Intel P6 microcode update files format

Microcode patch file - or microcode update file. Can be decoded/encoded using p6patchtool.

Official microcode patch header

offset 0x00, len 0x30, all fields are 32bit values.

Header Version 4
Update Revision 4
Date 4
Processor Signature 4
Checksum 4
Loader Revision 4
Processor Flags 4
Data Size 4
Total Size 4
Reserved 12 (3*4 bytes)

Data are encrypted using simple LFSR-style cipher and integrity checked using multiple dwords at various locations, refer to p6patchtool source code for more information.

Checksum

To check for a corrupt microcode update, software must perform a unsigned DWORD (32-bit) checksum of the microcode update. Even though some fields are signed, the checksum procedure treats all DWORDs as unsigned. Microcode updates with a header version equal to 00000001H must sum all DWORDs that comprise the microcode update. A valid checksum check will yield a value of 00000000H.

Extended (undocumented) header w/ RSA

Structure of undocumented additional Intel microcode update header

Field	Size	Value (Typical)
Unknown 1	4	0h
Magic Number	4	a1h
Unknown 3	4	20001h
Update Revision	4	Varies
Unknown 4	4	Varies
Unknown 5	4	Varies
Date	4	Varies
Update Length	4	Varies
Unknown 6	4	1h
Processor Signature	4	0h
Unknown 7	56	0h
Unknown 8	16	Varies
RSA Modulus	256	Varies across processor family
RSA Exponent	4	11h
RSA Signature	256	Varies

RSA format

RSA format uses 2048-bit RSA-signed SHA-1 hash of plaintext patch, data encryption using RC4 with key derived from 128-bit secret key (read from CPU FROM) combined with nonce (in patch file). Similar to Intel Atom Goldmont - ieeexplore.ieee.org/stampPDF/getPDF.jsp...JlLmllZWUub3JnL2RvY3VtZW50LzEwMTg4NjU3↗

Decoding supported by p6patchtool for CPUIDs 0x6F9 and 0x6FB (which is the only one with known rc4 key).

0x000 x - official patch header
0x030 000 - extended patch header (undocumented)
0x090 060 - Probably 32 bytes of NONCE (a unique, random number that serves to secure and validate transactions or blocks)
0x0B0 080 - Public key. Hash of the key is validated - hash is obtained in MSROM via "FREADROM       (CONST_16+189  , CONST_16+189" (and 18A, 18B, 18C, 18D)
0x1B0 180 - long 0x11 (17)  - validated using "SUB.DSZ32      (CONST_16+011  , CONST_16+011"
0x1B4 184 - signature
0x2B4 284 - probably patch data

plaintext signature looks like this:

00 01 ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff 00 66 ed 14 39  76 c1 e0 77 1e e7 0b 51 1a c4 f6 26 8b bb 7d 16

The signature plaintext (before exponentiation) under PKCS #1 v1.5 for signing has the format:

Starts with 00 01 - block type for signature.
Followed by a long run of 0xFF - the padding string PS.
Then 00 - padding terminator.
Then 20 bytes (160 bits) at the end hash at the end is likely SHA-1.

Core2 and later CPUs using RSA

Listing of patches with rsa public key SHA-1:

Known RC4 key:

cpu006F9_plat01_ver00000082_2006-09-03_PRD_59C9FE00.bin 577267305230a5002c0800903d824c2aa4de91df Conroe: Core2 Duo (Conroe)
cpu006F9_plat04_ver00000082_2006-09-03_PRD_59C9FDFD.bin 577267305230a5002c0800903d824c2aa4de91df (Conroe)
cpu006F9_plat08_ver00000084_2006-10-12_PRD_6BADD6B5.bin 577267305230a5002c0800903d824c2aa4de91df (Conroe)
cpu006F9_plat10_ver00000082_2006-09-03_PRD_59C9FDF1.bin 577267305230a5002c0800903d824c2aa4de91df (Conroe)
cpu006F9_plat40_ver00000084_2006-10-12_PRD_6BADD67D.bin 577267305230a5002c0800903d824c2aa4de91df (Conroe)
cpu006F9_plat80_ver00000083_2006-09-28_PRD_85B7E1DF.bin 577267305230a5002c0800903d824c2aa4de91df (Conroe)

