Bootloader app_start_timer cause HardFault

[Kaaml]

Hi,

Im trying to modify secure_bootloader demo in SDK_12.3, to use timers. I modify nerf_dfu.c file in libraries/bootloaders catalog. I want to achieve bootloader wait for 30s for update next start application normally if app is valid. 

After call app_start_timer() function bootloader hang on hard fault. I'm using PCA10028 development board and own device and on both it's not working. Could You give me some advices what I am doing wrong?

[Kaaml]

Hi, 

I discovered that reason of this is gcc flag -flto. After disable this flag all working well. Will be nice if anyone could tell me why this flag causes that behaviour.

[Rune Holmgren]

I am not sure what you may have changed for lto to break the build, there are many ways for the optimization to break a build if you have a small issue with the implementation. In SDK 14.0.0 we introduced the "nrf_dfu_inactivity_timeout_timer" which you might want to take a look at to see if you are doing something differently. This timer seems to work as intended also when lto is enabled, so if you can find a difference or copy our implementation it should work as intended.

Another alternative is to run without link time optimization. The SDK bootloader has it disabled by default.

Best regards,
Rune Holmgren

[Kaaml]

Im using nRF51, so I can't use SDK >=12.3. 

I read to remove -flto flag here but now I can't found this thread. Compling without this flag resolve problem.

[Turbo J]

Which compiler do you use? I see reports of recent GCC (or LD?) not picking up the correct handler when usig -flto. Older versions (4.9.x) seem to be fine.

[Kaaml]

gcc version 7.2.1 20170904 (release) [ARM/embedded-7-branch revision 255204] (GNU Tools for Arm Embedded Processors 7-2017-q4-major