The patch titled
Subject: scripts: add script to extract built-in firmware blobs
has been added to the -mm mm-nonmm-unstable branch. Its filename is
scripts-add-script-to-extract-built-in-firmware-blobs.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/scripts-add-script-to-extract-built-in-firmware-blobs.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxx>
Subject: scripts: add script to extract built-in firmware blobs
Date: Mon, 20 Jan 2025 16:04:26 -0300
Through the options CONFIG_EXTRA_FIRMWARE{_DIR} one is able to build a
kernel including firmware blobs in a built-in fashion. This is usually
the case of built-in drivers that require some blobs in order to work
properly, 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 interface
saves such built-in blobs as rodata entries, having a field for the FW
name as "_fw_<module_name>_<firmware_name>_bin"; the tool extracts files
named "<module_name>_<firmware_name>" for each rodata firmware entry
detected. It makes use of awk, bash, dd and readelf, pretty standard
tooling for Linux development.
Link: https://lkml.kernel.org/r/20250120190436.127578-1-gpiccoli@xxxxxxxxxx
Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx>
Suggested-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxx>
Reviewed-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxx>
Cc: Danilo Krummrich <dakr@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Luis Chamberalin <mcgrof@xxxxxxxxxx>
Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nicolas Schier <nicolas@xxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Russ Weight <russ.weight@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
scripts/extract-fwblobs | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/scripts/extract-fwblobs a/scripts/extract-fwblobs
new file mode 100755
--- /dev/null
+++ a/scripts/extract-fwblobs
@@ -0,0 +1,31 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# -----------------------------------------------------------------------------
+# Extracts the vmlinux built-in firmware blobs - requires a non-stripped image
+# -----------------------------------------------------------------------------
+
+if [ -z "$1" ]; then
+ echo "Must provide a non-stripped vmlinux as argument"
+ exit 1
+fi
+
+read -r RD_ADDR_HEX RD_OFF_HEX <<< "$( readelf -SW "$1" |\
+grep -w rodata | awk '{print "0x"$5" 0x"$6}' )"
+
+FW_SYMS="$(readelf -sW "$1" |\
+awk -n '/fw_end/ { end=$2 ; print name " 0x" start " 0x" end; } { start=$2; name=$8; }')"
+
+while IFS= read -r entry; do
+ read -r FW_NAME FW_ADDR_ST_HEX FW_ADDR_END_HEX <<< "$entry"
+
+ # Notice kernel prepends _fw_ and appends _bin to the FW name
+ # in rodata; hence we hereby filter that out.
+ FW_NAME=${FW_NAME:4:-4}
+
+ FW_OFFSET="$(printf "%d" $((FW_ADDR_ST_HEX - RD_ADDR_HEX + RD_OFF_HEX)))"
+ FW_SIZE="$(printf "%d" $((FW_ADDR_END_HEX - FW_ADDR_ST_HEX)))"
+
+ dd if="$1" of="./${FW_NAME}" bs="${FW_SIZE}" count=1 iflag=skip_bytes skip="${FW_OFFSET}"
+done <<< "${FW_SYMS}"
+
_
Patches currently in -mm which might be from gpiccoli@xxxxxxxxxx are
scripts-add-script-to-extract-built-in-firmware-blobs.patch
