drivers/intel/fsp1_1: Fake microcode update to make FSP happy

The FSP loops through microcode updates and at the end checks if
the microcode revision is not zero. Since we update the microcode
before loading FSP, this is the case and a fake microcode can be
passed to the FSP.

The advantage is that the Kconfig symbols to specify the location and
the size of the microcode blob can be dropped.

Change-Id: I63cfb7b19e9795da85566733fb4c1ff989e85d03
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36255
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/drivers/intel/fsp1_1/Kconfig

@@ -56,19 +56,6 @@ config FSP_LOC
 	  value that is set in the FSP binary.  If the FSP needs to be moved,
 	  rebase the FSP with Intel's BCT (tool).
 
-config CPU_MICROCODE_CBFS_LEN
-	hex "Microcode update region length in bytes"
-	default 0x0
-	help
-	  The length in bytes of the microcode update region.
-
-config CPU_MICROCODE_CBFS_LOC
-	hex "Microcode update base address in CBFS"
-	default 0x0
-	help
-	  The location (base address) in CBFS that contains the microcode update
-	  binary.
-
 config DISPLAY_HOBS
 	bool "Display hand-off-blocks (HOBs)"
 	default n

src/drivers/intel/fsp1_1/cache_as_ram.S

@@ -239,11 +239,30 @@ fake_fsp_stack:
 	.long	CONFIG_FSP_LOC		/* FSP base address */
 
 CAR_init_params:
-	.long	CONFIG_CPU_MICROCODE_CBFS_LOC		/* Microcode Location */
+	.long	fake_microcode				/* Microcode Location */
-	.long	CONFIG_CPU_MICROCODE_CBFS_LEN		/* Microcode Length */
+	.long	fake_microcode_end - fake_microcode	/* Microcode Length */
 	.long	0xFFFFFFFF - CONFIG_ROM_SIZE + 1	/* Firmware Location */
 	.long	CONFIG_ROM_SIZE				/* Firmware Length */
 
 CAR_init_stack:
 	.long	CAR_init_done
 	.long	CAR_init_params
+
+	/* coreboot updates microcode itself. FSP still needs a pointer
+	   to something that looks like microcode, so provide it with fake
+	   microcode. */
+fake_microcode:
+fake_microcode_header_start:
+	.long	1		/* Header Version */
+	.long	1		/* Microcode revision */
+	.long	0x10232019	/* Date: Time of writing 23-10-2019 */
+	.long	0x00010ff0	/* Sig: (non existing) Family: 0xf, Model: 0x1f, stepping: 0 */
+	.long	0		/* Checksum: not checked by FSP, so won't care */
+	.long	1		/* Loader Revision */
+	.long	1		/* Processor Flags */
+	.long	fake_microcode_end - fake_microcode_header_end	/* Data Size */
+	.long	fake_microcode_end - fake_microcode	/* Total Size */
+	.space	12		/* Reserved */
+fake_microcode_header_end:
+	.space 0x10	/* 16 bytes of empty data */
+fake_microcode_end:

src/mainboard/facebook/fbg1701/Kconfig

@@ -50,16 +50,6 @@ config CBFS_SIZE
 	hex
 	default 0x00600000
 
-config CPU_MICROCODE_CBFS_LEN
-	hex
-	default 0x10C00
-	help
-	  This should be updated when the microcode patch changes.
-
-config CPU_MICROCODE_CBFS_LOC
-	hex
-	default 0xFFFE9400
-
 config MRC_SETTINGS_CACHE_SIZE
 	hex
 	default 0x08000

src/mainboard/portwell/m107/Kconfig

@@ -61,16 +61,6 @@ config CBFS_SIZE
 	hex
 	default 0x00800000
 
-config CPU_MICROCODE_CBFS_LEN
-	hex
-	default 0x10C00
-	help
-	  This should be updated when the microcode patch changes.
-
-config CPU_MICROCODE_CBFS_LOC
-	hex
-	default 0xFFFE9400
-
 config MRC_SETTINGS_CACHE_SIZE
 	hex
 	default 0x08000