From b9f75396ec107628cc5f52fb6e055c1c9dc68401 Mon Sep 17 00:00:00 2001 From: Jeremy Linton Date: Mon, 14 Jul 2025 17:29:23 -0500 Subject: [PATCH] scripts: add zboot support to extract-vmlinux Zboot compressed kernel images are used for arm64 kernels on various distros. extract-vmlinux fails with those kernels because the wrapped image is another PE. While this could be a bit confusing, the tools primary purpose of unwrapping and decompressing the contained kernel image makes it the obvious place for this functionality. Add a 'file' check in check_vmlinux() that detects a contained PE image before trying readelf. Recent (FILES_39, Jun/2020) file implementations output something like: "Linux kernel ARM64 boot executable Image, little-endian, 4K pages" Which is also a stronger statement than readelf provides so drop that part of the comment. At the same time this means that kernel images which don't appear to contain a compressed image will be returned rather than reporting an error. Which matches the behavior for existing ELF files. The extracted PE image can then be inspected, or used as would any other kernel PE. Signed-off-by: Jeremy Linton Signed-off-by: Masahiro Yamada --- scripts/extract-vmlinux | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/scripts/extract-vmlinux b/scripts/extract-vmlinux index 8995cd304e6e..189956b5a5c8 100755 --- a/scripts/extract-vmlinux +++ b/scripts/extract-vmlinux @@ -12,13 +12,12 @@ check_vmlinux() { - # Use readelf to check if it's a valid ELF - # TODO: find a better to way to check that it's really vmlinux - # and not just an elf - readelf -h $1 > /dev/null 2>&1 || return 1 - - cat $1 - exit 0 + if file "$1" | grep -q 'Linux kernel.*boot executable' || + readelf -h "$1" > /dev/null 2>&1 + then + cat "$1" + exit 0 + fi } try_decompress() -- 2.25.1