forked from Imagelibrary/rtems
1172 lines
30 KiB
C
1172 lines
30 KiB
C
/*
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* This is the gdb i386 remote debug stub from gdb 4.XX.
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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 it's 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 386 by Jim Kingdon, Cygnus Support.
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* Modified for RTEMS by Aleksey Romanov, Quality Quorum, Inc.
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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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* The external function exceptionHandler() is
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* used to attach a specific handler to a specific 386 vector number.
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* It should use the same privilege level it runs at. It should
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* install it as an interrupt gate so that interrupts are masked
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* while the handler runs.
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* Also, need to assign exceptionHook and oldExceptionHook.
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*
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* Because gdb will sometimes write to the stack area to execute function
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* calls, this program cannot rely on using the supervisor stack so it
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* uses it's own stack area reserved in the int array remcomStack.
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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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*
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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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* 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 <stdio.h>
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#include <string.h>
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#include <stdbool.h>
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#include <bsp.h>
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/*
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* Number of debug registers.
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*/
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#define NUM_DEBUG_REGISTERS 4
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/*
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* Prototypes we need to avoid warnings but not going into public space.
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*/
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void bsp_reset(void);
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void breakpoint (void);
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void set_debug_traps(void);
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void set_mem_err(void);
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void _returnFromException(void);
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void exceptionHandler (int, void (*handler) (void));
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/************************************************************************
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*
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* external low-level support routines
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*/
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extern int putDebugChar (int ch); /* write a single character */
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extern int getDebugChar (void); /* read and return a single char */
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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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#define BUFMAX 400
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static bool initialized = false; /* boolean flag. != 0 means we've been initialized */
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extern int remote_debug;
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/* debug > 0 prints ill-formed commands in valid packets & checksum errors */
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extern void waitabit (void);
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static const char hexchars[] = "0123456789abcdef";
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/* Number of registers. */
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#define NUMREGS 16
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/* Number of bytes per register. */
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#define REGBYTES 4
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/* Number of bytes of registers. */
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#define NUMREGBYTES (NUMREGS * REGBYTES)
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enum regnames
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{
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EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI,
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PC /* also known as eip */ ,
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PS /* also known as eflags */ ,
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CS, SS, DS, ES, FS, GS
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};
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/*
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* these should not be static cuz they can be used outside this module
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*/
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int i386_gdb_registers[NUMREGS];
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#define STACKSIZE 10000
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int i386_gdb_remcomStack[STACKSIZE / sizeof (int)];
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int *i386_gdb_stackPtr = &i386_gdb_remcomStack[STACKSIZE / sizeof (int) - 1];
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static int gdb_connected;
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/*************************** ASSEMBLY CODE MACROS *************************/
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/* */
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extern void
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return_to_prog (void);
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/* Restore the program's registers (including the stack pointer, which
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means we get the right stack and don't have to worry about popping our
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return address and any stack frames and so on) and return. */
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__asm__ (".text");
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__asm__ (".globl return_to_prog");
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__asm__ ("return_to_prog:");
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__asm__ (" movw i386_gdb_registers+44, %ss");
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__asm__ (" movl i386_gdb_registers+16, %esp");
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__asm__ (" movl i386_gdb_registers+4, %ecx");
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__asm__ (" movl i386_gdb_registers+8, %edx");
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__asm__ (" movl i386_gdb_registers+12, %ebx");
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__asm__ (" movl i386_gdb_registers+20, %ebp");
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__asm__ (" movl i386_gdb_registers+24, %esi");
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__asm__ (" movl i386_gdb_registers+28, %edi");
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__asm__ (" movw i386_gdb_registers+48, %ds");
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__asm__ (" movw i386_gdb_registers+52, %es");
