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https://github.com/darlinghq/darling-gdb.git
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Initial revision
This commit is contained in:
John Gilmore
parent
5d98a5cd94
commit
bd313dad25
980
gdb/m68k-stub.c
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980
gdb/m68k-stub.c
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@ -0,0 +1,980 @@
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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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||||
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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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/****************************************************************************
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* $Header$
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*
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* $Module name: remcom.c $
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* $Revision$
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* $Date$
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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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* 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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* Some explanation is probably necessary to explain how exceptions are
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* handled. When an exception is encountered the 68000 pushes the current
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* program counter and status register onto the supervisor stack and then
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* transfers execution to a location specified in it's vector table.
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* The handlers for the exception vectors are hardwired to jmp to an address
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* given by the relation: (exception - 256) * 6. These are decending
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* addresses starting from -6, -12, -18, ... By allowing 6 bytes for
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* each entry, a jsr, jmp, bsr, ... can be used to enter the exception
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* handler. Using a jsr to handle an exception has an added benefit of
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* allowing a single handler to service several exceptions and use the
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* return address as the key differentiation. The vector number can be
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* computed from the return address by [ exception = (addr + 1530) / 6 ].
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* The sole purpose of the routine _catchException is to compute the
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* exception number and push it on the stack in place of the return address.
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* The external function exceptionHandler() is
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* used to attach a specific handler to a specific 68k exception.
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* For 68020 machines, the ability to have a return address around just
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* so the vector can be determined is not necessary because the '020 pushes an
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* extra word onto the stack containing the vector offset
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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 <setjmp.h>
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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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typedef void (*ExceptionHook)(int); /* pointer to function with int parm */
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typedef void (*Function)(); /* pointer to a function */
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extern putDebugChar(); /* write a single character */
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extern getDebugChar(); /* read and return a single char */
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extern Function exceptionHandler(); /* assign an exception handler */
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extern ExceptionHook exceptionHook; /* hook variable for errors/exceptions */
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/************************/
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/* FORWARD DECLARATIONS */
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/************************/
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void initializeRemcomErrorFrame(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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#define BUFMAX 400
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static char initialized; /* boolean flag. != 0 means we've been initialized */
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int remote_debug;
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/* debug > 0 prints ill-formed commands in valid packets & checksum errors */
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static const char hexchars[]="0123456789abcdef";
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/* there are 180 bytes of registers on a 68020 w/68881 */
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/* many of the fpa registers are 12 byte (96 bit) registers */
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#define NUMREGBYTES 180
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enum regnames {D0,D1,D2,D3,D4,D5,D6,D7,
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A0,A1,A2,A3,A4,A5,A6,A7,
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PS,PC,
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FP0,FP1,FP2,FP3,FP4,FP5,FP6,FP7,
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FPCONTROL,FPSTATUS,FPIADDR
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};
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typedef struct FrameStruct
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{
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struct FrameStruct *previous;
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int exceptionPC; /* pc value when this frame created */
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int exceptionVector; /* cpu vector causing exception */
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short frameSize; /* size of cpu frame in words */
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short sr; /* for 68000, this not always sr */
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int pc;
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short format;
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int fsaveHeader;
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int morejunk[0]; /* exception frame, fp save... */
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} Frame;
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#define FRAMESIZE 500
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int gdbFrameStack[FRAMESIZE];
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static Frame *lastFrame;
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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 registers[NUMREGBYTES/4];
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int superStack;
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#define STACKSIZE 10000
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int remcomStack[STACKSIZE/sizeof(int)];
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static int* stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1];
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/*
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* In many cases, the system will want to continue exception processing
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* when a continue command is given.
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* oldExceptionHook is a function to invoke in this case.
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||||
*/
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static ExceptionHook oldExceptionHook;
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/* the size of the exception stack on the 68020 varies with the type of
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* exception. The following table is the number of WORDS used
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* for each exception format.
