boot: bootutil: move scratch swap functionality
This moves the functionality that is unique to a scratch based swap
upgrade into a separate file. Later other upgrade strategies can be
added by reimplementing those functions.
Signed-off-by: Fabio Utzig <utzig@apache.org>
diff --git a/boot/bootutil/src/swap_priv.h b/boot/bootutil/src/swap_priv.h
new file mode 100644
index 0000000..7507595
--- /dev/null
+++ b/boot/bootutil/src/swap_priv.h
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2019 JUUL Labs
+ *
+ * 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 H_SWAP_PRIV_
+#define H_SWAP_PRIV_
+
+#include "mcuboot_config/mcuboot_config.h"
+
+#if defined(MCUBOOT_SWAP_USING_SCRATCH) || defined(MCUBOOT_SWAP_USING_MOVE)
+
+/**
+ * Calculates the amount of space required to store the trailer, and erases
+ * all sectors required for this storage in the given flash_area.
+ */
+int swap_erase_trailer_sectors(const struct boot_loader_state *state,
+ const struct flash_area *fap);
+
+/**
+ * Initialize the given flash_area with the metadata required to start a new
+ * swap upgrade.
+ */
+int swap_status_init(const struct boot_loader_state *state,
+ const struct flash_area *fap,
+ const struct boot_status *bs);
+
+/**
+ * Tries to locate an interrupted swap status (metadata). If not metadata
+ * was found returns BOOT_STATUS_SOURCE_NONE.
+ *
+ * Must return one of:
+ * - BOOT_STATUS_SOURCE_NONE
+ * - BOOT_STATUS_SOURCE_SCRATCH
+ * - BOOT_STATUS_SOURCE_PRIMARY_SLOT
+ */
+int swap_status_source(struct boot_loader_state *state);
+
+/**
+ * Reads the boot status from the flash. The boot status contains
+ * the current state of an interrupted image copy operation. If the boot
+ * status is not present, or it indicates that previous copy finished,
+ * there is no operation in progress.
+ */
+int swap_read_status(struct boot_loader_state *state, struct boot_status *bs);
+
+/**
+ * Iterate over the swap status bytes in the given flash_area and populate
+ * the given boot_status with the calculated index where a swap upgrade was
+ * interrupted.
+ */
+int swap_read_status_bytes(const struct flash_area *fap,
+ struct boot_loader_state *state,
+ struct boot_status *bs);
+
+/**
+ * Marks the image in the primary slot as fully copied.
+ */
+int swap_set_copy_done(uint8_t image_index);
+
+/**
+ * Marks a reverted image in the primary slot as confirmed. This is necessary to
+ * ensure the status bytes from the image revert operation don't get processed
+ * on a subsequent boot.
+ *
+ * NOTE: image_ok is tested before writing because if there's a valid permanent
+ * image installed on the primary slot and the new image to be upgrade to has a
+ * bad sig, image_ok would be overwritten.
+ */
+int swap_set_image_ok(uint8_t image_index);
+
+/**
+ * Start a new or resume an interrupted swap according to the parameters
+ * found in the given boot_status.
+ */
+void swap_run(struct boot_loader_state *state,
+ struct boot_status *bs,
+ uint32_t copy_size);
+
+#if MCUBOOT_SWAP_USING_SCRATCH
+#define BOOT_SCRATCH_AREA(state) ((state)->scratch.area)
+
+static inline size_t boot_scratch_area_size(const struct boot_loader_state *state)
+{
+ return BOOT_SCRATCH_AREA(state)->fa_size;
+}
+#endif
+
+#endif /* defined(MCUBOOT_SWAP_USING_SCRATCH) || defined(MCUBOOT_SWAP_USING_MOVE) */
+
+#endif /* H_SWAP_PRIV_ */