Add support for booting into alternative boot loaders

Add a generic way of selecting an alternative bootloader to run from the
developer-mode menu. This enables keys 1-9 to select a particular numbered
bootloader.

Adjust VbExLegacy() to take a numeric parameter to signal which boot
loader to run.

CQ-DEPEND=CL:1228875
BUG=chromium:837018
BRANCH=none
TEST=FEATURES=test emerge-grunt --nodeps vboot_reference

Change-Id: I02eab1b87e21a6401ec42317c4c1fa1bd2767b53
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1060854
Reviewed-by: Julius Werner <jwerner@chromium.org>

6 files changed, 87 insertions, 9 deletions

diff --git a/firmware/include/vboot_api.h b/firmware/include/vboot_api.h
index 33b997f8..abc8213d 100644
--- a/firmware/include/vboot_api.h
+++ b/firmware/include/vboot_api.h
@@ -959,8 +959,11 @@ enum {
 
 /**
  * Execute legacy boot option.
+ *
+ * @param altfw_num	Bootloader sequence number to execute. Use
+ *	0 to boot the default payload, if any
  */
-int VbExLegacy(void);
+int VbExLegacy(int altfw_num);
 
 /* Regions for VbExRegionRead() */
 enum vb_firmware_region {
diff --git a/firmware/lib/vboot_ui.c b/firmware/lib/vboot_ui.c
index 470e1500..217090ad 100644
--- a/firmware/lib/vboot_ui.c
+++ b/firmware/lib/vboot_ui.c
@@ -52,14 +52,22 @@ static int VbWantShutdown(struct vb2_context *ctx, uint32_t key)
 	return !!shutdown_request;
 }
 
-static void VbTryLegacy(int allowed)
+/**
+ * Call out to firmware to boot a numbered boot loader
+ *
+ * Provided that it is permitted, this function starts up the numbered boot
+ * loader.
+ *
+ * @param altfw_num   Boot loader number to boot (0=any, 1=first, etc.)
+ */
+static void VbTryLegacy(int allowed, int altfw_num)
 {
 	if (!allowed)
 		VB2_DEBUG("VbBootDeveloper() - Legacy boot is disabled\n");
 	else if (0 != RollbackKernelLock(0))
 		VB2_DEBUG("Error locking kernel versions on legacy boot.\n");
 	else
-		VbExLegacy();	/* will not return if successful */
+		VbExLegacy(altfw_num);	/* will not return if successful */
 
 	/* If legacy boot fails, beep and return to calling UI loop. */
 	VbExBeep(120, 400);
@@ -320,7 +328,7 @@ VbError_t vb2_developer_ui(struct vb2_context *ctx)
 		case 0x0c:
 			VB2_DEBUG("VbBootDeveloper() - "
 				  "user pressed Ctrl+L; Try legacy boot\n");
-			VbTryLegacy(allow_legacy);
+			VbTryLegacy(allow_legacy, 0);
 			break;
 
 		case VB_KEY_CTRL_ENTER:
@@ -358,6 +366,12 @@ VbError_t vb2_developer_ui(struct vb2_context *ctx)
 				}
 			}
 			break;
+		case '1'...'9':
+			VB2_DEBUG("VbBootDeveloper() - "
+				  "user pressed key '%c': Boot alternative "
+				  "firmware\n", key);
+			VbTryLegacy(allow_legacy, key - '0');
+			break;
 		default:
 			VB2_DEBUG("VbBootDeveloper() - pressed key %d\n", key);
 			VbCheckDisplayKey(ctx, key);
@@ -372,7 +386,7 @@ VbError_t vb2_developer_ui(struct vb2_context *ctx)
 	/* If defaulting to legacy boot, try that unless Ctrl+D was pressed */
 	if (use_legacy && !ctrl_d_pressed) {
 		VB2_DEBUG("VbBootDeveloper() - defaulting to legacy\n");
-		VbTryLegacy(allow_legacy);
+		VbTryLegacy(allow_legacy, 0);
 	}
 
