pxe: Blancco initrd pulls in module deps and NIC firmware

The kexec-initrd build copied a fixed set of module directories plus
drivers/net/mii.ko. Ubuntu ships that as mii.ko.zst, so the -e test
skipped it, and usbnet, r8152 and cdc_ether then failed to load with
"Unknown symbol mii_*": USB-C to RJ45 adapters never appeared (seen
2026-10-05, Dell USB-C adapter). igb lacked dca and i2c-algo-bit the
same way.

Walk the host modules.dep from the copied modules and copy every
dependency (73 on 6.8.0-71). Also copy rtl_nic, tigon, bnx2, bnx2x and
e100 firmware, which those drivers request at probe.

playbook/pxe_server_setup.yml

@@ -862,13 +862,47 @@
                 cp -r "$NETDIR/$sub/"* "$WORK/lib/modules/$KVER/kernel/drivers/net/$sub/" 2>/dev/null || true
             fi
         done
-        # Overlay + squashfs + loop + usb + hid + ptp + mii + net/core deps
+        # Overlay + squashfs + loop + usb + hid + ptp + net/core
-        for modpath in fs/overlayfs fs/squashfs drivers/block drivers/usb/core drivers/usb/host drivers/hid drivers/ptp drivers/net/mii.ko net/core; do
+        for modpath in fs/overlayfs fs/squashfs drivers/block drivers/usb/core drivers/usb/host drivers/hid drivers/ptp net/core; do
             if [ -e "/lib/modules/$KVER/kernel/$modpath" ]; then
                 mkdir -p "$WORK/lib/modules/$KVER/kernel/$(dirname $modpath)"
                 cp -r "/lib/modules/$KVER/kernel/$modpath" "$WORK/lib/modules/$KVER/kernel/$modpath" 2>/dev/null || true
             fi
         done
+        # Pull in every module the copied ones depend on, from the host's
+        # modules.dep. A fixed list misses them: drivers/net/mii.ko was named
+        # here but ships as mii.ko.zst, so the test skipped it and usbnet,
+        # r8152 (USB-C to RJ45 adapters) and cdc_ether failed with "Unknown
+        # symbol mii_*"; igb likewise lacked dca and i2c-algo-bit.
+        python3 - "$KVER" "$WORK" <<'PYDEP'
+        import os, shutil, sys
+        kver, work = sys.argv[1], sys.argv[2]
+        src = f"/lib/modules/{kver}"
+        dst = f"{work}/lib/modules/{kver}"
+        dep = {}
+        for line in open(f"{src}/modules.dep"):
+            k, v = line.split(":", 1)
+            dep[k] = v.split()
+        have = {os.path.relpath(os.path.join(r, f), dst)
+                for r, _, fs in os.walk(dst) for f in fs if ".ko" in f}
+        todo, added = list(have), 0
+        while todo:
+            for d in dep.get(todo.pop(), []):
+                if d not in have:
+                    have.add(d); todo.append(d); added += 1
+                    os.makedirs(os.path.dirname(f"{dst}/{d}"), exist_ok=True)
+                    shutil.copy2(f"{src}/{d}", f"{dst}/{d}")
+        print(f"added {added} dependency modules")
+        PYDEP
+
+        # NIC firmware the drivers request at probe (r8152/r8169 rtl_nic
+        # patches, tg3, bnx2/bnx2x, e100). The kernel loads .zst firmware.
+        for fw in rtl_nic tigon bnx2 bnx2x e100; do
+            if [ -d "/lib/firmware/$fw" ]; then
+                mkdir -p "$WORK/lib/firmware"
+                cp -r "/lib/firmware/$fw" "$WORK/lib/firmware/"
+            fi
+        done
 
         # Decompress zstd modules in-place (busybox insmod can't handle .zst)
         find "$WORK/lib/modules" -name '*.ko.zst' -print0 | \