feat(xteink): wire USB serial JTAG interrupts

Report SOF and serial-in-empty as always pending and route the peripheral
IRQ through the interrupt matrix so the ESP-IDF console driver progresses.
Merge emulator stdout into serial.log so crash output lands in one place.

.pi/skills/test-xteink-firmware/SKILL.md

@@ -70,8 +70,7 @@ Resolve script paths relative to this skill directory. `scripts/xteink-emu.sh` s
 
 ## Diagnose Failures
 
-- Firmware serial output: `$XTEINK_EMU_STATE/serial.log`
+- Firmware serial output and emulator messages: `$XTEINK_EMU_STATE/serial.log`
-- Emulator output: `$XTEINK_EMU_STATE/qemu.log`
 - Assembled flash image: `$XTEINK_EMU_STATE/flash.bin`
 - Resolve crash addresses against the exact ELF produced with the tested binary, using the project's RISC-V `addr2line` tool.
 - Preserve the SD image when reproducing persistence bugs; replace it when testing first-boot behavior.

hw/misc/esp32c3_jtag.c

@@ -12,31 +12,65 @@
 #include "qemu/module.h"
 #include "qemu/error-report.h"
 #include "hw/hw.h"
+#include "hw/irq.h"
 #include "hw/sysbus.h"
 #include "hw/misc/esp32c3_jtag.h"
 
 
 /* USB Serial JTAG Console Tap - The firmware routes ESP-IDF console output (incl. panic dumps) through this peripheral. EP1 is the byte FIFO; EP1_CONF bit1 (SERIAL_IN_EP_DATA_FREE) must read set so the driver believes the TX FIFO can always accept a byte. */
-#define ESP32C3_JTAG_EP1_REG       0x00
+#define ESP32C3_JTAG_EP1_REG         0x00
-#define ESP32C3_JTAG_EP1_CONF_REG  0x04
+#define ESP32C3_JTAG_EP1_CONF_REG    0x04
+#define ESP32C3_JTAG_INT_RAW_REG     0x08
+#define ESP32C3_JTAG_INT_ST_REG      0x0c
+#define ESP32C3_JTAG_INT_ENA_REG     0x10
+#define ESP32C3_JTAG_INT_CLR_REG     0x14
 #define ESP32C3_JTAG_IN_EP_DATA_FREE (1u << 1)
+#define ESP32C3_JTAG_SOF_INT          (1u << 1)
+#define ESP32C3_JTAG_SERIAL_IN_EMPTY  (1u << 3)
+
+static uint32_t esp32c3_jtag_raw_interrupts(void)
+{
+    return ESP32C3_JTAG_SOF_INT | ESP32C3_JTAG_SERIAL_IN_EMPTY;
+}
+
+static void esp32c3_jtag_update_irq(ESP32C3UsbJtagState *s)
+{
+    qemu_set_irq(s->irq, !!(s->int_ena & esp32c3_jtag_raw_interrupts()));
+}
 
 static uint64_t esp32c3_jtag_read(void *opaque, hwaddr addr, unsigned int size)
 {
     ESP32C3UsbJtagState *s = ESP32C3_JTAG(opaque);
-    (void) s;
+    switch (addr) {
-    if (addr == ESP32C3_JTAG_EP1_CONF_REG) {
+    case ESP32C3_JTAG_EP1_CONF_REG:
         return ESP32C3_JTAG_IN_EP_DATA_FREE;
+    case ESP32C3_JTAG_INT_RAW_REG:
+        return esp32c3_jtag_raw_interrupts();
+    case ESP32C3_JTAG_INT_ST_REG:
+        return s->int_ena & esp32c3_jtag_raw_interrupts();
+    case ESP32C3_JTAG_INT_ENA_REG:
+        return s->int_ena;
+    default:
+        return 0;
     }
-    return 0;
 }
 
 static void esp32c3_jtag_write(void *opaque, hwaddr addr, uint64_t value, unsigned int size)
 {
     ESP32C3UsbJtagState *s = ESP32C3_JTAG(opaque);
-    (void) s;
+    switch (addr) {
-    if (addr == ESP32C3_JTAG_EP1_REG) {
+    case ESP32C3_JTAG_EP1_REG:
         fputc((int)(value & 0xff), stderr);
+        break;
+    case ESP32C3_JTAG_INT_ENA_REG:
+        s->int_ena = value;
+        esp32c3_jtag_update_irq(s);
+        break;
+    case ESP32C3_JTAG_INT_CLR_REG:
+        esp32c3_jtag_update_irq(s);
+        break;
+    default:
+        break;
     }
 }
 
