mcuboot/boot/zephyr/flash_map_legacy.c

105 lines
3.2 KiB
C

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
/**
* @file
* @brief Legacy flash fallbacks
*
* This file contains hacks for flash drivers without page layout
* support. They're hacks because they guess a page layout that may be
* incorrect, but is likely to "work". Needless to say, such guesswork
* is undesirable in trusted bootloader code.
*
* The behavior is:
*
* - If FLASH_AREA_IMAGE_SECTOR_SIZE is defined (this was used by
* older Zephyr ports), the image sectors have uniform sector sizes.
* We also assume that's the size of the scratch sectors.
*
* - Otherwise, we assume that the size of the entire scratch area is
* a least common multiple of all sector sizes, and use that as
* FLASH_AREA_IMAGE_SECTOR_SIZE.
*/
#include "bootutil/bootutil_log.h"
#include <flash_map_backend/flash_map_backend.h>
#include <inttypes.h>
#include <target.h>
#warning "The flash driver lacks page layout support; falling back on hacks."
#if !defined(FLASH_AREA_IMAGE_SECTOR_SIZE)
#define FLASH_AREA_IMAGE_SECTOR_SIZE FLASH_AREA_IMAGE_SCRATCH_SIZE
#endif
MCUBOOT_LOG_MODULE_DECLARE(mcuboot);
/*
* Lookup the sector map for a given flash area. This should fill in
* `ret` with all of the sectors in the area. `*cnt` will be set to
* the storage at `ret` and should be set to the final number of
* sectors in this area.
*/
int flash_area_get_sectors(int idx, uint32_t *cnt, struct flash_sector *ret)
{
const struct flash_area *fa;
uint32_t max_cnt = *cnt;
uint32_t rem_len;
int rc = -1;
if (flash_area_open(idx, &fa)) {
goto out;
}
BOOT_LOG_DBG("area %d: offset=0x%x, length=0x%x", idx, fa->fa_off,
fa->fa_size);
if (*cnt < 1) {
goto fa_close_out;
}
rem_len = fa->fa_size;
*cnt = 0;
while (rem_len > 0 && *cnt < max_cnt) {
if (rem_len < FLASH_AREA_IMAGE_SECTOR_SIZE) {
BOOT_LOG_ERR("area %d size 0x%x not divisible by sector size 0x%x",
idx, fa->fa_size, FLASH_AREA_IMAGE_SECTOR_SIZE);
goto fa_close_out;
}
ret[*cnt].fs_off = FLASH_AREA_IMAGE_SECTOR_SIZE * (*cnt);
ret[*cnt].fs_size = FLASH_AREA_IMAGE_SECTOR_SIZE;
*cnt = *cnt + 1;
rem_len -= FLASH_AREA_IMAGE_SECTOR_SIZE;
}
if (*cnt >= max_cnt) {
BOOT_LOG_ERR("flash area %d sector count overflow", idx);
goto fa_close_out;
}
rc = 0;
fa_close_out:
flash_area_close(fa);
out:
return rc;
}