cpu006FB_plat01_ver000000C1_2011-10-04_PRD_0EF87396.bin 577267305230a5002c0800903d824c2aa4de91df Conroe/Allendale LGA775 (Conroe/Allendale)
cpu006FB_plat04_ver000000BC_2010-10-03_PRD_9394765A.bin 577267305230a5002c0800903d824c2aa4de91df Xeon - LGA771 (Conroe/Woodcrest)
cpu006FB_plat08_ver000000BB_2010-10-03_PRD_E7FBF398.bin 577267305230a5002c0800903d824c2aa4de91df (Conroe)
cpu006FB_plat10_ver000000BA_2010-10-03_PRD_ED247070.bin 577267305230a5002c0800903d824c2aa4de91df LGA775 (Conroe/Allendale)
cpu006FB_plat20_ver000000BA_2010-10-03_PRD_9777492E.bin 577267305230a5002c0800903d824c2aa4de91df (Conroe)
cpu006FB_plat40_ver000000BC_2010-10-03_PRD_F1A7A484.bin 577267305230a5002c0800903d824c2aa4de91df Xeon - LGA771 (Conroe/Woodcrest)
cpu006FB_plat80_ver000000BA_2010-10-03_PRD_F953DC67.bin 577267305230a5002c0800903d824c2aa4de91df (Conroe)

RC4 keys not known:

cpu106A4_plat03_ver00000013_2015-06-30_PRD_35DDB232.bin c655a8fdafe1b6d38496c307f7723c4a7cfa6a72 Lynnfield/Bloomfield : Intel Xeon / Intel(R) Core(TM) i7 (Nehalem)
cpu106A5_plat03_ver0000001D_2018-05-11_PRD_AB179397.bin c655a8fdafe1b6d38496c307f7723c4a7cfa6a72 Nehalem: EP, WS & EX (Nehalem)
cpu106E4_plat09_ver00000003_2013-07-01_PRD_A8C7E0F3.bin c655a8fdafe1b6d38496c307f7723c4a7cfa6a72 Jasper Forest: Celeron and Xeon (Nehalem)
cpu106E5_plat13_ver0000000A_2018-05-08_PRD_B16FCEEB.bin c655a8fdafe1b6d38496c307f7723c4a7cfa6a72 Clarksfield: Core (Nehalem)

cpu10670_plat80_ver00000005_2007-02-09_PRD_7E1FBC19.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Merom)
cpu10671_plat01_ver00000106_2007-03-29_PRD_80731BAC.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Merom)
cpu10671_plat10_ver00000106_2007-03-29_PRD_80731B9D.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Merom)
cpu10671_plat44_ver00000106_2007-03-29_PRD_80731B69.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Merom)
cpu10671_plat80_ver00000106_2007-03-29_PRD_80731B2D.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Merom)
cpu10674_plat01_ver00000404_2007-06-08_PRD_F9DEC4C0.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Merom/Penryn transition; Core 2 family)
cpu10674_plat10_ver00000404_2007-06-08_PRD_F9DEC4B1.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Merom/Penryn transition; Core 2 family)
cpu10674_plat44_ver00000404_2007-06-08_PRD_F9DEC47D.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Merom/Penryn transition; Core 2 family)
cpu10674_plat80_ver00000405_2007-07-20_PRD_735D9FE0.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Merom/Penryn transition; Core 2 family)

cpu10676_plat04_ver00000612_2015-08-02_PRD_AEAA6CC1.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 Harpertown (Xeon) (Penryn)
cpu10676_plat40_ver00000612_2015-08-02_PRD_B6F50E9C.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Penryn)
cpu10676_plat44_ver0000060F_2010-09-29_PRD_8FE1A203.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Penryn)
cpu10676_plat54_ver0000060C_2008-01-19_PRD_FBAC0F19.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Penryn)
cpu10676_plat91_ver00000612_2015-08-02_PRD_1750A2A6.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Penryn)

cpu10677_plat01_ver00000701_2007-10-26_PRD_7D1E6483.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 Yorkfield: Core 2 and Xeon (Penryn)
cpu10677_plat10_ver0000070D_2015-08-02_PRD_DAE8586D.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Penryn)

