extract-vmlinux 1.7 KB

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  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 <dick@streefland.net>
  8. #
  9. # (c) 2011 Corentin Chary <corentin.chary@gmail.com>
  10. #
  11. # ----------------------------------------------------------------------
  12. check_vmlinux()
  13. {
  14. # Use readelf to check if it's a valid ELF
  15. # TODO: find a better to way to check that it's really vmlinux
  16. # and not just an elf
  17. readelf -h $1 > /dev/null 2>&1 || return 1
  18. cat $1
  19. exit 0
  20. }
  21. try_decompress()
  22. {
  23. # The obscure use of the "tr" filter is to work around older versions of
  24. # "grep" that report the byte offset of the line instead of the pattern.
  25. # Try to find the header ($1) and decompress from here
  26. for pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"`
  27. do
  28. pos=${pos%%:*}
  29. tail -c+$pos "$img" | $3 > $tmp 2> /dev/null
  30. check_vmlinux $tmp
  31. done
  32. }
  33. # Check invocation:
  34. me=${0##*/}
  35. img=$1
  36. if [ $# -ne 1 -o ! -s "$img" ]
  37. then
  38. echo "Usage: $me <kernel-image>" >&2
  39. exit 2
  40. fi
  41. # Prepare temp files:
  42. tmp=$(mktemp /tmp/vmlinux-XXX)
  43. trap "rm -f $tmp" 0
  44. # That didn't work, so retry after decompression.
  45. try_decompress '\037\213\010' xy gunzip
  46. try_decompress '\3757zXZ\000' abcde unxz
  47. try_decompress 'BZh' xy bunzip2
  48. try_decompress '\135\0\0\0' xxx unlzma
  49. try_decompress '\211\114\132' xy 'lzop -d'
  50. try_decompress '\002!L\030' xxx 'lz4 -d'
  51. try_decompress '(\265/\375' xxx unzstd
  52. # Finally check for uncompressed images or objects:
  53. check_vmlinux $img
  54. # Bail out:
  55. echo "$me: Cannot find vmlinux." >&2