rewrite based on reference project from github

build-image.sh

@@ -199,26 +199,21 @@ umount -l $BUILD_DIR/rootfs/proc
 
 rm $BUILD_DIR/rootfs/setup.sh
 
-# Build initramfs with dracut using the rootfs modules
+# Build initramfs with custom netboot hooks/scripts
-echo "Building initramfs with dracut using rootfs kernel and modules..."
+echo "Building custom netboot initramfs..."
 KERNEL_VERSION=$(ls -1 $BUILD_DIR/rootfs/boot/vmlinuz-* | sed 's|.*/vmlinuz-||' | head -1)
 
-# Mount proc/sys temporarily for dracut if needed
+# Use mkinitramfs with custom initramfs directory
-mount -t proc proc $BUILD_DIR/rootfs/proc 2>/dev/null || true
+INITRAMFS_CONFIG="/srv/netboot/initramfs"
-
+if [ -d "$INITRAMFS_CONFIG" ]; then
-dracut -f \
+    mkinitramfs -d "$INITRAMFS_CONFIG" \
-    --add "network" \
+        -k "$KERNEL_VERSION" \
-    --hostonly \
+        -o $BUILD_DIR/rootfs/boot/initrd-netboot.img
-    --hostonly-cmdline \
+    echo "Initramfs build complete. Size: $(du -h $BUILD_DIR/rootfs/boot/initrd-netboot.img | cut -f1)"
-    --include "/usr/share/initramfs-tools/hooks/rooturl" "/usr/share/initramfs-tools/hooks/" \
+else
-    --include "/usr/share/initramfs-tools/scripts/local-top/rooturl" "/usr/share/initramfs-tools/scripts/local-top/" \
+    echo "ERROR: Custom initramfs config not found at $INITRAMFS_CONFIG"
-    -k $KERNEL_VERSION \
+    exit 1
-    -r $BUILD_DIR/rootfs \
+fi
-    $BUILD_DIR/rootfs/boot/initrd-netboot.img
-
-umount -l $BUILD_DIR/rootfs/proc 2>/dev/null || true
-
-echo "Initramfs build complete. Size: $(du -h $BUILD_DIR/rootfs/boot/initrd-netboot.img | cut -f1)"
 
 # Copy kernel and netboot initramfs
 mkdir -p $IMAGE_DIR/$VERSION

dracut-module/90netboot/module-setup.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+check() {
+    return 0
+}
+
+depends() {
+    echo network url-lib
+    return 0
+}
+
+install() {
+    inst_hook cmdline 90 "$moddir/parse-netboot.sh"
+    inst_hook pre-mount 90 "$moddir/mount-netboot.sh"
+    inst_multiple wget curl
+}

dracut-module/90netboot/mount-netboot.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+# Download and mount squashfs root with overlay
+
+. /tmp/netboot.conf
+
+info "Downloading root filesystem from http://${BOOT_SERVER}/${IMAGE_VERSION}/filesystem.squashfs"
+
+mkdir -p /run/netboot
+wget -O /run/netboot/root.squashfs \
+    "http://${BOOT_SERVER}/${IMAGE_VERSION}/filesystem.squashfs" || \
+    die "Failed to download root filesystem from $BOOT_SERVER"
+
+info "Download complete, mounting filesystems..."
+
+# Mount squashfs (read-only base)
+mkdir -p /run/rootfs/lower
+mount -t squashfs /run/netboot/root.squashfs /run/rootfs/lower || \
+    die "Failed to mount squashfs"
+
+# Create tmpfs for overlay (writable layer)
+mkdir -p /run/rootfs/upper /run/rootfs/work
+mount -t tmpfs -o size=4G tmpfs /run/rootfs/upper || \
+    die "Failed to create tmpfs overlay"
+mkdir -p /run/rootfs/upper/upper /run/rootfs/upper/work
+
+# Mount overlay (combines read-only base + writable tmpfs)
+mount -t overlay overlay \
+    -o lowerdir=/run/rootfs/lower,upperdir=/run/rootfs/upper/upper,workdir=/run/rootfs/upper/work \
+    /sysroot || \
+    die "Failed to mount overlay"
+
+info "Root filesystem mounted successfully"

dracut-module/90netboot/parse-netboot.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+# Parse netboot parameters from kernel command line
+
+BOOT_SERVER=$(getarg boot_server=)
+IMAGE_VERSION=$(getarg image_version=)
+
+[ -z "$BOOT_SERVER" ] && BOOT_SERVER="192.168.100.1"
+[ -z "$IMAGE_VERSION" ] && IMAGE_VERSION="latest"
+
+echo "BOOT_SERVER=$BOOT_SERVER" > /tmp/netboot.conf
+echo "IMAGE_VERSION=$IMAGE_VERSION" >> /tmp/netboot.conf
+
+info "Netboot: server=$BOOT_SERVER version=$IMAGE_VERSION"