bootloader_support: Move secure boot code to bootloader_support

2016-11-02 17:54:47 +11:00
parent aceb6517c0
commit 98a0387854
5 changed files with 85 additions and 82 deletions
@@ -0,0 +1,65 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#ifndef __ESP32_SECUREBOOT_H
+#define __ESP32_SECUREBOOT_H
+
+#include <stdbool.h>
+#include <esp_err.h>
+#include "soc/efuse_reg.h"
+
+/* Support functions for secure boot features.
+
+   Can be compiled as part of app or bootloader code.
+*/
+
+/** @brief Is secure boot currently enabled in hardware?
+ *
+ * Secure boot is enabled if the ABS_DONE_0 efuse is blown. This means
+ * that the ROM bootloader code will only boot a verified secure
+ * bootloader digest from now on.
+ *
+ * @return true if secure boot is enabled.
+ */
+static inline bool esp_secure_boot_enabled(void) {
+    return REG_GET_FIELD(EFUSE_BLK0_RDATA6_REG, EFUSE_RD_ABS_DONE_0);
+}
+
+
+/** @brief Enable secure boot if it is not already enabled.
+ *
+ * @important If this function succeeds, secure boot is permanently
+ * enabled on the chip via efuse.
+ *
+ * @important This function is intended to be called from bootloader code only.
+ *
+ * If secure boot is not yet enabled for bootloader, this will
+ * generate the secure boot digest and enable secure boot by blowing
+ * the EFUSE_RD_ABS_DONE_0 efuse.
+ *
+ * This function does not verify secure boot of the bootloader (the
+ * ROM bootloader does this.)
+ *
+ * Will fail if efuses have been part-burned in a way that indicates
+ * secure boot should not or could not be correctly enabled.
+ *
+ *
+ * @return ESP_ERR_INVALID_STATE if efuse state doesn't allow
+ * secure boot to be enabled cleanly. ESP_OK if secure boot
+ * is enabled on this chip from now on.
+ */
+esp_err_t esp_secure_boot_permanently_enable(void);
+
+
+
+#endif