| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame] | 1 | #!/bin/sh |
| 2 | |
| 3 | BLKSZ=65536 |
| 4 | |
| 5 | [ -f "$1" -a -f "$2" ] || { |
| 6 | echo "Usage: $0 <kernel image> <rootfs image> [output file]" |
| 7 | exit 1 |
| 8 | } |
| 9 | |
| 10 | IMAGE=${3:-openwrt-combined.img} |
| 11 | |
| 12 | # Make sure provided images are 64k aligned. |
| 13 | kern="${IMAGE}.kernel" |
| 14 | root="${IMAGE}.rootfs" |
| 15 | dd if="$1" of="$kern" bs=$BLKSZ conv=sync 2>/dev/null |
| 16 | dd if="$2" of="$root" bs=$BLKSZ conv=sync 2>/dev/null |
| 17 | |
| 18 | # Calculate md5sum over combined kernel and rootfs image. |
| 19 | md5=$(cat "$kern" "$root" | $MKHASH md5) |
| 20 | |
| 21 | # Write image header followed by kernel and rootfs image. |
| 22 | # The header is padded to 64k, format is: |
| 23 | # CI magic word ("Combined Image") |
| 24 | # <kernel length> length of kernel encoded as zero padded 8 digit hex |
| 25 | # <rootfs length> length of rootfs encoded as zero padded 8 digit hex |
| 26 | # <md5sum> checksum of the combined kernel and rootfs image |
| 27 | ( printf "CI%08x%08x%32s" \ |
| 28 | $(stat -c "%s" "$kern") $(stat -c "%s" "$root") "${md5%% *}" | \ |
| 29 | dd bs=$BLKSZ conv=sync; |
| 30 | cat "$kern" "$root" |
| 31 | ) > ${IMAGE} 2>/dev/null |
| 32 | |
| 33 | # Clean up. |
| 34 | rm -f "$kern" "$root" |