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firmware-utils: bcm4908img: replace size with offset

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It's much easier to operate on BCM4908 image data with absolute offset
of each section stored. It doesn't require summing sizes over and over.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
This commit is contained in:
Rafał Miłecki 2021-04-06 01:06:52 +02:00
parent f4f4259ca1
commit 5314cab729
1 changed files with 35 additions and 20 deletions
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55
tools/firmware-utils/src/bcm4908img.c
View file

@ -64,11 +64,21 @@ struct bcm4908img_tail {
uint32_t flags;
};
/* Info about BCM4908 image */
/**
* struct bcm4908img_info - info about BCM4908 image
*
* Standard BCM4908 image consists of:
* 1. (Optional) vedor header
* 2. (Optional) cferom
* 3. bootfs ─┐
* 4. padding ├─ firmware
* 5. rootfs ─┘
* 6. BCM4908 tail
*/
struct bcm4908img_info {
size_t file_size;
size_t vendor_header_size; /* Vendor header size */
size_t cferom_size;
size_t cferom_offset;
size_t bootfs_offset;
uint32_t crc32; /* Calculated checksum */
struct bcm4908img_tail tail;
};
@ -200,10 +210,11 @@ static int bcm4908img_calc_crc32(FILE *fp, struct bcm4908img_info *info) {
size_t length;
size_t bytes;
fseek(fp, info->vendor_header_size, SEEK_SET);
/* Start with cferom (or bootfs) - skip vendor header */
fseek(fp, info->cferom_offset, SEEK_SET);
info->crc32 = 0xffffffff;
length = info->file_size - info->vendor_header_size - sizeof(struct bcm4908img_tail);
length = info->file_size - info->cferom_offset - sizeof(struct bcm4908img_tail);
while (length && (bytes = fread(buf, 1, bcm4908img_min(sizeof(buf), length), fp)) > 0) {
info->crc32 = bcm4908img_crc32(info->crc32, buf, bytes);
length -= bytes;
@ -263,14 +274,16 @@ static int bcm4908img_parse(FILE *fp, struct bcm4908img_info *info) {
}
chk = (void *)buf;
if (be32_to_cpu(chk->magic) == 0x2a23245e)
info->vendor_header_size = be32_to_cpu(chk->header_len);
info->cferom_offset = be32_to_cpu(chk->header_len);
/* Sizes */
/* Offsets */
for (; info->vendor_header_size + info->cferom_size <= info->file_size; info->cferom_size += 0x20000) {
if (fseek(fp, info->vendor_header_size + info->cferom_size, SEEK_SET)) {
for (info->bootfs_offset = info->cferom_offset;
info->bootfs_offset < info->file_size;
info->bootfs_offset += 0x20000) {
if (fseek(fp, info->bootfs_offset, SEEK_SET)) {
err = -errno;
fprintf(stderr, "Failed to fseek to the 0x%zx\n", info->cferom_size);
fprintf(stderr, "Failed to fseek to the 0x%zx\n", info->bootfs_offset);
return err;
}
if (fread(&tmp16, 1, sizeof(tmp16), fp) != sizeof(tmp16)) {
@ -280,17 +293,18 @@ static int bcm4908img_parse(FILE *fp, struct bcm4908img_info *info) {
if (be16_to_cpu(tmp16) == 0x8519)
break;
}
if (info->vendor_header_size + info->cferom_size >= info->file_size) {
fprintf(stderr, "Failed to find cferom size (no bootfs found)\n");
if (info->bootfs_offset >= info->file_size) {
fprintf(stderr, "Failed to find bootfs offset\n");
return -EPROTO;
}
/* CRC32 */
fseek(fp, info->vendor_header_size, SEEK_SET);
/* Start with cferom (or bootfs) - skip vendor header */
fseek(fp, info->cferom_offset, SEEK_SET);
info->crc32 = 0xffffffff;
length = info->file_size - info->vendor_header_size - sizeof(*tail);
length = info->file_size - info->cferom_offset - sizeof(*tail);
while (length && (bytes = fread(buf, 1, bcm4908img_min(sizeof(buf), length), fp)) > 0) {
info->crc32 = bcm4908img_crc32(info->crc32, buf, bytes);
length -= bytes;
@ -349,8 +363,9 @@ static int bcm4908img_info(int argc, char **argv) {
goto err_close;
}
printf("Vendor header length:\t%zu\n", info.vendor_header_size);
printf("cferom size:\t0x%zx\n", info.cferom_size);
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);
printf("Checksum:\t0x%08x\n", info.crc32);
err_close:
@ -537,14 +552,14 @@ static int bcm4908img_extract(int argc, char **argv) {
if (!strcmp(type, "cferom")) {
offset = 0;
length = info.cferom_size;
length = info.bootfs_offset - offset;
if (!length) {
err = -ENOENT;
fprintf(stderr, "This BCM4908 image doesn't contain cferom\n");
goto err_close;
}
} else if (!strcmp(type, "firmware")) {
offset = info.vendor_header_size + info.cferom_size;
offset = info.bootfs_offset;
length = info.file_size - offset - sizeof(struct bcm4908img_tail);
} else {
err = -EINVAL;
@ -648,7 +663,7 @@ static int bcm4908img_bootfs_ls(FILE *fp, struct bcm4908img_info *info) {
size_t bytes;
int err = 0;
for (offset = info->vendor_header_size + info->cferom_size; ; offset += (je32_to_cpu(node.totlen) + 0x03) & ~0x03) {
for (offset = info->bootfs_offset; ; offset += (je32_to_cpu(node.totlen) + 0x03) & ~0x03) {
char name[FILENAME_MAX + 1];
if (fseek(fp, offset, SEEK_SET)) {
@ -719,7 +734,7 @@ static int bcm4908img_bootfs_mv(FILE *fp, struct bcm4908img_info *info, int argc
return -EINVAL;
}
for (offset = info->vendor_header_size + info->cferom_size; ; offset += (je32_to_cpu(node.totlen) + 0x03) & ~0x03) {
for (offset = info->bootfs_offset; ; offset += (je32_to_cpu(node.totlen) + 0x03) & ~0x03) {
char name[FILENAME_MAX];
uint32_t crc32;