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__asm__ (" movw i386_gdb_registers+56, %fs");
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__asm__ (" movw i386_gdb_registers+60, %gs");
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__asm__ (" movl i386_gdb_registers+36, %eax");
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__asm__ (" pushl %eax"); /* saved eflags */
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__asm__ (" movl i386_gdb_registers+40, %eax");
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__asm__ (" pushl %eax"); /* saved cs */
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__asm__ (" movl i386_gdb_registers+32, %eax");
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__asm__ (" pushl %eax"); /* saved eip */
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__asm__ (" movl i386_gdb_registers, %eax");
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/* use iret to restore pc and flags together so
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that trace flag works right. */
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__asm__ (" iret");
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#define BREAKPOINT() __asm__ (" int $3");
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/* Put the error code here just in case the user cares. */
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int gdb_i386errcode;
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/* Likewise, the vector number here (since GDB only gets the signal
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number through the usual means, and that's not very specific). */
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int gdb_i386vector = -1;
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/* GDB stores segment registers in 32-bit words (that's just the way
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m-i386v.h is written). So zero the appropriate areas in registers. */
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#define SAVE_REGISTERS1() \
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__asm__ ("movl %eax, i386_gdb_registers"); \
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__asm__ ("movl %ecx, i386_gdb_registers+4"); \
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__asm__ ("movl %edx, i386_gdb_registers+8"); \
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__asm__ ("movl %ebx, i386_gdb_registers+12"); \
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__asm__ ("movl %ebp, i386_gdb_registers+20"); \
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__asm__ ("movl %esi, i386_gdb_registers+24"); \
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__asm__ ("movl %edi, i386_gdb_registers+28"); \
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__asm__ ("movw $0, %ax"); \
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__asm__ ("movw %ds, i386_gdb_registers+48"); \
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__asm__ ("movw %ax, i386_gdb_registers+50"); \
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__asm__ ("movw %es, i386_gdb_registers+52"); \
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__asm__ ("movw %ax, i386_gdb_registers+54"); \
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__asm__ ("movw %fs, i386_gdb_registers+56"); \
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__asm__ ("movw %ax, i386_gdb_registers+58"); \
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__asm__ ("movw %gs, i386_gdb_registers+60"); \
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__asm__ ("movw %ax, i386_gdb_registers+62");
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#define SAVE_ERRCODE() \
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__asm__ ("popl %ebx"); \
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__asm__ ("movl %ebx, gdb_i386errcode");
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#define SAVE_REGISTERS2() \
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__asm__ ("popl %ebx"); /* old eip */ \
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__asm__ ("movl %ebx, i386_gdb_registers+32"); \
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__asm__ ("popl %ebx"); /* old cs */ \
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__asm__ ("movl %ebx, i386_gdb_registers+40"); \
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__asm__ ("movw %ax, i386_gdb_registers+42"); \
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__asm__ ("popl %ebx"); /* old eflags */ \
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__asm__ ("movl %ebx, i386_gdb_registers+36"); \
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/* Now that we've done the pops, we can save the stack pointer."); */ \
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__asm__ ("movw %ss, i386_gdb_registers+44"); \
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__asm__ ("movw %ax, i386_gdb_registers+46"); \
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__asm__ ("movl %esp, i386_gdb_registers+16");
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/* See if mem_fault_routine is set, if so just IRET to that address. */
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#define CHECK_FAULT() \
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__asm__ ("cmpl $0, mem_fault_routine"); \
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__asm__ ("jne mem_fault");
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__asm__ (".text");
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__asm__ ("mem_fault:");
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/* OK to clobber temp registers; we're just going to end up in set_mem_err. */
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/* Pop error code from the stack and save it. */
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__asm__ (" popl %eax");
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__asm__ (" movl %eax, gdb_i386errcode");
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__asm__ (" popl %eax"); /* eip */
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/* We don't want to return there, we want to return to the function
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pointed to by mem_fault_routine instead. */
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__asm__ (" movl mem_fault_routine, %eax");
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__asm__ (" popl %ecx"); /* cs (low 16 bits; junk in hi 16 bits). */
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__asm__ (" popl %edx"); /* eflags */
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/* Remove this stack frame; when we do the iret, we will be going to
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the start of a function, so we want the stack to look just like it
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would after a "call" instruction. */
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__asm__ (" leave");
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/* Push the stuff that iret wants. */
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__asm__ (" pushl %edx"); /* eflags */
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__asm__ (" pushl %ecx"); /* cs */
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__asm__ (" pushl %eax"); /* eip */
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/* Zero mem_fault_routine. */
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__asm__ (" movl $0, %eax");
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__asm__ (" movl %eax, mem_fault_routine");
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__asm__ ("iret");
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#define CALL_HOOK() __asm__ ("call _remcomHandler");
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/* This function is called when a i386 exception occurs. It saves
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* all the cpu regs in the registers array, munges the stack a bit,
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* and invokes an exception handler (remcom_handler).
