Logical sectors

[de-nordic]

So far tested on nrf52840 with internal memory only.
Normal build from main, with hardware pages/sectors

Memory region         Used Size  Region Size  %age Used
           FLASH:       32716 B        48 KB     66.56%
             RAM:       22464 B       256 KB      8.57%
        IDT_LIST:          0 GB        32 KB      0.00%

Logical sectors ( -DCONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE=4096 -DCONFIG_FLASH_PAGE_LAYOUT=n)

Memory region         Used Size  Region Size  %age Used
           FLASH:       32188 B        48 KB     65.49%
             RAM:       20544 B       256 KB      7.84%
        IDT_LIST:          0 GB        32 KB      0.00%

Logical sectors validation build (-DCONFIG_MCUBOOT_LOGICAL_SECTOR_SIZE=4096 -DCONFIG_MCUBOOT_VERIFY_LOGICAL_SECTORS=y)

Memory region         Used Size  Region Size  %age Used
           FLASH:       33452 B        48 KB     68.06%
             RAM:       20544 B       256 KB      7.84%
        IDT_LIST:          0 GB        32 KB      0.00%

[Copilot]

Pull Request Overview

Adds support for using fixed-size “logical” flash sectors (and optional run-time validation) instead of querying hardware page layouts in MCUBoot on Zephyr.

• Introduce MCUBOOT_LOGICAL_SECTOR_SIZE and validation macros in mcuboot_config.h and Kconfig
• Update flash_map_extended.c, CMakeLists, and loader/private/util code to switch between hardware and logical sectors
• Remove legacy flash_map_legacy.c fallback and adjust build logic for flash layout

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
boot/zephyr/include/mcuboot_config/mcuboot_config.h	Define MCUBOOT_LOGICAL_SECTOR_SIZE and MCUBOOT_LOGICAL_SECTOR_VALIDATION
boot/zephyr/flash_map_legacy.c	Removed obsolete legacy page-layout fallback
boot/zephyr/flash_map_extended.c	Conditional logic for logical sectors and validation in flash APIs
boot/zephyr/Kconfig	Add Kconfig options for logical sector size and validation
boot/zephyr/CMakeLists.txt	Stop including legacy flash_map fallback unconditionally
boot/bootutil/src/loader.c	Wrap split_image_check and context code to skip on logical sectors
boot/bootutil/src/bootutil_priv.h	Conditional sector fields and inline functions for logical sectors
boot/bootutil/src/bootutil_misc.c	Add boot_validate_logical_sectors and adjust area initialization

Comments suppressed due to low confidence (4)

boot/zephyr/CMakeLists.txt:89

• Unconditionally removing the legacy flash_map_legacy.c include may break builds when neither FLASH_PAGE_LAYOUT nor logical sectors are enabled. Consider re-adding a conditional to include it when both are off.

      )

boot/zephyr/Kconfig:1104

• [nitpick] The name MCUBOOT_LOGICAL_SECTOR_SIZE_SET is ambiguous; consider renaming to something like MCUBOOT_LOGICAL_SECTOR_ENABLED to clearly indicate it toggles logical-sector mode.

config MCUBOOT_LOGICAL_SECTOR_SIZE_SET

boot/zephyr/Kconfig:1124

• If logical sectors are enabled but validation is disabled, FLASH_PAGE_LAYOUT will not be selected, which can break flash layout support. Ensure FLASH_PAGE_LAYOUT is selected whenever hardware page info is needed.

	select FLASH_PAGE_LAYOUT if FLASH_HAS_PAGE_LAYOUT && !MCUBOOT_LOGICAL_SECTOR_SIZE_SET

boot/bootutil/src/loader.c:654

• [nitpick] Add a matching comment on the #endif (e.g. /* logical sectors disabled */) to clearly link the conditional guard to its closing directive.

#if !defined(MCUBOOT_LOGICAL_SECTOR_SIZE) || MCUBOOT_LOGICAL_SECTOR_SIZE == 0

[tpambor]

Any update on this PR? We would be interested in using this.

[pdgendt]

I'm working with this PR and providing feedback to @de-nordic on discord here:
https://discord.com/channels/720317445772017664/1416006909873361030
I'll be continuing to test the current proposal, feel free to chime in.

[de-nordic]

Any update on this PR? We would be interested in using this.

This is quite ready as is, I am working on enabling tests for this.