sprout: version 0.0.11

Autoconfiguration Support

Cargo.lock

@@ -28,9 +28,9 @@ checksum = "1e4b40c7323adcfc0a41c4b88143ed58346ff65a288fc144329c5c45e05d70c6"
 
 [[package]]
 name = "bitflags"
-version = "2.9.4"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2261d10cca569e4643e526d8dc2e62e433cc8aba21ab764233731f8d369bf394"
+checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
 
 [[package]]
 name = "bytemuck"
@@ -46,9 +46,9 @@ checksum = "8f1fe948ff07f4bd06c30984e69f5b4899c516a3ef74f34df92a2df2ab535495"
 
 [[package]]
 name = "cfg-if"
-version = "1.0.3"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "crc32fast"
@@ -61,7 +61,7 @@ dependencies = [
 
 [[package]]
 name = "edera-sprout"
-version = "0.0.9"
+version = "0.0.11"
 dependencies = [
  "anyhow",
  "image",
@@ -89,9 +89,9 @@ dependencies = [
 
 [[package]]
 name = "flate2"
-version = "1.1.3"
+version = "1.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "04bcaeafafdd3cd1cb5d986ff32096ad1136630207c49b9091e3ae541090d938"
+checksum = "bfe33edd8e85a12a67454e37f8c75e730830d83e313556ab9ebf9ee7fbeb3bfb"
 dependencies = [
  "crc32fast",
  "miniz_oxide",
@@ -118,9 +118,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.11.4"
+version = "2.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b0f83760fb341a774ed326568e19f5a863af4a952def8c39f9ab92fd95b88e5"
+checksum = "6717a8d2a5a929a1a2eb43a12812498ed141a0bcfb7e8f7844fbdbe4303bba9f"
 dependencies = [
  "equivalent",
  "hashbrown",
@@ -175,9 +175,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.101"
+version = "1.0.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89ae43fd86e4158d6db51ad8e2b80f313af9cc74f5c0e03ccb87de09998732de"
+checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
 dependencies = [
  "unicode-ident",
 ]
@@ -204,9 +204,9 @@ dependencies = [
 
 [[package]]
 name = "pxfm"
-version = "0.1.24"
+version = "0.1.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "83f9b339b02259ada5c0f4a389b7fb472f933aa17ce176fd2ad98f28bb401fde"
+checksum = "a3cbdf373972bf78df4d3b518d07003938e2c7d1fb5891e55f9cb6df57009d84"
 dependencies = [
  "num-traits",
 ]
@@ -266,9 +266,9 @@ source = "git+https://github.com/edera-dev/sprout-patched-deps.git?rev=2c4fcc84b
 
 [[package]]
 name = "syn"
-version = "2.0.106"
+version = "2.0.108"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ede7c438028d4436d71104916910f5bb611972c5cfd7f89b8300a8186e6fada6"
+checksum = "da58917d35242480a05c2897064da0a80589a2a0476c9a3f2fdc83b53502e917"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -325,9 +325,9 @@ dependencies = [
 
 [[package]]
 name = "uefi"
-version = "0.35.0"
+version = "0.36.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "da7569ceafb898907ff764629bac90ac24ba4203c38c33ef79ee88c74aa35b11"
+checksum = "f123e69767fc287c44d70ee19af3b39d1bfb735dbaff5090e95b5b13cd656d16"
 dependencies = [
  "bitflags",
  "cfg-if",
@@ -341,9 +341,9 @@ dependencies = [
 
 [[package]]
 name = "uefi-macros"
-version = "0.18.1"
+version = "0.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b3dad47b3af8f99116c0f6d4d669c439487d9aaf1c8d9480d686cda6f3a8aa23"
+checksum = "4687412b5ac74d245d5bfb1733ede50c31be19bf8a4b6a967a29b451bab49e67"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -352,9 +352,9 @@ dependencies = [
 
 [[package]]
 name = "uefi-raw"
-version = "0.11.0"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7cad96b8baaf1615d3fdd0f03d04a0b487d857c1b51b19dcbfe05e2e3c447b78"
+checksum = "8aff2f4f2b556a36a201d335a1e0a57754967a96857b1f47a52d5a23825cac84"
 dependencies = [
  "bitflags",
  "uguid",
@@ -362,15 +362,15 @@ dependencies = [
 
 [[package]]
 name = "uguid"
-version = "2.2.0"
+version = "2.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab14ea9660d240e7865ce9d54ecdbd1cd9fa5802ae6f4512f093c7907e921533"
+checksum = "0c8352f8c05e47892e7eaf13b34abd76a7f4aeaf817b716e88789381927f199c"
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.19"
+version = "1.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f63a545481291138910575129486daeaf8ac54aee4387fe7906919f7830c7d9d"
+checksum = "462eeb75aeb73aea900253ce739c8e18a67423fadf006037cd3ff27e82748a06"
 
 [[package]]
 name = "winnow"

Cargo.toml

@@ -2,7 +2,7 @@
 name = "edera-sprout"
 description = "Modern UEFI bootloader"
 license = "Apache-2.0"
-version = "0.0.9"
+version = "0.0.11"
 homepage = "https://sprout.edera.dev"
 repository = "https://github.com/edera-dev/sprout"
 edition = "2024"
@@ -23,11 +23,11 @@ version = "1.0.228"
 features = ["derive"]
 
 [dependencies.uefi]
-version =  "0.35.0"
+version = "0.36.0"
 features = ["alloc", "logger"]
 
 [dependencies.uefi-raw]
-version =  "0.11.0"
+version = "0.12.0"
 
 [features]
 default = ["splash"]

README.md

@@ -39,6 +39,7 @@ simplify installation and usage.
 
 - [Fedora Setup Guide]
 - [Generic Linux Setup Guide]
+- [Alpine Edge Setup Guide]
 - [Windows Setup Guide]
 - [Development Guide]
 - [Contributing Guide]
@@ -48,8 +49,8 @@ simplify installation and usage.
 
