Mesh DFU - Free flash space & bank erasure

RE: Mesh DFU - Free flash space & bank erasure

user15475 — Tue, 14 Jun 2022 13:30:34 GMT

Hi,

Yes, one of our developer have tested the patches and it works.

RE: Mesh DFU - Free flash space & bank erasure

user93769 — Mon, 13 Jun 2022 18:58:46 GMT

[quote userid="15475" url="~/f/nordic-q-a/86393/mesh-dfu---free-flash-space-bank-erasure/371406#371406"]Please consider that these are only assumptions after the source code investigation. Every solution might face additional issues that will require separate solving. Additionally, both solutions require good testing since the system `bootloader + app ---> DFU` is quite fragile from a stability point of view. [/quote]

Has Nordic done a complete test of these patches all the way through, i.e. upgraded an actual device using the sequence of suggested steps?

RE: Mesh DFU - Free flash space & bank erasure

user15475 — Wed, 08 Jun 2022 12:45:52 GMT

Hi,

An update from the team:

1. The first issue might be solved in two ways:

1.1 Modify DFU command DFU_START_TARGET and add as a command field the address of the app mesh config end. Then modify bootloader to consider this address instead of BOOTLOADERADDR. Pros: automated communication between app and bootloader that considers ongoing sizes of areas. Cons: it requires fixing both bootloader and app dfu parts. Upload both bootloader and app but bootloader only once.

It will require uploading application first. Then uploading of bootloader. Since command format incompatibility it will corrupt some memory in the command buffer but it should be safe enough.

1.2 Add compile-time definition in bootloader then bootloader can consider BOOTLOADERADDR + NEW_DEFINED_ADDRESS. Then you should follow up on this.
Pros: it requires fixing only bootloader. Cons: it requires following up on app mesh config size and definition and aligning them manually. Upload both bootloader and app every definition change.

2. The second issue requires implementation erasing allocated bank if bootloader succeeds uploaded image applying.

The sequence of applying patches

add_cleaningup_after_succeed ---- erase flash bank area after dfu succeeded
add_app_data_as_upper_boundary ------ reject image if it overlaps with application data area
fix_assertion_during_bootbank_erasing ----- fix assertion if bootloader bank is erased
rebuild application and bootloader

`DFU start target` command between application and bootloader has been changed and is not compatible with old versions.

To upgrade devices with 5.0.0 on the current one you need to upload the application image first and then upload the bootloader image (not another way around).

test-devzone.nordicsemi.com/.../add_5F00_app_5F00_data_5F00_as_5F00_upper_5F00_boundary.diff test-devzone.nordicsemi.com/.../add_5F00_cleaningup_5F00_after_5F00_succeed.diff test-devzone.nordicsemi.com/.../fix_5F00_assertion_5F00_during_5F00_bootbank_5F00_erasing.diff

Please consider that these are only assumptions after the source code investigation. Every solution might face additional issues that will require separate solving. Additionally, both solutions require good testing since the system `bootloader + app ---> DFU` is quite fragile from a stability point of view.

RE: Mesh DFU - Free flash space & bank erasure

user15475 — Fri, 08 Apr 2022 16:14:23 GMT

Hi,

It looks like both concerns are correct. These are bugs but this will most likely be not be fixed since the nRF5 SDK for Mesh is in maintenance mode.

We can only recommend cleaning up the flash area that is required for Mesh Configuration before running Mesh after DFU.

RE: Mesh DFU - Free flash space & bank erasure

user15475 — Mon, 04 Apr 2022 13:51:23 GMT

Hi,

I have forwarded this to our mesh team, I will give you an update as soon as possible.