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*/
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const short exceptionSize[] = { 4,4,6,4,4,4,4,4,29,10,16,46,12,4,4,4 };
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/************* jump buffer used for setjmp/longjmp **************************/
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jmp_buf remcomEnv;
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/*************************** ASSEMBLY CODE MACROS *************************/
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/* */
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#ifdef __HAVE_68881__
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/* do an fsave, then remember the address to begin a restore from */
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#define SAVE_FP_REGS() asm(" fsave a0@-"); \
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asm(" fmovemx fp0-fp7,_registers+72"); \
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asm(" fmoveml fpcr/fpsr/fpi,_registers+168");
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#define RESTORE_FP_REGS() \
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asm(" \n\
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fmoveml _registers+168,fpcr/fpsr/fpi \n\
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fmovemx _registers+72,fp0-fp7 \n\
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cmpl #-1,a0@ | skip frestore flag set ? \n\
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beq skip_frestore \n\
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frestore a0@+ \n\
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skip_frestore: \n\
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");
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#else
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#define SAVE_FP_REGS()
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#define RESTORE_FP_REGS()
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#endif /* __HAVE_68881__ */
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void return_to_super(void);
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void return_to_user(void);
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asm("
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.text
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.globl _return_to_super
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_return_to_super:
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movel _registers+60,sp /* get new stack pointer */
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movel _lastFrame,a0 /* get last frame info */
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bra return_to_any
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.globl _return_to_user
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_return_to_user:
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movel _registers+60,a0 /* get usp */
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movel a0,usp /* set usp */
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movel _superStack,sp /* get original stack pointer */
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return_to_any:
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movel _lastFrame,a0 /* get last frame info */
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movel a0@+,_lastFrame /* link in previous frame */
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addql #8,a0 /* skip over pc, vector#*/
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movew a0@+,d0 /* get # of words in cpu frame */
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addw d0,a0 /* point to end of data */
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addw d0,a0 /* point to end of data */
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movel a0,a1
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#
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# copy the stack frame
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subql #1,d0
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copyUserLoop:
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movew a1@-,sp@-
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dbf d0,copyUserLoop
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");
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RESTORE_FP_REGS()
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asm(" moveml _registers,d0-d7/a0-a6");
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asm(" rte"); /* pop and go! */
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|
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#define DISABLE_INTERRUPTS() asm(" oriw #0x0700,sr");
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||||
#define BREAKPOINT() asm(" trap #1");
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/* this function is called immediately when a level 7 interrupt occurs */
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/* if the previous interrupt level was 7 then we're already servicing */
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/* this interrupt and an rte is in order to return to the debugger. */
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/* For the 68000, the offset for sr is 6 due to the jsr return address */
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asm("
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.text
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.globl __debug_level7
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__debug_level7:
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movew d0,sp@-");
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#ifdef mc68020
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asm(" movew sp@(2),d0");
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#else
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asm(" movew sp@(6),d0");
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#endif
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asm(" andiw #0x700,d0
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cmpiw #0x700,d0
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beq _already7
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movew sp@+,d0
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||||
bra __catchException
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_already7:
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movew sp@+,d0");
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#ifndef mc68020
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asm(" lea sp@(4),sp"); /* pull off 68000 return address */
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||||
#endif
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asm(" rte");
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||||
|
||||
extern void _catchException();
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||||
|
||||
#ifdef mc68020
|
||||
/* This function is called when a 68020 exception occurs. It saves
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||||
* all the cpu and fpcp regs in the _registers array, creates a frame on a
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* linked list of frames which has the cpu and fpcp stack frames needed
|
||||
* to properly restore the context of these processors, and invokes
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* an exception handler (remcom_handler).
