sd_softdevice_enable() under gdb causing reboots

[Jean-Louis Bonnaffé]

Hi,

I'm developing on a custom nrf51822-based board, and using the s110 softdevice, version 7.0.0. With JLinkGDBServer and the toolchain's gdb, I can debug softdevice-less applications normally.

Problems arise when I build my apps on top of s110. Running from flash is ok, but during GDB sessions, my device seems to be reset soon after the call to sd_softdevice_enable(), and my gdb breaks again on the main(). No such reset can be observed when running from flash.

In the s110 documentation, I can read, that after a successful call, "A portion of RAM will be unavailable". Can this issue be related to RAM mapping overlap, and is there a way to avoid this ?

Thanks,

[Jean-Louis Bonnaffé]

Browsing the devzone brought up the answers :

• Ole Morten's comment has been quite instructive here:

No matter if you use GDB or Keil's debugger, you will not be able to keep the BLE link while you're halted on a breakpoint, or keep running softdevice code after having halted on a breakpoint. [...]

• Hung Bui also confirmed in this topic:

It's not possible to get back to a connection after you stop for a break point when debugging. The timing will not be correct after you resume, and most likely you will have a connection timeout from the peer device (which is not halted). [...]

• Also worth mentioning, this note from Øyvind about the PRIMASK register :

If you stop the execution somewhere in the application code e.g. by using a breakpoint, you can step forward from there if you set the PRIMASK CPU system register to 1 after hitting the breakpoint. You can do this in the "Registers" window in Keil while in debugging mode. [...]