xref: /aosp_15_r20/external/coreboot/src/cpu/intel/microcode/Kconfig (revision b9411a12aaaa7e1e6a6fb7c5e057f44ee179a49c)
1## SPDX-License-Identifier: GPL-2.0-only
2
3config MICROCODE_UPDATE_PRE_RAM
4	bool
5	depends on SUPPORT_CPU_UCODE_IN_CBFS
6	default n if CPU_INTEL_FIRMWARE_INTERFACE_TABLE
7	default y
8	help
9	  Select this option if you want to update the microcode
10	  during the cache as RAM setup.
11
12config RELOAD_MICROCODE_PATCH
13	bool
14	default n
15	help
16	  Select this option if SoC recommends to re-load microcode
17	  patch as part of CPU multiprocessor initialization process.
18	  This feature is mostly required with Intel latest generation
19	  processors starting with Alder Lake (with modified MCHECK init
20	  flow).
21
22config CPU_INTEL_MICROCODE_CBFS_SPLIT_BINS
23	bool "For Intel CPU, include microcode per CPUID into CBFS"
24	depends on CBFS_VERIFICATION && !MICROCODE_UPDATE_PRE_RAM
25	default n
26	help
27	  This option controls whether to include external microcode binaries per
28	  CPUID in CBFS.
29
30	  The current approach of loading microcode blobs post CPU reset is to search
31	  the unified blob in the CBFS and then perform the CBFS verification. The bigger
32	  the unified microcode blob in size the longer it takes to perform the verification.
33
34	  Select this option to store the split microcode blobs per CPUID in the CBFS.
35	  As the microcode blobs will be divided into smaller chunks per CPUID, which will
36	  reduce the overall search, verify and load time.
37
38	  The microcode file may be removed from the ROM image at a later
39	  time with cbfstool, if desired.
40
41	  If unsure, and applicable, select "Generate from tree"
42
43config CPU_INTEL_UCODE_SPLIT_BINARIES
44	string "Specify the split microcode blob directory path"
45	depends on CPU_INTEL_MICROCODE_CBFS_SPLIT_BINS
46	default ""
47	help
48	  Provide the split microcode blob directory path if
49	  CPU_INTEL_MICROCODE_CBFS_SPLIT_BINS config is enabled.
50
51	  CPU_INTEL_MICROCODE_CBFS_SPLIT_BINS config is allowed to pack the individual microcode
52	  patch file per CPUID inside the CBFS.
53
54	  Intel distributes CPU microcode updates based on CPUID as part of the github repository
55	  in INC format and expects it also getting used in binary form.
56
57	  For example: Intel CPU microcode `m506e3.inc` is getting converted into F-MO-S
58	  (06-5e-03) binary file for Linux kernel.
59
60	  `MicrocodeConverter` is an Intel-provided tool for converting binary form MCU into
61	  several other common formats for integration.
62
63	  Implementation logic behind CPU_INTEL_MICROCODE_CBFS_SPLIT_BINS config relies on
64	  converting Intel CPU microcode INC file into the binary file as per format specified
65	  here `cpu_microcode_$(CPUID).bin`. For example: Intel CPU microcode `m506e3.inc` to
66	  convert into `cpu_microcode_506e3.bin` binary file for coreboot to integrate if
67	  CPU_INTEL_MICROCODE_CBFS_SPLIT_BINS config is enabled.
68
69	  This config provides the directory name (including path) that holds the split microcode
70	  binary files per CPUID as mentioned above for each coreboot variants. For example: if
71	  google/kunimitsu had built with Intel SkyLake processor with CPUID `506e3` and `506e4`
72	  then CPU_INTEL_UCODE_SPLIT_BINARIES refers to the directory path that holds the split
73	  microcode binary files aka `cpu_microcode_506e3.bin` and `cpu_microcode_506e4.bin`.
74
75	  CONFIG_CPU_UCODE_SPLIT_BINARIES="3rdparty/blobs/mainboard/google/kunimitsu/microcode_inputs/kunimitsu"
76	  Refer to the file representation below:
77	  |---3rdparty
78	  |   |--- blobs
79	  |   |    |--- mainboard
80	  |   |    |   |--- google
81	  |   |    |   |    |--- kunimitsu
82	  |   |    |   |    |    |--- microcode_inputs
83	  |   |    |   |    |    |    |--- kunimitsu
84	  |   |    |   |    |    |    |    |--- cpu_microcode_506e3.bin
85	  |   |    |   |    |    |    |    |--- cpu_microcode_506e4.bin
86
87	  Users of this config option requires to manually place the microcode binary files per
88	  CPUIDs as per the given format (`cpu_microcode_$(CPUID).bin`) in a directory.
89	  Finally specify the microcode binary directory path using CPU_UCODE_SPLIT_BINARIES
90	  config.
91
92	  At runtime (either from romstage/ramstage), coreboot read the CPUID and search for the
93	  `cpu_microcode_$(CPUID).bin` file (in this example: cpu_microcode_506e3.bin) inside RW
94	  CBFS. Eventually able to locate the appropriate `cpu_microcode_$(CPUID).bin` file and
95	  perform the verification prior loading into the CPUs (BSP and APs).
96
97	  If unsure, leave this blank.
98