| 1 | #!/bin/sh |
| 2 | # SPDX-License-Identifier: GPL-2.0-only |
| 3 | # ---------------------------------------------------------------------- |
| 4 | # extract-vmlinux - Extract uncompressed vmlinux from a kernel image |
| 5 | # |
| 6 | # Inspired from extract-ikconfig |
| 7 | # (c) 2009,2010 Dick Streefland <[email protected]> |
| 8 | # |
| 9 | # (c) 2011 Corentin Chary <[email protected]> |
| 10 | # |
| 11 | # ---------------------------------------------------------------------- |
| 12 | |
| 13 | me=${0##*/} |
| 14 | |
| 15 | check_vmlinux() |
| 16 | { |
| 17 | if file "$1" | grep -q 'Linux kernel.*boot executable' || |
| 18 | readelf -h "$1" > /dev/null 2>&1 |
| 19 | then |
| 20 | cat "$1" |
| 21 | echo "$me: Extracted vmlinux using '$2' from offset $3" >&2 |
| 22 | exit 0 |
| 23 | fi |
| 24 | } |
| 25 | |
| 26 | try_decompress() |
| 27 | { |
| 28 | # The obscure use of the "tr" filter is to work around older versions of |
| 29 | # "grep" that report the byte offset of the line instead of the pattern. |
| 30 | |
| 31 | # Try to find the header ($1) and decompress from here |
| 32 | for pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"` |
| 33 | do |
| 34 | pos=${pos%%:*} |
| 35 | tail -c+$pos "$img" | $3 > $tmp 2> /dev/null |
| 36 | check_vmlinux $tmp "$3" $pos |
| 37 | done |
| 38 | } |
| 39 | |
| 40 | # Check invocation: |
| 41 | img=$1 |
| 42 | if [ $# -ne 1 -o ! -s "$img" ] |
| 43 | then |
| 44 | echo "Usage: $me <kernel-image>" >&2 |
| 45 | exit 2 |
| 46 | fi |
| 47 | |
| 48 | # Prepare temp files: |
| 49 | tmp=$(mktemp /tmp/vmlinux-XXX) |
| 50 | trap "rm -f $tmp" 0 |
| 51 | |
| 52 | # That didn't work, so retry after decompression. |
| 53 | try_decompress '\037\213\010' xy gunzip |
| 54 | try_decompress '\3757zXZ\000' abcde unxz |
| 55 | try_decompress 'BZh' xy bunzip2 |
| 56 | try_decompress '\135\0\0\0' xxx unlzma |
| 57 | try_decompress '\211\114\132' xy 'lzop -d' |
| 58 | try_decompress '\002!L\030' xxx 'lz4 -d' |
| 59 | try_decompress '(\265/\375' xxx unzstd |
| 60 | |
| 61 | # Finally check for uncompressed images or objects: |
| 62 | check_vmlinux "$img" cat 0 |
| 63 | |
| 64 | # Bail out: |
| 65 | echo "$me: Cannot find vmlinux." >&2 |