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||||
*
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||||
* stack on entry: stack on exit:
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* N bytes of junk exception # MSWord
|
||||
* Exception Format Word exception # MSWord
|
||||
* Program counter LSWord
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||||
* Program counter MSWord
|
||||
* Status Register
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||||
*
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||||
*
|
||||
*/
|
||||
asm("
|
||||
.text
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||||
.globl __catchException
|
||||
__catchException:");
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DISABLE_INTERRUPTS();
|
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asm("
|
||||
moveml d0-d7/a0-a6,_registers /* save registers */
|
||||
movel _lastFrame,a0 /* last frame pointer */
|
||||
");
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SAVE_FP_REGS();
|
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asm("
|
||||
lea _registers,a5 /* get address of registers */
|
||||
movew sp@,d1 /* get status register */
|
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movew d1,a5@(66) /* save sr */
|
||||
movel sp@(2),a4 /* save pc in a4 for later use */
|
||||
movel a4,a5@(68) /* save pc in _regisers[] */
|
||||
|
||||
#
|
||||
# figure out how many bytes in the stack frame
|
||||
movew sp@(6),d0 /* get '020 exception format */
|
||||
movew d0,d2 /* make a copy of format word */
|
||||
andiw #0xf000,d0 /* mask off format type */
|
||||
rolw #5,d0 /* rotate into the low byte *2 */
|
||||
lea _exceptionSize,a1
|
||||
addw d0,a1 /* index into the table */
|
||||
movew a1@,d0 /* get number of words in frame */
|
||||
movew d0,d3 /* save it */
|
||||
subw d0,a0 /* adjust save pointer */
|
||||
subw d0,a0 /* adjust save pointer(bytes) */
|
||||
movel a0,a1 /* copy save pointer */
|
||||
subql #1,d0 /* predecrement loop counter */
|
||||
#
|
||||
# copy the frame
|
||||
saveFrameLoop:
|
||||
movew sp@+,a1@+
|
||||
dbf d0,saveFrameLoop
|
||||
#
|
||||
# now that the stack has been clenaed,
|
||||
# save the a7 in use at time of exception
|
||||
movel sp,_superStack /* save supervisor sp */
|
||||
andiw #0x2000,d1 /* were we in supervisor mode ? */
|
||||
beq userMode
|
||||
movel a7,a5@(60) /* save a7 */
|
||||
bra a7saveDone
|
||||
userMode:
|
||||
movel usp,a1
|
||||
movel a1,a5@(60) /* save user stack pointer */
|
||||
a7saveDone:
|
||||
|
||||
#
|
||||
# save size of frame
|
||||
movew d3,a0@-
|
||||
|
||||
#
|
||||
# compute exception number
|
||||
andl #0xfff,d2 /* mask off vector offset */
|
||||
lsrw #2,d2 /* divide by 4 to get vect num */
|
||||
movel d2,a0@- /* save it */
|
||||
#
|
||||
# save pc causing exception
|
||||
movel a4,a0@-
|
||||
#
|
||||
# save old frame link and set the new value
|
||||
movel _lastFrame,a1 /* last frame pointer */
|
||||
movel a1,a0@- /* save pointer to prev frame */
|
||||
movel a0,_lastFrame
|
||||
|
||||
movel d2,sp@- /* push exception num */
|
||||
movel _exceptionHook,a0 /* get address of handler */
|
||||
jbsr a0@ /* and call it */
|
||||
clrl sp@ /* replace exception num parm with frame ptr */
|
||||
jbsr __returnFromException /* jbsr, but never returns */
|
||||
");
|
||||
#else /* mc68000 */
|
||||
/* This function is called when an exception occurs. It translates the
|
||||
* return address found on the stack into an exception vector # which
|
||||
* is then handled by either handle_exception or a system handler.
|
||||
* _catchException provides a front end for both.