cpu1067A_plat44_ver00000A0E_2015-07-29_PRD_A3107D75.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 Penryn/QC (Core 2, Pentium, and Celeron) (Penryn)
cpu1067A_platB1_ver00000A0E_2015-07-29_PRD_59BF808E.bin 53bdc4a8180ba0e95591a0848cc4073046b274c2 (Penryn) (SLGJ4/478-pin micro-FCPGA)

cpu206D5_plat6D_ver00000513_2011-10-13_PRD_BDB805CB.bin 317a835c02944e4cb27eb772a2ff3b7c23fa69a1 (Sandy Bridge-EP)
cpu206D6_plat6D_ver00000621_2020-03-04_PRD_7ED51E79.bin 317a835c02944e4cb27eb772a2ff3b7c23fa69a1 (Sandy Bridge-EP)
cpu206D7_plat6D_ver0000071A_2020-03-24_PRD_AC8779F8.bin 317a835c02944e4cb27eb772a2ff3b7c23fa69a1 (Sandy Bridge-EP)

cpu206F0_plat05_ver00000005_2010-07-29_PRD_3E473C93.bin 538722ef24e55376286dcbc2a042ec465a10131a (Westmere-EX)
cpu206F1_plat05_ver00000008_2010-10-13_PRD_00D18792.bin 538722ef24e55376286dcbc2a042ec465a10131a (Westmere-EX)
cpu206F2_plat05_ver0000003B_2018-05-16_PRD_28612AC4.bin 538722ef24e55376286dcbc2a042ec465a10131a (Westmere-EX)

cpu206A0_plat12_ver00000029_2009-11-02_PRD_D6930586.bin f8e3e04c79a63a02f1713242dfbcb3e00c468d13 (Sandy Bridge)
cpu206A1_plat12_ver00000007_2009-12-23_PRD_8F1081F2.bin f8e3e04c79a63a02f1713242dfbcb3e00c468d13 (Sandy Bridge)
cpu206A2_plat12_ver00000027_2010-05-02_PRD_EB510B0E.bin f8e3e04c79a63a02f1713242dfbcb3e00c468d13 (Sandy Bridge)
cpu206A3_plat12_ver00000009_2010-06-09_PRD_261BDACD.bin f8e3e04c79a63a02f1713242dfbcb3e00c468d13 (Sandy Bridge)
cpu206A4_plat12_ver00000022_2010-04-14_PRD_8A6F7F91.bin f8e3e04c79a63a02f1713242dfbcb3e00c468d13 (Sandy Bridge)
cpu206A5_plat12_ver00000007_2010-07-22_PRD_20B7FDE6.bin f8e3e04c79a63a02f1713242dfbcb3e00c468d13 (Sandy Bridge)
cpu206A6_plat12_ver00000028_2010-09-15_PRD_2B9BECC8.bin f8e3e04c79a63a02f1713242dfbcb3e00c468d13 (Sandy Bridge)
cpu206A7_plat12_ver0000002F_2019-02-17_PRD_8D15DF31.bin f8e3e04c79a63a02f1713242dfbcb3e00c468d13 Sandy Bridge: Core i3, Core i5, Celeron, Pentium, and Xeon E3-1200 (Sandy Bridge)

cpu30650_plat08_ver00000009_2012-01-18_PRD_21D95B62.bin 041d14491be2b114f1521a212c3c795f169db4ff (Ivy Bridge family)
cpu30651_plat01_ver00000110_2013-10-14_PRD_854EDC90.bin 041d14491be2b114f1521a212c3c795f169db4ff (Ivy Bridge family)
cpu30651_plat08_ver0000010D_2013-05-20_PRD_0C8D59A0.bin 041d14491be2b114f1521a212c3c795f169db4ff (Ivy Bridge family)
cpu30660_plat04_ver00000003_2010-11-03_PRD_5173ABD8.bin 041d14491be2b114f1521a212c3c795f169db4ff (Ivy Bridge family)
cpu30660_plat08_ver00000003_2010-11-03_PRD_0B1DEE36.bin 041d14491be2b114f1521a212c3c795f169db4ff (Ivy Bridge family)
cpu30661_plat01_ver0000010D_2011-12-22_PRD_B4762578.bin 041d14491be2b114f1521a212c3c795f169db4ff (Ivy Bridge family)
cpu30661_plat02_ver0000010D_2011-12-22_PRD_D687F85A.bin 041d14491be2b114f1521a212c3c795f169db4ff (Ivy Bridge family)
cpu30661_plat04_ver0000010F_2015-07-21_PRD_F422CDF9.bin 041d14491be2b114f1521a212c3c795f169db4ff (Ivy Bridge family)
cpu30661_plat08_ver0000010F_2015-07-21_PRD_0E2514F3.bin 041d14491be2b114f1521a212c3c795f169db4ff (Ivy Bridge family)
cpu30669_plat01_ver0000010D_2013-05-15_PRD_3F0531D2.bin 041d14491be2b114f1521a212c3c795f169db4ff (Ivy Bridge family)