 	if ((use_usb && !ctrl_d_pressed) && allow_usb) {
diff --git a/firmware/lib/vboot_ui_menu.c b/firmware/lib/vboot_ui_menu.c
index 8cd65af6..3a9d9e52 100644
--- a/firmware/lib/vboot_ui_menu.c
+++ b/firmware/lib/vboot_ui_menu.c
@@ -145,7 +145,7 @@ static VbError_t boot_legacy_action(struct vb2_context *ctx)
 	}
 
 	if (0 == RollbackKernelLock(0))
-		VbExLegacy();	/* Will not return if successful */
+		VbExLegacy(0);/* Will not return if successful */
 	else
 		VB2_DEBUG("Error locking kernel versions on legacy boot.\n");
 
diff --git a/firmware/stub/vboot_api_stub.c b/firmware/stub/vboot_api_stub.c
index 1dbeca0f..effa237d 100644
--- a/firmware/stub/vboot_api_stub.c
+++ b/firmware/stub/vboot_api_stub.c
@@ -164,7 +164,7 @@ enum VbEcBootMode_t VbGetMode(void)
 	return vboot_mode;
 }
 
-int VbExLegacy(void)
+int VbExLegacy(int altfw_num)
 {
 	return 1;
 }
diff --git a/tests/vboot_api_kernel2_tests.c b/tests/vboot_api_kernel2_tests.c
index 11c4c2f6..f9d061f8 100644
--- a/tests/vboot_api_kernel2_tests.c
+++ b/tests/vboot_api_kernel2_tests.c
@@ -36,6 +36,7 @@ static int shutdown_request_calls_left;
 static int audio_looping_calls_left;
 static uint32_t vbtlk_retval;
 static int vbexlegacy_called;
+static int altfw_num;
 static int trust_ec;
 static int virtdev_set;
 static uint32_t virtdev_retval;
@@ -76,6 +77,7 @@ static void ResetMocks(void)
 	audio_looping_calls_left = 30;
 	vbtlk_retval = 1000;
 	vbexlegacy_called = 0;
+	altfw_num = -1;
 	trust_ec = 0;
 	virtdev_set = 0;
 	virtdev_retval = 0;
@@ -132,9 +134,11 @@ uint32_t VbExGetSwitches(uint32_t request_mask)
 		return 0;
 }
 
-int VbExLegacy(void)
+int VbExLegacy(int _altfw_num)
 {
 	vbexlegacy_called++;
+	altfw_num = _altfw_num;
+
 	return 0;
 }
 
@@ -271,6 +275,8 @@ static void VbBootTest(void)
 
 static void VbBootDevTest(void)
 {
+	int key;
+
 	printf("Testing VbBootDeveloper()...\n");
 
 	/* Proceed after timeout */
@@ -290,6 +296,15 @@ static void VbBootDevTest(void)
 			VB2_GBB_FLAG_FORCE_DEV_BOOT_LEGACY;
 	TEST_EQ(VbBootDeveloper(&ctx), 1002, "Timeout");
 	TEST_EQ(vbexlegacy_called, 1, "  try legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
+
+	/* Proceed to legacy after timeout if GBB flag set */
+	ResetMocks();
+	sd->gbb_flags |= VB2_GBB_FLAG_DEFAULT_DEV_BOOT_LEGACY |
+			VB2_GBB_FLAG_FORCE_DEV_BOOT_LEGACY;
+	TEST_EQ(VbBootDeveloper(&ctx), 1002, "Timeout");
+	TEST_EQ(vbexlegacy_called, 1, "  try legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
 
 	/* Proceed to legacy after timeout if boot legacy and default boot
 	 * legacy are set */
@@ -299,6 +314,7 @@ static void VbBootDevTest(void)
 	vb2_nv_set(&ctx, VB2_NV_DEV_BOOT_LEGACY, 1);
 	TEST_EQ(VbBootDeveloper(&ctx), 1002, "Timeout");
 	TEST_EQ(vbexlegacy_called, 1, "  try legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
 