|
||||
*
|
||||
* stack on entry: stack on exit:
|
||||
* Program counter MSWord exception # MSWord
|
||||
* Program counter LSWord exception # MSWord
|
||||
* Status Register
|
||||
* Return Address MSWord
|
||||
* Return Address LSWord
|
||||
*/
|
||||
asm("
|
||||
.text
|
||||
.globl __catchException
|
||||
__catchException:");
|
||||
DISABLE_INTERRUPTS();
|
||||
asm("
|
||||
moveml d0-d7/a0-a6,_registers /* save registers */
|
||||
movel _lastFrame,a0 /* last frame pointer */
|
||||
");
|
||||
SAVE_FP_REGS();
|
||||
asm("
|
||||
lea _registers,a5 /* get address of registers */
|
||||
movel sp@+,d2 /* pop return address */
|
||||
addl #1530,d2 /* convert return addr to */
|
||||
divs #6,d2 /* exception number */
|
||||
extl d2
|
||||
|
||||
moveql #3,d3 /* assume a three word frame */
|
||||
|
||||
cmpiw #3,d2 /* bus error or address error ? */
|
||||
bgt normal /* if >3 then normal error */
|
||||
movel sp@+,a0@- /* copy error info to frame buff*/
|
||||
movel sp@+,a0@- /* these are never used */
|
||||
moveql #7,d3 /* this is a 7 word frame */
|
||||
|
||||
normal:
|
||||
movew sp@+,d1 /* pop status register */
|
||||
movel sp@+,a4 /* pop program counter */
|
||||
movew d1,a5@(66) /* save sr */
|
||||
movel a4,a5@(68) /* save pc in _regisers[] */
|
||||
movel a4,a0@- /* copy pc to frame buffer */
|
||||
movew d1,a0@- /* copy sr to frame buffer */
|
||||
|
||||
movel sp,_superStack /* save supervisor sp */
|
||||
|
||||
andiw #0x2000,d1 /* were we in supervisor mode ? */
|
||||
beq userMode
|
||||
movel a7,a5@(60) /* save a7 */
|
||||
bra saveDone
|
||||
userMode:
|
||||
movel usp,a1 /* save user stack pointer */
|
||||
movel a1,a5@(60) /* save user stack pointer */
|
||||
saveDone:
|
||||
|
||||
movew d3,a0@- /* push frame size in words */
|
||||
movel d2,a0@- /* push vector number */
|
||||
movel a4,a0@- /* push exception pc */
|
||||
|
||||
#
|
||||
# save old frame link and set the new value
|
||||
movel _lastFrame,a1 /* last frame pointer */
|
||||
movel a1,a0@- /* save pointer to prev frame */
|
||||
movel a0,_lastFrame
|
||||
|
||||
movel d2,sp@- /* push exception num */
|
||||
movel _exceptionHook,a0 /* get address of handler */
|
||||
jbsr a0@ /* and call it */
|
||||
clrl sp@ /* replace exception num parm with frame ptr */
|
||||
jbsr __returnFromException /* jbsr, but never returns */
|
||||
");
|
||||
#endif
|
||||
|
||||
|
||||
/*
|
||||
* remcomHandler is a front end for handle_exception. It moves the
|
||||
* stack pointer into an area reserved for debugger use in case the
|
||||
* breakpoint happened in supervisor mode.
|
||||
*/
|
||||
asm("_remcomHandler:");
|
||||
asm(" addl #4,sp"); /* pop off return address */
|
||||
asm(" movel sp@+,d0"); /* get the exception number */
|
||||
asm(" movel _stackPtr,sp"); /* move to remcom stack area */
|
||||
asm(" movel d0,sp@-"); /* push exception onto stack */
|
||||
asm(" jbsr _handle_exception"); /* this never returns */
|
||||
asm(" rts"); /* return */
|
||||
|
||||
void _returnFromException( Frame *frame )
|
||||
{
|
||||
/* if no passed in frame, use the last one */
|
||||
if (! frame)
|
||||
{
|
||||
frame = lastFrame;
|
||||
frame->frameSize = 4;
|
||||
frame->format = 0;
|
||||
frame->fsaveHeader = -1; /* restore regs, but we dont have fsave info*/
|
||||
}
|
||||
|
||||
#ifndef mc68020
|
||||
/* a 68000 cannot use the internal info pushed onto a bus error
|
||||
* or address error frame when doing an RTE so don't put this info
|
||||
* onto the stack or the stack will creep every time this happens.
