u-boot/fs/cbfs/cbfs.c

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/*
* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <cbfs.h>
#include <malloc.h>
#include <asm/byteorder.h>
enum cbfs_result file_cbfs_result;
const char *file_cbfs_error(void)
{
switch (file_cbfs_result) {
case CBFS_SUCCESS:
return "Success";
case CBFS_NOT_INITIALIZED:
return "CBFS not initialized";
case CBFS_BAD_HEADER:
return "Bad CBFS header";
case CBFS_BAD_FILE:
return "Bad CBFS file";
case CBFS_FILE_NOT_FOUND:
return "File not found";
default:
return "Unknown";
}
}
static const u32 good_magic = 0x4f524243;
static const u8 good_file_magic[] = "LARCHIVE";
static int initialized;
static struct cbfs_header cbfs_header;
static struct cbfs_cachenode *file_cache;
/* Do endian conversion on the CBFS header structure. */
static void swap_header(struct cbfs_header *dest, struct cbfs_header *src)
{
dest->magic = be32_to_cpu(src->magic);
dest->version = be32_to_cpu(src->version);
dest->rom_size = be32_to_cpu(src->rom_size);
dest->boot_block_size = be32_to_cpu(src->boot_block_size);
dest->align = be32_to_cpu(src->align);
dest->offset = be32_to_cpu(src->offset);
}
/* Do endian conversion on a CBFS file header. */
static void swap_file_header(struct cbfs_fileheader *dest,
const struct cbfs_fileheader *src)
{
memcpy(&dest->magic, &src->magic, sizeof(dest->magic));
dest->len = be32_to_cpu(src->len);
dest->type = be32_to_cpu(src->type);
dest->checksum = be32_to_cpu(src->checksum);
dest->offset = be32_to_cpu(src->offset);
}
/*
* Given a starting position in memory, scan forward, bounded by a size, and
* find the next valid CBFS file. No memory is allocated by this function. The
* caller is responsible for allocating space for the new file structure.
*
* @param start The location in memory to start from.
* @param size The size of the memory region to search.
* @param align The alignment boundaries to check on.
* @param newNode A pointer to the file structure to load.
* @param used A pointer to the count of of bytes scanned through,
* including the file if one is found.
*
* @return 1 if a file is found, 0 if one isn't.
*/
static int file_cbfs_next_file(u8 *start, u32 size, u32 align,
struct cbfs_cachenode *newNode, u32 *used)
{
struct cbfs_fileheader header;
*used = 0;
while (size >= align) {
const struct cbfs_fileheader *fileHeader =
(const struct cbfs_fileheader *)start;
u32 name_len;
u32 step;
/* Check if there's a file here. */
if (memcmp(good_file_magic, &(fileHeader->magic),
sizeof(fileHeader->magic))) {
*used += align;
size -= align;
start += align;
continue;
}
swap_file_header(&header, fileHeader);
if (header.offset < sizeof(const struct cbfs_cachenode *) ||
header.offset > header.len) {
file_cbfs_result = CBFS_BAD_FILE;
return -1;
}
newNode->next = NULL;
newNode->type = header.type;
newNode->data = start + header.offset;
newNode->data_length = header.len;
name_len = header.offset - sizeof(struct cbfs_cachenode *);
newNode->name = (char *)fileHeader +
sizeof(struct cbfs_cachenode *);
newNode->name_length = name_len;
newNode->checksum = header.checksum;
step = header.len;
if (step % align)
step = step + align - step % align;
*used += step;
return 1;
}
return 0;
}
/* Look through a CBFS instance and copy file metadata into regular memory. */
static void file_cbfs_fill_cache(u8 *start, u32 size, u32 align)
{
struct cbfs_cachenode *cache_node;
struct cbfs_cachenode *newNode;
struct cbfs_cachenode **cache_tail = &file_cache;
/* Clear out old information. */
cache_node = file_cache;
while (cache_node) {
