Hi Peter, On Fri, Jun 16, 2017 at 04:10:52PM -0700, Peter Jones wrote: > It's very likely that I'm doing something wrong so I'm reaching out for > help. All I want to do right now is to get Blinky working on an nRF52. > > I followed the tutorial and built the boot loader and blinky. I then > created an image so the boot loader would be happy about the magic > number. > > I used GDB and the Black Magic Probe to flash the boot loader ELF file > to address offset 0x0000. Then I used the `restore' command to flash the > blinky IMG file to offset 0x8000. (I debugged the jlink shell scripts > to figure this out.) > > At this point I would expect that resetting the board would cause the > LED to blink once a second. Of course, that's not happening. > > So I started GDB, used the `file' command to load symbols from the boot > loader ELF file, and restarted the boot loader with `run'. That's when > I get: > > > Program received signal SIGSEGV, Segmentation fault. > os_pkg_init () at repos/apache-mynewt-core/kernel/os/src/os.c:223 > > > I stepped through the code and I end up inside `os_start' which appears > to only have `assert(0)' as its body (because `#if > MYNEWT_VAL(OS_SCHEDULING)').
Your procedure sounds correct to me, so I'm afraid I don't have an explanation. I am not familiar with the black magic probe, though. The behavior you described is definitely unexpected. The boot loader should not call os_start() at all; it should jump to the image's start up code instead. Could you paste a stack trace at the point of failure? Thanks, Chris