|
||||
*/
|
||||
frame->frameSize=3;
|
||||
#endif
|
||||
|
||||
/* throw away any frames in the list after this frame */
|
||||
lastFrame = frame;
|
||||
|
||||
frame->sr = registers[(int) PS];
|
||||
frame->pc = registers[(int) PC];
|
||||
|
||||
if (registers[(int) PS] & 0x2000)
|
||||
{
|
||||
/* return to supervisor mode... */
|
||||
return_to_super();
|
||||
}
|
||||
else
|
||||
{ /* return to user mode */
|
||||
return_to_user();
|
||||
}
|
||||
}
|
||||
|
||||
int hex(ch)
|
||||
char ch;
|
||||
{
|
||||
if ((ch >= 'a') && (ch <= 'f')) return (ch-'a'+10);
|
||||
if ((ch >= '0') && (ch <= '9')) return (ch-'0');
|
||||
if ((ch >= 'A') && (ch <= 'F')) return (ch-'A'+10);
|
||||
return (-1);
|
||||
}
|
||||
|
||||
|
||||
/* scan for the sequence $<data>#<checksum> */
|
||||
void getpacket(buffer)
|
||||
char * buffer;
|
||||
{
|
||||
unsigned char checksum;
|
||||
unsigned char xmitcsum;
|
||||
int i;
|
||||
int count;
|
||||
char ch;
|
||||
|
||||
do {
|
||||
/* wait around for the start character, ignore all other characters */
|
||||
while ((ch = getDebugChar()) != '$');
|
||||
checksum = 0;
|
||||
xmitcsum = -1;
|
||||
|
||||
count = 0;
|
||||
|
||||
/* now, read until a # or end of buffer is found */
|
||||
while (count < BUFMAX) {
|
||||
ch = getDebugChar();
|
||||
if (ch == '#') break;
|
||||
checksum = checksum + ch;
|
||||
buffer[count] = ch;
|
||||
count = count + 1;
|
||||
}
|
||||
buffer[count] = 0;
|
||||
|
||||
if (ch == '#') {
|
||||
xmitcsum = hex(getDebugChar()) << 4;
|
||||
xmitcsum += hex(getDebugChar());
|
||||
if ((remote_debug ) && (checksum != xmitcsum)) {
|
||||
fprintf(stderr,"bad checksum. My count = 0x%x, sent=0x%x. buf=%s\n",
|
||||
checksum,xmitcsum,buffer);
|
||||
}
|
||||
|
||||
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. The host get's one chance to read it.
|
||||
This routine does not wait for a positive acknowledge. */
|
||||
|
||||
|
||||
void putpacket(buffer)
|
||||
char * buffer;
|
||||
{
|
||||
unsigned char checksum;
|
||||
int count;
|
||||
char ch;
|
||||
|
||||
/* $<packet info>#<checksum>. */
|
||||
do {
|
||||
putDebugChar('$');
|
||||
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]);
|
||||
|
||||
} while (1 == 0); /* (getDebugChar() != '+'); */
|
||||
|
||||
}
|
||||
|
||||
char remcomInBuffer[BUFMAX];
|
||||
char remcomOutBuffer[BUFMAX];
|
||||
static short error;
|
||||
|
||||
|
||||
void debug_error(format, parm)
|
||||
char * format;
|
||||
char * parm;
|
||||
{
|
||||
if (remote_debug) fprintf(stderr,format,parm);
|
||||
}
|
||||
|
||||
/* convert the memory pointed to by mem into hex, placing result in buf */
|
||||
/* return a pointer to the last char put in buf (null) */
|
||||
char* mem2hex(mem, buf, count)
|
||||
char* mem;
|
||||
char* buf;
|
||||
int count;
|
||||
{
|
||||
int i;
|
||||
unsigned char ch;
|
||||
for (i=0;i<count;i++) {
|
||||
ch = *mem++;
|
||||
*buf++ = hexchars[ch >> 4];
|
||||
*buf++ = hexchars[ch % 16];
|
||||
}
|
||||
*buf = 0;
|
||||
return(buf);
|
||||
}
|
||||
|
||||
/* convert the hex array pointed to by buf into binary to be placed in mem */
|
||||
/* return a pointer to the character AFTER the last byte written */
