From 5f9c01aa7c49a2d74474d6d879a797b8badf29e6 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 3 Feb 2016 12:33:29 +0100 Subject: x86/microcode: Untangle from BLK_DEV_INITRD Thomas Voegtle reported that doing oldconfig with a .config which has CONFIG_MICROCODE enabled but BLK_DEV_INITRD disabled prevents the microcode loading mechanism from being built. So untangle it from the BLK_DEV_INITRD dependency so that oldconfig doesn't turn it off and add an explanatory text to its Kconfig help what the supported methods for supplying microcode are. Reported-by: Thomas Voegtle Tested-by: Thomas Voegtle Signed-off-by: Borislav Petkov Cc: # 4.4 Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1454499225-21544-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) (limited to 'arch/x86/Kconfig') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 9af2e6338400..405b1858134b 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1159,22 +1159,23 @@ config MICROCODE bool "CPU microcode loading support" default y depends on CPU_SUP_AMD || CPU_SUP_INTEL - depends on BLK_DEV_INITRD select FW_LOADER ---help--- - If you say Y here, you will be able to update the microcode on - certain Intel and AMD processors. The Intel support is for the - IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, - Xeon etc. The AMD support is for families 0x10 and later. You will - obviously need the actual microcode binary data itself which is not - shipped with the Linux kernel. - - This option selects the general module only, you need to select - at least one vendor specific module as well. - - To compile this driver as a module, choose M here: the module - will be called microcode. + Intel and AMD processors. The Intel support is for the IA32 family, + e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The + AMD support is for families 0x10 and later. You will obviously need + the actual microcode binary data itself which is not shipped with + the Linux kernel. + + The preferred method to load microcode from a detached initrd is described + in Documentation/x86/early-microcode.txt. For that you need to enable + CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the + initrd for microcode blobs. + + In addition, you can build-in the microcode into the kernel. For that you + need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode + to the CONFIG_EXTRA_FIRMWARE config option. config MICROCODE_INTEL bool "Intel microcode loading support" -- cgit v1.2.3