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/* Copyright 2012 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.
*
* Exports the kernel commandline from a given partition/image.
*/
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include "host_common.h"
#include "kernel_blob.h"
#include "vboot_api.h"
#include "vboot_host.h"
static uint8_t* GetKernelConfig(uint8_t* blob, size_t blob_size,
uint64_t kernel_body_load_address) {
VbKeyBlockHeader* key_block;
VbKernelPreambleHeader* preamble;
uint32_t now = 0;
uint32_t offset = 0;
/* Skip the key block */
key_block = (VbKeyBlockHeader*)blob;
now += key_block->key_block_size;
if (now + blob > blob + blob_size) {
VbExError("key_block_size advances past the end of the blob\n");
return NULL;
}
/* Open up the preamble */
preamble = (VbKernelPreambleHeader*)(blob + now);
now += preamble->preamble_size;
if (now + blob > blob + blob_size) {
VbExError("preamble_size advances past the end of the blob\n");
return NULL;
}
/* Read body_load_address from preamble if no kernel_body_load_address */
if (kernel_body_load_address == USE_PREAMBLE_LOAD_ADDR)
kernel_body_load_address = preamble->body_load_address;
/* The x86 kernels have a pointer to the kernel commandline in the zeropage
* table, but that's irrelevant for ARM. Both types keep the config blob in
* the same place, so just go find it. */
offset = preamble->bootloader_address -
(kernel_body_load_address + CROS_PARAMS_SIZE +
CROS_CONFIG_SIZE) + now;
if (offset > blob_size) {
VbExError("params are outside of the memory blob: %x\n", offset);
return NULL;
}
return blob + offset;
}
static void* MMapFile(const char* filename, size_t *size) {
FILE* f;
uint8_t* buf;
long file_size = 0;
f = fopen(filename, "rb");
if (!f) {
VBDEBUG(("Unable to open file %s\n", filename));
return NULL;
}
fseek(f, 0, SEEK_END);
file_size = ftell(f);
rewind(f);
if (file_size <= 0) {
fclose(f);
return NULL;
}
*size = (size_t) file_size;
/* Uses a host primitive as this is not meant for firmware use. */
buf = mmap(NULL, *size, PROT_READ, MAP_PRIVATE, fileno(f), 0);
if (buf == MAP_FAILED) {
VbExError("Failed to mmap the file %s\n", filename);
fclose(f);
return NULL;
}
fclose(f);
return buf;
}
char *FindKernelConfig(const char *infile, uint64_t kernel_body_load_address)
{
uint8_t* blob;
size_t blob_size;
uint8_t *config = NULL;
char *newstr = NULL;
blob = MMapFile(infile, &blob_size);
if (!blob) {
VbExError("Error reading input file\n");
return 0;
}
config = GetKernelConfig(blob, blob_size, kernel_body_load_address);
if (!config) {
VbExError("Error parsing input file\n");
munmap(blob, blob_size);
return 0;
}
newstr = strndup((char *)config, CROS_CONFIG_SIZE);
if (!newstr)
VbExError("Can't allocate new string\n");
munmap(blob, blob_size);
return newstr;
}
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