35dac71c - scripts: add script to extract built-in firmware blobs

Mon, 20 Jan 2025 19:04:26 +0000

scripts: add script to extract built-in firmware blobsThere is currently no tool to extract a firmware blob that is built-inon vmlinux to the best of my knowledge. So if we have a kernel imagecontaining the blobs, and we want to rebuild the kernel with some debugpatches for example (and given that the image also has IKCONFIG=y), wecurrently can't do that for the same versions for all the firmwareblobs, _unless_ we have exact commits of linux-firmware for thespecific versions for each firmware included.Through the options CONFIG_EXTRA_FIRMWARE{_DIR} one is able to build akernel including firmware blobs in a built-in fashion. This is usuallythe case of built-in drivers that require some blobs in order to workproperly, for example, like in non-initrd based systems.Add hereby a script to extract these blobs from a non-stripped vmlinux,similar to the idea of "extract-ikconfig". The firmware loader interfacesaves such built-in blobs as rodata entries, having a field for the FWname as "_fw___bin"; the tool extracts filesnamed "_" for each rodata firmware entrydetected. It makes use of awk, bash, dd and readelf, pretty standardtooling for Linux development.With this tool, we can blindly extract the FWs and easily re-add themin the new debug kernel build, allowing a more deterministic testingwithout the burden of "hunting down" the proper version of eachfirmware binary.Link: https://lkml.kernel.org/r/20250120190436.127578-1-gpiccoli@igalia.comSigned-off-by: Guilherme G. Piccoli Suggested-by: Thadeu Lima de Souza Cascardo Reviewed-by: Thadeu Lima de Souza Cascardo Cc: Danilo Krummrich Cc: Greg Kroah-Hartman Cc: Luis Chamberalin Cc: Masahiro Yamada Cc: Nathan Chancellor Cc: Nicolas Schier Cc: "Rafael J. Wysocki" Cc: Russ Weight Signed-off-by: Andrew Morton List of files: /linux-6.15/scripts/extract-fwblobs

Changes in extract-fwblobs

35dac71c - scripts: add script to extract built-in firmware blobs