1 files changed, 52 insertions, 0 deletions
diff --git a/chip/stm32/dfu_bootmanager_shared.c b/chip/stm32/dfu_bootmanager_shared.c
new file mode 100644
index 0000000000..212ee0a9e9
--- /dev/null
+++ b/chip/stm32/dfu_bootmanager_shared.c
@@ -0,0 +1,52 @@
+/* Copyright 2022 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.
+ *
+ * DFU Boot Manager shared utilities for STM32
+ */
+
+#include "bkpdata.h"
+#include "clock.h"
+#include "dfu_bootmanager_shared.h"
+#include "flash.h"
+#include "registers.h"
+#include "task.h"
+
+/*
+ * The Servo platforms do not have any free backup regions. The scratchpad
+ * is only with the console command scratchpad and on some of the tests so
+ * we'll use the scratchpad region.
+ */
+#ifdef CONFIG_CMD_SCRATCHPAD
+#error "The scratchpad is used, define a backup region for the DFU fields."
+#endif /* CONFIG_CMD_SCRATCHPAD */
+
+int dfu_bootmanager_enter_dfu(void)
+{
+	dfu_bootmanager_backup_write(DFU_BOOTMANAGER_VALUE_DFU);
+	system_reset(0);
+	return 0;
+}
+
+void dfu_bootmanager_clear(void)
+{
+	dfu_bootmanager_backup_write(DFU_BOOTMANAGER_VALUE_CLEAR);
+}
+
+void dfu_bootmanager_backup_write(uint8_t value)
+{
+	uint16_t data = DFU_BOOTMANAGER_VALID_CHECK | value;
+
+	bkpdata_write(BKPDATA_INDEX_SCRATCHPAD, data);
+}
+
+int dfu_bootmanager_backup_read(uint8_t *value)
+{
+	uint16_t data = bkpdata_read(BKPDATA_INDEX_SCRATCHPAD);
+	uint16_t valid_check = data & DFU_BOOTMANAGER_VALID_MASK;
+
+	*value = (uint8_t)(data & DFU_BOOTMANAGER_VALUE_MASK);
+	if (valid_check != DFU_BOOTMANAGER_VALID_CHECK)
+		return EC_ERROR_UNKNOWN;
+	return EC_SUCCESS;
+}