Teensy 4 compile error due to missing symbol

[tyalie]

From cd38223090558cc0ef00c17b749277320f105801 onward the compiler will throw:

Linking .pio/build/teensy40/firmware.elf
/home/elizabeth/.platformio/packages/toolchain-arm-cortexm-linux/bin/../lib/gcc/arm-cortexm7f-eabi/11.1.0/../../../../arm-cortexm7f-eabi/bin/ld: .pio/build/teensy40/libb49/libfreertos-teensy.a(teensy_4.cpp.o): in function `vPortSetupTimerInterrupt':
teensy_4.cpp:(.flashmem+0x25c): undefined reference to `unused_interrupt_vector'
collect2: error: ld returned 1 exit status
*** [.pio/build/teensy40/firmware.elf] Error 1

I assume it is due to the introduction of unused_interrupt_vector as an external void in the file src/portable/teensy_4.cpp without mentioning it anywhere else in the code except in vPortSetupTimerInterrupt

[tsandmann]

Are you using the latest version of the teensy core framework? Could you run pio update (or pio update --dry-run) to check if there are any outdated libraries in use?

void unused_interrupt_vector(void) was a static function of the framework startup code in an earlier version which is incompatible now with latest freertos-teensy.

Maybe it's the same for #7?

[tyalie]

Well. It still seems to be mentioned in the current version of the code: https://github.com/tsandmann/freertos-teensy/blob/c0ff2e5e25514b7aa131be2094f841ab96d5019b/src/portable/teensy_4.cpp#L243

And: https://github.com/tsandmann/freertos-teensy/blob/c0ff2e5e25514b7aa131be2094f841ab96d5019b/src/portable/teensy_4.cpp#L203

pio update doesn't seem to be the issue here. I've traced back the problem to a single commit by doing repeated rollbacks and trying out whether it compiles or not. In there I've always tested against the latest library version. I also haven't included any extra libraries but tried it out on a minimal running sample.

[tsandmann]

Yes, that's fine, because void unused_interrupt_vector(void) isn't declared static any more in the latest framework version: https://github.com/PaulStoffregen/cores/blob/2e9aa7a34f2e7914767fde52fd1a9c3be7c30dd1/teensy4/startup.c#L527

As I can't reproduce your issue, could you please tell me the version of the package framework-arduinoteensy you're using?

[tyalie]

Well that's interesting. I'll do so later, but it should be about 3 days old at most. At least that is when I did a pio init on one of the projects that threw this error.

[tyalie]

Okay. It does seem like that you are right and the problem resolves itself with a pio update.

If others hit this: A simple pio update wasn't the solution for me. The update process crashed whilst pulling the tsandmann/platform-teensy. I needed to delete the teensy@... platform in ~/.platformio/platforms, install the teensy platform again and was only then able to pull the latest freertos platform-teensy using pio run and pio update afterwards

[tsandmann]

If others hit this: A simple pio update wasn't the solution for me. The update process crashed whilst pulling the tsandmann/platform-teensy. I needed to delete the teensy@... platform in ~/.platformio/platforms, install the teensy platform again and was only then able to pull the latest freertos platform-teensy using pio run and pio update afterwards

Thanks for the hint on this 🙂