cpu306A0_plat12_ver00000007_2011-04-07_PRD_5F4A8285.bin 23292046ad71dccc067b5ad0af8397b2fda9613e (Ivy Bridge)
cpu306A2_plat12_ver0000000C_2011-07-25_PRD_45CEAA5F.bin 23292046ad71dccc067b5ad0af8397b2fda9613e (Ivy Bridge)
cpu306A4_plat12_ver00000007_2011-09-08_PRD_7E23E5AF.bin 23292046ad71dccc067b5ad0af8397b2fda9613e (Ivy Bridge)
cpu306A5_plat12_ver00000009_2011-11-10_PRD_9F575F21.bin 23292046ad71dccc067b5ad0af8397b2fda9613e (Ivy Bridge)
cpu306A6_plat12_ver00000004_2011-11-14_PRD_1D1150A5.bin 23292046ad71dccc067b5ad0af8397b2fda9613e (Ivy Bridge)
cpu306A8_plat12_ver00000010_2012-02-20_PRD_E44A4EF2.bin 23292046ad71dccc067b5ad0af8397b2fda9613e (Ivy Bridge)
cpu306A9_plat12_ver00000021_2019-02-13_PRD_A8DF9213.bin 23292046ad71dccc067b5ad0af8397b2fda9613e (Ivy Bridge Pentium 2117U) (Ivy Bridge)

cpu306F1_platEF_ver00000014_2014-01-10_PRD_9F835FBB.bin 29d8d4000bfeaf53d559f24855299af79ff5365a (Haswell-EP)
cpu306F2_plat6F_ver00000049_2021-08-11_PRD_79C6E826.bin 29d8d4000bfeaf53d559f24855299af79ff5365a (Haswell-EP)
cpu306F2_plat80_ver00000F07_2014-07-07_PRD_D88AA181.bin 29d8d4000bfeaf53d559f24855299af79ff5365a (Haswell-EP)
cpu306F3_plat80_ver0000000D_2016-02-11_PRD_2BB5E8E3.bin 29d8d4000bfeaf53d559f24855299af79ff5365a (Haswell-EP)
cpu306F4_plat80_ver0000001A_2021-05-24_PRD_A3E4C533.bin 29d8d4000bfeaf53d559f24855299af79ff5365a (Haswell-EP/EX)

cpu50671_plat78_ver000001B6_2018-01-08_PRD_A1921B5B.bin 0b17fc17104afe45f76f3c70427f4906e1ce6d3e (Skylake family)
cpu80650_plat08_ver00000018_2018-01-08_PRD_19B5F433.bin 0b17fc17104afe45f76f3c70427f4906e1ce6d3e Atom Z27xx: Cloverview (Saltwell)

cpu406C1_plat01_ver0000010B_2014-08-14_PRD_13129396.bin 0e9a028a4625f594a8fb94e60a7e23b48c9bb03a (Bay Trail)
cpu406C2_plat01_ver00000221_2015-02-18_PRD_B46209E1.bin 0e9a028a4625f594a8fb94e60a7e23b48c9bb03a (Bay Trail)
cpu406C3_plat01_ver00000368_2019-04-23_PRD_CE4070DC.bin 0e9a028a4625f594a8fb94e60a7e23b48c9bb03a (Bay Trail)
cpu406C4_plat01_ver00000411_2019-04-23_PRD_ABE7BD38.bin 0e9a028a4625f594a8fb94e60a7e23b48c9bb03a (Bay Trail)

