function Return value
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*
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* g return the value of the CPU registers hex data or ENN
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* G set the value of the CPU registers OK or ENN
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* qOffsets Get section offsets. Reply is Text=xxx;Data=yyy;Bss=zzz
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*
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* mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN
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* MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN
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*
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* c Resume at current address SNN ( signal NN)
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* cAA..AA Continue at address AA..AA SNN
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*
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* s Step one instruction SNN
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* sAA..AA Step one instruction from AA..AA SNN
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*
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* k kill
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*
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* ? What was the last sigval ? SNN (signal NN)
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*
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* bBB..BB Set baud rate to BB..BB OK or BNN, then sets
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* baud rate
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*
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* All commands and responses are sent with a packet which includes a
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* checksum. A packet consists of
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*
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* $<packet info>#<checksum>.
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*
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* where
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* <packet info> :: <characters representing the command or response>
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* <checksum> :: <two hex digits computed as modulo 256 sum of <packetinfo>>
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*
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* When a packet is received, it is first acknowledged with either '+' or '-'.
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* '+' indicates a successful transfer. '-' indicates a failed transfer.
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*
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* Example:
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*
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* Host: Reply:
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* $m0,10#2a +$00010203040506070809101112131415#42
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*
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****************************************************************************/
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#include <linux/config.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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#include <linux/init.h>
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#include <linux/sysrq.h>
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#include <asm/cacheflush.h>
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#include <asm/system.h>
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#include <asm/signal.h>
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#include <asm/kgdb.h>
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#include <asm/pgtable.h>
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#include <asm/ptrace.h>
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void breakinst(void);
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/*
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* BUFMAX defines the maximum number of characters in inbound/outbound buffers
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* at least NUMREGBYTES*2 are needed for register packets
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*/
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#define BUFMAX 2048
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static char remcomInBuffer[BUFMAX];
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static char remcomOutBuffer[BUFMAX];
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static int initialized;
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static int kgdb_active;
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static int kgdb_started;
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static u_int fault_jmp_buf[100];
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static int kdebug;
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static const char hexchars[]="0123456789abcdef";
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/* Place where we save old trap entries for restoration - sparc*/
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/* struct tt_entry kgdb_savettable[256]; */
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/* typedef void (*trapfunc_t)(void); */
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static void kgdb_fault_handler(struct pt_regs *regs);
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static int handle_exception (struct pt_regs *regs);
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#if 0
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/* Install an exception handler for kgdb */
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static void exceptionHandler(int tnum, unsigned int *tfunc)
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{
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/* We are dorking with a live trap table, all irqs off */
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}
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#endif
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int
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kgdb_setjmp(long *buf)
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{
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asm ("mflr 0; stw 0,0(%0);"
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"stw 1,4(%0); stw 2,8(%0);"
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"mfcr 0; stw 0,12(%0);"
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"stmw 13,16(%0)"
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: : "r" (buf));
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/* XXX should save fp regs as well */
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return 0;
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}
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void
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kgdb_longjmp(long *buf, int val)
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{
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if (val == 0)
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val = 1;
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asm ("lmw 13,16(%0);"
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"lwz 0,12(%0); mtcrf 0x38,0;"
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"lwz 0,0(%0); lwz 1,4(%0); lwz 2,8(%0);"
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"mtlr 0; mr 3,%1"
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: : "r" (buf), "r" (val));
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}
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/* Convert ch from a hex digit to an int */
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static int
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hex(unsigned char ch)
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{
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if (ch >= 'a' && ch <= 'f')
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return ch-'a'+10;
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if (ch >= '0' && ch <= '9')
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return ch-'0';
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if (ch >= 'A' && ch <= 'F')
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return ch-'A'+10;
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return -1;
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}
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/* Convert the memory pointed to by mem into hex, placing result in buf.
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* Return a pointer to the last char put in buf (null), in case of mem fault,
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* return 0.