 	/* Proceed to legacy boot mode only if enabled */
 	ResetMocks();
@@ -463,6 +479,7 @@ static void VbBootDevTest(void)
 	TEST_EQ(VbBootDeveloper(&ctx), 1002,
 		"Ctrl+L force legacy");
 	TEST_EQ(vbexlegacy_called, 1, "  try legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
 
 	ResetMocks();
 	vb2_nv_set(&ctx, VB2_NV_DEV_BOOT_LEGACY, 1);
@@ -470,6 +487,7 @@ static void VbBootDevTest(void)
 	TEST_EQ(VbBootDeveloper(&ctx), 1002,
 		"Ctrl+L nv legacy");
 	TEST_EQ(vbexlegacy_called, 1, "  try legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
 
 	ResetMocks();
 	VbApiKernelGetFwmp()->flags |= FWMP_DEV_ENABLE_LEGACY;
@@ -477,6 +495,39 @@ static void VbBootDevTest(void)
 	TEST_EQ(VbBootDeveloper(&ctx), 1002,
 		"Ctrl+L fwmp legacy");
 	TEST_EQ(vbexlegacy_called, 1, "  fwmp legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
+
+	/* Pressing 1-9 boots alternative firmware only if enabled */
+	for (key = '1'; key <= '9'; key++) {
+		ResetMocks();
+		mock_keypress[0] = key;
+		TEST_EQ(VbBootDeveloper(&ctx), 1002, "'1' normal");
+		TEST_EQ(vbexlegacy_called, 0, "  not legacy");
+
+		ResetMocks();
+		sd->gbb_flags |= VB2_GBB_FLAG_FORCE_DEV_BOOT_LEGACY;
+		mock_keypress[0] = key;
+		TEST_EQ(VbBootDeveloper(&ctx), 1002,
+			"Ctrl+L force legacy");
+		TEST_EQ(vbexlegacy_called, 1, "  try legacy");
+		TEST_EQ(altfw_num, key - '0', "  check altfw_num");
+
+		ResetMocks();
+		vb2_nv_set(&ctx, VB2_NV_DEV_BOOT_LEGACY, 1);
+		mock_keypress[0] = key;
+		TEST_EQ(VbBootDeveloper(&ctx), 1002,
+			"Ctrl+L nv legacy");
+		TEST_EQ(vbexlegacy_called, 1, "  try legacy");
+		TEST_EQ(altfw_num, key - '0', "  check altfw_num");
+
+		ResetMocks();
+		VbApiKernelGetFwmp()->flags |= FWMP_DEV_ENABLE_LEGACY;
+		mock_keypress[0] = key;
+		TEST_EQ(VbBootDeveloper(&ctx), 1002,
+			"Ctrl+L fwmp legacy");
+		TEST_EQ(vbexlegacy_called, 1, "  fwmp legacy");
+		TEST_EQ(altfw_num, key - '0', "  check altfw_num");
+	}
 
 	/* Ctrl+U boots USB only if enabled */
 	ResetMocks();
diff --git a/tests/vboot_detach_menu_tests.c b/tests/vboot_detach_menu_tests.c
index 264fbf86..6ec9f334 100644
--- a/tests/vboot_detach_menu_tests.c
+++ b/tests/vboot_detach_menu_tests.c
@@ -41,6 +41,7 @@ static VbError_t vbtlk_last_retval;
 static int vbtlk_retval_count;
 static const VbError_t vbtlk_retval_fixed = 1002;
 static int vbexlegacy_called;
+static int altfw_num;
 static int debug_info_displayed;
 static int trust_ec;
 static int virtdev_set;
@@ -84,6 +85,7 @@ static void ResetMocks(void)
 	shutdown_request_calls_left = 301;
 	audio_looping_calls_left = 60;
 	vbexlegacy_called = 0;
+	altfw_num = -1;
 	debug_info_displayed = 0;
 	trust_ec = 0;
 	virtdev_set = 0;
@@ -160,9 +162,11 @@ uint32_t VbExGetSwitches(uint32_t request_mask)
 		return 0;
 }
 