struct cbfs_cachenode *oldNode = cache_node;
cache_node = cache_node->next;
free(oldNode);
}
file_cache = NULL;
while (size >= align) {
int result;
u32 used;
newNode = (struct cbfs_cachenode *)
malloc(sizeof(struct cbfs_cachenode));
result = file_cbfs_next_file(start, size, align,
newNode, &used);
if (result < 0) {
free(newNode);
return;
} else if (result == 0) {
free(newNode);
break;
}
*cache_tail = newNode;
cache_tail = &newNode->next;
size -= used;
start += used;
}
file_cbfs_result = CBFS_SUCCESS;
}
/* Get the CBFS header out of the ROM and do endian conversion. */
static int file_cbfs_load_header(uintptr_t end_of_rom,
struct cbfs_header *header)
{
struct cbfs_header *header_in_rom;
header_in_rom = (struct cbfs_header *)(uintptr_t)
*(u32 *)(end_of_rom - 3);
swap_header(header, header_in_rom);
if (header->magic != good_magic || header->offset >
header->rom_size - header->boot_block_size) {
file_cbfs_result = CBFS_BAD_HEADER;
return 1;
}
return 0;
}
void file_cbfs_init(uintptr_t end_of_rom)
{
u8 *start_of_rom;
initialized = 0;
if (file_cbfs_load_header(end_of_rom, &cbfs_header))
return;
start_of_rom = (u8 *)(end_of_rom + 1 - cbfs_header.rom_size);
file_cbfs_fill_cache(start_of_rom + cbfs_header.offset,
cbfs_header.rom_size, cbfs_header.align);
if (file_cbfs_result == CBFS_SUCCESS)
initialized = 1;
}
const struct cbfs_header *file_cbfs_get_header(void)
{
if (initialized) {
file_cbfs_result = CBFS_SUCCESS;
return &cbfs_header;
} else {
file_cbfs_result = CBFS_NOT_INITIALIZED;
return NULL;
}
}
const struct cbfs_cachenode *file_cbfs_get_first(void)
{
if (!initialized) {
file_cbfs_result = CBFS_NOT_INITIALIZED;
return NULL;
} else {
file_cbfs_result = CBFS_SUCCESS;
return file_cache;
}
}
void file_cbfs_get_next(const struct cbfs_cachenode **file)
{
if (!initialized) {
file_cbfs_result = CBFS_NOT_INITIALIZED;
file = NULL;
return;
}
if (*file)
*file = (*file)->next;
file_cbfs_result = CBFS_SUCCESS;
}
const struct cbfs_cachenode *file_cbfs_find(const char *name)
{
struct cbfs_cachenode *cache_node = file_cache;
if (!initialized) {
file_cbfs_result = CBFS_NOT_INITIALIZED;
return NULL;
}
while (cache_node) {
if (!strcmp(name, cache_node->name))
break;
cache_node = cache_node->next;
}
if (!cache_node)
file_cbfs_result = CBFS_FILE_NOT_FOUND;
else
file_cbfs_result = CBFS_SUCCESS;
return cache_node;
}
const struct cbfs_cachenode *file_cbfs_find_uncached(uintptr_t end_of_rom,
const char *name)
{
u8 *start;
u32 size;
u32 align;
static struct cbfs_cachenode node;
if (file_cbfs_load_header(end_of_rom, &cbfs_header))
return NULL;
start = (u8 *)(end_of_rom + 1 - cbfs_header.rom_size);
size = cbfs_header.rom_size;
align = cbfs_header.align;
while (size >= align) {
int result;
u32 used;
result = file_cbfs_next_file(start, size, align, &node, &used);
if (result < 0)
return NULL;
else if (result == 0)
break;
if (!strcmp(name, node.name))
return &node;
size -= used;
start += used;
}
file_cbfs_result = CBFS_FILE_NOT_FOUND;
return NULL;
}
const char *file_cbfs_name(const struct cbfs_cachenode *file)
{
file_cbfs_result = CBFS_SUCCESS;
return file->name;
}
u32 file_cbfs_size(const struct cbfs_cachenode *file)
{
file_cbfs_result = CBFS_SUCCESS;
return file->data_length;
}
u32 file_cbfs_type(const struct cbfs_cachenode *file)
{
file_cbfs_result = CBFS_SUCCESS;
return file->type;
}
long file_cbfs_read(const struct cbfs_cachenode *file, void *buffer,
unsigned long maxsize)
{
u32 size;
size = file->data_length;
if (maxsize && size > maxsize)
size = maxsize;
memcpy(buffer, file->data, size);
file_cbfs_result = CBFS_SUCCESS;
return size;
}