 ## Features
 
-NOTE: Currently, Sprout is experimental and is not intended for production use. For example, it doesn't currently
-have secure boot support. In fact, as of writing, it doesn't even have a boot menu. Instead, it boots the first entry it sees, or fails.
+NOTE: Currently, Sprout is experimental and is not intended for production use.
+The boot menu mechanism is very rudimentary.
 
 ### Current
 
@@ -59,11 +60,12 @@ have secure boot support. In fact, as of writing, it doesn't even have a boot me
 - [x] Linux boot support via EFI stub
 - [x] Windows boot support via chainload
 - [x] Load Linux initrd from disk
-- [x] Boot first configured entry
+- [x] Basic boot menu
+- [x] BLS autoconfiguration support
 
 ### Roadmap
 
-- [ ] Boot menu
+- [ ] Full-featured boot menu
 - [ ] Secure Boot support: work in progress
 - [ ] UKI support: partial
 - [ ] multiboot2 support
@@ -99,6 +101,8 @@ Sprout supports some command line options that can be combined to modify behavio
 $ sprout.efi --config=\path\to\config.toml
 # Boot a specific entry, bypassing the menu.
 $ sprout.efi --boot="Boot Xen"
+# Autoconfigure Sprout, without loading a configuration file.
+$ sprout.efi --autoconfigure
 ```
 
 ### Boot Linux from ESP
@@ -133,32 +137,17 @@ version = 1
 [drivers.ext4]
 path = "\\sprout\\drivers\\ext4.efi"
 
-# extract the full path of the first filesystem
-# that contains \loader\entries as a directory
-# into the value called "boot"
-[extractors.boot.filesystem-device-match]
-has-item = "\\loader\\entries"
-
-# use the sprout bls module to scan a bls
-# directory for entries and load them as boot
-# entries in sprout, using the entry template
-# as specified here. the bls action below will
-# be passed the extracted values from bls.
-[generators.boot.bls]
-path = "$boot\\loader\\entries"
-entry.title = "$title"
-entry.actions = ["bls"]
-
-# the action that is used for each bls entry above.
-[actions.bls]
-chainload.path = "$boot\\$chainload"
-chainload.options = ["$options"]
-chainload.linux-initrd = "$boot\\$initrd"
+# global options.
+[defaults]
+# enable autoconfiguration by detecting bls enabled
+# filesystems and generating boot entries for them.
+autoconfigure = true
 ```
 
 [Edera]: https://edera.dev
 [Fedora Setup Guide]: ./docs/fedora-setup.md
 [Generic Linux Setup Guide]: ./docs/generic-linux-setup.md
+[Alpine Edge Setup Guide]: ./docs/alpine-edge-setup.md
 [Windows Setup Guide]: ./docs/windows-setup.md
 [Development Guide]: ./DEVELOPMENT.md
 [Contributing Guide]: ./CONTRIBUTING.md

docs/alpine-edge-setup.md

@@ -0,0 +1,113 @@
+# Setup Sprout on Alpine Edge
+
+## Prerequisites
+
+- Alpine Edge
+- EFI System Partition mounted on `/boot/efi` (the default)
+- ext4 or FAT32/exFAT formatted `/boot` partition
+
+## Step 1: Base Installation
+
+Download the latest sprout.efi release from the [GitHub releases page](https://github.com/edera-dev/sprout/releases).
+For x86_64 systems, download the `sprout-x86_64.efi` file, and for ARM systems, download the `sprout-aarch64.efi` file.
+Copy the downloaded `sprout.efi` file to `/boot/efi/EFI/boot/sprout.efi` on your EFI System Partition.
+
+Additionally, you will want to install the `efifs` package, which provides the filesystem support for Sprout.
+
+```bash
+# Install the efifs package which provides filesystem support for Sprout.
+$ apk install efifs
+```
+
+## Step 2: Configure Sprout
+
+Since Alpine uses standard image paths based on the `linux` package installed, it's quite easy to configure Sprout
+to boot Alpine.
+
+Write the following file to `/boot/efi/sprout.toml`:
+
+```toml
+# sprout configuration: version 1
+version = 1
+
+# load an EFI driver for ext2/ext3/ext4.
+[drivers.ext2]
+path = "\\EFI\\efifs\\ext2.efi"
+
+# extract the full path of the first filesystem
+# that contains \boot\vmlinuz-stable as a file
+# into the value called "root"
+[extractors.root.filesystem-device-match]
+has-item = "\\boot\\vmlinuz-stable"
+
+# add a boot entry for booting linux
+# which will run the boot-linux action.
+[entries.boot-linux-stable]
+title = "Boot Linux Stable"
+actions = ["boot-linux-stable"]
+
+# use the chainload action to boot linux-stable via the efi stub.
+# the options below are passed to the efi stub as the
+# kernel command line. the initrd is loaded using the efi stub
+# initrd loader mechanism.
+[actions.boot-linux-stable]
+chainload.path = "$root\\boot\\vmlinuz-stable"
+chainload.options = ["root=/dev/sda1", "my-kernel-option"]
+chainload.linux-initrd = "$root\\boot\\initramfs-stable"
+```
+
+You can replace `vmlinuz-stable` and `initramfs-stable` with the actual
+files for the `linux` package you have installed. For example, for `linux-lts` it is `vmlinuz-lts` and `initramfs-lts`.
+
+## Step 3, Option 1: Configure GRUB to load Sprout (recommended)
+
+You can configure GRUB to add a boot entry for Sprout, so you can continue to use GRUB without interruption.
+
+GRUB needs to be configured with the chainloader module to load Sprout.
+
+You will need to find the UUID of your EFI System Partition. You can do this by running the following command:
+```bash
+$ grep "/boot/efi" /etc/fstab | awk '{print $1}' | awk -F '=' '{print $2}'
+SAMPLE-VALUE
+```
+
+The GRUB configuration for Sprout is as follows, replace `SAMPLE-VALUE` with the UUID of your EFI System Partition:
+
+```grub
+menuentry 'Sprout' $menuentry_id_option 'sprout' {
+        insmod part_gpt
+        insmod fat
+        insmod chain
+        search --no-floppy --fs-uuid --set=root SAMPLE-VALUE
+        chainloader /EFI/boot/sprout.efi
+}
+```
+
+You can append this to `/etc/grub.d/40_custom` and run the following command to update your configuration:
+```bash
+$ update-grub
+```
+
+To update your GRUB configuration.
+
+You may now reboot your system and select Sprout from the GRUB menu.
+
+## Step 3, Option 2: Configure your EFI firmware for Sprout
+
+You can configure your EFI boot menu to show Sprout as an option.
+
+You will need to install the `efibootmgr` package:
+
+```
+$ apk add efibootmgr
+```
+
+Once `efibootmgr` is installed, find the partition device of your EFI System Partition and run the following:
+
+```bash
+$ efibootmgr -d /dev/esp_partition_here -C -L 'Sprout' -l '\EFI\boot\sprout.efi'
+```
+
+This will add a new entry to your EFI boot menu called `Sprout` that will boot Sprout with your configuration.
+
+Now if you boot into your UEFI firmware, you should see Sprout as an option to boot.

