debugstub/source/breakpoints.c

/*
 * $Id: breakpoints.c,v 1.1.1.1 2006/09/06 10:13:19 ben Exp $
 */
/** \file
 * \brief The breakpoint handling functions.
 */
#include <stdint.h>
#include <stdlib.h>

#include "breakpoints.h"
#include "logging.h"


/** The ARM BKPT instruction opcode */
#define ARM_BKPT_OPCODE ((uint32_t)0xE1200070)

/** The Thumb BKPT instruction opcode */
#define THUMB_BKPT_OPCODE ((uint16_t)0xBE00)

/** Remove the breakpoints in a list from memory */
void
removeAll_breakpoint( const struct breakpoint_descr *list_head) {
  const struct breakpoint_descr *bkpt = list_head;

  while ( bkpt != NULL) {
    LOG( "Removing bkpt at %08x (n %08x)\n", bkpt->address, (uint32_t)bkpt->next);
    /* place the stored instruction back into memory */
    if ( bkpt->thumb) {
      *(uint16_t *)bkpt->address = bkpt->instruction.thumb;
    }
    else {
      *(uint32_t *)bkpt->address = bkpt->instruction.arm;
    }

    bkpt = bkpt->next;
  }
}


/** Insert the breakpoint in a list into memory */
void
insertAll_breakpoint( struct breakpoint_descr *list_head) {
  struct breakpoint_descr *bkpt = list_head;

  while ( bkpt != NULL) {
    LOG( "Inserting bkpt at %08x (next %08x)\n", bkpt->address, (uint32_t)bkpt->next);
    /* store the current contents of memory and replace it with the bkpt opcode */
    if ( bkpt->thumb) {
      bkpt->instruction.thumb = *(uint16_t *)bkpt->address;
      *(uint16_t *)bkpt->address = THUMB_BKPT_OPCODE;
    }
    else {
      bkpt->instruction.arm = *(uint32_t *)bkpt->address;
      *(uint32_t *)bkpt->address = ARM_BKPT_OPCODE;
    }

    bkpt = bkpt->next;
  }
  LOG( "Finished Inserting bkpts\n");
}


/*
 * Breakpoint list functions
 */
/** Concatenate two lists */
void
catLists_breakpoint( struct breakpoint_descr **list1_ptr,
		     struct breakpoint_descr *list2) {
  if ( *list1_ptr == NULL) {
    *list1_ptr = list2;
  }
  else {
    struct breakpoint_descr *descr = *list1_ptr;

    while ( descr->next != NULL) {
      descr = descr->next;
    }
    descr->next = list2;
  }
}


/** Remove a breakpoint from a list based on the breakpoint address */
struct breakpoint_descr *
removeFromList_breakpoint( struct breakpoint_descr **list_ptr, uint32_t bkpt_addr) {
  struct breakpoint_descr *found = NULL;
  struct breakpoint_descr *prev = NULL;
  struct breakpoint_descr *current = *list_ptr;

  while ( found == NULL && current != NULL) {
    if ( current->address == bkpt_addr) {
      found = current;

      /* remove from the list */
      if ( prev == NULL) {
	*list_ptr = current->next;
      }
      else {
	prev->next = current->next;
      }
      current->next = NULL;
    }

    prev = current;
    current = current->next;
  }

  return found;
}


/** Add a breakpoint to the head of a breakpoint list */
void
addHead_breakpoint( struct breakpoint_descr **list_ptr,
		    struct breakpoint_descr *bkpt_descr) {
  bkpt_descr->next = *list_ptr;

  *list_ptr = bkpt_descr;
}


/** Remove a breakpoint descriptor from the head of a list */
struct breakpoint_descr *
removeHead_breakpoint( struct breakpoint_descr **list_ptr) {
  struct breakpoint_descr *head = *list_ptr;

  if ( head != NULL) {
    *list_ptr = head->next;
    head->next = NULL;
  }

  return head;
}


/** Initialise a breakpoint descriptor */
void
initDescr_breakpoint( struct breakpoint_descr *bkpt_descr,
		      uint32_t address, int thumb_flag) {
  bkpt_descr->next = NULL;
  bkpt_descr->address = address;
  bkpt_descr->thumb = thumb_flag;
}