1 files changed, 152 insertions, 0 deletions
diff --git a/src/vboot/recovery.c b/src/vboot/recovery.c
new file mode 100644
index 0000000000..6e6eb0e159
--- /dev/null
+++ b/src/vboot/recovery.c
@@ -0,0 +1,152 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <assert.h>
+#include <bootmode.h>
+#include <bootstate.h>
+#include <rules.h>
+#include <string.h>
+#include <vb2_api.h>
+#include <vboot/misc.h>
+#include <vboot/vbnv.h>
+#include <vboot/vboot_common.h>
+
+static int vb2_get_recovery_reason_shared_data(void)
+{
+	/* Shared data does not exist for Ramstage and Post-CAR stage. */
+	if (ENV_RAMSTAGE || ENV_POSTCAR)
+		return 0;
+
+	struct vb2_shared_data *sd = vb2_get_shared_data();
+	assert(sd);
+	return sd->recovery_reason;
+}
+
+void vb2_save_recovery_reason_vbnv(void)
+{
+	if (!IS_ENABLED(CONFIG_VBOOT_SAVE_RECOVERY_REASON_ON_REBOOT))
+		return;
+
+	int reason =  vb2_get_recovery_reason_shared_data();
+	if (!reason)
+		return;
+
+	set_recovery_mode_into_vbnv(reason);
+}
+
+static void vb2_clear_recovery_reason_vbnv(void *unused)
+{
+	if (!IS_ENABLED(CONFIG_VBOOT_SAVE_RECOVERY_REASON_ON_REBOOT))
+		return;
+
+	set_recovery_mode_into_vbnv(0);
+}
+
+/*
+ * Recovery reason stored in VBNV needs to be cleared before the state of VBNV
+ * is backed-up anywhere or jumping to the payload (whichever occurs
+ * first). Currently, vbnv_cmos.c backs up VBNV on POST_DEVICE. Thus, we need to
+ * make sure that the stored recovery reason is cleared off before that
+ * happens.
+ * IMPORTANT: Any reboot occurring after BS_DEV_INIT state will cause loss of
+ * recovery reason on reboot. Until now, we have seen reboots occuring on x86
+ * only in FSP stages which run before BS_DEV_INIT.
+ */
+BOOT_STATE_INIT_ENTRY(BS_DEV_INIT, BS_ON_EXIT,
+		      vb2_clear_recovery_reason_vbnv, NULL);
+
+/*
+ * Returns 0 for the stages where we know that cbmem does not come online.
+ * Even if this function returns 1 for romstage, depending upon the point in
+ * bootup, cbmem might not actually be online.
+ */
+static int cbmem_possibly_online(void)
+{
+	if (ENV_BOOTBLOCK)
+		return 0;
+
+	if (ENV_VERSTAGE && IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * Returns 1 if vboot is being used and currently in a stage which might have
+ * already executed vboot verification.
+ */
+static int vboot_possibly_executed(void)
+{
+	if (IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK)) {
+		if (ENV_BOOTBLOCK && IS_ENABLED(CONFIG_SEPARATE_VERSTAGE))
+			return 0;
+		return 1;
+	}
+
+	if (IS_ENABLED(CONFIG_VBOOT_STARTS_IN_ROMSTAGE)) {
+		if (ENV_BOOTBLOCK)
+			return 0;
+		return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * vb2_check_recovery_request looks up different components to identify if there
+ * is a recovery request and returns appropriate reason code:
+ * 1. Checks if recovery mode is initiated by EC. If yes, returns
+ * VB2_RECOVERY_RO_MANUAL.
+ * 2. Checks if recovery request is present in VBNV and returns the code read
+ * from it.
+ * 3. Checks recovery request in handoff for stages post-cbmem.
+ * 4. For non-CBMEM stages, check if vboot verification is done and look-up
+ * selected region to identify if vboot_refence library has requested recovery
+ * path. If yes, return the reason code from shared data.
+ * 5. If nothing applies, return 0 indicating no recovery request.
+ */
+int vboot_check_recovery_request(void)
+{
+	int reason = 0;
+
+	/* EC-initiated recovery. */
+	if (get_recovery_mode_switch())
+		return VB2_RECOVERY_RO_MANUAL;
+
+	/* Recovery request in VBNV. */
+	if ((reason = get_recovery_mode_from_vbnv()) != 0)
+		return reason;
+
+	/*
+	 * Check recovery flag in vboot_handoff for stages post CBMEM coming
+	 * online. Since for some stages there is no way to know if cbmem has
+	 * already come online, try looking up handoff anyways. If it fails,
+	 * flow will fallback to looking up shared data.
+	 */
+	if (cbmem_possibly_online() &&
+	    ((reason = vboot_handoff_get_recovery_reason()) != 0))
+		return reason;
+
+	/*
+	 * For stages where CBMEM might not be online, identify if vboot
+	 * verification is already complete and no slot was selected
+	 * i.e. recovery path was requested.
+	 */
+	if (vboot_possibly_executed() && vb2_logic_executed() &&
+	    !vb2_is_slot_selected())
+		return vb2_get_recovery_reason_shared_data();
+
+	return 0;
+}