docs/fedora-setup.md

@@ -39,27 +39,11 @@ version = 1
 [drivers.ext4]
 path = "\\sprout\\drivers\\ext4.efi"
 
-# extract the full path of the first filesystem
-# that contains \loader\entries as a directory
-# into the value called "boot"
-[extractors.boot.filesystem-device-match]
-has-item = "\\loader\\entries"
-
-# use the sprout bls module to scan a bls
-# directory for entries and load them as boot
-# entries in sprout, using the entry template
-# as specified here. the bls action below will
-# be passed the extracted values from bls.
-[generators.boot.bls]
-path = "$boot\\loader\\entries"
-entry.title = "$title"
-entry.actions = ["bls"]
-
-# the action that is used for each bls entry above.
-[actions.bls]
-chainload.path = "$boot\\$chainload"
-chainload.options = ["$options"]
-chainload.linux-initrd = "$boot\\$initrd"
+# global options.
+[defaults]
+# enable autoconfiguration by detecting bls enabled
+# filesystems and generating boot entries for them.
+autoconfigure = true
 ```
 
 ## Step 3, Option 1: Configure GRUB to load Sprout (recommended)

hack/common.sh

@@ -36,9 +36,7 @@ DOCKER_TARGET="linux/${TARGET_ARCH}"
 FINAL_DIR="target/final/${TARGET_ARCH}"
 ASSEMBLE_DIR="target/assemble"
 
-if [ -z "${QEMU_ACCEL}" ] && [ "${TARGET_ARCH}" = "${HOST_ARCH}" ] &&
-	[ -f "/proc/cpuinfo" ] &&
-	grep -E '^flags.*:.+ vmx .*' /proc/cpuinfo >/dev/null; then
+if [ -z "${QEMU_ACCEL}" ] && [ "${TARGET_ARCH}" = "${HOST_ARCH}" ] && [ -e "/dev/kvm" ]; then
 	QEMU_ACCEL="kvm"
 fi
 

hack/dev/boot.sh

@@ -35,13 +35,15 @@ set -- "${@}" -smp 2 -m 4096
 if [ "${NO_GRAPHICAL_BOOT}" = "1" ]; then
 	set -- "${@}" -nographic
 else
-	if [ "${QEMU_LEGACY_SERIAL}" = "1" ]; then
-		set -- "${@}" -serial stdio
-	else
-		set -- "${@}" \
-			-device virtio-serial-pci,id=vs0 \
-			-chardev stdio,id=stdio0 \
-			-device virtconsole,chardev=stdio0,id=console0
+	if [ "${GRAPHICAL_ONLY}" != "1" ]; then
+		if [ "${QEMU_LEGACY_SERIAL}" = "1" ]; then
+			set -- "${@}" -serial stdio
+		else
+			set -- "${@}" \
+				-device virtio-serial-pci,id=vs0 \
+				-chardev stdio,id=stdio0 \
+				-device virtconsole,chardev=stdio0,id=console0
+		fi
 	fi
 
 	if [ "${QEMU_LEGACY_VGA}" = "1" ]; then
@@ -63,13 +65,8 @@ set -- "${@}" \
 	-drive "if=pflash,file=${FINAL_DIR}/ovmf-boot.fd,format=raw,readonly=on" \
 	-device nvme,drive=disk1,serial=cafebabe
 
-if [ "${DISK_BOOT}" = "1" ]; then
-	set -- "${@}" \
-		-drive "if=none,file=${FINAL_DIR}/sprout.img,format=raw,id=disk1,readonly=on"
-else
-	set -- "${@}" \
-		-drive "if=none,file=fat:rw:${FINAL_DIR}/efi,format=raw,id=disk1"
-fi
+set -- "${@}" \
+	-drive "if=none,file=${FINAL_DIR}/sprout.img,format=raw,id=disk1,readonly=on"
 
 set -- "${@}" -name "sprout ${TARGET_ARCH}"
 

hack/dev/boot/Dockerfile

@@ -13,6 +13,7 @@ COPY xen.efi /work/XEN.EFI
 COPY xen.cfg /work/XEN.CFG
 COPY initramfs /work/INITRAMFS
 COPY edera-splash.png /work/EDERA-SPLASH.PNG
+COPY bls.conf /work/BLS.CONF
 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 && \
@@ -20,6 +21,8 @@ RUN truncate -s128MiB sprout.img && \
     mkfs.vfat -F32 -n EFI sprout.img && \
     mmd -i sprout.img ::/EFI && \
     mmd -i sprout.img ::/EFI/BOOT && \
+    mmd -i sprout.img ::/LOADER && \
+    mmd -i sprout.img ::/LOADER/ENTRIES && \
     mcopy -i sprout.img ${EFI_NAME}.EFI ::/EFI/BOOT/ && \
     mcopy -i sprout.img KERNEL.EFI ::/EFI/BOOT/ && \
     mcopy -i sprout.img SHELL.EFI ::/EFI/BOOT/ && \
@@ -28,6 +31,7 @@ RUN truncate -s128MiB sprout.img && \
     mcopy -i sprout.img SPROUT.TOML ::/ && \
     mcopy -i sprout.img EDERA-SPLASH.PNG ::/ && \
     mcopy -i sprout.img INITRAMFS ::/ && \
+    mcopy -i sprout.img BLS.CONF ::/LOADER/ENTRIES/ && \
     mv sprout.img /sprout.img
 
 FROM scratch AS final

hack/dev/build.sh

@@ -11,7 +11,7 @@ if [ "${TARGET_ARCH}" = "aarch64" ]; then
 fi
 
 if [ -z "${SPROUT_CONFIG_NAME}" ]; then
-	SPROUT_CONFIG_NAME="kernel"
+	SPROUT_CONFIG_NAME="all"
 fi
 
 echo "[build] ${TARGET_ARCH} ${RUST_PROFILE}"
@@ -108,6 +108,7 @@ if [ "${SKIP_SPROUT_BUILD}" != "1" ]; then
 	cp "hack/dev/configs/${SPROUT_CONFIG_NAME}.sprout.toml" "${FINAL_DIR}/sprout.toml"
 	cp "hack/dev/configs/xen.cfg" "${FINAL_DIR}/xen.cfg"
 	cp "hack/dev/assets/edera-splash.png" "${FINAL_DIR}/edera-splash.png"
+	cp "hack/dev/configs/bls.conf" "${FINAL_DIR}/bls.conf"
 
 	mkdir -p "${FINAL_DIR}/efi/EFI/BOOT"
 	cp "${FINAL_DIR}/sprout.efi" "${FINAL_DIR}/efi/EFI/BOOT/${EFI_NAME}.EFI"

hack/dev/configs/all.sprout.toml

@@ -0,0 +1,30 @@
+version = 1
+
+[defaults]
+entry = "kernel"
+
+[extractors.boot.filesystem-device-match]
+has-item = "\\EFI\\BOOT\\kernel.efi"
+
+[actions.chainload-kernel]
+chainload.path = "$boot\\EFI\\BOOT\\kernel.efi"
+chainload.options = ["console=hvc0"]
+chainload.linux-initrd = "$boot\\initramfs"
+
+[entries.kernel]
+title = "Boot Linux"
+actions = ["chainload-kernel"]
+
+[actions.chainload-shell]
+chainload.path = "$boot\\EFI\\BOOT\\shell.efi"
+
+[entries.shell]
+title = "Boot Shell"
+actions = ["chainload-shell"]
+
+[actions.chainload-xen]