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*/
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static unsigned char *
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mem2hex(const char *mem, char *buf, int count)
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{
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unsigned char ch;
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unsigned short tmp_s;
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unsigned long tmp_l;
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if (kgdb_setjmp((long*)fault_jmp_buf) == 0) {
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debugger_fault_handler = kgdb_fault_handler;
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/* Accessing 16 bit and 32 bit objects in a single
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** load instruction is required to avoid bad side
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** effects for some IO registers.
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*/
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if ((count == 2) && (((long)mem & 1) == 0)) {
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tmp_s = *(unsigned short *)mem;
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mem += 2;
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*buf++ = hexchars[(tmp_s >> 12) & 0xf];
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*buf++ = hexchars[(tmp_s >> 8) & 0xf];
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*buf++ = hexchars[(tmp_s >> 4) & 0xf];
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*buf++ = hexchars[tmp_s & 0xf];
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} else if ((count == 4) && (((long)mem & 3) == 0)) {
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tmp_l = *(unsigned int *)mem;
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mem += 4;
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*buf++ = hexchars[(tmp_l >> 28) & 0xf];
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*buf++ = hexchars[(tmp_l >> 24) & 0xf];
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*buf++ = hexchars[(tmp_l >> 20) & 0xf];
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*buf++ = hexchars[(tmp_l >> 16) & 0xf];
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*buf++ = hexchars[(tmp_l >> 12) & 0xf];
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*buf++ = hexchars[(tmp_l >> 8) & 0xf];
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*buf++ = hexchars[(tmp_l >> 4) & 0xf];
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*buf++ = hexchars[tmp_l & 0xf];
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} else {
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while (count-- > 0) {
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ch = *mem++;
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*buf++ = hexchars[ch >> 4];
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*buf++ = hexchars[ch & 0xf];
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}
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}
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} else {
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/* error condition */
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}
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debugger_fault_handler = NULL;
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*buf = 0;
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return buf;
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}
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/* convert the hex array pointed to by buf into binary to be placed in mem
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* return a pointer to the character AFTER the last byte written.
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*/
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static char *
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hex2mem(char *buf, char *mem, int count)
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{
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unsigned char ch;
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int i;
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char *orig_mem;
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unsigned short tmp_s;
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unsigned long tmp_l;
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orig_mem = mem;
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if (kgdb_setjmp((long*)fault_jmp_buf) == 0) {
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debugger_fault_handler = kgdb_fault_handler;
|
||
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|
||
|
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/* Accessing 16 bit and 32 bit objects in a single
|
||
|
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** store instruction is required to avoid bad side
|
||
|
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** effects for some IO registers.
|
||
|
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*/
|
||
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||
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if ((count == 2) && (((long)mem & 1) == 0)) {
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tmp_s = hex(*buf++) << 12;
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||
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tmp_s |= hex(*buf++) << 8;
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||
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tmp_s |= hex(*buf++) << 4;
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tmp_s |= hex(*buf++);
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||
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*(unsigned short *)mem = tmp_s;
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||
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mem += 2;
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||
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|
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||
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} else if ((count == 4) && (((long)mem & 3) == 0)) {
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||
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tmp_l = hex(*buf++) << 28;
|
||
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tmp_l |= hex(*buf++) << 24;
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||
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tmp_l |= hex(*buf++) << 20;
|
||
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tmp_l |= hex(*buf++) << 16;
|
||
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tmp_l |= hex(*buf++) << 12;
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||
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tmp_l |= hex(*buf++) << 8;
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tmp_l |= hex(*buf++) << 4;
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||
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tmp_l |= hex(*buf++);
|
||
|
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||
|
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*(unsigned long *)mem = tmp_l;
|
||
|
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mem += 4;
|
||
|
|
|
||
|
|
} else {
|
||
|
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for (i=0; i<count; i++) {
|
||
|
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ch = hex(*buf++) << 4;
|
||
|
|
ch |= hex(*buf++);
|
||
|
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*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);
|