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*
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* stack on entry: stack on exit:
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* old eflags vector number
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* old cs (zero-filled to 32 bits)
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* old eip
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*
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*/
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extern void _catchException3 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException3");
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__asm__ ("_catchException3:");
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SAVE_REGISTERS1 ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $3");
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CALL_HOOK ();
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/* Same thing for exception 1. */
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extern void _catchException1 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException1");
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__asm__ ("_catchException1:");
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SAVE_REGISTERS1 ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $1");
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CALL_HOOK ();
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/* Same thing for exception 0. */
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extern void _catchException0 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException0");
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__asm__ ("_catchException0:");
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SAVE_REGISTERS1 ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $0");
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CALL_HOOK ();
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/* Same thing for exception 4. */
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extern void _catchException4 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException4");
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__asm__ ("_catchException4:");
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SAVE_REGISTERS1 ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $4");
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CALL_HOOK ();
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/* Same thing for exception 5. */
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extern void _catchException5 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException5");
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__asm__ ("_catchException5:");
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SAVE_REGISTERS1 ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $5");
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CALL_HOOK ();
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/* Same thing for exception 6. */
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extern void _catchException6 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException6");
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__asm__ ("_catchException6:");
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SAVE_REGISTERS1 ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $6");
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CALL_HOOK ();
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/* Same thing for exception 7. */
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extern void _catchException7 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException7");
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__asm__ ("_catchException7:");
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SAVE_REGISTERS1 ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $7");
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CALL_HOOK ();
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/* Same thing for exception 8. */
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extern void _catchException8 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException8");
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__asm__ ("_catchException8:");
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SAVE_REGISTERS1 ();
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SAVE_ERRCODE ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $8");
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CALL_HOOK ();
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/* Same thing for exception 9. */
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extern void _catchException9 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException9");
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__asm__ ("_catchException9:");
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SAVE_REGISTERS1 ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $9");
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CALL_HOOK ();
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/* Same thing for exception 10. */
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extern void _catchException10 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException10");
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__asm__ ("_catchException10:");
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SAVE_REGISTERS1 ();
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SAVE_ERRCODE ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $10");
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CALL_HOOK ();
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/* Same thing for exception 12. */
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extern void _catchException12 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException12");
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__asm__ ("_catchException12:");
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SAVE_REGISTERS1 ();
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SAVE_ERRCODE ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $12");
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CALL_HOOK ();
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/* Same thing for exception 16. */
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extern void _catchException16 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException16");
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__asm__ ("_catchException16:");
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SAVE_REGISTERS1 ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $16");
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CALL_HOOK ();
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/* For 13, 11, and 14 we have to deal with the CHECK_FAULT stuff. */
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/* Same thing for exception 13. */
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extern void _catchException13 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException13");
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__asm__ ("_catchException13:");
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CHECK_FAULT ();
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SAVE_REGISTERS1 ();
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SAVE_ERRCODE ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $13");
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CALL_HOOK ();
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/* Same thing for exception 11. */
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extern void _catchException11 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException11");
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__asm__ ("_catchException11:");
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CHECK_FAULT ();
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SAVE_REGISTERS1 ();
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SAVE_ERRCODE ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $11");
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CALL_HOOK ();
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/* Same thing for exception 14. */
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extern void _catchException14 (void);
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__asm__ (".text");
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__asm__ (".globl _catchException14");
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__asm__ ("_catchException14:");
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CHECK_FAULT ();
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SAVE_REGISTERS1 ();
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SAVE_ERRCODE ();
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SAVE_REGISTERS2 ();
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__asm__ ("pushl $14");
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CALL_HOOK ();
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/*
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* remcomHandler is a front end for handle_exception. It moves the
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* stack pointer into an area reserved for debugger use.