+chainload.path = "$boot\\EFI\\BOOT\\xen.efi"
+
+[entries.xen]
+title = "Boot Xen"
+actions = ["chainload-xen"]

hack/dev/configs/autoconfigure.sprout.toml

@@ -0,0 +1,4 @@
+version = 1
+
+[defaults]
+autoconfigure = true

hack/dev/configs/bls.conf

@@ -0,0 +1,4 @@
+title Boot Linux
+linux /efi/boot/kernel.efi
+options console=hvc0
+initrd /initramfs

hack/dev/configs/edera.sprout.toml

@@ -1,5 +1,9 @@
 version = 1
 
+[defaults]
+entry = "edera"
+menu-timeout = 0
+
 [extractors.boot.filesystem-device-match]
 has-item = "\\EFI\\BOOT\\xen.efi"
 

hack/dev/configs/kernel.sprout.toml

@@ -1,5 +1,9 @@
 version = 1
 
+[defaults]
+entry = "kernel"
+menu-timeout = 0
+
 [extractors.boot.filesystem-device-match]
 has-item = "\\EFI\\BOOT\\kernel.efi"
 

hack/dev/configs/shell.sprout.toml

@@ -1,11 +1,15 @@
 version = 1
 
+[defaults]
+entry = "shell"
+menu-timeout = 0
+
 [extractors.boot.filesystem-device-match]
 has-item = "\\EFI\\BOOT\\shell.efi"
 
 [actions.chainload-shell]
 chainload.path = "$boot\\EFI\\BOOT\\shell.efi"
 
-[entries.xen]
+[entries.shell]
 title = "Boot Shell"
 actions = ["chainload-shell"]

hack/dev/configs/xen.sprout.toml

@@ -1,5 +1,9 @@
 version = 1
 
+[defaults]
+entry = "xen"
+menu-timeout = 0
+
 [extractors.boot.filesystem-device-match]
 has-item = "\\EFI\\BOOT\\xen.efi"
 

hack/dev/kernel/docker-build.sh

@@ -29,11 +29,10 @@ else
 fi
 
 make CROSS_COMPILE="${MAYBE_CROSS_COMPILE}" ARCH="${TARGET_KARCH}" defconfig
-if [ "${TARGET_KARCH}" = "x86_64" ]
-then
-  make CROSS_COMPILE="${MAYBE_CROSS_COMPILE}" ARCH="${TARGET_KARCH}" xen.config
-  ./scripts/config -e XEN_PV
-  ./scripts/config -e XEN_PV_DOM0
+if [ "${TARGET_KARCH}" = "x86_64" ]; then
+	make CROSS_COMPILE="${MAYBE_CROSS_COMPILE}" ARCH="${TARGET_KARCH}" xen.config
+	./scripts/config -e XEN_PV
+	./scripts/config -e XEN_PV_DOM0
 fi
 make CROSS_COMPILE="${MAYBE_CROSS_COMPILE}" ARCH="${TARGET_KARCH}" mod2yesconfig
 
@@ -45,5 +44,5 @@ make CROSS_COMPILE="${MAYBE_CROSS_COMPILE}" ARCH="${TARGET_KARCH}" mod2yesconfig
 make "-j$(nproc)" CROSS_COMPILE="${MAYBE_CROSS_COMPILE}" ARCH="${TARGET_KARCH}"
 
 [ -f "arch/x86/boot/bzImage" ] && cp "arch/x86/boot/bzImage" kernel.image
-[ -f "arch/arm64/boot/Image.gz" ] && gzip -d < "arch/arm64/boot/Image.gz" > kernel.image
+[ -f "arch/arm64/boot/Image.gz" ] && gzip -d <"arch/arm64/boot/Image.gz" >kernel.image
 exit 0

hack/format.sh

@@ -1,7 +1,7 @@
-#!/bin/sh
+#!/bin/bash
 set -e
 
 cd "$(dirname "${0}")/.." || exit 1
 
-cargo fmt --all
-shfmt -w hack/**/*.sh
+cargo fmt --all || true
+shfmt -w hack/**/*.sh || true

src/actions.rs

@@ -1,5 +1,5 @@
 use crate::context::SproutContext;
-use anyhow::{Result, bail};
+use anyhow::{Context, Result, bail};
 use serde::{Deserialize, Serialize};
 use std::rc::Rc;
 
@@ -19,7 +19,7 @@ pub mod splash;
 /// that you can specify via other concepts.
 ///
 /// Actions are the main work that Sprout gets done, like booting Linux.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct ActionDeclaration {
     /// Chainload to another EFI application.
     /// This allows you to load any EFI application, either to boot an operating system
@@ -50,7 +50,10 @@ pub fn execute(context: Rc<SproutContext>, name: impl AsRef<str>) -> Result<()>
         bail!("unknown action '{}'", name.as_ref());
     };
     // Finalize the context and freeze it.
-    let context = context.finalize().freeze();
+    let context = context
+        .finalize()
+        .context("unable to finalize context")?
+        .freeze();
 
     // Execute the action.
     if let Some(chainload) = &action.chainload {
@@ -61,6 +64,7 @@ pub fn execute(context: Rc<SproutContext>, name: impl AsRef<str>) -> Result<()>
         return Ok(());
     } else if let Some(edera) = &action.edera {
         edera::edera(context.clone(), edera)?;
+        return Ok(());
     }
 
     #[cfg(feature = "splash")]

src/actions/chainload.rs

@@ -10,7 +10,7 @@ use uefi::CString16;
 use uefi::proto::loaded_image::LoadedImage;
 
 /// The configuration of the chainload action.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct ChainloadConfiguration {
     /// The path to the image to chainload.
     /// This can be a Linux EFI stub (vmlinuz usually) or a standard EFI executable.
@@ -99,10 +99,6 @@ pub fn chainload(context: Rc<SproutContext>, configuration: &ChainloadConfigurat
         initrd_handle = Some(handle);
     }
 
-    // Retrieve the base and size of the loaded image to display.
-    let (base, size) = loaded_image_protocol.info();
-    info!("loaded image: base={:#x} size={:#x}", base.addr(), size);
-
     // Start the loaded image.
     // This call might return, or it may pass full control to another image that will never return.
     // Capture the result to ensure we can return an error if the image fails to start, but only

src/actions/edera.rs

@@ -22,7 +22,7 @@ use crate::{
 /// The configuration of the edera action which boots the Edera hypervisor.
 /// Edera is based on Xen but modified significantly with a Rust stack.
