vc/amd,soc/amd/mendocino: Add SVC_CMD_GET_PREV_BOOT_STATUS

Add an SVC command to get the previous boot status. If there is any
pre-x86 boot failure in the previous boot cycle, PSP stores it in warm
reset persistent register and triggers a warm reset. PSP verstage on the
subsequent boot gets the previous boot status and reports any failure to
the vboot before a FW slot is selected.

BUG=b:242825052
TEST=Build Skyrim BIOS image and boot to OS in Skyrim. Trigger a failure
scenario by corrupting certain firmware blobs and observe that PSP
reports the failure boot status. On a normal boot, observed that PSP
reports successful boot.

Change-Id: I440deee560b72c80491bfdd7fda38a1c3a4299e5
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70381
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/src/vendorcode/amd/fsp/picasso/include/bl_uapp/bl_syscall_public.h b/src/vendorcode/amd/fsp/picasso/include/bl_uapp/bl_syscall_public.h
index 0c168a93b2..20cebe65bd 100644
--- a/src/vendorcode/amd/fsp/picasso/include/bl_uapp/bl_syscall_public.h
+++ b/src/vendorcode/amd/fsp/picasso/include/bl_uapp/bl_syscall_public.h
@@ -410,6 +410,15 @@ static inline uint32_t svc_ccp_dma(uint32_t spi_rom_offset, void *dest, uint32_t
 	return BL_ERR_UNSUPPORTED_PLATFORM;
 }
 
+/* Get the previous boot status.
+ *
+ * Parameters:
+ * 	- boot_status - Address where the boot status is read into
+ *
+ * Return value: BL_OK or error code
+ */
+uint32_t svc_get_prev_boot_status(uint32_t *boot_status);
+
 /* C entry point for the Bootloader Userspace Application */
 void Main(void);