This can be useful for debugging critical bugs in code. I haven't added
human-readable exceptions (such as "illegal instruction" or "stack
overflow") yet, they can be added when they happen in practice (to avoid
increasing code size too much).
This commit adds support for timer interrupts, replacing the busy loop
that was used before. It is perhaps the most simple interrupt to
implement and should serve as the basis for further interrupt support in
RISC-V.
The CLINT is implemented both on the fe310-g002 chip and in the sifive_e
QEMU machine type. Therefore, use that peripheral for consistency.
The only difference is the clock speed, which runs at 10MHz in QEMU for
some reason instead of 32.768kHz as on the physical HiFive1 boards.
QEMU doesn't support the RTC peripheral yet so work around it for now.
This makes the following command work:
tinygo run -target=hifive1-qemu ./testdata/coroutines.go
See the following bug: https://bugs.llvm.org/show_bug.cgi?id=42881
I think this is a bug in LLVM, but the code in question wasn't the best
code anyway. By fixing this, about 16 bytes of code are saved on ARM
chips (and much more on AVR).
Ayke van Laethem
Ron Evans