From b584303261b7041f209afde4bf7ddb7a21598a1f Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 3 Feb 2016 12:33:45 +0100 Subject: [PATCH] x86/microcode: Document builtin microcode loading method Add some text and an example to Documentation/x86/early-microcode.txt explaining how to build in microcode. Tested-by: Thomas Voegtle Signed-off-by: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1454499225-21544-18-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar --- Documentation/x86/early-microcode.txt | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/Documentation/x86/early-microcode.txt b/Documentation/x86/early-microcode.txt index d62bea6796da..c956d99cf1de 100644 --- a/Documentation/x86/early-microcode.txt +++ b/Documentation/x86/early-microcode.txt @@ -40,3 +40,28 @@ cp ../microcode.bin kernel/x86/microcode/GenuineIntel.bin (or AuthenticAMD.bin) find . | cpio -o -H newc >../ucode.cpio cd .. cat ucode.cpio /boot/initrd-3.5.0.img >/boot/initrd-3.5.0.ucode.img + +Builtin microcode +================= + +We can also load builtin microcode supplied through the regular firmware +builtin method CONFIG_FIRMWARE_IN_KERNEL. Here's an example: + +CONFIG_FIRMWARE_IN_KERNEL=y +CONFIG_EXTRA_FIRMWARE="intel-ucode/06-3a-09 amd-ucode/microcode_amd_fam15h.bin" +CONFIG_EXTRA_FIRMWARE_DIR="/lib/firmware" + +This basically means, you have the following tree structure locally: + +/lib/firmware/ +|-- amd-ucode +... +| |-- microcode_amd_fam15h.bin +... +|-- intel-ucode +... +| |-- 06-3a-09 +... + +so that the build system can find those files and integrate them into +the final kernel image. The early loader finds them and applies them.