common/cmd_bedbug.c

/*
 * BedBug Functions
 */

#include <common.h>
#include <command.h>
#include <linux/ctype.h>
#include <net.h>

#include <cmd_bedbug.h>
#include <bedbug/bedbug.h>
#include <bedbug/regs.h>
#include <bedbug/ppc.h>
#include <elf.h>

#if (CONFIG_COMMANDS & CFG_CMD_BEDBUG)

#ifndef MAX
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#endif

extern void show_regs __P((struct pt_regs*));
extern int  run_command __P((const char*, int));
extern char console_buffer[];

ulong	      dis_last_addr = 0;        /* Last address disassembled   */
ulong	      dis_last_len = 20;        /* Default disassembler length */
CPU_DEBUG_CTX bug_ctx;                  /* Bedbug context structure    */


/* ======================================================================
 * U-Boot's puts function does not append a newline, so the bedbug stuff
 * will use this for the output of the dis/assembler.
 * ====================================================================== */

int bedbug_puts(const char *str)
{
  /* -------------------------------------------------- */

  printf( "%s\r\n", str );
  return 0;
} /* bedbug_puts */



/* ======================================================================
 * Initialize the bug_ctx structure used by the bedbug debugger.  This is
 * specific to the CPU since each has different debug registers and
 * settings.
 * ====================================================================== */

void bedbug_init( void )
{
  /* -------------------------------------------------- */

#if defined(CONFIG_4xx)
  void bedbug405_init( void );
  bedbug405_init();
#elif defined(CONFIG_MPC860)
  void bedbug860_init( void );
  bedbug860_init();
#endif

#if defined(CONFIG_MPC824X) || defined(CONFIG_MPC8260)
  /* Processors that are 603e core based */
  void bedbug603e_init( void );

  bedbug603e_init();
#endif

  return;
} /* bedbug_init */



/* ======================================================================
 * Entry point from the interpreter to the disassembler.  Repeated calls
 * will resume from the last disassembled address.
 * ====================================================================== */
int do_bedbug_dis (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
  ulong	addr;   /* Address to start disassembly from    */
  ulong	len;    /* # of instructions to disassemble     */
  /* -------------------------------------------------- */

  /* Setup to go from the last address if none is given */
  addr = dis_last_addr;
  len  = dis_last_len;

  if (argc < 2)
  {
    printf ("Usage:\n%s\n", cmdtp->usage);
    return 1;
  }

  if(( flag & CMD_FLAG_REPEAT ) == 0 )
  {
    /* New command */
    addr = simple_strtoul( argv[1], NULL, 16 );

    /* If an extra param is given then it is the length */
    if( argc > 2 )
      len = simple_strtoul( argv[2], NULL, 16 );
  }

  /* Run the disassembler */
  disppc( (unsigned char *)addr, 0, len, bedbug_puts, F_RADHEX );

  dis_last_addr = addr + (len * 4);
  dis_last_len = len;
  return 0;
} /* do_bedbug_dis */



/* ======================================================================
 * Entry point from the interpreter to the assembler.  Assembles
 * instructions in consecutive memory locations until a '.' (period) is
 * entered on a line by itself.
 * ====================================================================== */
int do_bedbug_asm (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
  long		mem_addr;               /* Address to assemble into     */
  unsigned long instr;                  /* Machine code for text        */
  char		prompt[ 15 ];           /* Prompt string for user input */
  int		asm_err;                /* Error code from the assembler*/
  /* -------------------------------------------------- */
   int          rcode = 0;

  if (argc < 2)
  {
    printf ("Usage:\n%s\n", cmdtp->usage);
    return 1;
  }

  printf( "\nEnter '.' when done\n" );
  mem_addr = simple_strtoul( argv[ 1 ], NULL, 16 );

  while( 1 )
  {
    putc( '\n' );
    disppc( (unsigned char *)mem_addr, 0, 1, bedbug_puts, F_RADHEX );

    sprintf( prompt, "%08lx:    ", mem_addr );
    readline( prompt );

    if( console_buffer[ 0 ] && strcmp( console_buffer, "." ))
    {
      if(( instr = asmppc( mem_addr, console_buffer, &asm_err )) != 0 )
      {
	*(unsigned long *)mem_addr = instr;
	mem_addr += 4;
      }
      else
      {
	printf( "*** Error: %s ***\n", asm_error_str( asm_err ));
        rcode = 1;
      }
    }
    else
    {
      break;
    }
  }
  return rcode;
} /* do_bedbug_asm */



/* ======================================================================
 * Used to set a break point from the interpreter.  Simply calls into the
 * CPU-specific break point set routine.
 * ====================================================================== */

int do_bedbug_break (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
  /* -------------------------------------------------- */
  if( bug_ctx.do_break )
    (*bug_ctx.do_break)( cmdtp, flag, argc, argv );
    return 0;

} /* do_bedbug_break */



/* ======================================================================
 * Called from the debug interrupt routine.  Simply calls the CPU-specific
 * breakpoint handling routine.
 * ====================================================================== */

void do_bedbug_breakpoint (struct pt_regs *regs)
{
  /* -------------------------------------------------- */

  if( bug_ctx.break_isr )
    (*bug_ctx.break_isr)( regs );

  return;
} /* do_bedbug_breakpoint */



/* ======================================================================
 * Called from the CPU-specific breakpoint handling routine.  Enter a
 * mini main loop until the stopped flag is cleared from the breakpoint
 * context.
 *
 * This handles the parts of the debugger that are common to all CPU's.
 * ====================================================================== */

void bedbug_main_loop( unsigned long addr, struct pt_regs *regs )
{
  int		len;                    /* Length of command line */
  int           flag;                   /* Command flags          */
  int           rc = 0;                 /* Result from run_command*/
  char          prompt_str[ 20 ];       /* Prompt string          */
  static char   lastcommand[ CFG_CBSIZE ] = {0}; /* previous command */
  /* -------------------------------------------------- */

  if( bug_ctx.clear )
    (*bug_ctx.clear)( bug_ctx.current_bp );

  printf( "Breakpoint %d: ", bug_ctx.current_bp );
  disppc( (unsigned char *)addr, 0, 1, bedbug_puts, F_RADHEX );

  bug_ctx.stopped = 1;
  bug_ctx.regs = regs;

  sprintf( prompt_str, "BEDBUG.%d =>", bug_ctx.current_bp );

