| /* |
| * Copyright (c) 2011 The Chromium OS Authors. All rights reserved. |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include "fmap.h" |
| |
| static int is_fmap(uint8_t *ptr) |
| { |
| FmapHeader *fmap_header = (FmapHeader *)ptr; |
| |
| if (0 != memcmp(ptr, FMAP_SIGNATURE, FMAP_SIGNATURE_SIZE)) |
| return 0; |
| |
| if (fmap_header->fmap_ver_major == FMAP_VER_MAJOR) |
| return 1; |
| |
| fprintf(stderr, "Found FMAP, but major version is %u instead of %u\n", |
| fmap_header->fmap_ver_major, FMAP_VER_MAJOR); |
| return 0; |
| } |
| |
| /* Find and point to the FMAP header within the buffer */ |
| FmapHeader *fmap_find(uint8_t *ptr, size_t size) |
| { |
| ssize_t offset, align; |
| ssize_t lim = size - sizeof(FmapHeader); |
| |
| if (lim >= 0 && is_fmap(ptr)) |
| return (FmapHeader *)ptr; |
| |
| /* Search large alignments before small ones to find "right" FMAP. */ |
| for (align = FMAP_SEARCH_STRIDE; align <= lim; align *= 2); |
| for (; align >= FMAP_SEARCH_STRIDE; align /= 2) |
| for (offset = align; offset <= lim; offset += align * 2) |
| if (is_fmap(ptr + offset)) |
| return (FmapHeader *)(ptr + offset); |
| |
| return NULL; |
| } |
| |
| /* Search for an area by name, return pointer to its beginning */ |
| uint8_t *fmap_find_by_name(uint8_t *ptr, size_t size, FmapHeader *fmap, |
| const char *name, FmapAreaHeader **ah_ptr) |
| { |
| int i; |
| FmapAreaHeader *ah; |
| |
| if (!fmap) |
| fmap = fmap_find(ptr, size); |
| if (!fmap) |
| return NULL; |
| |
| ah = (FmapAreaHeader*)((void *)fmap + sizeof(FmapHeader)); |
| for (i = 0; i < fmap->fmap_nareas; i++) |
| if (!strncmp(ah[i].area_name, name, FMAP_NAMELEN)) { |
| if (ah_ptr) |
| *ah_ptr = ah + i; |
| return ptr + ah[i].area_offset; |
| } |
| |
| return NULL; |
| } |