 /// Sprout is a component of the Edera stack and provides the boot functionality of Xen.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct EderaConfiguration {
     /// The path to the Xen hypervisor EFI image.
     pub xen: String,

src/actions/print.rs

@@ -1,10 +1,11 @@
 use crate::context::SproutContext;
 use anyhow::Result;
+use log::info;
 use serde::{Deserialize, Serialize};
 use std::rc::Rc;
 
 /// The configuration of the print action.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct PrintConfiguration {
     /// The text to print to the console.
     #[serde(default)]
@@ -13,6 +14,6 @@ pub struct PrintConfiguration {
 
 /// Executes the print action with the specified `configuration` inside the provided `context`.
 pub fn print(context: Rc<SproutContext>, configuration: &PrintConfiguration) -> Result<()> {
-    println!("{}", context.stamp(&configuration.text));
+    info!("{}", context.stamp(&configuration.text));
     Ok(())
 }

src/actions/splash.rs

@@ -15,7 +15,7 @@ use uefi::proto::console::gop::GraphicsOutput;
 const DEFAULT_SPLASH_TIME: u32 = 0;
 
 /// The configuration of the splash action.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct SplashConfiguration {
     /// The path to the image to display.
     /// Currently, only PNG images are supported.
@@ -52,6 +52,11 @@ fn fit_to_frame(image: &DynamicImage, frame: Rect) -> Rect {
         height: image.height(),
     };
 
+    // Handle the case where the image is zero-sized.
+    if input.height == 0 || input.width == 0 {
+        return input;
+    }
+
     // Calculate the ratio of the image dimensions.
     let input_ratio = input.width as f32 / input.height as f32;
 
@@ -66,6 +71,11 @@ fn fit_to_frame(image: &DynamicImage, frame: Rect) -> Rect {
         height: frame.height,
     };
 
+    // Handle the case where the output is zero-sized.
+    if output.height == 0 || output.width == 0 {
+        return output;
+    }
+
     if input_ratio < frame_ratio {
         output.width = (frame.height as f32 * input_ratio).floor() as u32;
         output.height = frame.height;
@@ -110,7 +120,8 @@ fn draw(image: DynamicImage) -> Result<()> {
     let image = resize_to_fit(&image, fit);
 
     // Create a framebuffer to draw the image on.
-    let mut framebuffer = Framebuffer::new(width, height);
+    let mut framebuffer =
+        Framebuffer::new(width, height).context("unable to create framebuffer")?;
 
     // Iterate over the pixels in the image and put them on the framebuffer.
     for (x, y, pixel) in image.enumerate_pixels() {

src/autoconfigure.rs

@@ -0,0 +1,129 @@
+use crate::actions::ActionDeclaration;
+use crate::actions::chainload::ChainloadConfiguration;
+use crate::config::RootConfiguration;
+use crate::entries::EntryDeclaration;
+use crate::generators::GeneratorDeclaration;
+use crate::generators::bls::BlsConfiguration;
+use anyhow::{Context, Result};
+use uefi::cstr16;
+use uefi::fs::{FileSystem, Path};
+use uefi::proto::device_path::DevicePath;
+use uefi::proto::device_path::text::{AllowShortcuts, DisplayOnly};
+use uefi::proto::media::fs::SimpleFileSystem;
+
+/// The name prefix of the BLS chainload action that will be used
+/// by the BLS generator to chainload entries.
+const BLS_CHAINLOAD_ACTION_PREFIX: &str = "bls-chainload-";
+
+/// Scan the specified `filesystem` for BLS configurations.
+fn scan_for_bls(
+    filesystem: &mut FileSystem,
+    root: &DevicePath,
+    config: &mut RootConfiguration,
+) -> Result<bool> {
+    // BLS has a loader.conf file that can specify its own auto-entries mechanism.
+    let bls_loader_conf_path = Path::new(cstr16!("\\loader\\loader.conf"));
+    // BLS also has an entries directory that can specify explicit entries.
+    let bls_entries_path = Path::new(cstr16!("\\loader\\entries"));
+
+    // Convert the device path root to a string we can use in the configuration.
+    let mut root = root
+        .to_string(DisplayOnly(false), AllowShortcuts(false))
+        .context("unable to convert device root to string")?
+        .to_string();
+    // Add a trailing slash to the root to ensure the path is valid.
+    root.push('/');
+
+    // Whether we have a loader.conf file.
+    let has_loader_conf = filesystem
+        .try_exists(bls_loader_conf_path)
+        .context("unable to check for BLS loader.conf file")?;
+
+    // Whether we have an entries directory.
+    // We actually iterate the entries to see if there are any.
+    let has_entries_dir = filesystem
+        .read_dir(bls_entries_path)
+        .ok()
+        .and_then(|mut iterator| iterator.next())
+        .map(|entry| entry.is_ok())
+        .unwrap_or(false);
+
+    // Detect if a BLS supported configuration is on this filesystem.
+    // We check both loader.conf and entries directory as only one of them is required.
+    if !(has_loader_conf || has_entries_dir) {
+        return Ok(false);
+    }
+
+    // Generate a unique name for the BLS chainload action.
+    let chainload_action_name = format!("{}{}", BLS_CHAINLOAD_ACTION_PREFIX, root);
