Replace the minimal inline ISR (which only disabled INTENABLE) with a
full level-1 interrupt handler that saves/restores the interrupted
context and dispatches to Go's handleInterrupt.
The handler uses callx4 (not callx0) to call into Go code because:
- callx0 does not set PS.CALLINC, so the Go function's entry
instruction uses stale CALLINC from the interrupted code, causing
wrong window rotation and a garbage stack pointer.
- callx4 explicitly sets CALLINC=1, and our frame pointer (a1) is
outside the callee's register window so it is preserved.
Also updates the USB Serial/JTAG ISR to disable INT_ENA (peripheral
level) instead of relying on INTENABLE, and adds signalInterrupt to
the dispatcher so sleepTicks can be woken by any interrupt.
* esp32s3: add interrupt support
This finally adds the long awaited support for interrupts on the
Xtensa arch. Initially just for the ESP32-S3 but then others.
Signed-off-by: deadprogram <ron@hybridgroup.com>
* esp32s3: get interrupts working correctly
There were a number of needed changes in order to get interrupts correctly working
on the esp32s3 processor:
- PS.UM=1 in interruptInit() - routed interrupts to user exception vector (0x340)
instead of kernel (0x300)
- Inline ISR in the vector slot - external handlers via j/call0 crashed (likely
clang Xtensa literal pool issue with large movi constants in separate sections)
- Disable INTENABLE (not just INT_CLR) - the USB RX interrupt is level-triggered;
clearing INT_CLR alone causes infinite re-entry since data is still in the FIFO
- Buffered() re-enables INTENABLE after draining the hardware FIFO
Signed-off-by: deadprogram <ron@hybridgroup.com>
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Signed-off-by: deadprogram <ron@hybridgroup.com>
deadprogram