This fixes MCUB-39.
On Zephyr targets, flash_area_to_sectors() assumes that the flash
device's sector size is equal to the size of the scratch area.
That breaks swap and rollback when scratch size doesn't divide image
size, since the image flash areas will not be correctly configured.
This is a valid configuration supported by the rest of mcuboot.
The best way to fix this would be to get the flash layout from Zephyr,
but that's not possible yet.
Instead, provide a new FLASH_AREA_IMAGE_SECTOR_SIZE define from
target.h. This must be the sector size for these areas:
- FLASH_AREA_IMAGE_0
- FLASH_AREA_IMAGE_1
- FLASH_AREA_IMAGE_SCRATCH
Other areas on the device may have sizes different than
FLASH_AREA_IMAGE_SECTOR_SIZE.
This won't work on platforms where those areas have nonuniform sector
sizes, but we'll cross that bridge when we come to it. (At that point,
an upstream Zephyr change to the flash API really seems needed.)
Revert to the old/buggy behavior when FLASH_AREA_IMAGE_SECTOR_SIZE
isn't provided, but emit a warning. Additionally, touch up the logging
and error handling while we're here.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
The current configuration only allows ~170 updates before we can
expect wear on the flash device (per product spec that the flash
device supports 10,000 erase cycles). Increase the scratch size to
make this better by removing some application space, to allow for
~2500 application updates or rollbacks.
The new configuration is 52 KiB (13 sectors) for scratch, and 208
KiB (52 sectors) for each application image.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Let's stay in-sync automatically with Zephyr master by referring
to CONFIGs for the flash device names.
Signed-off-by: Michael Scott <michael.scott@linaro.org>
Marti Bolivar