+
+    // BLS is now detected, generate a configuration for it.
+    let generator = BlsConfiguration {
+        entry: EntryDeclaration {
+            title: "$title".to_string(),
+            actions: vec![chainload_action_name.clone()],
+            ..Default::default()
+        },
+        path: format!("{}\\loader", root),
+    };
+
+    // Generate a unique name for the BLS generator and insert the generator into the configuration.
+    config.generators.insert(
+        format!("autoconfigure-bls-{}", root),
+        GeneratorDeclaration {
+            bls: Some(generator),
+            ..Default::default()
+        },
+    );
+
+    // Generate a chainload configuration for BLS.
+    // BLS will provide these values to us.
+    let chainload = ChainloadConfiguration {
+        path: format!("{}\\$chainload", root),
+        options: vec!["$options".to_string()],
+        linux_initrd: Some(format!("{}\\$initrd", root)),
+    };
+
+    // Insert the chainload action into the configuration.
+    config.actions.insert(
+        chainload_action_name,
+        ActionDeclaration {
+            chainload: Some(chainload),
+            ..Default::default()
+        },
+    );
+
+    // We had a BLS supported configuration, so return true.
+    Ok(true)
+}
+
+/// Generate a [RootConfiguration] based on the environment.
+/// Intakes a `config` to use as the basis of the autoconfiguration.
+pub fn autoconfigure(config: &mut RootConfiguration) -> Result<()> {
+    // Find all the filesystems that are on the system.
+    let filesystem_handles =
+        uefi::boot::find_handles::<SimpleFileSystem>().context("unable to scan filesystems")?;
+
+    // For each filesystem that was detected, scan it for supported autoconfig mechanisms.
+    for handle in filesystem_handles {
+        // Acquire the device path root for the filesystem.
+        let root = {
+            uefi::boot::open_protocol_exclusive::<DevicePath>(handle)
+                .context("unable to get root for filesystem")?
+                .to_boxed()
+        };
+
+        // Open the filesystem that was detected.
+        let filesystem = uefi::boot::open_protocol_exclusive::<SimpleFileSystem>(handle)
+            .context("unable to open filesystem")?;
+
+        // Trade the filesystem protocol for the uefi filesystem helper.
+        let mut filesystem = FileSystem::new(filesystem);
+
+        // Scan the filesystem for BLS supported configurations.
+        // If we find any, we will add a BLS generator to the configuration.
+        scan_for_bls(&mut filesystem, &root, config).context("unable to scan filesystem")?;
+    }
+
+    Ok(())
+}

src/config.rs

@@ -14,14 +14,20 @@ pub mod loader;
 /// This must be incremented when the configuration breaks compatibility.
 pub const LATEST_VERSION: u32 = 1;
 
+/// The default timeout for the boot menu in seconds.
+pub const DEFAULT_MENU_TIMEOUT_SECONDS: u64 = 10;
+
 /// The Sprout configuration format.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct RootConfiguration {
     /// The version of the configuration. This should always be declared
     /// and be the latest version that is supported. If not specified, it is assumed
     /// the configuration is the latest version.
     #[serde(default = "latest_version")]
     pub version: u32,
+    /// Default options for Sprout.
+    #[serde(default)]
+    pub defaults: DefaultsConfiguration,
     /// Values to be inserted into the root sprout context.
     #[serde(default)]
     pub values: BTreeMap<String, String>,
@@ -59,6 +65,23 @@ pub struct RootConfiguration {
     pub phases: PhasesConfiguration,
 }
 
+/// Default configuration for Sprout, used when the corresponding options are not specified.
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
+pub struct DefaultsConfiguration {
+    /// The entry to boot without showing the boot menu.
+    /// If not specified, a boot menu is shown.
+    pub entry: Option<String>,
+    /// The timeout of the boot menu.
+    #[serde(rename = "menu-timeout", default = "default_menu_timeout")]
+    pub menu_timeout: u64,
+    /// Enables autoconfiguration of Sprout based on the environment.
+    pub autoconfigure: bool,
+}
+
 fn latest_version() -> u32 {
     LATEST_VERSION
 }
+
+fn default_menu_timeout() -> u64 {
+    DEFAULT_MENU_TIMEOUT_SECONDS
+}

src/context.rs

@@ -1,11 +1,15 @@
 use crate::actions::ActionDeclaration;
 use crate::options::SproutOptions;
-use anyhow::Result;
 use anyhow::anyhow;
+use anyhow::{Result, bail};
+use std::cmp::Reverse;
 use std::collections::{BTreeMap, BTreeSet};
 use std::rc::Rc;
 use uefi::proto::device_path::DevicePath;
 
+/// The maximum number of iterations that can be performed in [SproutContext::finalize].
+const CONTEXT_FINALIZE_ITERATION_LIMIT: usize = 100;
+
 /// Declares a root context for Sprout.
 /// This contains data that needs to be shared across Sprout.
 #[derive(Default)]
@@ -79,6 +83,11 @@ impl SproutContext {
         self.root.as_ref()
