static void handle_irq_ucode_debug(struct b43_wldev *dev)
 {
-       //TODO
+       unsigned int i, cnt;
+       u16 reason;
+       __le16 *buf;
+
+       /* The proprietary firmware doesn't have this IRQ. */
+       if (!dev->fw.opensource)
+               return;
+
+       /* Microcode register 63 contains the debug-IRQ reason. */
+       reason = b43_shm_read16(dev, B43_SHM_SCRATCH, 63);
+       switch (reason) {
+       case B43_DEBUGIRQ_PANIC:
+               /* The reason for the panic is in register 3. */
+               reason = b43_shm_read16(dev, B43_SHM_SCRATCH, 3);
+               b43err(dev->wl, "Whoopsy, the microcode panic'ed! Reason: %u\n",
+                      reason);
+               b43_controller_restart(dev, "Microcode panic");
+               break;
+       case B43_DEBUGIRQ_DUMP_SHM:
+               if (!B43_DEBUG)
+                       break; /* Only with driver debugging enabled. */
+               buf = kmalloc(4096, GFP_ATOMIC);
+               if (!buf) {
+                       b43dbg(dev->wl, "SHM-dump: Failed to allocate memory\n");
+                       goto out;
+               }
+               for (i = 0; i < 4096; i += 2) {
+                       u16 tmp = b43_shm_read16(dev, B43_SHM_SHARED, i);
+                       buf[i / 2] = cpu_to_le16(tmp);
+               }
+               b43info(dev->wl, "Shared memory dump:\n");
+               print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET,
+                              16, 2, buf, 4096, 1);
+               kfree(buf);
+               break;
+       case B43_DEBUGIRQ_DUMP_REGS:
+               if (!B43_DEBUG)
+                       break; /* Only with driver debugging enabled. */
+               b43info(dev->wl, "Microcode register dump:\n");
+               for (i = 0, cnt = 0; i < 64; i++) {
+                       u16 tmp = b43_shm_read16(dev, B43_SHM_SCRATCH, i);
+                       if (cnt == 0)
+                               printk(KERN_INFO);
+                       printk("r%02u: 0x%04X  ", i, tmp);
+                       cnt++;
+                       if (cnt == 6) {
+                               printk("\n");
+                               cnt = 0;
+                       }
+               }
+               printk("\n");
+               break;
+       default:
+               b43dbg(dev->wl, "Debug-IRQ triggered for unknown reason: %u\n",
+                      reason);
+       }
+out:
+       b43_shm_write16(dev, B43_SHM_SCRATCH, 63, B43_DEBUGIRQ_ACK);
 }
 
 /* Interrupt handler bottom-half */
                err = -EOPNOTSUPP;
                goto error;
        }
-       b43info(dev->wl, "Loading firmware version %u.%u "
-               "(20%.2i-%.2i-%.2i %.2i:%.2i:%.2i)\n",
-               fwrev, fwpatch,
-               (fwdate >> 12) & 0xF, (fwdate >> 8) & 0xF, fwdate & 0xFF,
-               (fwtime >> 11) & 0x1F, (fwtime >> 5) & 0x3F, fwtime & 0x1F);
-
        dev->fw.rev = fwrev;
        dev->fw.patch = fwpatch;
+       dev->fw.opensource = (fwdate == 0xFFFF);
+
+       if (dev->fw.opensource) {
+               /* Patchlevel info is encoded in the "time" field. */
+               dev->fw.patch = fwtime;
+               b43info(dev->wl, "Loading OpenSource firmware version %u.%u\n",
+                       dev->fw.rev, dev->fw.patch);
+       } else {
+               b43info(dev->wl, "Loading firmware version %u.%u "
+                       "(20%.2i-%.2i-%.2i %.2i:%.2i:%.2i)\n",
+                       fwrev, fwpatch,
+                       (fwdate >> 12) & 0xF, (fwdate >> 8) & 0xF, fwdate & 0xFF,
+                       (fwtime >> 11) & 0x1F, (fwtime >> 5) & 0x3F, fwtime & 0x1F);
+       }
 
        if (b43_is_old_txhdr_format(dev)) {
                b43warn(dev->wl, "You are using an old firmware image. "