cpu606E0_plat01_ver0000000B_2016-11-04_PRD_8D10D855.bin 0e9a028a4625f594a8fb94e60a7e23b48c9bb03a (Skylake/Kaby Lake family)
cpu606E1_plat01_ver00000108_2019-04-23_PRD_66444E22.bin 0e9a028a4625f594a8fb94e60a7e23b48c9bb03a (Skylake/Kaby Lake family)

cpu306D4_platC0_ver0000002F_2019-11-12_PRD_8B6D899D.bin 4177909a16cb332d02b0f87091835f3eac21f761 Broadwell-U/Y (Broadwell)

cpu40671_plat22_ver00000022_2019-11-12_PRD_00B9F4B1.bin 4177909a16cb332d02b0f87091835f3eac21f761 Broadwell-H (Broadwell)

cpu60660_plat80_ver0000000C_2016-08-21_PRD_B3C8D44D.bin 5690c62171048bacb4d4b17a02b55bd2a730cf19 (Cannon Lake)
cpu60661_plat80_ver0000000E_2017-01-28_PRD_398CC081.bin 5690c62171048bacb4d4b17a02b55bd2a730cf19 (Cannon Lake)
cpu60662_plat80_ver00000022_2017-11-29_PRD_D6CC7995.bin 5690c62171048bacb4d4b17a02b55bd2a730cf19 (Cannon Lake)
cpu60663_plat80_ver0000002A_2018-04-17_PRD_C7B6F35C.bin 5690c62171048bacb4d4b17a02b55bd2a730cf19 (Cannon Lake)

cpu50653_plat97_ver01000191_2023-07-28_PRD_476A9E92.bin 6c742c10d0238abb87d1069b375ce606fc7f8ef9 (Skylake Server)
cpu50654_platB7_ver02007206_2024-04-15_PRD_BEBD3AE4.bin 6c742c10d0238abb87d1069b375ce606fc7f8ef9 (Skylake Server/D)
cpu50655_platB7_ver03000012_2019-04-12_PRD_50E6B5F2.bin 6c742c10d0238abb87d1069b375ce606fc7f8ef9 (Skylake Server/D)
cpu50656_platBF_ver04003901_2024-12-12_PRD_7D55DE29.bin 6c742c10d0238abb87d1069b375ce606fc7f8ef9 (Cascade Lake)
cpu50657_platBF_ver05003901_2024-12-12_PRD_94DBE757.bin 6c742c10d0238abb87d1069b375ce606fc7f8ef9 (Cascade Lake)
cpu5065B_platBF_ver07002B01_2024-12-12_PRD_45B559A3.bin 6c742c10d0238abb87d1069b375ce606fc7f8ef9 (Cascade Lake)

cpu306E0_platED_ver00000008_2012-07-26_PRD_D9675AA0.bin 6dcb4fcac7cae0256e7d949b9e770bc2682f2c21 (Ivy Bridge-EP)
cpu306E2_platED_ver0000020D_2013-03-21_PRD_5C18F686.bin 6dcb4fcac7cae0256e7d949b9e770bc2682f2c21 (Ivy Bridge-EP)
cpu306E3_platED_ver00000308_2013-03-21_PRD_205AE8FA.bin 6dcb4fcac7cae0256e7d949b9e770bc2682f2c21 (Ivy Bridge-EP)
cpu306E4_platED_ver0000042E_2019-03-14_PRD_3C222CE1.bin 6dcb4fcac7cae0256e7d949b9e770bc2682f2c21 (Ivy Bridge-EP)
cpu306E6_platED_ver00000600_2013-06-19_PRD_14788DCE.bin 6dcb4fcac7cae0256e7d949b9e770bc2682f2c21 (Ivy Bridge-EP)
cpu306E7_platED_ver00000715_2019-03-14_PRD_AD89AC0D.bin 6dcb4fcac7cae0256e7d949b9e770bc2682f2c21 (Ivy Bridge-EP)