-int VbExLegacy(void)
+int VbExLegacy(int _altfw_num)
 {
 	vbexlegacy_called++;
+	altfw_num = _altfw_num;
+
 	return 0;
 }
 
@@ -271,6 +275,7 @@ static void VbBootDevTest(void)
 	TEST_EQ(VbBootDeveloperMenu(&ctx), vbtlk_retval_fixed,
 		"default legacy GBB");
 	TEST_EQ(vbexlegacy_called, 1, "  try legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
 	TEST_EQ(screens_displayed[0], VB_SCREEN_DEVELOPER_WARNING_MENU,
 		"  warning screen");
 	TEST_EQ(screens_displayed[1], VB_SCREEN_BLANK, "  blank (error flash)");
@@ -290,6 +295,7 @@ static void VbBootDevTest(void)
 	TEST_EQ(VbBootDeveloperMenu(&ctx), vbtlk_retval_fixed,
 		"default legacy NV");
 	TEST_EQ(vbexlegacy_called, 1, "  try legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
 	TEST_EQ(screens_displayed[0], VB_SCREEN_DEVELOPER_WARNING_MENU,
 		"  warning screen");
 	TEST_EQ(screens_displayed[1], VB_SCREEN_BLANK, "  blank (error flash)");
@@ -611,6 +617,7 @@ static void VbBootDevTest(void)
 	TEST_EQ(VbBootDeveloperMenu(&ctx), vbtlk_retval_fixed,
 		"Ctrl+L force legacy");
 	TEST_EQ(vbexlegacy_called, 1, "  try legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
 	TEST_EQ(screens_displayed[0], VB_SCREEN_DEVELOPER_WARNING_MENU,
 		"  warning screen");
 	TEST_EQ(screens_displayed[1], VB_SCREEN_BLANK, "  blank (error flash)");
@@ -646,6 +653,7 @@ static void VbBootDevTest(void)
 	TEST_EQ(VbBootDeveloperMenu(&ctx), vbtlk_retval_fixed,
 		"Ctrl+L fwmp legacy");
 	TEST_EQ(vbexlegacy_called, 1, "  fwmp legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
 	TEST_EQ(screens_displayed[0], VB_SCREEN_DEVELOPER_WARNING_MENU,
 		"  warning screen");
 	TEST_EQ(screens_displayed[1], VB_SCREEN_BLANK, "  blank (error flash)");
@@ -908,6 +916,7 @@ static void VbBootDevTest(void)
 		"Menu selected legacy boot");
 	TEST_EQ(debug_info_displayed, 0, "  no debug info");
 	TEST_EQ(vbexlegacy_called, 2, "  tried legacy boot twice");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
 	TEST_EQ(audio_looping_calls_left, 0, "  audio timeout");
 	TEST_EQ(vb2_nv_get(&ctx, VB2_NV_RECOVERY_REQUEST), 0, "  no recovery");
 	i = 0;
@@ -2189,6 +2198,7 @@ static void VbNavigationTest(void)
 		"developer mode long navigation");
 	TEST_EQ(debug_info_displayed, 1, "  showed debug info");
 	TEST_EQ(vbexlegacy_called, 1, "  tried legacy");
+	TEST_EQ(altfw_num, 0, "  check altfw_num");
 	TEST_EQ(audio_looping_calls_left, 0, "  audio timeout");
 	TEST_EQ(vb2_nv_get(&ctx, VB2_NV_RECOVERY_REQUEST), 0, "  no recovery");
 	i = 0;