Write multiple compile time constants into UICR

RE: Write multiple compile time constants into UICR

Remco Poelstra — Tue, 26 May 2020 12:07:57 GMT

The following flash_placement segment works:

<MemorySegment name="UICR" start="0x10001000" size="0x308" fill="0xff">
      <ProgramSection alignment="4" keep="yes" load="no" name=".uicr_fill" fill="0xff" size="0x1" />
      <ProgramSection alignment="4" keep="Yes" load="Yes" name=".uicr_pselreset" start="0x10001200" size="8"/>
      <ProgramSection alignment="4" keep="yes" load="no" name=".uicr_fill2" fill="0xff" size="0x1" />
      <ProgramSection alignment="4" keep="Yes" load="Yes" name=".uicr_regout0" start="0x10001304" size="4"/>
  </MemorySegment>

This example sets the PSELRESET and REGOUT registers, while leaving the others at 0xff.

RE: Write multiple compile time constants into UICR

Remco Poelstra — Wed, 20 May 2020 05:50:13 GMT

Hi,

Thanks for the suggestion. This does indeed load the file correctly and does indeed not load the symbols. I'll ask on the Segger forum and report back if I find a solution.

RE: Write multiple compile time constants into UICR

Jørgen Holmefjord — Tue, 19 May 2020 13:29:13 GMT

SES is setup to flash the ELF file by default. This may have different padding rules than the HEX-file. It is possible to configure SES to flash the HEX file by setting the "Load File" option to "$(OutDir)/$(ProjectName).hex", but this may cause debugging symbols to not be loaded automatically, etc.

I have not found any working options for changing the padding rules. Maybe you could ask that on the SEGGER forum?

RE: Write multiple compile time constants into UICR

Remco Poelstra — Thu, 14 May 2020 13:52:21 GMT

I can confirm this difference in behaviour.

Is there anything we can do about it?

RE: Write multiple compile time constants into UICR

Jørgen Holmefjord — Thu, 14 May 2020 12:43:33 GMT

It looks like this is an issue with how Segger Embedded Studio flashes the chip. I see the same behavior when flashed from SES, but when flashing the exact same HEX file with nrfjprog, the UICR registers in between are not cleared.

RE: Write multiple compile time constants into UICR

Remco Poelstra — Thu, 14 May 2020 08:28:30 GMT

I now have:

  <MemorySegment name="uicr_bootloader_start_address" start="0x10001014" size="0x4">
    <ProgramSection alignment="4" keep="Yes" load="Yes" name=".uicr_bootloader_start_address" address_symbol="__start_uicr_bootloader_start_address" end_symbol="__stop_uicr_bootloader_start_address" start = "0x10001014" size="0x4" />
  </MemorySegment>
  <MemorySegment name="uicr_mbr_params_page" start="0x10001018" size="0x4">
    <ProgramSection alignment="4" keep="Yes" load="Yes" name=".uicr_mbr_params_page" address_symbol="__start_uicr_mbr_params_page" end_symbol="__stop_uicr_mbr_params_page" start = "0x10001018" size="0x4" />
  </MemorySegment>
  <MemorySegment name="UICR" start="0x10001304" size="0x4">
      <ProgramSection alignment="4" keep="Yes" load="Yes" name=".uicr_regout0" start="0x10001304" size="4"/>
  </MemorySegment>

But this shows the same behaviour.

RE: Write multiple compile time constants into UICR

Turbo J — Thu, 14 May 2020 08:21:50 GMT

[quote userid="81291" url="~/f/nordic-q-a/61387/write-multiple-compile-time-constants-into-uicr"]such that the remaining registers remain untouched?[/quote]

Split your one memory segment into two. Just creating two program sections is not enough.

You might also need to change the linker script/settings accordingly.