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*/
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extern void remcomHandler (void);
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__asm__ ("_remcomHandler:");
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__asm__ (" popl %eax"); /* pop off return address */
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__asm__ (" popl %eax"); /* get the exception number */
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__asm__ (" movl i386_gdb_stackPtr, %esp"); /* move to remcom stack area */
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__asm__ (" pushl %eax"); /* push exception onto stack */
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__asm__ (" call handle_exception"); /* this never returns */
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void
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_returnFromException (void)
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{
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return_to_prog ();
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}
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|
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static int
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hex (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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/* scan for the sequence $<data>#<checksum> */
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|
static void
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getpacket (char *buffer)
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{
|
|
unsigned char checksum;
|
|
unsigned char xmitcsum;
|
|
int i;
|
|
int count;
|
|
char ch;
|
|
|
|
do
|
|
{
|
|
/* wait around for the start character, ignore all other characters */
|
|
while ((ch = (getDebugChar () & 0x7f)) != '$');
|
|
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))
|
|
{
|
|
printk ("bad checksum. My count = 0x%x, sent=0x%x. buf=%s\n",
|
|
checksum, xmitcsum, buffer);
|
|
}
|
|
|
|
if (remote_debug) {
|
|
printk("GETP: $%s...%s\n", buffer,
|
|
checksum == xmitcsum ? "Ack" : "Nack");
|
|
}
|
|
|
|
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 (checksum != xmitcsum);
|
|
|
|
}
|
|
|
|
/* send the packet in buffer. */
|
|
|
|
static void
|
|
putpacket (char *buffer)
|
|
{
|
|
/* $<packet info>#<checksum>. */
|
|
while (true)
|
|
{
|
|
unsigned char checksum;
|
|
int count;
|
|
char ch;
|
|
|
|
if (remote_debug)
|
|
printk("PUTP: $%s", buffer);
|
|
|
|
putDebugChar ('$');
|
|
checksum = 0;
|
|
count = 0;
|
|
|
|
while ((ch = buffer[count]))
|
|
{
|
|
if (!putDebugChar (ch))
|
|
return;
|
|
checksum += ch;
|
|
count += 1;
|
|
}
|
|
|
|
putDebugChar ('#');
|
|
putDebugChar (hexchars[checksum >> 4]);
|
|
putDebugChar (hexchars[checksum % 16]);
|
|
|
|
if (remote_debug)
|
|
printk("#%c%c...", hexchars[checksum >> 4], hexchars[checksum % 16]);
|
|
|
|
ch = getDebugChar () & 0x7f;
|
|
if (ch == '+') {
|
|
if (remote_debug)
|
|
printk("Ack\n");
|
|
break;
|
|
}
|
|
if (remote_debug)
|
|
printk("Nack(%c)\n", ch);
|
|
}
|
|
}
|
|
|
|
char remcomInBuffer[BUFMAX];
|
|
char remcomOutBuffer[BUFMAX];
|
|
static short error;
|
|
|
|
static void
|
|
debug_error (
|
|
char *format,
|
|
char *parm
|
|
)
|
|
{
|
|
if (remote_debug)
|
|
printk (format, parm);
|
|
}
|
|
|
|
/* Address of a routine to RTE to if we get a memory fault. */
|
|
