NRF_LOG and SEGGER_RTT print statements working on PCA10028 development kit, but not on custom PCB

[scla]

I've been developing on the PCA10028 development kit with print statements working fine (though at the moment it seems only SEGGER_RTT print statements are working and not NRF_LOG, though I could have sworn I had this working earlier).

I have old legacy code (not written by me) that uses SDK 11 that will print SEGGER_RTT_printf statements on the custom PCB. This code also prints properly on the DK. When I use my new code that uses SDK 12.3, however, no print statements appear. This new code works on the development kit and *will* print just fine. The custom PCB is connected to J-Link BASE with the GND, SWDIO, SWDCLK, VCC pins. 

In JLinkExe debugger I can halt the CPU and step through assembly code so I believe that the code is running fine on the custom pcb (I have no LEDs on this custom pcb to test otherwise). 

SDK 12.3 PCA10028 examples will not print on the custom pcb, but will on the DK.

Other things:

1. NRF_LOG_BACKEND_SERIAL_USES_RTT 1  (in sdk_config.h)
2. CFLAGS += -DNRF_LOG_USES_RTT=1 (in Makefile)
3. Custom PCB is nRF51822, DK is nRF51422. I don't think this matters

Any ideas? Thank you!

[scla]

After working on this problem for several days, I finally found the solution. It looks like the pcb's RAM is different than the DK (I'm not sure why - because its nRF1822 and not nRF51422?).

I had to go to the linker file (.ld file) and change the LENGTH variable to fix this and now print statements are working.