Which SDK11 gcc examples work with nRF51822?

[Roger Clark]

I think similar issues have been posted before and not resolved

If I flash the hex precompiled hex files for virtually any project by using the pca10028 S130 version it works fine

e.g. examples\ble_peripheral\ble_app_hrs\hex\ble_app_hrs_s130_pca10028.hex

But if I try to compile using gcc 4.9.3 the resultant binary doesn't work.

(I have the S130 SDK11 installed), I just flash the code into 0x1b000

The only example that does compile and run is

examples\ble_peripheral\ble_app_beacon\pca20006\s130\armgcc

i.e This targets the pca20006 board.

The pca20006 is a nRF51822 where as the pca10028 is a nRF51422 - so I don't know if that's the problem.

I'm now downloading keil to see if this is a gcc issue (I'm using gcc 4.9.3 as recommended here devzone.nordicsemi.com/.../ )

But the gcc toolchain must be working as the beacon for pca20006 will compile, upload and run without any problems

[Einar Thorsrud]

I suspect you have a device with 16 kB RAM (which is the case for the pca20006 board). Then you must modify your linker script appropriately. Taking the HRS example in SDK 11, this is <SDK>examples\ble_peripheral\ble_app_hrs\pca10028\s130\armgcc\ble_app_hrs_gcc_nrf51.ld. There you need to take the RAM LENGTH and subtract 0x4000, as the existing value is for a 32 kB RAM part.

That means that you should change line 9 from this:

  RAM (rwx) :  ORIGIN = 0x20001870, LENGTH = 0x6790

to this:

  RAM (rwx) :  ORIGIN = 0x20001870, LENGTH = 0x2790

The reason this (coincidently) works with Keil and not with GCC is differences in the memory allocations, which is entirely up to the compiler.

[Einar Thorsrud]

You are right, GCC places the stack in the end of the RAM.