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/*
* This file is part of the libpayload project.
*
* Copyright (C) 2011 secunet Security Networks AG
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* The CBFS core requires a couple of #defines or functions to adapt it to the target environment:
*
* CBFS_CORE_WITH_LZMA (must be #define)
* if defined, ulzma() must exist for decompression of data streams
*
* phys_to_virt(x), virt_to_phys(x)
* translate physical addresses to virtual and vice versa
* can be idempotent if no mapping is necessary.
*
* ERROR(x...)
* print an error message x (in printf format)
*
* LOG(x...)
* print a debug message x (in printf format)
*
* romstart()
* returns the start address of the ROM image, or 0xffffffff if ROM is
* top-aligned. This is a physical address.
*
* romend()
* returns the highest address of the ROM image + 1, for use if
* romstart() == 0xffffffff. This is a physical address.
*/
#include <cbfs_core.h>
/* returns pointer to master header or 0xffffffff if not found */
struct cbfs_header *get_cbfs_header(void)
{
struct cbfs_header *header;
/* find header */
if (romstart() == 0xffffffff) {
header = (struct cbfs_header*)phys_to_virt(*(uint32_t*)phys_to_virt(romend() + CBFS_HEADPTR_ADDR));
} else {
// FIXME: where's the master header on ARM (our current bottom-aligned platform)?
header = NULL;
}
if (CBFS_HEADER_MAGIC != ntohl(header->magic)) {
ERROR("Could not find valid CBFS master header at %p: %x vs %x.\n", header, CBFS_HEADER_MAGIC, ntohl(header->magic));
if (header->magic == 0xffffffff) {
ERROR("Maybe ROM is not mapped properly?\n");
}
return (void*)0xffffffff;
}
return header;
}
// by must be power-of-two
#define CBFS_ALIGN(val, by) (typeof(val))((uint32_t)(val + by - 1) & (uint32_t)~(by - 1))
#define CBFS_ALIGN_UP(val, by) CBFS_ALIGN(val + 1, by)
/* public API starts here*/
struct cbfs_file *cbfs_find(const char *name)
{
struct cbfs_header *header = get_cbfs_header();
if (header == (void*)0xffffffff) return NULL;
LOG("Searching for %s\n", name);
void *data, *dataend, *origdata;
/* find first entry */
if (romstart() == 0xffffffff) {
data = (void*)phys_to_virt(romend()) - ntohl(header->romsize) + ntohl(header->offset);
dataend = (void*)phys_to_virt(romend());
} else {
data = (void*)phys_to_virt(romstart()) + ntohl(header->offset);
dataend = (void*)phys_to_virt(romstart()) + ntohl(header->romsize);
}
dataend -= ntohl(header->bootblocksize);
int align = ntohl(header->align);
origdata = data;
while ((data < (dataend - 1)) && (data >= origdata)) {
struct cbfs_file *file = data;
if (memcmp(CBFS_FILE_MAGIC, file->magic, strlen(CBFS_FILE_MAGIC)) != 0) {
// no file header found. corruption?
// proceed in aligned steps to resynchronize
LOG("ERROR: No file header found at %p, attempting to recover by searching for header\n", data);
data = phys_to_virt(CBFS_ALIGN_UP(virt_to_phys(data), align));
continue;
}
LOG("Check %s\n", CBFS_NAME(file));
if (strcmp(CBFS_NAME(file), name) == 0) {
return file;
}
void *olddata = data;
data = phys_to_virt(CBFS_ALIGN(virt_to_phys(data) + ntohl(file->len) + ntohl(file->offset), align));
if (olddata > data) {
LOG("Something is wrong here. File chain moved from %p to %p\n", olddata, data);
return NULL;
}
}
return NULL;
}
void *cbfs_get_file(const char *name)
{
struct cbfs_file *file = cbfs_find(name);
if (file == NULL) {
ERROR("Could not find file '%s'.\n", name);
return NULL;
}
return (void*)CBFS_SUBHEADER(file);
}
void *cbfs_find_file(const char *name, int type)
{
struct cbfs_file *file = cbfs_find(name);
if (file == NULL) {
ERROR("Could not find file '%s'.\n", name);
return NULL;
}
if (ntohl(file->type) != type) {
ERROR("File '%s' is of type %x, but we requested %x.\n", name, ntohl(file->type), type);
return NULL;
}
return (void*)CBFS_SUBHEADER(file);
}
int cbfs_decompress(int algo, void *src, void *dst, int len)
{
switch (algo) {
case CBFS_COMPRESS_NONE:
memcpy(dst, src, len);
return 0;
#ifdef CBFS_CORE_WITH_LZMA
case CBFS_COMPRESS_LZMA:
if (ulzma(src, dst) != 0) {
return 0;
}
return -1;
#endif
default:
ERROR("tried to decompress %d bytes with algorithm #%x, but that algorithm id is unsupported.\n", len, algo);
return -1;
}
}
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