add initial initramfs support, not quite working yet

boot/Dockerfile

@@ -9,8 +9,9 @@ COPY sprout.efi /work/${EFI_NAME}.EFI
 COPY sprout.toml /work/SPROUT.TOML
 COPY kernel.efi /work/KERNEL.EFI
 COPY shell.efi /work/SHELL.EFI
+COPY initramfs /work/INITRAMFS
 COPY edera-splash.png /work/EDERA-SPLASH.PNG
-RUN truncate -s256MiB sprout.img && \
+RUN truncate -s128MiB sprout.img && \
     parted --script sprout.img mklabel gpt > /dev/null 2>&1 && \
     parted --script sprout.img mkpart primary fat32 1MiB 100% > /dev/null 2>&1 && \
     parted --script sprout.img set 1 esp on > /dev/null 2>&1 && \
@@ -22,6 +23,7 @@ RUN truncate -s256MiB sprout.img && \
     mcopy -i sprout.img SHELL.EFI ::/EFI/BOOT/ && \
     mcopy -i sprout.img SPROUT.TOML ::/ && \
     mcopy -i sprout.img EDERA-SPLASH.PNG ::/ && \
+    mcopy -i sprout.img INITRAMFS ::/ && \
     mv sprout.img /sprout.img
 
 FROM scratch AS final

hack/boot.sh

@@ -27,14 +27,9 @@ else
 		-chardev stdio,id=stdio0 \
 		-device virtconsole,chardev=stdio0,id=console0
 
-	if [ "${TARGET_ARCH}" = "x86_64" ]; then
+	set -- "${@}" \
-		set -- "${@}" \
+		-vga none \
-			-vga std
+		-device "virtio-gpu,edid=on,xres=1024,yres=768"
-	else
-		set -- "${@}" \
-			-vga none \
-			-device "virtio-gpu,edid=on,xres=1024,yres=768"
-	fi
 fi
 
 rm -f "${FINAL_DIR}/ovmf-boot.fd"

hack/build.sh

@@ -79,6 +79,8 @@ if [ "${SKIP_VM_BUILD}" != "1" ]; then
 	docker build --platform="${DOCKER_TARGET}" -t "${DOCKER_PREFIX}/sprout-ovmf-${TARGET_ARCH}:${DOCKER_TAG}" -f vm/Dockerfile.ovmf "${FINAL_DIR}"
 	copy_from_image "${DOCKER_PREFIX}/sprout-ovmf-${TARGET_ARCH}" "ovmf.fd" "${FINAL_DIR}/ovmf.fd"
 	copy_from_image "${DOCKER_PREFIX}/sprout-ovmf-${TARGET_ARCH}" "shell.efi" "${FINAL_DIR}/shell.efi"
+	docker build --platform="${DOCKER_TARGET}" -t "${DOCKER_PREFIX}/sprout-initramfs-${TARGET_ARCH}:${DOCKER_TAG}" -f vm/Dockerfile.initramfs "${FINAL_DIR}"
+	copy_from_image "${DOCKER_PREFIX}/sprout-initramfs-${TARGET_ARCH}" "initramfs" "${FINAL_DIR}/initramfs"
 fi
 
 if [ "${SKIP_SPROUT_BUILD}" != "1" ]; then
@@ -102,6 +104,7 @@ if [ "${SKIP_SPROUT_BUILD}" != "1" ]; then
 	fi
 	cp "${FINAL_DIR}/sprout.toml" "${FINAL_DIR}/efi/SPROUT.TOML"
 	cp "${FINAL_DIR}/edera-splash.png" "${FINAL_DIR}/efi/EDERA-SPLASH.PNG"
+	cp "${FINAL_DIR}/initramfs" "${FINAL_DIR}/efi/INITRAMFS"
 fi
 
 if [ "${SKIP_BOOT_BUILD}" != "1" ]; then

hack/configs/kernel.sprout.toml

@@ -1,19 +1,22 @@
 version = 1
 
 [values]
-default-options = "console=hvc0"
+default-options = "initrd=\\initramfs init=/bin/sh console=hvc0"
 
 [actions.welcome]
 print.text = "Welcome to Sprout!"
 
 [actions.splash]
 splash.image = "edera-splash.png"
-splash.time = 5
+splash.time = 1
 
 [actions.chainload-kernel]
 chainload.path = "$path"
 chainload.options = ["$default-options"]
 
+[actions.chainload-shell]
+chainload.path = "\\EFI\\BOOT\\shell.efi"
+
 [generators.kernels.matrix]
 entry.title = "Boot Kernel $name"
 entry.values.path = "\\EFI\\BOOT\\$name"
@@ -21,4 +24,4 @@ entry.actions = ["chainload-kernel"]
 values.name = ["kernel.efi"]
 
 [[phases.startup]]
-actions = ["splash", "welcome"]
+actions = ["welcome", "splash"]

hack/configs/kernel.sprout.yaml

@@ -1,29 +0,0 @@
-version: 1
-
-values:
-  default-options: "console=hvc0"
-
-phases:
-  startup:
-  - actions: ["welcome"]
-
-actions:
-  welcome:
-    print:
-      text: "Welcome to Sprout!"
-  chainload-kernel:
-    chainload:
-      path: "$path"
-      options:
-      - "$default-options"
-
-generators:
-  kernels:
-    matrix:
-      entry:
-        title: "Boot Kernel $name"
-        values:
-          path: "\\EFI\\BOOT\\$name"
-        actions: ["chainload-kernel"]
-      values:
-        name: ["kernel.efi"]

vm/Dockerfile.initramfs

@@ -0,0 +1,11 @@
+FROM alpine:3.22@sha256:4bcff63911fcb4448bd4fdacec207030997caf25e9bea4045fa6c8c44de311d1 AS build
+RUN apk --no-cache add busybox-static
+RUN mkdir -p /tmp/initramfs/bin && cp /bin/busybox.static /tmp/initramfs/bin/busybox && \
+  chroot /tmp/initramfs /bin/busybox --install -s /bin && \
+  chroot /tmp/initramfs ln -s /bin/sh /init && \
+  cd /tmp/initramfs && \
+  find . | cpio -R 0:0 --ignore-devno --renumber-inodes -o -H newc --quiet > /initramfs && \
+  rm -rf /tmp/initramfs
+
+FROM scratch AS final
+COPY --from=build /initramfs /initramfs