|
||||
char* hex2mem(buf, mem, count)
|
||||
char* buf;
|
||||
char* mem;
|
||||
int count;
|
||||
{
|
||||
int i;
|
||||
unsigned char ch;
|
||||
for (i=0;i<count;i++) {
|
||||
ch = hex(*buf++) << 4;
|
||||
ch = ch + hex(*buf++);
|
||||
*mem++ = ch;
|
||||
}
|
||||
return(mem);
|
||||
}
|
||||
|
||||
/* a bus error has occurred, perform a longjmp
|
||||
to return execution and allow handling of the error */
|
||||
|
||||
void handle_buserror()
|
||||
{
|
||||
longjmp(remcomEnv,1);
|
||||
}
|
||||
|
||||
/* this function takes the 68000 exception number and attempts to
|
||||
translate this number into a unix compatible signal value */
|
||||
int computeSignal( exceptionVector )
|
||||
int exceptionVector;
|
||||
{
|
||||
int sigval;
|
||||
switch (exceptionVector) {
|
||||
case 2 : sigval = 10; break; /* bus error */
|
||||
case 3 : sigval = 10; break; /* address error */
|
||||
case 4 : sigval = 4; break; /* illegal instruction */
|
||||
case 5 : sigval = 8; break; /* zero divide */
|
||||
case 6 : sigval = 16; break; /* chk instruction */
|
||||
case 7 : sigval = 16; break; /* trapv instruction */
|
||||
case 8 : sigval = 11; break; /* privilege violation */
|
||||
case 9 : sigval = 5; break; /* trace trap */
|
||||
case 10: sigval = 4; break; /* line 1010 emulator */
|
||||
case 11: sigval = 4; break; /* line 1111 emulator */
|
||||
case 13: sigval = 8; break; /* floating point err */
|
||||
case 31: sigval = 2; break; /* interrupt */
|
||||
case 33: sigval = 5; break; /* breakpoint */
|
||||
case 40: sigval = 8; break; /* floating point err */
|
||||
case 48: sigval = 8; break; /* floating point err */
|
||||
case 49: sigval = 8; break; /* floating point err */
|
||||
case 50: sigval = 8; break; /* zero divide */
|
||||
case 51: sigval = 8; break; /* underflow */
|
||||
case 52: sigval = 8; break; /* operand error */
|
||||
case 53: sigval = 8; break; /* overflow */
|
||||
case 54: sigval = 8; break; /* NAN */
|
||||
default:
|
||||
sigval = 7; /* "software generated"*/
|
||||
}
|
||||
return (sigval);
|
||||
}
|
||||
|
||||
/**********************************************/
|
||||
/* WHILE WE FIND NICE HEX CHARS, BUILD AN INT */
|
||||
/* RETURN NUMBER OF CHARS PROCESSED */
|
||||
/**********************************************/
|
||||
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);
|
||||
}
|
||||
|
||||
/*
|
||||
* This function does all command procesing for interfacing to gdb.
|
||||
*/
|
||||
void handle_exception(int exceptionVector)
|
||||
{
|
||||
int sigval;
|
||||
int addr, length;
|
||||
char * ptr;
|
||||
int newPC;
|
||||
Frame *frame;
|
||||
|
||||
if (remote_debug) printf("vector=%d, sr=0x%x, pc=0x%x\n",
|
||||
exceptionVector,
|
||||
registers[ PS ],
|
||||
registers[ PC ]);
|
||||
|
||||
/* reply to host that an exception has occurred */
|
||||
sigval = computeSignal( exceptionVector );
|
||||
remcomOutBuffer[0] = 'S';
|
||||
remcomOutBuffer[1] = hexchars[sigval >> 4];
|
||||
remcomOutBuffer[2] = hexchars[sigval % 16];
|
||||
remcomOutBuffer[3] = 0;
|
||||
|
||||
putpacket(remcomOutBuffer);
|
||||
|
||||
while (1==1) {
|
||||
error = 0;
|
||||
remcomOutBuffer[0] = 0;
|
||||
