arch/x86/microcode.rst

1 .. SPDX-License-Identifier: GPL-2.0
7 :Authors: - Fenghua Yu <fenghua.yu@intel.com>
8           - Borislav Petkov <bp@suse.de>
9 	  - Ashok Raj <ashok.raj@intel.com>
13 updating the microcode on platforms beyond the OEM End-Of-Life support,
14 and updating the microcode on long-running systems without rebooting.
21 The kernel can update microcode very early during boot. Loading
23 kernel boot time.
25 The microcode is stored in an initrd file. During boot, it is read from
30 loader parses the combined initrd image during boot.
39 During BSP (BootStrapping Processor) boot (pre-SMP), the kernel
56   if [ -z "$1" ]; then
66   rm -rf $TMPDIR
70   mkdir -p $DSTDIR
72   if [ -d /lib/firmware/amd-ucode ]; then
73           cat /lib/firmware/amd-ucode/microcode_amd*.bin > $DSTDIR/AuthenticAMD.bin
76   if [ -d /lib/firmware/intel-ucode ]; then
77           cat /lib/firmware/intel-ucode/* > $DSTDIR/GenuineIntel.bin
80   find . | cpio -o -H newc >../ucode.cpio
85   rm -rf $TMPDIR
104 /lib/firmware/{intel-ucode,amd-ucode}. The default distro installation
109 The /dev/cpu/microcode method has been removed in 5.19.
115 ----------------------
134 To eliminate this case, a stop_machine()-based CPU synchronization was
141 (#SMI) and Non-Maskable interrupts (#NMI).
144 --------------
146 Machine Checks (#MC) are non-maskable. There are two kinds of MCEs.
147 Fatal un-recoverable MCEs and recoverable MCEs. While un-recoverable
165 ---------------------------
178 Non-Maskable Interrupts
179 -----------------------
189 -------------------------------------------
200 Between patch1 and patch3, patch2 might have deprecated a software-visible
208 for late-loading. This is another one of the problems that caused late
215 the regular builtin firmware method CONFIG_EXTRA_FIRMWARE. Only 64-bit is
220   CONFIG_EXTRA_FIRMWARE="intel-ucode/06-3a-09 amd-ucode/microcode_amd_fam15h.bin"
226   |-- amd-ucode
228   |   |-- microcode_amd_fam15h.bin
230   |-- intel-ucode
232   |   |-- 06-3a-09
238 Needless to say, this method is not the most flexible one because it