static void (*volatile mem_fault_routine) (void) = NULL;
|
|
|
|
/* Indicate to caller of mem2hex or hex2mem that there has been an
|
|
error. */
|
|
static volatile int mem_err = 0;
|
|
|
|
void
|
|
set_mem_err (void)
|
|
{
|
|
mem_err = 1;
|
|
}
|
|
|
|
/* These are separate functions so that they are so short and sweet
|
|
that the compiler won't save any registers (if there is a fault
|
|
to mem_fault, they won't get restored, so there better not be any
|
|
saved). */
|
|
static int
|
|
get_char (char *addr)
|
|
{
|
|
return *addr;
|
|
}
|
|
|
|
static void
|
|
set_char (char *addr, int val)
|
|
{
|
|
*addr = val;
|
|
}
|
|
|
|
/* convert the memory pointed to by mem into hex, placing result in buf */
|
|
/* return a pointer to the last char put in buf (null) */
|
|
/* If MAY_FAULT is non-zero, then we should set mem_err in response to
|
|
a fault; if zero treat a fault like any other fault in the stub. */
|
|
static char *
|
|
mem2hex (char *mem, char *buf, int count, int may_fault)
|
|
{
|
|
int i;
|
|
unsigned char ch;
|
|
|
|
if (may_fault)
|
|
mem_fault_routine = set_mem_err;
|
|
for (i = 0; i < count; i++)
|
|
{
|
|
ch = get_char (mem++);
|
|
if (may_fault && mem_err)
|
|
return (buf);
|
|
*buf++ = hexchars[ch >> 4];
|
|
*buf++ = hexchars[ch % 16];
|
|
}
|
|
*buf = 0;
|
|
if (may_fault)
|
|
mem_fault_routine = NULL;
|
|
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, int may_fault)
|
|
{
|
|
int i;
|
|
unsigned char ch;
|
|
|
|
if (may_fault)
|
|
mem_fault_routine = set_mem_err;
|
|
for (i = 0; i < count; i++)
|
|
{
|
|
ch = hex (*buf++) << 4;
|
|
ch = ch + hex (*buf++);
|
|
set_char (mem++, ch);
|
|
if (may_fault && mem_err)
|
|
return (mem);
|
|
}
|
|
if (may_fault)
|
|
mem_fault_routine = NULL;
|
|
return (mem);
|
|
}
|
|
|
|
/* this function takes the 386 exception vector and attempts to
|
|
translate this number into a unix compatible signal value */
|
|
static int
|
|
computeSignal (int exceptionVector)
|
|
{
|
|
int sigval;
|
|
switch (exceptionVector)
|
|
{
|
|
case 0:
|
|
sigval = 8;
|
|
break; /* divide by zero */
|
|
case 1:
|
|
sigval = 5;
|
|
break; /* debug exception */
|
|
case 3:
|
|
sigval = 5;
|
|
break; /* breakpoint */
|
|
case 4:
|
|
sigval = 16;
|
|
break; /* into instruction (overflow) */
|
|
case 5:
|
|
sigval = 16;
|
|
break; /* bound instruction */
|
|
case 6:
|
|
sigval = 4;
|
|
break; /* Invalid opcode */
|
|
case 7:
|
|
sigval = 8;
|
|
break; /* coprocessor not available */
|
|
case 8:
|
|
sigval = 7;
|
|
break; /* double fault */
|
|
case 9:
|
|
sigval = 11;
|
|
break; /* coprocessor segment overrun */
|
|
case 10:
|
|
sigval = 11;
|
|
break; /* Invalid TSS */
|
|
case 11:
|
|
sigval = 11;
|
|
break; /* Segment not present */
|
|
case 12:
|
|
sigval = 11;
|
|
break; /* stack exception */
|
|
case 13:
|
|
sigval = 11;
|
|
break; /* general protection */
|
|
case 14:
|
|
sigval = 11;
|
|
break; /* page fault */
|
|
case 16:
|
|
sigval = 7;
|
|
break; /* coprocessor error */
|
|
default:
|
|
sigval = 7; /* "software generated" */
|
|
}
|
|
return (sigval);
|
|
}
|
|
|
|
/**********************************************/
|
|
/* 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;
|
|
|
|
while (**ptr)
|
|
{
|
|
hexValue = hex (**ptr);
|
|
if (hexValue >= 0)
|
|
{
|
|
*intValue = (*intValue << 4) | hexValue;
|
|
numChars++;
|
|
}
|
|
else
|
|
break;
|
|
|
|
(*ptr)++;
|
|
}
|
|
|
|
return (numChars);
|
|
}
|
|
|
|
/*
|
|
* Get/Set the DR registers.
