Mesh SDK - NRF52840 flash page issue

RE: Mesh SDK - NRF52840 flash page issue

Justin — Thu, 30 May 2019 16:36:20 GMT

I have reserved 5 pages, which I believe is the minimum.

	Address	Size
MBR+SoftDevice	0x00000	0x26000
<your stuff here>	0x26000	0x4C000
Nordic Mesh Info	0x72000	0x5000
MBR	0x77000	0x1000
Nordic Bootloader	0x78000	0x6000
Bootloader Settings	0x7E000	0x2000

RE: Mesh SDK - NRF52840 flash page issue

bart — Thu, 30 May 2019 15:43:12 GMT

I'm also searching for how many pages to reserve for the mesh, but the documentation still says: 2 + ACCESS_FLASH_PAGE_COUNT + DSM_FLASH_PAGE_COUNT

So can anyone tell us the actual value?

RE: Mesh SDK - NRF52840 flash page issue

Mttrinh — Mon, 11 Feb 2019 12:39:44 GMT

Yes, it seems that part is outdated. This has been reported and we will fix this documentation error as soon as possible.

RE: Mesh SDK - NRF52840 flash page issue

Justin — Tue, 05 Feb 2019 18:27:22 GMT

Thanks, i was referencing a previous forum post, which is why i thought MBR was after the bootloader:
"Yes the bootloader uses the space at the end for MBR and bootloader setting."

Looking at the bootloader code, I see that it sets MBR in the UICR to the page before.
The bootloader is using 2 pages at the end for info and bank info.

You previously mentioned i was looking at outdated information. Was that for the flash_manager.md?
Is the following equation outdated:

x = 2 + ACCESS_FLASH_PAGE_COUNT + DSM_FLASH_PAGE_COUNT

Where can i find the current documentation for configuring mesh flash usage?
I understand that the mesh components are using 5 pages, starting at 0xF2000, but I would like to understand how my configuration is driving that.

Thanks!

RE: Mesh SDK - NRF52840 flash page issue

Mttrinh — Mon, 04 Feb 2019 15:37:53 GMT

You can place the MBR wherever you want, but the mesh bootloader put it right before the bootloader starts.

RE: Mesh SDK - NRF52840 flash page issue

Justin — Fri, 01 Feb 2019 17:48:33 GMT

I thought the MBR and bootloader settings were the last two pages in flash, FE000-FF000? Has this changed?

Note that this is for the NRF52840 device.

RE: Mesh SDK - NRF52840 flash page issue

Mttrinh — Fri, 01 Feb 2019 15:11:16 GMT

Hi,

Sorry for the late response.

It seems like you found some outdated documentation, I have reported this internally. It is the MBR that are using 0xF7000. You can have a look at the SDS for more information. The extra page you are seeing are for mesh_config.

RE: Mesh SDK - NRF52840 flash page issue

Justin — Wed, 30 Jan 2019 22:52:06 GMT

can you offer any additional comments on this? thanks!

RE: Mesh SDK - NRF52840 flash page issue

Justin — Wed, 23 Jan 2019 19:25:30 GMT

In mesh_sdk/doc/how_to_nordicSDK.md there is the following information:

Furthermore, when writing to flash, ensure to not write or erase areas utilized by the mesh stack
modules and the bootloader (if present). By default, the mesh modules utilize the last `x` number of
pages before the start of the bootloader, if present, or the last `x` number of pages of the
available flash on the Nordic SoC.
The value of `x` depends on the configuration of the mesh stack and can be calculated by:

    x = 2 + ACCESS_FLASH_PAGE_COUNT + DSM_FLASH_PAGE_COUNT

Based on my mesh sdk configuration, x = 4, which is why I have allocated 4 pages in my layout.

In mesh_sdk/doc/libraries/flash_manager.md there is the following information:

By default, the defrag recovery page is the last page before the bootloader starts, or the last page in device flash if the bootloader is not present (determined by the `UICR->BOOTLOADERADDR` register). This location can be overriden by defining `FLASH_MANAGER_RECOVERY_PAGE` in the compiler defines. Note that the recovery page should be the same page in every iteration of the firmware, to avoid loss of backed up recovery data.

So, this recovery page is not part of the 4 pages mentioned earlier in how_to_nordicSDK.md?
Also, I expect the recovery page to be at 0xF7000 not 0xF6000, since the bootloader begins at 0xF8000. If the recovery page is actually at 0xF6000, what is using 0xF7000?

I have added the call to mesh_stack_persistence_flash_usage, and it returns the following values: start(0xF2000), size(0x5000).

So 5 pages are being used by SDK components. What in the configuration accounts for the extra page?
I expected it to use 4 pages based on the information in how_to_nordicSDK.md.

Thanks.

RE: Mesh SDK - NRF52840 flash page issue

Mttrinh — Wed, 23 Jan 2019 14:33:44 GMT

You seem to have missed mesh_config. You can use mesh_stack_persistence_flash_usage() to get out the actual memory usage of the mesh.

RE: Mesh SDK - NRF52840 flash page issue

Justin — Fri, 18 Jan 2019 17:29:43 GMT

Mesh SDK v3.1.0
nRF5 SDK v15.2.0

RE: Mesh SDK - NRF52840 flash page issue

Mttrinh — Fri, 18 Jan 2019 15:05:08 GMT

Hi,

Which Mesh SDK version are you using?

RE: Mesh SDK - NRF52840 flash page issue

Justin — Thu, 17 Jan 2019 21:44:53 GMT

I see from /doc/libraries/flash_manager.md that this (08 04 10 10 01 00 FF FF) is the flash manager metadata header.

Based on the other documents, I should only need 4 pages for the mesh info (which is what I have reserved).

However, 2 extra pages are being consumed, F2000 and F3000. Where are these 2 extra pages coming from?

In this 52840 device, it is not a problem to adjust memory layout since there is plenty of flash space. In our 52832 device however, losing 2 more pages makes things really tight.