  /* A miniature main loop */
  while( bug_ctx.stopped )
  {
    len = readline( prompt_str );

    flag = 0;	/* assume no special flags for now */

    if (len > 0)
      strcpy( lastcommand, console_buffer );
    else if( len == 0 )
      flag |= CMD_FLAG_REPEAT;

    if (len == -1)
      printf ("<INTERRUPT>\n");
    else
      rc = run_command( lastcommand, flag );

    if (rc <= 0) {
      /* invalid command or not repeatable, forget it */
      lastcommand[0] = 0;
    }
  }

  bug_ctx.regs = NULL;
  bug_ctx.current_bp = 0;

  return;
} /* bedbug_main_loop */



/* ======================================================================
 * Interpreter command to continue from a breakpoint.  Just clears the
 * stopped flag in the context so that the breakpoint routine will
 * return.
 * ====================================================================== */
int do_bedbug_continue (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])

{
  /* -------------------------------------------------- */

  if( ! bug_ctx.stopped )
  {
    printf( "Not at a breakpoint\n" );
    return 1;
  }

  bug_ctx.stopped = 0;
  return 0;
} /* do_bedbug_continue */



/* ======================================================================
 * Interpreter command to continue to the next instruction, stepping into
 * subroutines.  Works by calling the find_next_addr() routine to compute
 * the address passes control to the CPU-specific set breakpoint routine
 * for the current breakpoint number.
 * ====================================================================== */
int do_bedbug_step (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
  unsigned long addr;   /* Address to stop at */
  /* -------------------------------------------------- */

  if( ! bug_ctx.stopped )
  {
    printf( "Not at a breakpoint\n" );
    return 1;
  }

  if( !find_next_address( (unsigned char *)&addr, FALSE, bug_ctx.regs ))
    return 1;

  if( bug_ctx.set )
    (*bug_ctx.set)( bug_ctx.current_bp, addr );

  bug_ctx.stopped = 0;
  return 0;
} /* do_bedbug_step */



/* ======================================================================
 * Interpreter command to continue to the next instruction, stepping over
 * subroutines.  Works by calling the find_next_addr() routine to compute
 * the address passes control to the CPU-specific set breakpoint routine
 * for the current breakpoint number.
 * ====================================================================== */
int do_bedbug_next (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
  unsigned long addr;   /* Address to stop at */
  /* -------------------------------------------------- */

  if( ! bug_ctx.stopped )
  {
    printf( "Not at a breakpoint\n" );
    return 1;
  }

  if( !find_next_address( (unsigned char *)&addr, TRUE, bug_ctx.regs ))
    return 1;

  if( bug_ctx.set )
    (*bug_ctx.set)( bug_ctx.current_bp, addr );

  bug_ctx.stopped = 0;
  return 0;
} /* do_bedbug_next */



/* ======================================================================
 * Interpreter command to print the current stack.  This assumes an EABI
 * architecture, so it starts with GPR R1 and works back up the stack.
 * ====================================================================== */
int do_bedbug_stack (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
	DECLARE_GLOBAL_DATA_PTR;

  unsigned long sp;             /* Stack pointer                */
  unsigned long func;           /* LR from stack                */
  int           depth;          /* Stack iteration level        */
  int           skip = 1;       /* Flag to skip the first entry */
  unsigned long top;            /* Top of memory address        */
  /* -------------------------------------------------- */

  if( ! bug_ctx.stopped )
  {
    printf( "Not at a breakpoint\n" );
    return 1;
  }

  top = gd->bd->bi_memstart + gd->bd->bi_memsize;
  depth = 0;

  printf( "Depth     PC\n" );
  printf( "-----  --------\n" );
  printf( "%5d  %08lx\n", depth++, bug_ctx.regs->nip );

  sp = bug_ctx.regs->gpr[ 1 ];
  func = *(unsigned long *)(sp+4);

  while(( func < top ) && ( sp < top ))
  {
    if( !skip )
      printf( "%5d  %08lx\n", depth++, func );
    else
      --skip;

    sp = *(unsigned long *)sp;
    func = *(unsigned long *)(sp+4);
  }
  return 0;
} /* do_bedbug_stack */



/* ======================================================================
 * Interpreter command to dump the registers.  Calls the CPU-specific
 * show registers routine.
 * ====================================================================== */
int do_bedbug_rdump (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
  /* -------------------------------------------------- */

  if( ! bug_ctx.stopped )
  {
    printf( "Not at a breakpoint\n" );
    return 1;
  }

  show_regs( bug_ctx.regs );
  return 0;
} /* do_bedbug_rdump */


/* ====================================================================== */
#endif	/* CFG_CMD_BEDBUG */


/*
 * Copyright (c) 2001 William L. Pitts
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are freely
 * permitted provided that the above copyright notice and this
 * paragraph and the following disclaimer are duplicated in all
 * such forms.
 *
 * This software is provided "AS IS" and without any express or
 * implied warranties, including, without limitation, the implied
 * warranties of merchantability and fitness for a particular
 * purpose.
 */