getpacket(remcomInBuffer);
|
||||
switch (remcomInBuffer[0]) {
|
||||
case '?' : remcomOutBuffer[0] = 'S';
|
||||
remcomOutBuffer[1] = hexchars[sigval >> 4];
|
||||
remcomOutBuffer[2] = hexchars[sigval % 16];
|
||||
remcomOutBuffer[3] = 0;
|
||||
break;
|
||||
case 'd' : remote_debug = !(remote_debug); /* toggle debug flag */
|
||||
break;
|
||||
case 'g' : /* return the value of the CPU registers */
|
||||
mem2hex((char*) registers, remcomOutBuffer, NUMREGBYTES);
|
||||
break;
|
||||
case 'G' : /* set the value of the CPU registers - return OK */
|
||||
hex2mem(&remcomInBuffer[1], (char*) registers, NUMREGBYTES);
|
||||
strcpy(remcomOutBuffer,"OK");
|
||||
break;
|
||||
|
||||
/* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
|
||||
case 'm' :
|
||||
if (setjmp(remcomEnv) == 0)
|
||||
{
|
||||
exceptionHandler(2,handle_buserror);
|
||||
|
||||
/* 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;
|
||||
mem2hex((char*) addr, remcomOutBuffer, length);
|
||||
}
|
||||
|
||||
if (ptr)
|
||||
{
|
||||
strcpy(remcomOutBuffer,"E01");
|
||||
debug_error("malformed read memory command: %s",remcomInBuffer);
|
||||
}
|
||||
}
|
||||
else {
|
||||
exceptionHandler(2,_catchException);
|
||||
strcpy(remcomOutBuffer,"E03");
|
||||
debug_error("bus error");
|
||||
}
|
||||
|
||||
/* restore handler for bus error */
|
||||
exceptionHandler(2,_catchException);
|
||||
break;
|
||||
|
||||
/* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
|
||||
case 'M' :
|
||||
if (setjmp(remcomEnv) == 0) {
|
||||
exceptionHandler(2,handle_buserror);
|
||||
|
||||
/* 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++) == ':')
|
||||
{
|
||||
hex2mem(ptr, (char*) addr, length);
|
||||
ptr = 0;
|
||||
strcpy(remcomOutBuffer,"OK");
|
||||
}
|
||||
if (ptr)
|
||||
{
|
||||
strcpy(remcomOutBuffer,"E02");
|
||||
debug_error("malformed write memory command: %s",remcomInBuffer);
|
||||
}
|
||||
}
|
||||
else {
|
||||
exceptionHandler(2,_catchException);
|
||||
strcpy(remcomOutBuffer,"E03");
|
||||
debug_error("bus error");
|
||||
}
|
||||
|
||||
/* restore handler for bus error */
|
||||
exceptionHandler(2,_catchException);
|
||||
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))
|
||||
registers[ PC ] = addr;
|
||||
|
||||
newPC = registers[ PC];
|
||||
|
||||
/* clear the trace bit */
|
||||
registers[ PS ] &= 0x7fff;
|
||||
|
||||
/* set the trace bit if we're stepping */
|
||||
if (remcomInBuffer[0] == 's') registers[ PS ] |= 0x8000;
|
||||
|
||||
/*
|
||||
* look for newPC in the linked list of exception frames.
|
||||
* if it is found, use the old frame it. otherwise,
|
||||
* fake up a dummy frame in returnFromException().
|
||||
*/
|
||||
if (remote_debug) printf("new pc = 0x%x\n",newPC);
|
||||
frame = lastFrame;
|
||||
while (frame)
|
||||
{
|
||||
if (remote_debug)
|
||||
printf("frame at 0x%x has pc=0x%x, except#=%d\n",
|
||||
frame,frame->exceptionPC,
|
||||
frame->exceptionVector);
|
||||
if (frame->exceptionPC == newPC) break; /* bingo! a match */
|
||||
/*
|
||||
* for a breakpoint instruction, the saved pc may
|
||||
* be off by two due to re-executing the instruction
|
||||
* replaced by the trap instruction. Check for this.
