diff options
| author | Subrata Banik <subratabanik@google.com> | 2024-04-17 00:11:15 +0530 |
|---|---|---|
| committer | Subrata Banik <subratabanik@google.com> | 2024-04-18 03:30:44 +0000 |
| commit | 0b70b0b7901eff1f1f629c09d341bb0eeba5f6c2 (patch) | |
| tree | edb793292f7b51629e0493eb98299056d7838e9d /src/cpu | |
| parent | 24bc05d7971cebcccc73a31b837fe43e9bea1938 (diff) | |
cpu/intel/microcode: Defer microcode patching until after DRAM init
Follows Intel SoC recommendation to avoid potential cache contention
issues during early (pre-DRAM) microcode loading.
Source: MTL_ARL_Processor_Family_BiosSpec_Rev1p0
Document Number: 729384
BUG=b:330536271
TEST=Able to boot to ChromeOS.
w/o this patch:
[DEBUG] microcode: sig=0xa06a4 pf=0x80 revision=0x19
[INFO ] CBFS: Found 'cpu_microcode_a06a4.bin' @0x1d9c0 size 0x21400
in mcache @0xfef89680
[INFO ] VB2:vb2_digest_init() 136192 bytes, hash algo 2, HW
acceleration enabled
[INFO ] microcode: load microcode patch
[ERROR] microcode: Update failed
w/ this patch:
[ERROR] Microcode Error: Early microcode patching is not supported due
to NEM limitation
Change-Id: I1e433f5bede036800b27900b4b13a399b4f45d6f
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81954
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Eric Lai <ericllai@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src/cpu')
| -rw-r--r-- | src/cpu/intel/microcode/microcode.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/cpu/intel/microcode/microcode.c b/src/cpu/intel/microcode/microcode.c index 0d52bafb31..b22822641a 100644 --- a/src/cpu/intel/microcode/microcode.c +++ b/src/cpu/intel/microcode/microcode.c @@ -241,6 +241,12 @@ const void *intel_microcode_find(void) static bool microcode_checked; static const void *ucode_update; + if (ENV_CACHE_AS_RAM) { + printk(BIOS_ERR, "Microcode Error: Early microcode patching is not supported due" + "to NEM limitation\n"); + return NULL; + } + if (microcode_checked) return ucode_update; |