DFU: add module for interact with mcuboot

read, update status
trigger flashing
erase image bank
Module is intended to be use by a higher-level
image management protocol module.

Signed-off-by: Fabio Utzig <utzig@apache.org>
Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>

subsys/dfu/boot/mcuboot.c

@@ -0,0 +1,266 @@
+/*
+ * Copyright (c) 2017 Nordic Semiconductor ASA
+ * Copyright (c) 2016-2017 Linaro Limited
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stddef.h>
+#include <errno.h>
+#include <string.h>
+#include <flash.h>
+#include <zephyr.h>
+#include <init.h>
+
+#include <misc/__assert.h>
+#include "boot/mcuboot_constraints.h"
+#include "mcuboot.h"
+
+/*
+ * Helpers for image trailer, as defined by mcuboot.
+ * Image trailer consists of sequence of fields:
+ *   u8_t copy_done
+ *   u8_t padding_1[BOOT_MAX_ALIGN - 1]
+ *   u8_t image_ok
+ *   u8_t padding_2[BOOT_MAX_ALIGN - 1]
+ *   u8_t magic[16]
+ */
+
+/*
+ * Strict defines: Defines in block below must be equal to coresponding
+ * mcuboot defines
+ */
+#define BOOT_MAX_ALIGN 8
+#define BOOT_MAGIC_SZ  16
+#define BOOT_FLAG_SET 0x01
+#define BOOT_FLAG_UNSET 0xff
+/* end_of Strict defines */
+
+#define BOOT_MAGIC_GOOD  1
+#define BOOT_MAGIC_BAD   2
+#define BOOT_MAGIC_UNSET 3
+
+#define BOOT_FLAG_IMAGE_OK 0
+#define BOOT_FLAG_COPY_DONE 1
+
+#define FLASH_MIN_WRITE_SIZE FLASH_ALIGN
+#define FLASH_BANK0_OFFSET FLASH_AREA_IMAGE_0_OFFSET
+
+/* FLASH_AREA_IMAGE_XX_YY values used below are auto-generated thanks to DT */
+#define FLASH_BANK_SIZE FLASH_AREA_IMAGE_0_SIZE
+#define FLASH_BANK1_OFFSET FLASH_AREA_IMAGE_1_OFFSET
+#define FLASH_STATE_OFFSET (FLASH_AREA_IMAGE_SCRATCH_OFFSET +\
+			    FLASH_AREA_IMAGE_SCRATCH_SIZE)
+
+#define COPY_DONE_OFFS(bank_offs) (bank_offs + FLASH_BANK_SIZE -\
+				   BOOT_MAGIC_SZ - BOOT_MAX_ALIGN * 2)
+
+#define IMAGE_OK_OFFS(bank_offs) (bank_offs + FLASH_BANK_SIZE - BOOT_MAGIC_SZ -\
+				  BOOT_MAX_ALIGN)
+#define MAGIC_OFFS(bank_offs) (bank_offs + FLASH_BANK_SIZE - BOOT_MAGIC_SZ)
+
+const u32_t boot_img_magic[4] = {
+	0xf395c277,
+	0x7fefd260,
+	0x0f505235,
+	0x8079b62c,
+};
+
+static struct device *flash_dev;
+
+static int boot_flag_offs(int flag, u32_t bank_offs, u32_t *offs)
+{
+	switch (flag) {
+	case BOOT_FLAG_COPY_DONE:
+		*offs = COPY_DONE_OFFS(bank_offs);
+		return 0;
+	case BOOT_FLAG_IMAGE_OK:
+		*offs = IMAGE_OK_OFFS(bank_offs);
+		return 0;
+	default:
+		return -ENOTSUP;
+	}
+}
+
+
+static int boot_flash_write(off_t offs, const void *data, size_t len)
+{
+	int rc;
+
+	rc = flash_write_protection_set(flash_dev, false);
+	if (rc) {
+		return rc;
+	}
+
+	rc = flash_write(flash_dev, offs, data, len);
+	if (rc) {
+		return rc;
+	}
+
+	rc = flash_write_protection_set(flash_dev, true);
+
+	return rc;
+}
+
+static int boot_flag_write(int flag, u32_t bank_offs)
+{
+	u8_t buf[FLASH_MIN_WRITE_SIZE];