     }
 
+    /// Access the root context to modify it, if possible.
+    pub fn root_mut(&mut self) -> Option<&mut RootContext> {
+        Rc::get_mut(&mut self.root)
+    }
+
     /// Retrieve the value specified by `key` from this context or its parents.
     /// Returns `None` if the value is not found.
     pub fn get(&self, key: impl AsRef<str>) -> Option<&String> {
@@ -151,11 +160,20 @@ impl SproutContext {
     /// Finalizes a context by producing a context with no parent that contains all the values
     /// of all parent contexts merged. This makes it possible to ensure [SproutContext] has no
     /// inheritance with other [SproutContext]s. It will still contain a [RootContext] however.
-    pub fn finalize(&self) -> SproutContext {
+    pub fn finalize(&self) -> Result<SproutContext> {
         // Collect all the values from the context and its parents.
         let mut current_values = self.all_values();
 
+        // To ensure that there is no possible infinite loop, we need to check
+        // the number of iterations. If it exceeds 100, we bail.
+        let mut iterations: usize = 0;
         loop {
+            iterations += 1;
+
+            if iterations > CONTEXT_FINALIZE_ITERATION_LIMIT {
+                bail!("infinite loop detected in context finalization");
+            }
+
             let mut did_change = false;
             let mut values = BTreeMap::new();
             for (key, value) in &current_values {
@@ -176,11 +194,11 @@ impl SproutContext {
         }
 
         // Produce the final context.
-        Self {
+        Ok(Self {
             root: self.root.clone(),
             parent: None,
             values: current_values,
-        }
+        })
     }
 
     /// Stamps the `text` value with the specified `values` map. The returned value indicates
@@ -188,7 +206,25 @@ impl SproutContext {
     fn stamp_values(values: &BTreeMap<String, String>, text: impl AsRef<str>) -> (bool, String) {
         let mut result = text.as_ref().to_string();
         let mut did_change = false;
-        for (key, value) in values {
+
+        // Sort the keys by length. This is to ensure that we stamp the longest keys first.
+        // If we did not do this, "$abc" could be stamped by "$a" into an invalid result.
+        let mut keys = values.keys().collect::<Vec<_>>();
+
+        // Sort by key length, reversed. This results in the longest keys appearing first.
+        keys.sort_by_key(|key| Reverse(key.len()));
+
+        for key in keys {
+            // Empty keys are not supported.
+            if key.is_empty() {
+                continue;
+            }
+
+            // We can fetch the value from the map. It is verifiable that the key exists.
+            let Some(value) = values.get(key) else {
+                unreachable!("keys iterated over is collected on a map that cannot be modified");
+            };
+
             let next_result = result.replace(&format!("${key}"), value);
             if result != next_result {
                 did_change = true;
@@ -204,4 +240,10 @@ impl SproutContext {
     pub fn stamp(&self, text: impl AsRef<str>) -> String {
         Self::stamp_values(&self.all_values(), text.as_ref()).1
     }
+
+    /// Unloads a [SproutContext] back into an owned context. This
+    /// may not succeed if something else is holding onto the value.
+    pub fn unload(self: Rc<SproutContext>) -> Option<SproutContext> {
+        Rc::into_inner(self)
+    }
 }

src/drivers.rs

@@ -12,7 +12,7 @@ use uefi::proto::device_path::LoadedImageDevicePath;
 /// Drivers allow extending the functionality of Sprout.
 /// Drivers are loaded at runtime and can provide extra functionality like filesystem support.
 /// Drivers are loaded by their name, which is used to reference them in other concepts.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct DriverDeclaration {
     /// The filesystem path to the driver.
     /// This file should be an EFI executable that can be located and executed.

src/entries.rs

@@ -7,7 +7,7 @@ use std::rc::Rc;
 ///
 /// Entries are the user-facing concept of Sprout, making it possible
 /// to run a set of actions with a specific context.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct EntryDeclaration {
     /// The title of the entry which will be display in the boot menu.
     /// This is the pre-stamped value.
@@ -27,6 +27,7 @@ pub struct BootableEntry {
     title: String,
     context: Rc<SproutContext>,
     declaration: EntryDeclaration,
+    default: bool,
 }
 
 impl BootableEntry {
@@ -42,6 +43,7 @@ impl BootableEntry {
             title,
             context,
             declaration,
+            default: false,
         }
     }
 
@@ -65,6 +67,11 @@ impl BootableEntry {
         &self.declaration
     }
 
+    /// Fetch whether the entry is the default entry.
+    pub fn is_default(&self) -> bool {
+        self.default
+    }
+
     /// Swap out the context of the entry.
     pub fn swap_context(&mut self, context: Rc<SproutContext>) {