cpu506C2_plat01_ver00000014_2018-05-11_PRD_BD3490B6.bin 7d4a222e433b7c4344d8c9de523eee3814db8239 (Broxton / Goldmont Atom)
cpu506C8_plat01_ver00000010_2016-03-04_PRD_DE6EBB18.bin 7d4a222e433b7c4344d8c9de523eee3814db8239 (Goldmont Atom)
cpu506C9_plat03_ver00000048_2021-11-16_PRD_C82C5521.bin 7d4a222e433b7c4344d8c9de523eee3814db8239 (Apollo Lake / Goldmont Atom)
cpu506CA_plat03_ver00000028_2021-11-16_PRD_B48BCA1E.bin 7d4a222e433b7c4344d8c9de523eee3814db8239 (Apollo Lake / Goldmont Atom)
cpu506F0_plat01_ver00000010_2016-06-07_PRD_4ED9573A.bin 7d4a222e433b7c4344d8c9de523eee3814db8239 (Goldmont)
cpu506F1_plat01_ver0000003E_2023-10-05_PRD_D23BE9E2.bin 7d4a222e433b7c4344d8c9de523eee3814db8239 (Denverton / Goldmont Atom)

cpu406F0_platEF_ver00000014_2015-07-02_PRD_F22A3585.bin 7e80f7976e82a225f74f2996790315d3a447bf67 (Broadwell-EX)
cpu406F1_platEF_ver0B000040_2021-05-19_PRD_E5BABFDB.bin 7e80f7976e82a225f74f2996790315d3a447bf67 (Broadwell-EP/EX)
cpu50662_plat10_ver0000001C_2019-06-17_PRD_6A540EAF.bin 7e80f7976e82a225f74f2996790315d3a447bf67 (Broadwell-DE)
cpu50663_plat10_ver0700001C_2021-06-12_PRD_FE624729.bin 7e80f7976e82a225f74f2996790315d3a447bf67 (Broadwell-DE)
cpu50664_plat10_ver0F00001A_2021-06-12_PRD_BF95B0FA.bin 7e80f7976e82a225f74f2996790315d3a447bf67 (Broadwell-DE)
cpu50665_plat10_ver0E000015_2023-08-03_PRD_78AB538E.bin 7e80f7976e82a225f74f2996790315d3a447bf67 (Broadwell-DE)

cpu20652_plat12_ver00000011_2018-05-08_PRD_6E121A49.bin 80a6e741cdf9800338dfe1078a84788cba6cf971 Clarkdale/Arrandale: Core and Celeron (Westmere)
cpu20652_plat80_ver00000006_2009-09-15_PRD_B12EF96C.bin 80a6e741cdf9800338dfe1078a84788cba6cf971 (Westmere)
cpu20655_plat92_ver00000007_2018-04-23_PRD_8B585C97.bin 80a6e741cdf9800338dfe1078a84788cba6cf971 (Westmere)
cpu206C1_plat03_ver00000006_2009-12-22_PRD_45E27C49.bin 80a6e741cdf9800338dfe1078a84788cba6cf971 (Westmere)
cpu206C2_plat03_ver0000001F_2018-05-08_PRD_77DADA73.bin 80a6e741cdf9800338dfe1078a84788cba6cf971 Westmere/Gulftown : Xeon/Core (Westmere)

cpu306C3_plat32_ver00000028_2019-11-12_PRD_DBD4CFD1.bin 810c959df98e3b170c5acb50e6e374e11ac085bd (Haswell)
cpu40651_plat72_ver00000026_2019-11-12_PRD_7784160A.bin 810c959df98e3b170c5acb50e6e374e11ac085bd (Haswell)
cpu40661_plat32_ver0000001C_2019-11-12_PRD_D552A842.bin 810c959df98e3b170c5acb50e6e374e11ac085bd (Haswell)

cpu206E6_plat04_ver0000000D_2018-05-15_PRD_09B7B395.bin 82a086fcbd94dbec9d4c4b517c5a2468207735fd (Nehalem-EX / Beckton)

cpuA06A2_platC6_ver00000011_2023-06-27_PRD_E57D4F01.bin 9e19dea7066a1cbfe4e8b5d5f8e7d8f25855885e (Meteor Lake / Redwood Cove)

