[S] Change in coreboot[main]: device/pci_rom: Move VBIOS checksum fix

[Felix Held (Code Review)]

Felix Held has submitted this change. ( https://review.coreboot.org/c/coreboot/+/86384?usp=email )

Change subject: device/pci_rom: Move VBIOS checksum fix
......................................................................

device/pci_rom: Move VBIOS checksum fix

Move the VBIOS checksum code into the soc/amd folder, as it's
specific to AMD's FSP. The code now fixes the VBIOS in place
instead only fixing it for the VFCT table.

TEST: VBIOS has correct checksum after loading in BS_DEV_RESOURCES.
      VBIOS checksum is invalid entering graphics_dev_init().
      VBIOS checksum is correct leaving graphics_dev_init().

Change-Id: I63aaaefaf01ea456e2ed39cd0891e552a7fb5135
Signed-off-by: Patrick Rudolph 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/86384
Reviewed-by: Ana Carolina Cabral 
Tested-by: build bot (Jenkins) 
Reviewed-by: Felix Held 
---
M src/device/pci_rom.c
M src/soc/amd/common/fsp/fsp_graphics.c
2 files changed, 20 insertions(+), 9 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Felix Held: Looks good to me, approved
  Ana Carolina Cabral: Looks good to me, but someone else must approve

diff --git a/src/device/pci_rom.c b/src/device/pci_rom.c
index 7e19646d..0fe94db 100644
--- a/src/device/pci_rom.c
+++ b/src/device/pci_rom.c
@@ -242,15 +242,6 @@

vfct_struct->VBIOSImageOffset = (size_t)header - (size_t)vfct_struct;

-	/* Calculate and set checksum for VBIOS data if FSP GOP driver used,
-	   Since GOP driver modifies ATOMBIOS tables at end of VBIOS */
-	if (CONFIG(RUN_FSP_GOP)) {
-		/* Clear existing checksum before recalculating */
-		header->VbiosContent[VFCT_VBIOS_CHECKSUM_OFFSET] = 0;
-		header->VbiosContent[VFCT_VBIOS_CHECKSUM_OFFSET] =
-				acpi_checksum(header->VbiosContent, header->ImageLength);
-	}
-
    current += header->ImageLength;
    return current;
 }
diff --git a/src/soc/amd/common/fsp/fsp_graphics.c b/src/soc/amd/common/fsp/fsp_graphics.c
index 3e082e6..776711b 100644
--- a/src/soc/amd/common/fsp/fsp_graphics.c
+++ b/src/soc/amd/common/fsp/fsp_graphics.c
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */

#include <amdblocks/graphics.h>
+#include <amdblocks/vbt.h>
 #include <console/console.h>
 #include <device/device.h>
 #include <device/pci.h>
@@ -15,4 +16,23 @@
    else
    	printk(BIOS_ERR, "%s: Unable to find resource for %s\n",
    			__func__, dev_path(dev));
+
+	/*
+	 * Calculate and set checksum for VBIOS data if FSP GOP driver used,
+	 * Since GOP driver modifies ATOMBIOS tables at end of BS_DEV_RESOURCES.
+	 * While Linux does not verify the checksum the Windows kernel driver does.
+	 */
+	struct rom_header *vbios = (struct rom_header *)vbt_get();
+	if (!vbios || !vbios->size) {
+		printk(BIOS_ERR, "%s: No VGA BIOS loaded for %s\n",
+				__func__, dev_path(dev));
+		return;
+	}
+
+	uint8_t *data = (uint8_t *)vbios;
+
+	/* Clear existing checksum before recalculating */
+	data[VFCT_VBIOS_CHECKSUM_OFFSET] = 0;
+	data[VFCT_VBIOS_CHECKSUM_OFFSET] =
+			acpi_checksum(data, vbios->size * 512);
 }