1 files changed, 124 insertions, 0 deletions
diff --git a/firmware/bdb/misc.c b/firmware/bdb/misc.c
new file mode 100644
index 00000000..fd3e0c9b
--- /dev/null
+++ b/firmware/bdb/misc.c
@@ -0,0 +1,124 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <stdint.h>
+#include "bdb.h"
+#include "bdb_api.h"
+#include "vboot_register.h"
+
+static int did_current_slot_fail(struct vba_context *ctx)
+{
+	uint32_t val = vbe_get_vboot_register(VBOOT_REGISTER_PERSIST);
+
+	if (ctx->slot)
+		return val & VBOOT_REGISTER_FAILED_RW_SECONDARY;
+	else
+		return val & VBOOT_REGISTER_FAILED_RW_PRIMARY;
+}
+
+static int did_other_slot_fail(struct vba_context *ctx)
+{
+	uint32_t val = vbe_get_vboot_register(VBOOT_REGISTER_PERSIST);
+
+	if (ctx->slot)
+		return val & VBOOT_REGISTER_FAILED_RW_PRIMARY;
+	else
+		return val & VBOOT_REGISTER_FAILED_RW_SECONDARY;
+}
+
+static void set_try_other_slot(struct vba_context *ctx)
+{
+	uint32_t val = vbe_get_vboot_register(VBOOT_REGISTER_PERSIST);
+
+	if (ctx->slot)
+		val &= ~VBOOT_REGISTER_TRY_SECONDARY_BDB;
+	else
+		val |= VBOOT_REGISTER_TRY_SECONDARY_BDB;
+
+	vbe_set_vboot_register(VBOOT_REGISTER_PERSIST, val);
+}
+
+static void set_recovery_request(struct vba_context *ctx)
+{
+	uint32_t val = vbe_get_vboot_register(VBOOT_REGISTER_PERSIST);
+
+	val |= VBOOT_REGISTER_RECOVERY_REQUEST;
+
+	vbe_set_vboot_register(VBOOT_REGISTER_PERSIST, val);
+}
+
+static void get_current_slot(struct vba_context *ctx)
+{
+	/* Assume SP-RO selects slot this way */
+	ctx->slot = (vbe_get_vboot_register(VBOOT_REGISTER_PERSIST)
+			& VBOOT_REGISTER_TRY_SECONDARY_BDB) ? 1 : 0;
+}
+
+static void set_current_slot_failed(struct vba_context *ctx)
+{
+	uint32_t val = vbe_get_vboot_register(VBOOT_REGISTER_PERSIST);
+
+	if (ctx->slot)
+		val |= VBOOT_REGISTER_FAILED_RW_SECONDARY;
+	else
+		val |= VBOOT_REGISTER_FAILED_RW_PRIMARY;
+
+	vbe_set_vboot_register(VBOOT_REGISTER_PERSIST, val);
+}
+
+static void unset_current_slot_failed(struct vba_context *ctx)
+{
+	uint32_t val = vbe_get_vboot_register(VBOOT_REGISTER_PERSIST);
+
+	if (ctx->slot)
+		val &= ~VBOOT_REGISTER_FAILED_RW_SECONDARY;
+	else
+		val &= ~VBOOT_REGISTER_FAILED_RW_PRIMARY;
+
+	vbe_set_vboot_register(VBOOT_REGISTER_PERSIST, val);
+}
+
+int vba_bdb_init(struct vba_context *ctx)
+{
+	/* Get current slot */
+	get_current_slot(ctx);
+
+	/* Check current slot failed or not at the last boot */
+	if (!did_current_slot_fail(ctx)) {
+		/* If not, we try this slot. Prepare for any accidents */
+		set_current_slot_failed(ctx);
+		return BDB_SUCCESS;
+	}
+
+	/* Check other slot failed or not at the previous boot */
+	if (!did_other_slot_fail(ctx)) {
+		/* If not, we try the other slot after reboot. */
+		set_try_other_slot(ctx);
+		return BDB_ERROR_TRY_OTHER_SLOT;
+	} else {
+		/* Otherwise, both slots are bad. Reboot to recovery */
+		set_recovery_request(ctx);
+		return BDB_ERROR_RECOVERY_REQUEST;
+	}
+}
+
+int vba_bdb_finalize(struct vba_context *ctx)
+{
+	/* Mark the current slot good */
+	unset_current_slot_failed(ctx);
+
+	/* Disable NVM bus */
+
+	return BDB_SUCCESS;
+}
+
+void vba_bdb_fail(struct vba_context *ctx)
+{
+	/* We can do some logging here if we want */
+
+	/* Unconditionally reboot. FailedRW flag is already set.
+	 * At the next boot, bdb_init will decide what to do. */
+	vbe_reset();
+}