cpu706A0_plat01_ver00000026_2017-07-12_PRD_E129C7BC.bin cac00e685e08b5650534ba3514ee4b67aa83a80d (Skylake/Kaby Lake family)
cpu706A1_plat01_ver00000042_2024-04-19_PRD_0D78C158.bin cac00e685e08b5650534ba3514ee4b67aa83a80d (Skylake/Kaby Lake family)
cpu706A8_plat01_ver00000026_2024-12-05_PRD_6DEB6E00.bin cac00e685e08b5650534ba3514ee4b67aa83a80d (Skylake/Kaby Lake family)

cpu406E1_plat80_ver00000020_2014-11-11_PRD_FE1CC0E2.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu406E1_platF2_ver00000016_2014-08-06_PRD_2DFF9E39.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu406E2_platC0_ver0000002C_2015-05-21_PRD_D28F2B75.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu406E2_platF2_ver0000000A_2014-11-05_PRD_0A13EE5F.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu406E3_platC0_ver000000F0_2021-11-12_PRD_7AFB5766.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu406E8_plat80_ver00000026_2016-04-14_PRD_36CA522E.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu506E0_plat22_ver00000018_2014-11-19_PRD_0948424C.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu506E1_plat22_ver0000002A_2015-06-02_PRD_F48CBF3D.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu506E2_plat14_ver0000002E_2015-08-15_PRD_E8F66981.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu506E3_plat36_ver000000F2_2023-01-02_PRD_86DC342B.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu506E8_plat22_ver00000034_2016-07-10_PRD_57D53E7A.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Broadwell)
cpu806E9_plat10_ver000000F6_2024-02-01_PRD_E6ECA8E1.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Kaby Lake)
cpu806E9_platC0_ver000000F6_2024-02-01_PRD_86B37C01.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Kaby Lake)
cpu806EA_platC0_ver000000F6_2024-02-01_PRD_AA6F08D4.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Kaby Lake)
cpu806EB_platD0_ver000000F6_2024-02-01_PRD_8F812A37.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Kaby Lake)
cpu806EC_plat94_ver00000100_2024-11-17_PRD_2160E082.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Coffee Lake / Coffee Lake Refresh)
cpu906E9_plat2A_ver000000FA_2024-03-07_PRD_E8FA415B.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Coffee Lake / Coffee Lake Refresh)
cpu906EA_plat22_ver000000FA_2024-07-28_PRD_E262FE65.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Coffee Lake / Coffee Lake Refresh)
cpu906EB_plat02_ver000000F6_2024-02-01_PRD_9F8FF344.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Coffee Lake / Coffee Lake Refresh)
cpu906EC_plat22_ver000000F8_2024-02-01_PRD_7555BA5E.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Coffee Lake / Coffee Lake Refresh)
cpu906ED_plat22_ver00000104_2024-11-14_PRD_D78FF1A0.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Coffee Lake / Coffee Lake Refresh)
cpuA0650_plat22_ver000000BE_2019-10-10_PRD_B5D77A0C.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Comet Lake)
cpuA0651_plat22_ver000000C2_2019-11-13_PRD_F3861F27.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Comet Lake)
cpuA0652_plat20_ver00000100_2024-11-14_PRD_88939FA8.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Comet Lake)
cpuA0653_plat22_ver00000100_2024-11-14_PRD_ED62D1F7.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Comet Lake)
cpuA0654_plat22_ver000000C6_2020-01-23_PRD_C415D594.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Comet Lake)
cpuA0655_plat22_ver00000100_2024-11-14_PRD_7A072660.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Comet Lake)
cpuA0660_plat80_ver00000102_2024-11-14_PRD_DDA4508E.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Comet Lake)
cpuA0661_plat80_ver00000100_2024-11-14_PRD_05EC5182.bin f10a5aecb466888023a90733bdb03a68eb60e63a (Comet Lake)

Files can be downloaded from fuchsia.googlesource.com/.../intel-linux-processor-microcode-data-files/+refs↗ and github.com/platomav/CPUMicrocodes↗

NetBurst

cpu00F65_plat01_ver00000008_2006-04-26_PRD_5C58F575.bin aa24146c6393e5d8a9316cd9fb939902f4765786 (NetBurst, not P6!)  Intel(R) Pentium(R) D CPU 3.00GHz

