vboot_logic: Set VB2_CONTEXT_EC_TRUSTED in verstage_main

vboot_reference is introducing a new field (ctx) to store the current
boot mode in crrev/c/2944250 (ctx->bootmode), which will be leveraged
in both vboot flow and elog_add_boot_reason in coreboot.

In current steps of deciding bootmode, a function vb2ex_ec_trusted
is required. This function checks gpio EC_IN_RW pin and will return
'trusted' only if EC is not in RW. Therefore, we need to implement
similar utilities in coreboot.

We will deprecate vb2ex_ec_trusted and use the flag,
VB2_CONTEXT_EC_TRUSTED, in vboot, vb2api_fw_phase1 and set that flag
in coreboot, verstage_main.

Also add a help function get_ec_is_trusted which needed to be
implemented per mainboard.

BUG=b:177196147, b:181931817
BRANCH=none
TEST=Test on trogdor if manual recovery works

Signed-off-by: Hsuan Ting Chen <roccochen@chromium.org>
Change-Id: I479c8f80e45cc524ba87db4293d19b29bdfa2192
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57048
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/mainboard/google/auron/chromeos.c b/src/mainboard/google/auron/chromeos.c
index 50eeddce0a4a..f449c9cf7ffb 100644
--- a/src/mainboard/google/auron/chromeos.c
+++ b/src/mainboard/google/auron/chromeos.c
@@ -8,6 +8,13 @@
 /* SPI Write protect is GPIO 16 */
 #define CROS_WP_GPIO	58
 
+/* EC_IN_RW is GPIO 25 in samus and 14 otherwise */
+#if CONFIG(BOARD_GOOGLE_SAMUS)
+#define EC_IN_RW_GPIO	25
+#else
+#define EC_IN_RW_GPIO	14
+#endif
+
 void fill_lb_gpios(struct lb_gpios *gpios)
 {
 	struct lb_gpio chromeos_gpios[] = {
@@ -32,3 +39,9 @@ void mainboard_chromeos_acpi_generate(void)
 {
 	chromeos_acpi_gpio_generate(cros_gpios, ARRAY_SIZE(cros_gpios));
 }
+
+int get_ec_is_trusted(void)
+{
+	/* EC is trusted if not in RW. */
+	return !get_gpio(EC_IN_RW_GPIO);
+}