|
|
*/
|
|
static uint32_t getDR7(void)
|
|
{
|
|
uint32_t value = 0;
|
|
asm volatile (" movl %%dr7, %0;" : "=r" (value) : : );
|
|
return value;
|
|
}
|
|
|
|
static void setDR7(uint32_t value)
|
|
{
|
|
asm volatile (" movl %0, %%dr7;" : : "r" (value) : );
|
|
}
|
|
|
|
static uint32_t getDR(int reg)
|
|
{
|
|
uint32_t value = 0;
|
|
switch (reg)
|
|
{
|
|
case 0:
|
|
asm volatile (" movl %%dr0, %0;" : "=r" (value) : : );
|
|
break;
|
|
case 1:
|
|
asm volatile (" movl %%dr1, %0;" : "=r" (value) : : );
|
|
break;
|
|
case 2:
|
|
asm volatile (" movl %%dr2, %0;" : "=r" (value) : : );
|
|
break;
|
|
case 3:
|
|
asm volatile (" movl %%dr3, %0;" : "=r" (value) : : );
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return value;
|
|
}
|
|
|
|
static void setDR(int reg, uint32_t addr)
|
|
{
|
|
switch (reg)
|
|
{
|
|
case 0:
|
|
asm volatile (" movl %0, %%dr0;" : : "r" (addr) : );
|
|
break;
|
|
case 1:
|
|
asm volatile (" movl %0, %%dr1;" : : "r" (addr) : );
|
|
break;
|
|
case 2:
|
|
asm volatile (" movl %0, %%dr2;" : : "r" (addr) : );
|
|
break;
|
|
case 3:
|
|
asm volatile (" movl %0, %%dr3;" : : "r" (addr) : );
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This function does all command procesing for interfacing to gdb.
|
|
*
|
|
* NOTE: This method is called from assembly code so must be marked
|
|
* as used.
|
|
*/
|
|
static void handle_exception (int exceptionVector) __attribute__((used));
|
|
static void
|
|
handle_exception (int exceptionVector)
|
|
{
|
|
int sigval;
|
|
int addr, length, reg;
|
|
char *ptr;
|
|
|
|
gdb_i386vector = exceptionVector;
|
|
|
|
if (remote_debug)
|
|
printk ("GDB: EXECPTION: vector=%d, sr=0x%x, pc=0x%x\n",
|
|
exceptionVector,
|
|
i386_gdb_registers[PS],
|
|
i386_gdb_registers[PC]);
|
|
|
|
/* Reply to host that an exception has occurred. Always return the
|
|
PC, SP, and FP, since gdb always wants them. */
|
|
ptr = remcomOutBuffer;
|
|
*ptr++ = 'T';
|
|
sigval = computeSignal (exceptionVector);
|
|
*ptr++ = hexchars[sigval >> 4];
|
|
*ptr++ = hexchars[sigval % 16];
|
|
|
|
*ptr++ = hexchars[ESP];
|
|
*ptr++ = ':';
|
|
mem2hex ((char *) &i386_gdb_registers[ESP], ptr, REGBYTES, 0);
|
|
ptr += REGBYTES * 2;
|
|
*ptr++ = ';';
|
|
|
|
*ptr++ = hexchars[EBP];
|
|
*ptr++ = ':';
|
|
mem2hex ((char *) &i386_gdb_registers[EBP], ptr, REGBYTES, 0);
|
|
ptr += REGBYTES * 2;
|
|
*ptr++ = ';';
|
|
|
|
*ptr++ = hexchars[PC];
|
|
*ptr++ = ':';
|
|
mem2hex ((char *) &i386_gdb_registers[PC], ptr, REGBYTES, 0);
|
|
ptr += REGBYTES * 2;
|
|
*ptr++ = ';';
|
|
|
|
*ptr = '\0';
|
|
|
|
if (gdb_connected)
|
|
putpacket (remcomOutBuffer);
|
|
|
|
while (1 == 1)
|
|
{
|
|
error = 0;
|
|
remcomOutBuffer[0] = 0;
|
|