Atom

Cut-out from above tables, not related to this work.

cpu106C0_plat01_ver00000007_2007-08-24_PRD_923CDFA3.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu106C1_plat01_ver00000109_2007-12-03_PRD_349F67A3.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu106C2_plat01_ver00000217_2009-04-10_PRD_D987BC76.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076 Atom Diamondville (N270,..)
cpu106C2_plat04_ver00000218_2009-04-10_PRD_8FB7C1BA.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu106C2_plat08_ver00000219_2009-04-10_PRD_556338C1.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu106C9_plat01_ver00000007_2009-02-11_PRD_E1A67544.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076 intel atom N570
cpu106C9_plat04_ver00000007_2009-02-11_PRD_21C6E011.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu106C9_plat08_ver00000007_2009-02-11_PRD_62A4AD62.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu106C9_plat10_ver00000007_2009-02-13_PRD_C2DA0E36.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu106CA_plat01_ver00000107_2009-08-25_PRD_F851A3D9.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076 Atom. Model: N550
cpu106CA_plat04_ver00000107_2009-08-25_PRD_7DEB58B2.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu106CA_plat08_ver00000107_2009-08-25_PRD_BE667CA5.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu106CA_plat10_ver00000107_2009-08-25_PRD_482CAE0E.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu106CA_plat20_ver00000106_2009-08-25_PRD_9B4B3396.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076
cpu20661_plat01_ver00000104_2009-10-23_PRD_38CB12B9.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076 Intel Atom E640
cpu20661_plat02_ver00000105_2011-07-18_PRD_52558795.bin c1ed3b1dabc2d324a62eb3c62059c5e2f1312076

cpu30671_plat02_ver00000117_2013-04-10_PRD_2ABFD907.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu30672_plat01_ver0000022D_2014-01-14_PRD_72CFE73B.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu30672_plat02_ver0000022E_2014-04-01_PRD_94CB9F8B.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu30672_plat0C_ver00000218_2013-07-22_PRD_A02D65A7.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu30673_plat01_ver00000329_2019-09-16_PRD_81219E54.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu30673_plat02_ver00000329_2019-09-16_PRD_683DEB8A.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu30673_plat0C_ver00000329_2019-09-16_PRD_65EDD27A.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu30678_plat01_ver00000832_2015-02-09_PRD_875B494A.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu30678_plat02_ver00000838_2019-04-22_PRD_6BF2E4C4.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu30678_plat0C_ver00000838_2019-04-22_PRD_2FCBB165.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu30679_plat0F_ver0000090D_2019-07-10_PRD_6BD4EE11.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu406A8_plat01_ver0000081F_2014-08-12_PRD_1EC9E61C.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu406A9_plat01_ver0000081F_2014-08-12_PRD_1EC9E61B.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu406D0_plat01_ver0000000E_2013-06-12_PRD_DD4E4ECB.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu406D8_plat01_ver0000012D_2019-09-16_PRD_12D03BC2.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu506A0_plat01_ver00000038_2015-01-12_PRD_F3EDFCB8.bin 281838f54efe526364cb3b11ea27a350b33e1db3
cpu506D1_plat02_ver00000101_2014-11-20_PRD_BAB05F5F.bin 281838f54efe526364cb3b11ea27a350b33e1db3 Sofia 3GR: Atom processor
cpu506D1_plat04_ver00000102_2015-06-05_PRD_04DB0C29.bin 281838f54efe526364cb3b11ea27a350b33e1db3

Goldmont is 506C9/plat03 and uses different patchfile format (modulus sha256 hash is a1b4b7417f0fdcdb0feaa26eb5b78fb2cb86153f0ce98803f5cb84ae3a45901d )

Some funny reading

web.archive.org/.../http://www.eetimes.com/news/97/963news/hole.html↗

This project is an independent, unofficial work based on publicly available information and reverse-engineering research, and is not affiliated with, endorsed by, sponsored by, or associated with Intel Corporation or its affiliates. It is provided "as is", without warranty of any kind. The author assumes no responsibility or liability for any use, misuse, damage, data loss, hardware failure, or other consequences arising from its use. Intel, Pentium, Core and related trademarks are the property of their respective owners and are used solely for identification and informational purposes.