4 Commits

Author SHA1 Message Date
deadprogram a24dc8c543 esp32s3: improve exception handlers, add procPin/procUnpin, and linker wrap flags
Rewrite kernel and double exception handlers to save EXCCAUSE/EPC1 to
RTC STORE registers before triggering a software reset, replacing the
LED-blink diagnostic with post-mortem debug info that survives reset.

Add user exception dispatch in the level-1 handler with a weak
espradio_user_exception symbol so programs without espradio still link.

Implement procPin/procUnpin for Xtensa using RSIL/WSR PS to properly
disable interrupts during atomic operations. Fix abort() to use a
waiti loop instead of bare spin.

Add --wrap ldflags for malloc/calloc/free/realloc/ppCheckTxConnTrafficIdle
to support espradio WiFi blob integration.

Signed-off-by: deadprogram <ron@hybridgroup.com>
2026-04-07 16:27:02 +02:00
deadprogram aaf6a36c55 esp32s3: add flash XIP boot assembly with cache/MMU init
The ESP32-S3 ROM bootloader loads IRAM/DRAM into SRAM but does not
configure the flash cache or MMU. Previously the target incorrectly
reused the ESP32 boot assembly (esp32.S) which lacks flash XIP support.

Add a dedicated esp32s3.S boot assembly that:
- Sets up windowed-ABI registers, stack, and FPU
- Disables all watchdog timers (RTC, TIMG0, TIMG1, Super WDT)
- Configures VECBASE and clears PS.EXCM before any callx4
- Calls ROM functions to configure cache modes:
  rom_config_instruction_cache_mode (16KB, 8-way, 32B line)
  rom_config_data_cache_mode (32KB, 8-way, 32B line)
- Initializes MMU, maps flash page 0 for IROM and DROM,
  clears bus-shut bits, and enables both caches
- Jumps to runtime.main in IROM (flash)

Update the linker script (esp32s3.ld) to place .text and .rodata in
flash-mapped regions (IROM/DROM) with proper alignment for the MMU
page size. Update esp32s3-interrupts.S with proper exception vector
handlers. Point esp32s3.json at the new esp32s3.S instead of esp32.S.

Signed-off-by: deadprogram <ron@hybridgroup.com>
2026-04-07 16:27:02 +02:00
deadprogram a6a4f85e61 esp32s3: replace inline ISR with full interrupt vector handler
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.
2026-04-05 14:15:40 +02:00
Ron Evans 9b1a3a2236 esp32s3: add interrupt support (#5244)
* 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>
2026-04-05 14:15:40 +02:00