Provide a way to disable counting failed boots

When the lid is closed and external power is applied
the system may boot and shut down faster than required
for the OS to determine that things were alright.

In timed charging setups this led to systems ending up
to consider the current version broken because it "failed"
repeatedly.

Remain generic about the reason for not counting boots
since there may be more situations in which we want to
handle the situation optimistically.

BRANCH=none
BUG=chromium:446945
TEST=none

Change-Id: Iea350e3c98d5c00156da682e52c90a882ba017c0
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/249150
Reviewed-by: Randall Spangler <rspangler@chromium.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/tests/vboot_firmware_tests.c b/tests/vboot_firmware_tests.c
index 651197cf..f83d970f 100644
--- a/tests/vboot_firmware_tests.c
+++ b/tests/vboot_firmware_tests.c
@@ -371,6 +371,39 @@ static void LoadFirmwareTest(void) {
   VbNvGet(&vnc, VBNV_TRY_B_COUNT, &u);
   TEST_EQ(u, 4, "Used up a try");
 
+  /* There's a optimistic boot mode that doesn't consume tries.
+   * The behaviour should differ only in that the try count doesn't change. */
+  /* Optimistic boot case 1: count == 0: Go for A */
+  ResetMocks();
+  mpreamble[0].flags = VB_FIRMWARE_PREAMBLE_USE_RO_NORMAL;
+  mpreamble[1].flags = VB_FIRMWARE_PREAMBLE_USE_RO_NORMAL;
+  shared->flags |= VBSD_BOOT_RO_NORMAL_SUPPORT;
+  shared->flags |= VBSD_NOFAIL_BOOT;
+  VbNvSet(&vnc, VBNV_TRY_B_COUNT, 0);
+  TestLoadFirmware(VBERROR_SUCCESS, 0, "Give up on B");
+  TEST_EQ(shared->check_fw_a_result, VBSD_LF_CHECK_VALID, "RO normal A valid");
+  TEST_EQ(shared->check_fw_b_result, 0, "RO normal B not checked");
+  TEST_EQ(shared->firmware_index, 0, "Boot A");
+  TEST_EQ(shared->flags & VBSD_FWB_TRIED, 0, "Didn't try firmware B");
+  TEST_EQ(shared->kernel_subkey.algorithm, 7, "Copy kernel subkey");
+  VbNvGet(&vnc, VBNV_TRY_B_COUNT, &u);
+  TEST_EQ(u, 0, "try count still zero");
+  /* Optimistic boot case 2: count > 0: count unchanged, use B */
+  ResetMocks();
+  mpreamble[0].flags = VB_FIRMWARE_PREAMBLE_USE_RO_NORMAL;
+  mpreamble[1].flags = VB_FIRMWARE_PREAMBLE_USE_RO_NORMAL;
+  shared->flags |= VBSD_BOOT_RO_NORMAL_SUPPORT;
+  shared->flags |= VBSD_NOFAIL_BOOT;
+  VbNvSet(&vnc, VBNV_TRY_B_COUNT, 5);
+  TestLoadFirmware(VBERROR_SUCCESS, 0, "Check B then A");
+  TEST_EQ(shared->check_fw_a_result, 0, "RO normal A not checked ");
+  TEST_EQ(shared->check_fw_b_result, VBSD_LF_CHECK_VALID, "RO normal B valid");
+  TEST_EQ(shared->firmware_index, 1, "Boot B");
+  TEST_NEQ(shared->flags & VBSD_FWB_TRIED, 0, "Tried firmware B");
+  TEST_EQ(shared->kernel_subkey.algorithm, 8, "Copy kernel subkey");
+  VbNvGet(&vnc, VBNV_TRY_B_COUNT, &u);
+  TEST_EQ(u, 5, "Not used up a try");
+
   /* If both A and B are valid and grater version than TPM, A is
    * selected and B preamble (but not body) is verified. */
   ResetMocks();