hw_htab.c

这个是LINUX下的GDB调度工具的源码

  status = device_instance_call_method(memory, "claim", 3, args, 1, results);
  if (status != 0)
    device_error(me, "failed to claim memory");
  return results[0];
}

static void
htab_map_region(device *me,
		device_instance *memory,
		unsigned_word pte_ra,
		unsigned64 pte_va,
		unsigned nr_bytes,
		unsigned wimg,
		unsigned pp,
		unsigned32 htaborg,
		unsigned32 htabmask)
{
  unsigned_word ra;
  unsigned64 va;
  /* claim the memory */
  if (memory != NULL)
    claim_memory(me, memory, pte_ra, nr_bytes);
  /* go through all pages and create a pte for each */
  for (ra = pte_ra, va = pte_va;
       ra < pte_ra + nr_bytes;
       ra += 0x1000, va += 0x1000) {
    htab_map_page(me, ra, va, wimg, pp, htaborg, htabmask);
  }
}
  
typedef struct _htab_binary_sizes {
  unsigned_word text_ra;
  unsigned_word text_base;
  unsigned_word text_bound;
  unsigned_word data_ra;
  unsigned_word data_base;
  unsigned data_bound;
  device *me;
} htab_binary_sizes;

static void
htab_sum_binary(bfd *abfd,
		sec_ptr sec,
		PTR data)
{
  htab_binary_sizes *sizes = (htab_binary_sizes*)data;
  unsigned_word size = bfd_get_section_size (sec);
  unsigned_word vma = bfd_get_section_vma (abfd, sec);
#define bfd_get_section_lma(abfd, sec) ((sec)->lma + 0)
  unsigned_word ra = bfd_get_section_lma (abfd, sec);

  /* skip the section if no memory to allocate */
  if (! (bfd_get_section_flags(abfd, sec) & SEC_ALLOC))
    return;

  if ((bfd_get_section_flags (abfd, sec) & SEC_CODE)
      || (bfd_get_section_flags (abfd, sec) & SEC_READONLY)) {
    if (sizes->text_bound < vma + size)
      sizes->text_bound = ALIGN_PAGE(vma + size);
    if (sizes->text_base > vma)
      sizes->text_base = FLOOR_PAGE(vma);
    if (sizes->text_ra > ra)
      sizes->text_ra = FLOOR_PAGE(ra);
  }
  else if ((bfd_get_section_flags (abfd, sec) & SEC_DATA)
	   || (bfd_get_section_flags (abfd, sec) & SEC_ALLOC)) {
    if (sizes->data_bound < vma + size)
      sizes->data_bound = ALIGN_PAGE(vma + size);
    if (sizes->data_base > vma)
      sizes->data_base = FLOOR_PAGE(vma);
    if (sizes->data_ra > ra)
      sizes->data_ra = FLOOR_PAGE(ra);
  }
}

static void
htab_dma_binary(bfd *abfd,
		sec_ptr sec,
		PTR data)
{
  htab_binary_sizes *sizes = (htab_binary_sizes*)data;
  void *section_init;
  unsigned_word section_vma;
  unsigned_word section_size;
  unsigned_word section_ra;
  device *me = sizes->me;

  /* skip the section if no memory to allocate */
  if (! (bfd_get_section_flags(abfd, sec) & SEC_ALLOC))
    return;

  /* check/ignore any sections of size zero */
  section_size = bfd_get_section_size (sec);
  if (section_size == 0)
    return;

  /* if nothing to load, ignore this one */
  if (! (bfd_get_section_flags(abfd, sec) & SEC_LOAD))
    return;

  /* find where it is to go */
  section_vma = bfd_get_section_vma(abfd, sec);
  section_ra = 0;
  if ((bfd_get_section_flags (abfd, sec) & SEC_CODE)
      || (bfd_get_section_flags (abfd, sec) & SEC_READONLY))
    section_ra = (section_vma - sizes->text_base + sizes->text_ra);
  else if ((bfd_get_section_flags (abfd, sec) & SEC_DATA))
    section_ra = (section_vma - sizes->data_base + sizes->data_ra);
  else 
    return; /* just ignore it */

