Keith Short has uploaded this change for review.

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mainboard/sarien: Save the Cr50 recovery switch state in VBNV

Update sarien so the Cr50 recovery switch is only read during verstage
and save the recovery switch state to VBNV.

BUG=b:123360379
BRANCH=none
TEST=build coreboot on sarien and arcada. Test normal boot and recovery
boot on arcada - confirm that that tpm transaction errors are gone.

Change-Id: Iadf0cec651b3a26ceebadfeb637e189805c328bf
Signed-off-by: Keith Short <keithshort@chromium.org>
---
M src/mainboard/google/sarien/chromeos.c
1 file changed, 16 insertions(+), 19 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/01/31801/1

diff --git a/src/mainboard/google/sarien/chromeos.c b/src/mainboard/google/sarien/chromeos.c
index 1e363fd..308b682 100644
--- a/src/mainboard/google/sarien/chromeos.c
+++ b/src/mainboard/google/sarien/chromeos.c
@@ -20,18 +20,12 @@
 #include <variant/gpio.h>
 #include <vendorcode/google/chromeos/chromeos.h>
 #include <security/tpm/tss.h>
+#include <security/vboot/vbnv.h>
 #include <device/device.h>
 #include <intelblocks/pmclib.h>
 #include <soc/pmc.h>
 #include <soc/pci_devs.h>
 
-enum rec_mode_state {
-	REC_MODE_UNINITIALIZED,
-	REC_MODE_NOT_REQUESTED,
-	REC_MODE_REQUESTED,
-};
-static enum rec_mode_state saved_rec_mode;
-
 void fill_lb_gpios(struct lb_gpios *gpios)
 {
 	struct lb_gpio chromeos_gpios[] = {
@@ -84,30 +78,33 @@
 
 int get_recovery_mode_switch(void)
 {
-	enum rec_mode_state state = saved_rec_mode;
+	int rec_switch;
 	uint8_t recovery_button_state = 0;
 
-	/* Check the global variable first. */
-	if (state == REC_MODE_NOT_REQUESTED)
-		return 0;
-	else if (state == REC_MODE_REQUESTED)
-		return 1;
+	/*
+	 * Only verstage performs a real check of the Cr50 recovery switch.
+	 * The recovery switch state is cleared on the first access by the AP
+	 * so there's no point in querying the Cr50 at later stages.  All other
+	 * stages use the state saved in VBNV.
+	 */
+	if (!ENV_VERSTAGE &&
+		!get_recovery_switch_from_vbnv(&rec_switch))
+		return rec_switch;
 
-	state = REC_MODE_NOT_REQUESTED;
+	rec_switch = 0;
 
 	/* Read state from the GPIO controlled by servo. */
 	if (cros_get_gpio_value(CROS_GPIO_REC))
-		state = REC_MODE_REQUESTED;
+		rec_switch = 1;
 	/* Read one-time recovery request from cr50. */
 	else if (tlcl_cr50_get_recovery_button(&recovery_button_state)
 		 == TPM_SUCCESS)
-		state = recovery_button_state ?
-			REC_MODE_REQUESTED : REC_MODE_NOT_REQUESTED;
+		rec_switch = !!recovery_button_state;
 
 	/* Store the state in case this is called again in verstage. */
-	saved_rec_mode = state;
+	set_recovery_switch_into_vbnv(rec_switch);
 
-	return state == REC_MODE_REQUESTED;
+	return rec_switch;
 }
 
 int get_lid_switch(void)

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