[gentoo-dev] [PATCH] kernel-install.eclass: fix gentoo-kernel-bin with llvm-objcopy

[Andrew Ammerlaan <andrewammerlaan@gentoo.org>]

We ship the kernel in gentoo-kernel-bin in the form of an UKI, using
objcopy we extract from this the kernel image (and if desired the
generic initramfs).

However, llvm-objcopy does not properly handle the -O argument and as a
result the extracted kernel image is of the same file type as the UKI
(i.e. a PE32+ executable) instead of a regular kernel image. This causes
issues in bootloader such as grub which differentiate between loading
a normal kernel image and loading an EFI executable (such as an UKI).
And also causes the signature verification to fail since the kernel
image is bigger then it should be due to the additional headers.

Using the --dump-section argument instead resolves this problem.

See-also: https://github.com/llvm/llvm-project/issues/108946
Signed-off-by: Andrew Ammerlaan <andrewammerlaan@gentoo.org>
Closes: https://github.com/gentoo/gentoo/pull/38643
Signed-off-by: Andrew Ammerlaan <andrewammerlaan@gentoo.org>
---
 eclass/kernel-install.eclass | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/eclass/kernel-install.eclass b/eclass/kernel-install.eclass
index 930640188c26..dc337c7862fd 100644
--- a/eclass/kernel-install.eclass
+++ b/eclass/kernel-install.eclass
@@ -650,7 +650,7 @@ kernel-install_extract_from_uki() {
 	local uki=${2}
 	local out=${3}
 
-	$(tc-getOBJCOPY) -O binary "-j.${extract_type}" "${uki}" "${out}" ||
+	$(tc-getOBJCOPY) "${uki}" --dump-section ".${extract_type}=${out}" ||
 		die "Failed to extract ${extract_type}"
 	chmod 644 "${out}" || die
 }
-- 
2.46.0