exercises/01 fails when run in docker against ibex about cheriot-rtos

[davidchisnall]

Kunyan confirms that this is an Ibex bug. The refactoring of the PermitAccessSystemRegisters logic accidentally missed mcycleh.

[davidchisnall]

You shouldn't need it, but sometimes rm -rf .xmake build is necessary.

[davidchisnall]

And the exercise needs the simulator because the sail model doesn't have a uart - is that right ?

The Sail UART is output only, yes.

[davidchisnall]

If the board is sail then they're not using the Ibex simulator, they're the instruction simulator generated from the Sail formal model.

[davidchisnall]

I suspect that the recent(ish) changes to the AccessSystemRegisters permissions in Ibex may have broken mcycleh access. The test suite uses mcycle but not mcycleh (it doesn't run long enough to overflow a 32-bit cycle counter. @kliuMsft, can you check?

[PhilDay-CT]

If the board is sail then they're not using the Ibex simulator, they're the instruction simulator generated from the Sail formal model.

Ah, Ok thanks. I tried changing one of the examples to the ibex simulator and then doing "xmake config --sdk=/cheriot-tools/; xmake clean; xmake; xmake run" - but that didn't fail which made me think this was the wrong track. Looks like I need to "rm -rf .xmake .cache" to really get back to a clean state ?

And the exercise needs the simulator because the sail model doesn't have a uart - is that right ?

(Sorry for the questions - still feeling my way around here some)

[davidchisnall]

The dev container is updated with the fix so this should work now.

[PhilDay-CT]

Yep - runs fine now, thanks