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firmware-utils: bcm4908img: extract bootfs without padding

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JFFS2 bootfs partition in a BCM4908 image usually includes some padding.
For flashing it individually (writing to designed MTD partition) we want
just JFFS2 data.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
This commit is contained in:
Rafał Miłecki
2021-04-07 07:59:57 +02:00
parent dcbde11af1
commit ed7edf88e2
1 changed files with 27 additions and 6 deletions
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33
tools/firmware-utils/src/bcm4908img.c
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@@ -6,6 +6,7 @@
#include <byteswap.h>
#include <endian.h>
#include <errno.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
@@ -81,6 +82,7 @@ struct bcm4908img_info {
size_t file_size;
size_t cferom_offset;
size_t bootfs_offset;
size_t padding_offset;
size_t rootfs_offset;
uint32_t crc32; /* Calculated checksum */
struct bcm4908img_tail tail;
@@ -247,6 +249,19 @@ struct chk_header {
char board_id[0];
};
static bool bcm4908img_is_all_ff(const void *buf, size_t length)
{
const uint8_t *in = buf;
int i;
for (i = 0; i < length; i++) {
if (in[i] != 0xff)
return false;
}
return true;
}
static int bcm4908img_parse(FILE *fp, struct bcm4908img_info *info) {
struct bcm4908img_tail *tail = &info->tail;
struct chk_header *chk;
@@ -304,7 +319,7 @@ static int bcm4908img_parse(FILE *fp, struct bcm4908img_info *info) {
for (info->rootfs_offset = info->bootfs_offset;
info->rootfs_offset < info->file_size;
info->rootfs_offset += 0x20000) {
uint32_t magic;
uint32_t *magic = (uint32_t *)&buf[0];
if (fseek(fp, info->rootfs_offset, SEEK_SET)) {
err = -errno;
@@ -312,13 +327,17 @@ static int bcm4908img_parse(FILE *fp, struct bcm4908img_info *info) {
return err;
}
bytes = fread(&magic, 1, sizeof(magic), fp);
if (bytes != sizeof(magic)) {
fprintf(stderr, "Failed to read %zu bytes\n", sizeof(magic));
length = info->padding_offset ? sizeof(*magic) : 256;
bytes = fread(buf, 1, length, fp);
if (bytes != length) {
fprintf(stderr, "Failed to read %zu bytes\n", length);
return -EIO;
}
if (be32_to_cpu(magic) == UBI_EC_HDR_MAGIC)
if (!info->padding_offset && bcm4908img_is_all_ff(buf, length))
info->padding_offset = info->rootfs_offset;
if (be32_to_cpu(*magic) == UBI_EC_HDR_MAGIC)
break;
}
if (info->rootfs_offset >= info->file_size) {
@@ -394,6 +413,8 @@ static int bcm4908img_info(int argc, char **argv) {
if (info.bootfs_offset != info.cferom_offset)
printf("cferom offset:\t%zu\n", info.cferom_offset);
printf("bootfs offset:\t0x%zx\n", info.bootfs_offset);
if (info.padding_offset)
printf("padding offset:\t0x%zx\n", info.padding_offset);
printf("rootfs offset:\t0x%zx\n", info.rootfs_offset);
printf("Checksum:\t0x%08x\n", info.crc32);
@@ -589,7 +610,7 @@ static int bcm4908img_extract(int argc, char **argv) {
}
} else if (!strcmp(type, "bootfs")) {
offset = info.bootfs_offset;
length = info.rootfs_offset - offset;
length = (info.padding_offset ? info.padding_offset : info.rootfs_offset) - offset;
} else if (!strcmp(type, "rootfs")) {
offset = info.rootfs_offset;
length = info.file_size - offset - sizeof(struct bcm4908img_tail);