  DTRACE(htab,
	 ("load - name=%-7s vma=0x%.8lx size=%6ld ra=0x%.8lx flags=%3lx(%s%s%s%s%s )\n",
	  bfd_get_section_name(abfd, sec),
	  (long)section_vma,
	  (long)section_size,
	  (long)section_ra,
	  (long)bfd_get_section_flags(abfd, sec),
	  bfd_get_section_flags(abfd, sec) & SEC_LOAD ? " LOAD" : "",
	  bfd_get_section_flags(abfd, sec) & SEC_CODE ? " CODE" : "",
	  bfd_get_section_flags(abfd, sec) & SEC_DATA ? " DATA" : "",
	  bfd_get_section_flags(abfd, sec) & SEC_ALLOC ? " ALLOC" : "",
	  bfd_get_section_flags(abfd, sec) & SEC_READONLY ? " READONLY" : ""
	  ));

  /* dma in the sections data */
  section_init = zalloc(section_size);
  if (!bfd_get_section_contents(abfd,
				sec,
				section_init, 0,
				section_size)) {
    bfd_perror("devices/pte");
    device_error(me, "no data loaded");
  }
  if (device_dma_write_buffer(device_parent(me),
			      section_init,
			      0 /*space*/,
			      section_ra,
			      section_size,
			      1 /*violate_read_only*/)
      != section_size)
    device_error(me, "broken dma transfer");
  zfree(section_init); /* only free if load */
}

/* create a memory map from a binaries virtual addresses to a copy of
   the binary laid out linearly in memory */

static void
htab_map_binary(device *me,
		device_instance *memory,
		unsigned_word ra,
		unsigned wimg,
		unsigned pp,
		const char *file_name,
		unsigned32 htaborg,
		unsigned32 htabmask)
{
  htab_binary_sizes sizes;
  bfd *image;
  sizes.text_ra = -1;
  sizes.data_ra = -1;
  sizes.text_base = -1;
  sizes.data_base = -1;
  sizes.text_bound = 0;
  sizes.data_bound = 0;
  sizes.me = me;

  /* open the file */
  image = bfd_openr(file_name, NULL);
  if (image == NULL) {
    bfd_perror("devices/pte");
    device_error(me, "the file %s not loaded", file_name);
  }

  /* check it is valid */
  if (!bfd_check_format(image, bfd_object)) {
    bfd_close(image);
    device_error(me, "the file %s has an invalid binary format", file_name);
  }

  /* determine the size of each of the files regions */
  bfd_map_over_sections (image, htab_sum_binary, (PTR) &sizes);

  /* if needed, determine the real addresses of the sections */
  if (ra != -1) {
    sizes.text_ra = ra;
    sizes.data_ra = ALIGN_PAGE(sizes.text_ra + 
			       (sizes.text_bound - sizes.text_base));
  }

  DTRACE(htab, ("text map - base=0x%lx bound=0x%lx-1 ra=0x%lx\n",
		(unsigned long)sizes.text_base,
		(unsigned long)sizes.text_bound,
		(unsigned long)sizes.text_ra));
  DTRACE(htab, ("data map - base=0x%lx bound=0x%lx-1 ra=0x%lx\n",
		(unsigned long)sizes.data_base,
		(unsigned long)sizes.data_bound,
		(unsigned long)sizes.data_ra));

  /* check for and fix a botched image (text and data segments
     overlap) */
  if ((sizes.text_base <= sizes.data_base
       && sizes.text_bound >= sizes.data_bound)
      || (sizes.data_base <= sizes.text_base
	  && sizes.data_bound >= sizes.data_bound)
      || (sizes.text_bound > sizes.data_base
	  && sizes.text_bound <= sizes.data_bound)
      || (sizes.text_base >= sizes.data_base
	  && sizes.text_base < sizes.data_bound)) {
    DTRACE(htab, ("text and data segment overlaped - using just data segment\n"));
    /* check va->ra linear */
    if ((sizes.text_base - sizes.text_ra)
	!= (sizes.data_base - sizes.data_ra))
      device_error(me, "overlapping but missaligned text and data segments");
    /* enlarge the data segment */
    if (sizes.text_base < sizes.data_base)
      sizes.data_base = sizes.text_base;
    if (sizes.text_bound > sizes.data_bound)
      sizes.data_bound = sizes.text_bound;
    if (sizes.text_ra < sizes.data_ra)
      sizes.data_ra = sizes.text_ra;
    /* zap the text segment */
    sizes.text_base = 0;
    sizes.text_bound = 0;
    sizes.text_ra = 0;
    DTRACE(htab, ("common map - base=0x%lx bound=0x%lx-1 ra=0x%lx\n",
		  (unsigned long)sizes.data_base,
		  (unsigned long)sizes.data_bound,
		  (unsigned long)sizes.data_ra));
  }

