From 50cca76e546bc5528be28ff99e717982d2783356 Mon Sep 17 00:00:00 2001
From: Martin Roth <martinroth@chromium.org>
Date: Thu, 13 Aug 2020 11:06:18 -0600
Subject: soc/amd/picasso: Reboot for recovery if no psp workbuf is found

Instead of halting if the vboot workbuf is not passed to coreboot by the
PSP, reset and reboot into recovery mode.

This process is made more difficult because if the workbuf isn't
available, we can't reboot directly into recovery - the workbuf is
needed for that process to be done through the regular calls, and we
don't want to go around the vboot API and just write into VBNV directly.
To overcome this, we set a CMOS flag, and reset the system.
PSP_verstage checks for this flag so it will update VBNV and reset the
system after generating the workbuf.

BUG=b:152638343
TEST=Simulate the workbuf not being present and verify the reboot
process.

Signed-off-by: Martin Roth <martinroth@chromium.org>
Change-Id: I049db956a5209904b274747be28ff226ce542316
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44538
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
---
 src/soc/amd/picasso/psp_verstage/psp_verstage.c | 22 +++++++++++++++++++++-
 src/soc/amd/picasso/psp_verstage/psp_verstage.h |  1 +
 2 files changed, 22 insertions(+), 1 deletion(-)

(limited to 'src/soc/amd/picasso/psp_verstage')

diff --git a/src/soc/amd/picasso/psp_verstage/psp_verstage.c b/src/soc/amd/picasso/psp_verstage/psp_verstage.c
index 55687976df..005c8b0ac9 100644
--- a/src/soc/amd/picasso/psp_verstage/psp_verstage.c
+++ b/src/soc/amd/picasso/psp_verstage/psp_verstage.c
@@ -5,10 +5,11 @@
 #include <bl_uapp/bl_syscall_public.h>
 #include <boot_device.h>
 #include <cbfs.h>
-#include <commonlib/region.h>
 #include <console/console.h>
 #include <fmap.h>
+#include <pc80/mc146818rtc.h>
 #include <soc/psp_transfer.h>
+#include <security/vboot/vbnv.h>
 #include <security/vboot/misc.h>
 #include <security/vboot/symbols.h>
 #include <security/vboot/vboot_common.h>
@@ -35,6 +36,22 @@ static void reboot_into_recovery(struct vb2_context *ctx, uint32_t subcode)
 	vboot_reboot();
 }
 
+static uint32_t check_cmos_recovery(void)
+{
+	/* Only reset if cmos is valid */
+	if (vbnv_cmos_failed())
+		return 0;
+
+	/* If the byte is set, clear it, then return error to reboot */
+	if (cmos_read(CMOS_RECOVERY_BYTE) == CMOS_RECOVERY_MAGIC_VAL) {
+		cmos_write(0x00, CMOS_RECOVERY_BYTE);
+		printk(BIOS_DEBUG, "Reboot into recovery requested by coreboot\n");
+		return POSTCODE_CMOS_RECOVERY;
+	}
+
+	return 0;
+}
+
 static uintptr_t locate_amdfw(const char *name, struct region_device *rdev)
 {
 	struct cbfsf fh;
@@ -216,6 +233,9 @@ void Main(void)
 
 	vb2api_relocate(_vboot2_work, _vboot2_work, VB2_FIRMWARE_WORKBUF_RECOMMENDED_SIZE,
 			&ctx);
+	retval = check_cmos_recovery();
+	if (retval)
+		goto err;
 
 	post_code(POSTCODE_SAVE_BUFFERS);
 	retval = save_buffers(&ctx);
diff --git a/src/soc/amd/picasso/psp_verstage/psp_verstage.h b/src/soc/amd/picasso/psp_verstage/psp_verstage.h
index 3c7574d82b..ef5c452500 100644
--- a/src/soc/amd/picasso/psp_verstage/psp_verstage.h
+++ b/src/soc/amd/picasso/psp_verstage/psp_verstage.h
@@ -31,6 +31,7 @@
 #define POSTCODE_UPDATE_PSP_BIOS_DIR_ERROR	0xC7
 #define POSTCODE_FMAP_REGION_MISSING		0xC8
 #define POSTCODE_AMD_FW_MISSING			0xC9
+#define POSTCODE_CMOS_RECOVERY			0xCA
 
 #define POSTCODE_UNMAP_SPI_ROM			0xF0
 #define POSTCODE_UNMAP_FCH_DEVICES		0xF1
-- 
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