STM32WB/SBRSA: How to reprogram SBRSA?

[YRots.1]

Hello,

I have an ultra low power application and must share SRAM2a with BLE. For power reasons, RAM1, and SRAM2b cannot be used. The CubeProgrammer refuses to re-program SBRSA to anything but 0xA.

More details:

I am using Full BLE wireless stack: 'stm32wb5x_BLE_Stack_full_fw.bin'. SBRSA is programmed to 0xA, which matches the 10K provided to RAM_SHARED from the linker file. I believe, that means SRAM2a is completely occupied by RAM_SHARED (10 KB) plus the Secure section (22 KB).

I would like to shrink RAM_SHARED based on the map file, and push SBRSA up to make room for my application's data. I need about 10 KB, but it will be nice to get more.

I basically have three issues:

1) What is the procedure/tool to reprogram SBRSA as CubeProgrammer refuses to program anything but 0xA.

2) How much actual memory Full BLE Stack take from the Secure section. All 22KB?

3) Is there anything in RAM_SHARED that is not specified by the map file?

Thank you in advance.

[YRots.1 · Accepted solution]

Turns out that SBRSA value is fixed by the wireless stack. I ended up maximizing available RAM2a by using 'stm32wb5x_BLE_Stack_light_fw.bin', and linker file per 'BLE_p2pServer_Ext' example.