  /* set up virtual memory maps for each of the regions */
  if (sizes.text_bound - sizes.text_base > 0) {
    htab_map_region(me, memory, sizes.text_ra, sizes.text_base,
		    sizes.text_bound - sizes.text_base,
		    wimg, pp,
		    htaborg, htabmask);
  }

  htab_map_region(me, memory, sizes.data_ra, sizes.data_base,
		  sizes.data_bound - sizes.data_base,
		  wimg, pp,
		  htaborg, htabmask);

  /* dma the sections into physical memory */
  bfd_map_over_sections (image, htab_dma_binary, (PTR) &sizes);
}

static void
htab_init_data_callback(device *me)
{
  device_instance *memory = NULL;
  if (WITH_TARGET_WORD_BITSIZE != 32)
    device_error(me, "only 32bit targets currently suported");

  /* find memory device */
  if (device_find_property(me, "claim") != NULL)
    memory = tree_find_ihandle_property(me, "/chosen/memory");

  /* for the htab, just allocate space for it */
  if (strcmp(device_name(me), "htab") == 0) {
    unsigned_word address = device_find_integer_property(me, "real-address");
    unsigned_word length = device_find_integer_property(me, "nr-bytes");
    unsigned_word base = claim_memory(me, memory, address, length);
    if (base == -1 || base != address)
      device_error(me, "cannot allocate hash table");
  }

  /* for the pte, do all the real work */
  if (strcmp(device_name(me), "pte") == 0) {
    unsigned32 htaborg;
    unsigned32 htabmask;

    htab_decode_hash_table(me, &htaborg, &htabmask);

    if (device_find_property(me, "file-name") != NULL) {
      /* map in a binary */
      unsigned pte_wimg = device_find_integer_property(me, "wimg");
      unsigned pte_pp = device_find_integer_property(me, "pp");
      const char *file_name = device_find_string_property(me, "file-name");
      if (device_find_property(me, "real-address") != NULL) {
	unsigned32 pte_ra = device_find_integer_property(me, "real-address");
	DTRACE(htab, ("pte - ra=0x%lx, wimg=%ld, pp=%ld, file-name=%s\n",
		      (unsigned long)pte_ra,
		      (unsigned long)pte_wimg,
		      (long)pte_pp,
		      file_name));
	htab_map_binary(me, memory, pte_ra, pte_wimg, pte_pp, file_name,
			htaborg, htabmask);
      }
      else {
	DTRACE(htab, ("pte - wimg=%ld, pp=%ld, file-name=%s\n",
		      (unsigned long)pte_wimg,
		      (long)pte_pp,
		      file_name));
	htab_map_binary(me, memory, -1, pte_wimg, pte_pp, file_name,
			htaborg, htabmask);
      }
    }
    else {
      /* handle a normal mapping definition */
      unsigned64 pte_va = 0;
      unsigned32 pte_ra = device_find_integer_property(me, "real-address");
      unsigned pte_nr_bytes = device_find_integer_property(me, "nr-bytes");
      unsigned pte_wimg = device_find_integer_property(me, "wimg");
      unsigned pte_pp = device_find_integer_property(me, "pp");
      signed_cell partial_va;
      int i;
      for (i = 0;
	   device_find_integer_array_property(me, "virtual-address", i, &partial_va);
	   i++) {
	pte_va = (pte_va << WITH_TARGET_WORD_BITSIZE) | (unsigned_cell)partial_va;
      }
      DTRACE(htab, ("pte - ra=0x%lx, wimg=%ld, pp=%ld, va=0x%lx, nr_bytes=%ld\n",
		    (unsigned long)pte_ra,
		    (long)pte_wimg,
		    (long)pte_pp,
		    (unsigned long)pte_va,
		    (long)pte_nr_bytes));
      htab_map_region(me, memory, pte_ra, pte_va, pte_nr_bytes, pte_wimg, pte_pp,
		      htaborg, htabmask);
    }
  }
}


static device_callbacks const htab_callbacks = {
  { NULL, htab_init_data_callback, },
  { NULL, }, /* address */
  { NULL, }, /* IO */
  { passthrough_device_dma_read_buffer,
    passthrough_device_dma_write_buffer, },
  { NULL, }, /* interrupt */
  { generic_device_unit_decode,
    generic_device_unit_encode, },
};

const device_descriptor hw_htab_device_descriptor[] = {
  { "htab", NULL, &htab_callbacks },
  { "pte", NULL, &htab_callbacks }, /* yep - uses htab's table */
  { NULL },
};

#endif /* _HW_HTAB_C_ */