mb/google/rex: Update Rex Flash Layout

This patch updates the Rex flash layout to allow CSE Lite FW
update and accommodate multiple ESx SoC stepping blobs.

For default chromeos.fmd

SI_BIOS:
     RW_SECTION_A/B: Increased by ~1.9MB.
     RW_LEGACY: Reduce to 1MB.
     RW_MISC: Reduce to 152KB.
        - Drop RW_SPD_CACHE
	- Optimize other sections

Additionally, moved RW_LEGACY under extended BIOS region.

For chromeos-debug-fsp.fmd

SI_BIOS:
     RW_SECTION_A/B: Increased by ~1.2MB.
     RW_LEGACY: Dropped
     RW_MISC: Reduce to 152KB.
        - Drop RW_SPD_CACHE
	- Optimize other sections

BUG=b:262868089
TEST=Able to enable CSE update on google/rex and have free space
to add one more PUNIT FW for support different SoC stepping.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: I6146b36c4ce2c0141277eeb906d6ad1f503f3c78
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66288
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>

2 files changed, 27 insertions, 39 deletions

diff --git a/src/mainboard/google/rex/chromeos-debug-fsp.fmd b/src/mainboard/google/rex/chromeos-debug-fsp.fmd
index e57b4ddc850b..bd250f5fab5b 100644
--- a/src/mainboard/google/rex/chromeos-debug-fsp.fmd
+++ b/src/mainboard/google/rex/chromeos-debug-fsp.fmd
@@ -4,39 +4,33 @@ FLASH 32M {
 		SI_ME
 	}
 	SI_BIOS 23M {
-		RW_SECTION_A 7M {
-			VBLOCK_A 64K
+		RW_SECTION_A 7604K {
+			VBLOCK_A 8K
 			FW_MAIN_A(CBFS)
 			RW_FWID_A 64
-			ME_RW_A(CBFS) 3008K
+			ME_RW_A(CBFS) 4400K
 		}
-		RW_MISC 1M {
+		RW_MISC 152K {
+			RW_ELOG(PRESERVE) 4K
+			RW_SHARED 4K {
+				SHARED_DATA 4K
+			}
+			RW_VPD(PRESERVE) 8K
+			RW_NVRAM(PRESERVE) 8K
 			UNIFIED_MRC_CACHE(PRESERVE) 128K {
 				RECOVERY_MRC_CACHE 64K
 				RW_MRC_CACHE 64K
 			}
-			RW_ELOG(PRESERVE) 16K
-			RW_SHARED 16K {
-				SHARED_DATA 8K
-				VBLOCK_DEV 8K
-			}
-			# The RW_SPD_CACHE region is only used for rex variants that use DDRx memory.
-			# It is placed in the common `chromeos.fmd` file because it is only 4K and there
-			# is free space in the RW_MISC region that cannot be easily reclaimed because
-			# the RW_SECTION_B must start on the 16M boundary.
-			RW_SPD_CACHE(PRESERVE) 4K
-			RW_VPD(PRESERVE) 8K
-			RW_NVRAM(PRESERVE) 24K
 		}
 		# This section starts at the 16M boundary in SPI flash.
 		# MTL does not support a region crossing this boundary,
 		# because the SPI flash is memory-mapped into two non-
 		# contiguous windows.
-		RW_SECTION_B 7M {
-			VBLOCK_B 64K
+		RW_SECTION_B 7604K {
+			VBLOCK_B 8K
 			FW_MAIN_B(CBFS)
 			RW_FWID_B 64
-			ME_RW_B(CBFS) 3008K
+			ME_RW_B(CBFS) 4400K
 		}
 		# Make WP_RO region align with SPI vendor
 		# memory protected range specification.
diff --git a/src/mainboard/google/rex/chromeos.fmd b/src/mainboard/google/rex/chromeos.fmd
index 1714e805789a..3521232ece85 100644
--- a/src/mainboard/google/rex/chromeos.fmd
+++ b/src/mainboard/google/rex/chromeos.fmd
@@ -4,41 +4,35 @@ FLASH 32M {
 		SI_ME
 	}
 	SI_BIOS 23M {
-		RW_SECTION_A 6M {
-			VBLOCK_A 64K
+		RW_SECTION_A 7092K {
+			VBLOCK_A 8K
 			FW_MAIN_A(CBFS)
 			RW_FWID_A 64
-			ME_RW_A(CBFS) 3008K
+			ME_RW_A(CBFS) 4400K
 		}
-		RW_LEGACY(CBFS) 2M
-		RW_MISC 1M {
+		RW_MISC 152K {
+			RW_ELOG(PRESERVE) 4K
+			RW_SHARED 4K {
+				SHARED_DATA 4K
+			}
+			RW_VPD(PRESERVE) 8K
+			RW_NVRAM(PRESERVE) 8K
 			UNIFIED_MRC_CACHE(PRESERVE) 128K {
 				RECOVERY_MRC_CACHE 64K
 				RW_MRC_CACHE 64K
 			}
-			RW_ELOG(PRESERVE) 16K
-			RW_SHARED 16K {
-				SHARED_DATA 8K
-				VBLOCK_DEV 8K
-			}
-			# The RW_SPD_CACHE region is only used for rex variants that use DDRx memory.
-			# It is placed in the common `chromeos.fmd` file because it is only 4K and there
-			# is free space in the RW_MISC region that cannot be easily reclaimed because
-			# the RW_SECTION_B must start on the 16M boundary.
-			RW_SPD_CACHE(PRESERVE) 4K
-			RW_VPD(PRESERVE) 8K
-			RW_NVRAM(PRESERVE) 24K
 		}
 		# This section starts at the 16M boundary in SPI flash.
 		# MTL does not support a region crossing this boundary,
 		# because the SPI flash is memory-mapped into two non-
 		# contiguous windows.
-		RW_SECTION_B 6M {
-			VBLOCK_B 64K
+		RW_SECTION_B 7092K {
+			VBLOCK_B 8K
 			FW_MAIN_B(CBFS)
 			RW_FWID_B 64
-			ME_RW_B(CBFS) 3008K
+			ME_RW_B(CBFS) 4400K
 		}
+		RW_LEGACY(CBFS) 1M
 		# Make WP_RO region align with SPI vendor
 		# memory protected range specification.
 		WP_RO 8M {