|
||||
*/
|
||||
if ((frame->exceptionVector == 33) &&
|
||||
(frame->exceptionPC == (newPC+2))) break;
|
||||
if (frame == frame->previous)
|
||||
{
|
||||
frame = 0; /* no match found */
|
||||
break;
|
||||
}
|
||||
frame = frame->previous;
|
||||
}
|
||||
|
||||
/*
|
||||
* If we found a match for the PC AND we are not returning
|
||||
* as a result of a breakpoint (33),
|
||||
* trace exception (9), nmi (31), jmp to
|
||||
* the old exception handler as if this code never ran.
|
||||
*/
|
||||
if (frame)
|
||||
{
|
||||
if ((frame->exceptionVector != 9) &&
|
||||
(frame->exceptionVector != 31) &&
|
||||
(frame->exceptionVector != 33))
|
||||
{
|
||||
/*
|
||||
* invoke the previous handler.
|
||||
*/
|
||||
if (oldExceptionHook)
|
||||
(*oldExceptionHook) (frame->exceptionVector);
|
||||
newPC = registers[ PC ]; /* pc may have changed */
|
||||
if (newPC != frame->exceptionPC)
|
||||
{
|
||||
if (remote_debug)
|
||||
printf("frame at 0x%x has pc=0x%x, except#=%d\n",
|
||||
frame,frame->exceptionPC,
|
||||
frame->exceptionVector);
|
||||
/* re-use the last frame, we're skipping it (longjump?)*/
|
||||
frame = (Frame *) 0;
|
||||
_returnFromException( frame ); /* this is a jump */
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* if we couldn't find a frame, create one */
|
||||
if (frame == 0)
|
||||
{
|
||||
frame = lastFrame -1 ;
|
||||
|
||||
/* by using a bunch of print commands with breakpoints,
|
||||
it's possible for the frame stack to creep down. If it creeps
|
||||
too far, give up and reset it to the top. Normal use should
|
||||
not see this happen.
|
||||
*/
|
||||
if ((unsigned int) (frame-2) < (unsigned int) &gdbFrameStack)
|
||||
{
|
||||
initializeRemcomErrorFrame();
|
||||
frame = lastFrame;
|
||||
}
|
||||
frame->previous = lastFrame;
|
||||
lastFrame = frame;
|
||||
frame = 0; /* null so _return... will properly initialize it */
|
||||
}
|
||||
|
||||
_returnFromException( frame ); /* this is a jump */
|
||||
|
||||
break;
|
||||
|
||||
/* kill the program */
|
||||
case 'k' : /* do nothing */
|
||||
break;
|
||||
} /* switch */
|
||||
|
||||
/* reply to the request */
|
||||
putpacket(remcomOutBuffer);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
void initializeRemcomErrorFrame(void)
|
||||
{
|
||||
lastFrame = ((Frame *) &gdbFrameStack[FRAMESIZE-1]) - 1;
|
||||
lastFrame->previous = lastFrame;
|
||||
}
|
||||
|
||||
/* this function is used to set up exception handlers for tracing and
|
||||
breakpoints */
|
||||
void set_debug_traps()
|
||||
{
|
||||
extern void _debug_level7();
|
||||
extern void remcomHandler();
|
||||
int exception;
|
||||
|
||||
initializeRemcomErrorFrame();
|
||||
stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1];
|
||||
|
||||
for (exception = 2; exception <= 23; exception++)
|
||||
exceptionHandler(exception,_catchException);
|
||||
|
||||
/* level 7 interrupt */
|
||||
exceptionHandler(31,_debug_level7);
|
||||
|
||||
/* breakpoint exception (trap #1) */
|
||||
exceptionHandler(33,_catchException);
|
||||
|
||||
/* floating point error (trap #8) */
|
||||
exceptionHandler(40,_catchException);
|
||||
|
||||
/* 48 to 54 are floating point coprocessor errors */
|
||||
for (exception = 48; exception <= 54; exception++)
|
||||
exceptionHandler(exception,_catchException);
|
||||
|
||||
if (oldExceptionHook != remcomHandler)
|
||||
{
|
||||
oldExceptionHook = exceptionHook;
|
||||
exceptionHook = remcomHandler;
|
||||
}
|
||||
|
||||
initialized = 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()
|
||||
{
|
||||
if (initialized) BREAKPOINT();
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user