getpacket (remcomInBuffer);
|
|
gdb_connected = 1;
|
|
switch (remcomInBuffer[0])
|
|
{
|
|
case '?':
|
|
remcomOutBuffer[0] = 'S';
|
|
remcomOutBuffer[1] = hexchars[sigval >> 4];
|
|
remcomOutBuffer[2] = hexchars[sigval % 16];
|
|
remcomOutBuffer[3] = 0;
|
|
break;
|
|
case 'd': /* remove */
|
|
remote_debug = !(remote_debug); /* toggle debug flag */
|
|
break;
|
|
case 'g': /* return the value of the CPU registers */
|
|
mem2hex ((char *) i386_gdb_registers, remcomOutBuffer, NUMREGBYTES, 0);
|
|
break;
|
|
case 'G': /* set the value of the CPU registers - return OK */
|
|
hex2mem (&remcomInBuffer[1], (char *) i386_gdb_registers, NUMREGBYTES, 0);
|
|
strcpy (remcomOutBuffer, "OK");
|
|
break;
|
|
|
|
case 'P': /* Set specific register */
|
|
ptr = &remcomInBuffer[1];
|
|
if (hexToInt (&ptr, ®)
|
|
&& *ptr++ == '=')
|
|
{
|
|
hex2mem (ptr, (char *) &i386_gdb_registers[reg], REGBYTES, 0);
|
|
strcpy (remcomOutBuffer, "OK");
|
|
}
|
|
else
|
|
{
|
|
strcpy (remcomOutBuffer, "E01");
|
|
debug_error ("malformed register set command; %s",
|
|
remcomInBuffer);
|
|
}
|
|
break;
|
|
|
|
/* 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))
|
|
{
|
|
ptr = 0;
|
|
mem_err = 0;
|
|
mem2hex ((char *) addr, remcomOutBuffer, length, 1);
|
|
if (mem_err)
|
|
{
|
|
strcpy (remcomOutBuffer, "E03");
|
|
debug_error ("memory fault", 0);
|
|
}
|
|
}
|
|
|
|
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++) == ':')
|
|
{
|
|
mem_err = 0;
|
|
hex2mem (ptr, (char *) addr, length, 1);
|
|
|
|
if (mem_err)
|
|
{
|
|
strcpy (remcomOutBuffer, "E03");
|
|
debug_error ("memory fault", 0);
|
|
}
|
|
else
|
|
{
|
|
strcpy (remcomOutBuffer, "OK");
|
|
}
|
|
|
|
ptr = 0;
|
|
}
|
|
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':
|
|
/* try to read optional parameter, pc unchanged if no parm */
|
|
ptr = &remcomInBuffer[1];
|
|
if (hexToInt (&ptr, &addr))
|
|
i386_gdb_registers[PC] = addr;
|
|
|
|
/* clear the trace bit */
|
|
i386_gdb_registers[PS] &= 0xfffffeff;
|
|
|
|
/* set the trace bit if we're stepping */
|
|
if (remcomInBuffer[0] == 's')
|
|
i386_gdb_registers[PS] |= 0x100;
|
|
|
|
_returnFromException (); /* this is a jump */
|
|
break;
|
|
|
|
case 'Z':
|
|
case 'z':
|
|
/*
|
|
* Z1 = execute (00b)
|
|
* Z2 = write (01b)
|
|
* Z3 = read (??, need to use 11b))
|
|
* Z4 = read/write (11b)
|
|
*/
|
|
ptr = &remcomInBuffer[1];
|
|
reg = *(ptr++);
|
|
if (reg == '0')
|
|
break;
|
|
printk("hbreak\n");
|
|
switch ((char) reg)
|
|
{
|
|
case '1':
|
|
reg = 0;
|
|
break;
|
|
case '2':
|
|
reg = 1;
|
|
case '3':
|
|
case '4':
|
|
default:
|
|
reg = 3;
|
|
break;
|
|
}
|
|
if (*(ptr++) == ',')
|
|
{
|
|
bool insert = remcomInBuffer[0] == 'Z';
|
|