@@ -48,8 +82,9 @@ static const MemoryRegionOps esp32c3_jtag_ops = {
 
 static void esp32c3_jtag_reset_hold(Object *obj, ResetType type)
 {
-    (void) obj;
+    ESP32C3UsbJtagState *s = ESP32C3_JTAG(obj);
-    (void) type;
+    s->int_ena = 0;
+    esp32c3_jtag_update_irq(s);
 }
 
 static void esp32c3_jtag_realize(DeviceState *dev, Error **errp)
@@ -66,6 +101,7 @@ static void esp32c3_jtag_init(Object *obj)
     memory_region_init_io(&s->iomem, obj, &esp32c3_jtag_ops, s,
                           TYPE_ESP32C3_JTAG, ESP32C3_JTAG_REGS_SIZE);
     sysbus_init_mmio(sbd, &s->iomem);
+    sysbus_init_irq(sbd, &s->irq);
 }
 
 static void esp32c3_jtag_class_init(ObjectClass *klass, void *data)

hw/riscv/esp32c3.c

@@ -555,6 +555,8 @@ static void esp32c3_machine_init(MachineState *machine)
         sysbus_realize(SYS_BUS_DEVICE(&ms->jtag), &error_fatal);
         MemoryRegion *mr = sysbus_mmio_get_region(SYS_BUS_DEVICE(&ms->jtag), 0);
         memory_region_add_subregion_overlap(sys_mem, DR_REG_USB_SERIAL_JTAG_BASE, mr, 0);
+        sysbus_connect_irq(SYS_BUS_DEVICE(&ms->jtag), 0,
+                           qdev_get_gpio_in(intmatrix_dev, ETS_USB_SERIAL_JTAG_INTR_SOURCE));
     }
 
     /* RTC CNTL realization */

include/hw/misc/esp32c3_jtag.h

@@ -22,5 +22,7 @@
 typedef struct ESP32C3UsbJtagState {
     SysBusDevice parent_object;
     MemoryRegion iomem;
+    qemu_irq irq;
+    uint32_t int_ena;
 } ESP32C3UsbJtagState;
 

scripts/xteink-emu.py

@@ -140,7 +140,6 @@ def run(args, interactive):
     for name in ("pid", "qmp.sock", "serial.log", "qemu.log", "wait.offset"):
         (state / name).unlink(missing_ok=True)
     (state / "serial.log").touch()
-    (state / "qemu.log").touch()
     (state / "wait.offset").write_text("0\n")
     flash = state / "flash.bin"
     build_flash(firmware, flash)
@@ -155,7 +154,7 @@ def run(args, interactive):
         "-accel", "tcg",
         "-L", str(require_env("XTEINK_BIOS")),
         "-display", "gtk" if interactive else "none",
-        "-serial", "stdio" if interactive else f"file:{state / 'serial.log'}",
+        "-serial", "stdio",
         "-monitor", "none",
         "-qmp", f"unix:{state / 'qmp.sock'},server=on,wait=off",
         "-nic", "user,model=esp32c3_wifi,mac=52:54:00:12:34:56,net=192.168.4.0/24",
@@ -167,11 +166,11 @@ def run(args, interactive):
     if interactive:
         process = subprocess.Popen(command)
     else:
-        with (state / "qemu.log").open("ab") as qemu_log:
+        with (state / "serial.log").open("ab") as serial_log:
             process = subprocess.Popen(
                 command,
                 stdin=subprocess.DEVNULL,
-                stdout=qemu_log,
+                stdout=serial_log,
                 stderr=subprocess.STDOUT,
                 start_new_session=True,
             )
@@ -180,7 +179,7 @@ def run(args, interactive):
     deadline = time.monotonic() + 10
     while time.monotonic() < deadline:
         if process.poll() is not None:
-            message = (state / "qemu.log").read_text(errors="replace")
+            message = (state / "serial.log").read_text(errors="replace")
             raise RuntimeError(f"QEMU exited during startup\n{message}")
         try:
             qmp_command(state, "query-status")