bdb: Add vba_bdb_init

vba_bdb_init initializes the vboot context and decides what to do next
based on the vboot register content. Possible actions are:
1. proceed to verify the current slot
2. reset to try the other slot
3. reset to recovery mode

bdb_sprw_test demonstrates these actions.

BUG=chrome-os-partner:51907
BRANCH=tot
TEST=make runtests

Change-Id: If72cdd575d09b9162a871f088064ca853b7fd74d
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/342604
Reviewed-by: Randall Spangler <rspangler@chromium.org>

4 files changed, 220 insertions, 0 deletions

diff --git a/firmware/bdb/bdb.h b/firmware/bdb/bdb.h
index 91834913..30ecc17c 100644
--- a/firmware/bdb/bdb.h
+++ b/firmware/bdb/bdb.h
@@ -68,6 +68,10 @@ enum bdb_return_code {
 	/* Other errors in bdb_verify() */
 	BDB_ERROR_DIGEST,	/* Error calculating digest */
 	BDB_ERROR_VERIFY_SIG,	/* Error verifying signature */
+
+	/* Errors in vba_bdb_init */
+	BDB_ERROR_TRY_OTHER_SLOT,
+	BDB_ERROR_RECOVERY_REQUEST,
 };
 
 /*****************************************************************************/
diff --git a/firmware/bdb/bdb_api.h b/firmware/bdb/bdb_api.h
new file mode 100644
index 00000000..53823fae
--- /dev/null
+++ b/firmware/bdb/bdb_api.h
@@ -0,0 +1,68 @@
+/* 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.
+ */
+
+#ifndef VBOOT_REFERENCE_FIRMWARE_BDB_BDB_API_H
+#define VBOOT_REFERENCE_FIRMWARE_BDB_BDB_API_H
+
+#include <stdint.h>
+#include "vboot_register.h"
+
+struct vba_context {
+	/* Indicate which slot is being tried: 0 - primary, 1 - secondary */
+	uint8_t slot;
+};
+
+/**
+ * Initialize vboot process
+ *
+ * @param ctx
+ * @return	enum bdb_return_code
+ */
+int vba_bdb_init(struct vba_context *ctx);
+
+/**
+ * Finalize vboot process
+ *
+ * @param ctx
+ * @return	enum bdb_return_code
+ */
+int vba_bdb_finalize(struct vba_context *ctx);
+
+/**
+ * Log failed boot attempt and reset the chip
+ *
+ * @param ctx
+ */
+void vba_bdb_fail(struct vba_context *ctx);
+
+/**
+ * Get vboot register value
+ *
+ * Implemented by each chip
+ *
+ * @param type	Type of register to get
+ * @return	Register value
+ */
+uint32_t vbe_get_vboot_register(enum vboot_register type);
+
+/**
+ * Set vboot register value
+ *
+ * Implemented by each chip
+ *
+ * @param type	Type of register to set
+ * @param val	Value to set
+ */
+void vbe_set_vboot_register(enum vboot_register type, uint32_t val);
+
+/**
+ * Reset the SoC
+ *
+ * Implemented by each chip. This is different from reboot (a.k.a. board reset,
+ * cold reset).
+ */
+void vbe_reset(void);
+
+#endif
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();
+}
diff --git a/firmware/bdb/stub.c b/firmware/bdb/stub.c
new file mode 100644
index 00000000..87efbc33
--- /dev/null
+++ b/firmware/bdb/stub.c
@@ -0,0 +1,24 @@
+/* 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 "bdb_api.h"
+
+__attribute__((weak))
+uint32_t vbe_get_vboot_register(enum vboot_register type)
+{
+	return 0;
+}
+
+__attribute__((weak))
+void vbe_set_vboot_register(enum vboot_register type, uint32_t val)
+{
+	return;
+}
+
+__attribute__((weak))
+void vbe_reset(void)
+{
+	return;
+}