firmware/2lib: Introduce API to report previous boot failure

Currently when failures are reported before a slot is selected, vboot
directly requests for recovery. Add a new API to report previous boot
failure before a slot is selected. This will allow coreboot verstage to
report any failures that happened in the previous boot such that
verified boot can select the appropriate FW slot instead of booting into
recovery mode directly.

BUG=b:242825052
BRANCH=None
TEST=Build Skyrim BIOS image. Run the unit test built for this API. Boot
to OS in Skyrim. Corrupt certain sections in flashmap and report boot
failures and ensured that vboot selected the appropriate FW slot.

Change-Id: I3b1fe8e28fc754919cd4067eeed5029e7dbae7a4
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/4064425
Reviewed-by: Julius Werner <jwerner@chromium.org>

1 files changed, 61 insertions, 6 deletions

diff --git a/tests/vb2_misc_tests.c b/tests/vb2_misc_tests.c
index 0365f008..b73c0478 100644
--- a/tests/vb2_misc_tests.c
+++ b/tests/vb2_misc_tests.c
@@ -390,10 +390,10 @@ static void fail_tests(void)
 	reset_common_data();
 	vb2_nv_set(ctx, VB2_NV_TRY_COUNT, 3);
 	vb2_nv_set(ctx, VB2_NV_FW_RESULT, VB2_FW_RESULT_UNKNOWN);
+	vb2_nv_set(ctx, VB2_NV_FW_TRIED, 0);
+	vb2_nv_set(ctx, VB2_NV_FW_PREV_TRIED, 1);
+	vb2_nv_set(ctx, VB2_NV_FW_PREV_RESULT, VB2_FW_RESULT_UNKNOWN);
 	sd->status |= VB2_SD_STATUS_CHOSE_SLOT;
-	sd->fw_slot = 0;
-	sd->last_fw_slot = 1;
-	sd->last_fw_result = VB2_FW_RESULT_UNKNOWN;
 	vb2api_fail(ctx, 5, 6);
 	TEST_EQ(vb2_nv_get(ctx, VB2_NV_RECOVERY_REQUEST), 0, "vb2_failover");
 	TEST_EQ(vb2_nv_get(ctx, VB2_NV_FW_RESULT),
@@ -405,10 +405,10 @@ static void fail_tests(void)
 
 	/* Fail with other slot already failing triggers recovery */
 	reset_common_data();
+	vb2_nv_set(ctx, VB2_NV_FW_PREV_TRIED, 0);
+	vb2_nv_set(ctx, VB2_NV_FW_PREV_RESULT, VB2_FW_RESULT_FAILURE);
+	vb2_nv_set(ctx, VB2_NV_FW_TRIED, 1);
 	sd->status |= VB2_SD_STATUS_CHOSE_SLOT;
-	sd->fw_slot = 1;
-	sd->last_fw_slot = 0;
-	sd->last_fw_result = VB2_FW_RESULT_FAILURE;
 	vb2api_fail(ctx, 7, 8);
 	TEST_EQ(vb2_nv_get(ctx, VB2_NV_RECOVERY_REQUEST), 7,
 		"vb2api_fail both slots bad");
@@ -418,6 +418,60 @@ static void fail_tests(void)
 		"vb2api_fail try other slot");
 }
 
+static void previous_boot_fail_tests(void)
+{
+	/* Previous boot fail (before even NV init) */
+	/* Fail with other slot good doesn't trigger recovery */
+	reset_common_data();
+	vb2_nv_set(ctx, VB2_NV_FW_TRIED, VB2_FW_SLOT_A);
+	vb2_nv_set(ctx, VB2_NV_TRY_COUNT, 3);
+	vb2_nv_set(ctx, VB2_NV_FW_RESULT, VB2_FW_RESULT_UNKNOWN);
+	sd->status &= ~VB2_SD_STATUS_NV_INIT;
+	vb2api_previous_boot_fail(ctx, 1, 2);
+	TEST_NEQ(sd->status & VB2_SD_STATUS_NV_INIT,
+		 0, "vb2api_previous_boot_fail inits NV");
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_RECOVERY_REQUEST),
+		0, "vb2_previous_boot_fail over");
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_FW_RESULT),
+		VB2_FW_RESULT_FAILURE, "vb2api_previous_boot_fail result");
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_TRY_COUNT),
+		0, "vb2api_previous_boot_fail try count");
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_TRY_NEXT),
+		1, "vb2api_previous_boot_fail FW tried");
+
+	/* Fail with other slot already failing triggers recovery */
+	reset_common_data();
+	vb2_nv_set(ctx, VB2_NV_FW_PREV_TRIED, VB2_FW_SLOT_A);
+	vb2_nv_set(ctx, VB2_NV_FW_PREV_RESULT, VB2_FW_RESULT_FAILURE);
+	vb2_nv_set(ctx, VB2_NV_FW_TRIED, VB2_FW_SLOT_B);
+	vb2_nv_set(ctx, VB2_NV_TRY_COUNT, 3);
+	vb2_nv_set(ctx, VB2_NV_FW_RESULT, VB2_FW_RESULT_UNKNOWN);
+	sd->status &= ~VB2_SD_STATUS_NV_INIT;
+	vb2api_previous_boot_fail(ctx, 3, 4);
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_RECOVERY_REQUEST),
+		3, "vb2api_previous_boot_fail both slots bad");
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_FW_RESULT),
+		VB2_FW_RESULT_FAILURE, "vb2api_previous_boot_fail result");
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_TRY_COUNT),
+		0, "vb2api_previous_boot_fail try count");
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_TRY_NEXT),
+		0, "vb2api_previous_boot_fail FW tried");
+
+	/* Repeated fail doesn't overwrite the error code */
+	reset_common_data();
+	vb2_nv_set(ctx, VB2_NV_TRY_NEXT, VB2_FW_SLOT_A);
+	vb2_nv_set(ctx, VB2_NV_TRY_COUNT, 3);
+	vb2_nv_set(ctx, VB2_NV_FW_RESULT, VB2_FW_RESULT_FAILURE);
+	sd->status &= ~VB2_SD_STATUS_NV_INIT;
+	vb2api_previous_boot_fail(ctx, 5, 6);
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_FW_RESULT),
+		VB2_FW_RESULT_FAILURE, "vb2api_previous_boot_fail result");
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_TRY_COUNT),
+		3, "vb2api_previous_boot_fail try count");
+	TEST_EQ(vb2_nv_get(ctx, VB2_NV_TRY_NEXT),
+		VB2_FW_SLOT_A, "vb2api_previous_boot_fail try next");
+}
+
 static void recovery_tests(void)
 {
 	/* No recovery */
@@ -1085,6 +1139,7 @@ int main(int argc, char* argv[])
 	misc_tests();
 	gbb_tests();
 	fail_tests();
+	previous_boot_fail_tests();
 	recovery_tests();
 	dev_switch_tests();
 	enable_dev_tests();