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.
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
88 The system needs to have the microcode packages installed into
89 /lib/firmware or you need to fixup the paths above if yours are
99   # echo 1 > /sys/devices/system/cpu/microcode/reload
104 /lib/firmware/{intel-ucode,amd-ucode}. The default distro installation
115 ----------------------
118 between the two logical threads in a SMT system. Therefore, when
134 To eliminate this case, a stop_machine()-based CPU synchronization was
140 that can't be shut off. Those are Machine Check (#MC), System Management
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
152 system. If one thread is in the middle of executing WRMSR, a MCE will be
155 eventually if any of the threads in the system fail to check in to the
159 MCG_STATUS.MCIP. Since MCEs can be at most one in a system, if an
160 MCE was signaled, the above condition will promote to a system reset
164 System Management Interrupt
165 ---------------------------
178 Non-Maskable Interrupts
179 -----------------------
189 -------------------------------------------
191 Late loading is done when the system is fully operational and running
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"
221   CONFIG_EXTRA_FIRMWARE_DIR="/lib/firmware"
225   /lib/firmware/
226   |-- amd-ucode
228   |   |-- microcode_amd_fam15h.bin
230   |-- intel-ucode
232   |   |-- 06-3a-09
235 so that the build system can find those files and integrate them into