+	u32_t offs;
+	int rc;
+
+	rc = boot_flag_offs(flag, bank_offs, &offs);
+	if (rc != 0) {
+		return rc;
+	}
+
+	memset(buf, BOOT_FLAG_UNSET, sizeof(buf));
+	buf[0] = BOOT_FLAG_SET;
+
+	rc = boot_flash_write(offs, buf, sizeof(buf));
+
+	return rc;
+}
+
+static int boot_flag_read(int flag, u32_t bank_offs)
+{
+	u32_t offs;
+	int rc;
+	u8_t flag_val;
+
+	rc = boot_flag_offs(flag, bank_offs, &offs);
+	if (rc != 0) {
+		return rc;
+	}
+
+	rc = flash_read(flash_dev, offs, &flag_val, sizeof(flag_val));
+	if (rc != 0) {
+		return rc;
+	}
+
+	return flag_val;
+}
+
+static int boot_image_ok_read(u32_t bank_offs)
+{
+	return boot_flag_read(BOOT_FLAG_IMAGE_OK, bank_offs);
+}
+
+static int boot_image_ok_write(u32_t bank_offs)
+{
+	return boot_flag_write(BOOT_FLAG_IMAGE_OK, bank_offs);
+}
+
+static int boot_magic_write(u32_t bank_offs)
+{
+	u32_t offs;
+	int rc;
+
+	offs = MAGIC_OFFS(bank_offs);
+
+	rc = boot_flash_write(offs, boot_img_magic, BOOT_MAGIC_SZ);
+
+	return rc;
+}
+
+static int boot_magic_code_check(const u32_t *magic)
+{
+	int i;
+
+	if (memcmp(magic, boot_img_magic, sizeof(boot_img_magic)) == 0) {
+		return BOOT_MAGIC_GOOD;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(boot_img_magic); i++) {
+		if (magic[i] != 0xffffffff) {
+			return BOOT_MAGIC_BAD;
+		}
+	}
+
+	return BOOT_MAGIC_UNSET;
+}
+
+static int boot_magic_state_read(u32_t bank_offs)
+{
+	u32_t magic[4];
+	u32_t offs;
+	int rc;
+
+	offs = MAGIC_OFFS(bank_offs);
+	rc = flash_read(flash_dev, offs, magic, sizeof(magic));
+	if (rc != 0) {
+		return rc;
+	}
+
+	return boot_magic_code_check(magic);
+}
+
+int boot_request_upgrade(int permanent)
+{
+	int rc;
+
+	rc = boot_magic_write(FLASH_BANK1_OFFSET);
+	if (rc == 0 && permanent) {
+		rc = boot_image_ok_write(FLASH_BANK1_OFFSET);
+	}
+
+	return rc;
+}
+
+int boot_write_img_confirmed(void)
+{
+	int rc;
+
+	switch (boot_magic_state_read(FLASH_BANK0_OFFSET)) {
+	case BOOT_MAGIC_GOOD:
+		/* Confirm needed; proceed. */
+		break;
+
+	case BOOT_MAGIC_UNSET:
+		/* Already confirmed. */
+		return 0;
+
+	case BOOT_MAGIC_BAD:
+		/* Unexpected state. */
+		return -EFAULT;
+	}
+
+	if (boot_image_ok_read(FLASH_BANK0_OFFSET) != BOOT_FLAG_UNSET) {
+		/* Already confirmed. */
+		return 0;
+	}
+
+	rc = boot_image_ok_write(FLASH_BANK0_OFFSET);
+
+	return rc;
+}
+
+int boot_erase_img_bank(u32_t bank_offset)
+{
+	int rc;
+
+	rc = flash_write_protection_set(flash_dev, false);
+	if (rc) {
+		return rc;
+	}
+
+	rc = flash_erase(flash_dev, bank_offset, FLASH_BANK_SIZE);
+	if (rc) {
+		return rc;
+	}
+
+	rc = flash_write_protection_set(flash_dev, true);
+
+	return rc;
+}
+
+static int boot_init(struct device *dev)
+{
+	ARG_UNUSED(dev);
+	flash_dev = device_get_binding(FLASH_DRIVER_NAME);
+	if (!flash_dev) {
+		return -ENODEV;
+	}
+	return 0;
+}
+
+SYS_INIT(boot_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);