if (hexToInt (&ptr, &addr))
|
|
{
|
|
if (*(ptr++) == ',')
|
|
{
|
|
uint32_t dr7;
|
|
int i;
|
|
hexToInt(&ptr, &length);
|
|
dr7 = getDR7();
|
|
for (i = 0; i < NUM_DEBUG_REGISTERS; ++i)
|
|
{
|
|
if ((dr7 & (2 << (i * 2))) == 0)
|
|
{
|
|
if (insert)
|
|
{
|
|
setDR(i, addr);
|
|
dr7 |=
|
|
((length - 1) << ((i * 2) + 18)) |
|
|
(reg << ((i * 2) + 16)) |
|
|
(2 << (i * 2));
|
|
setDR7(dr7);
|
|
printk("set DR%i to %08x\n", i, addr);
|
|
break;
|
|
}
|
|
}
|
|
else if (!insert)
|
|
{
|
|
uint32_t dra = getDR(i);
|
|
if (dra == addr)
|
|
{
|
|
dr7 &= ~(2 << (i * 2));
|
|
setDR7(dr7);
|
|
printk("clear DR%i\n", i);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (insert && (i == NUM_DEBUG_REGISTERS))
|
|
{
|
|
ptr = 0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
ptr = 0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
ptr = 0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
ptr = 0;
|
|
}
|
|
|
|
if (ptr)
|
|
strcpy (remcomOutBuffer, "OK");
|
|
else
|
|
strcpy (remcomOutBuffer, "E1");
|
|
break;
|
|
|
|
/* Detach. */
|
|
case 'D':
|
|
putpacket (remcomOutBuffer);
|
|
i386_gdb_registers[PS] &= 0xfffffeff;
|
|
_returnFromException (); /* this is a jump */
|
|
break;
|
|
|
|
/* kill the program */
|
|
case 'k': /* do nothing */
|
|
bsp_reset();
|
|
continue;
|
|
|
|
default:
|
|
break;
|
|
} /* switch */
|
|
|
|
/* reply to the request */
|
|
putpacket (remcomOutBuffer);
|
|
}
|
|
}
|
|
|
|
/* this function is used to set up exception handlers for tracing and
|
|
breakpoints */
|
|
void
|
|
set_debug_traps (void)
|
|
{
|
|
i386_gdb_stackPtr = &i386_gdb_remcomStack[STACKSIZE / sizeof (int) - 1];
|
|
|
|
exceptionHandler (0, _catchException0);
|
|
exceptionHandler (1, _catchException1);
|
|
exceptionHandler (3, _catchException3);
|
|
exceptionHandler (4, _catchException4);
|
|
exceptionHandler (5, _catchException5);
|
|
exceptionHandler (6, _catchException6);
|
|
exceptionHandler (7, _catchException7);
|
|
exceptionHandler (8, _catchException8);
|
|
exceptionHandler (9, _catchException9);
|
|
exceptionHandler (10, _catchException10);
|
|
exceptionHandler (11, _catchException11);
|
|
exceptionHandler (12, _catchException12);
|
|
exceptionHandler (13, _catchException13);
|
|
exceptionHandler (14, _catchException14);
|
|
exceptionHandler (16, _catchException16);
|
|
|
|
/* In case GDB is started before us, ack any packets (presumably
|
|
"$?#xx") sitting there. */
|
|
putDebugChar ('+');
|
|
|
|
initialized = true;
|
|
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
BREAKPOINT ();
|
|
}
|
|
waitabit ();
|
|
}
|
|
|
|
int waitlimit = 1000000;
|
|
|
|
void
|
|
waitabit (void)
|
|
{
|
|
int i;
|
|
for (i = 0; i < waitlimit; i++);
|
|
}
|