         self.context = context;
@@ -75,8 +82,30 @@ impl BootableEntry {
         self.title = self.context.stamp(&self.title);
     }
 
+    /// Mark this entry as the default entry.
+    pub fn mark_default(&mut self) {
+        self.default = true;
+    }
+
     /// Prepend the name of the entry with `prefix`.
     pub fn prepend_name_prefix(&mut self, prefix: &str) {
         self.name.insert_str(0, prefix);
     }
+
+    /// Determine if this entry matches `needle` by comparing to the name or title of the entry.
+    pub fn is_match(&self, needle: &str) -> bool {
+        self.name == needle || self.title == needle
+    }
+
+    /// Find an entry by `needle` inside the entry iterator `haystack`.
+    /// This will search for an entry by name, title, or index.
+    pub fn find<'a>(
+        needle: &str,
+        haystack: impl Iterator<Item = &'a BootableEntry>,
+    ) -> Option<&'a BootableEntry> {
+        haystack
+            .enumerate()
+            .find(|(index, entry)| entry.is_match(needle) || index.to_string() == needle)
+            .map(|(_index, entry)| entry)
+    }
 }

src/extractors.rs

@@ -10,7 +10,7 @@ pub mod filesystem_device_match;
 /// Declares an extractor configuration.
 /// Extractors allow calculating values at runtime
 /// using built-in sprout modules.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct ExtractorDeclaration {
     /// The filesystem device match extractor.
     /// This extractor finds a filesystem using some search criteria and returns

src/extractors/filesystem_device_match.rs

@@ -20,7 +20,7 @@ use uefi_raw::Status;
 ///
 /// This function only requires one of the criteria to match.
 /// The fallback value can be used to provide a value if none is found.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct FilesystemDeviceMatchExtractor {
     /// Matches a filesystem that has the specified label.
     #[serde(default, rename = "has-label")]
@@ -81,7 +81,7 @@ pub fn extract(
                     } else {
                         // We should still handle other errors gracefully.
                         Err(error).context("unable to open filesystem partition info")?;
-                        None
+                        unreachable!()
                     }
                 }
             }

src/generators.rs

@@ -12,7 +12,7 @@ pub mod matrix;
 
 /// Declares a generator configuration.
 /// Generators allow generating entries at runtime based on a set of data.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct GeneratorDeclaration {
     /// Matrix generator configuration.
     /// Matrix allows you to specify multiple value-key values as arrays.

src/generators/bls.rs

@@ -6,25 +6,25 @@ use anyhow::{Context, Result};
 use serde::{Deserialize, Serialize};
 use std::rc::Rc;
 use std::str::FromStr;
-use uefi::CString16;
-use uefi::fs::{FileSystem, Path};
+use uefi::cstr16;
+use uefi::fs::{FileSystem, PathBuf};
 use uefi::proto::device_path::text::{AllowShortcuts, DisplayOnly};
 use uefi::proto::media::fs::SimpleFileSystem;
 
 /// BLS entry parser.
 mod entry;
 
-/// The default path to the BLS entries directory.
-const BLS_TEMPLATE_PATH: &str = "\\loader\\entries";
+/// The default path to the BLS directory.
+const BLS_TEMPLATE_PATH: &str = "\\loader";
 
 /// The configuration of the BLS generator.
 /// The BLS uses the Bootloader Specification to produce
 /// entries from an input template.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct BlsConfiguration {
     /// The entry to use for as a template.
     pub entry: EntryDeclaration,
-    /// The path to the BLS entries directory.
+    /// The path to the BLS directory.
     #[serde(default = "default_bls_path")]
     pub path: String,
 }
@@ -45,30 +45,31 @@ fn quirk_initrd_remove_tuned(input: String) -> String {
 pub fn generate(context: Rc<SproutContext>, bls: &BlsConfiguration) -> Result<Vec<BootableEntry>> {
     let mut entries = Vec::new();
 
-    // Stamp the path to the BLS entries directory.
+    // Stamp the path to the BLS directory.
     let path = context.stamp(&bls.path);
 
-    // Resolve the path to the BLS entries directory.
-    let resolved = utils::resolve_path(context.root().loaded_image_path()?, &path)
+    // Resolve the path to the BLS directory.
+    let bls_resolved = utils::resolve_path(context.root().loaded_image_path()?, &path)
         .context("unable to resolve bls path")?;
 
+    // Construct a filesystem path to the BLS entries directory.
+    let mut entries_path = PathBuf::from(
+        bls_resolved
+            .sub_path
+            .to_string(DisplayOnly(false), AllowShortcuts(false))
+            .context("unable to convert bls path to string")?,
+    );
+    entries_path.push(cstr16!("entries"));
+
     // Open exclusive access to the BLS filesystem.
-    let fs = uefi::boot::open_protocol_exclusive::<SimpleFileSystem>(resolved.filesystem_handle)
-        .context("unable to open bls filesystem")?;
+    let fs =
+        uefi::boot::open_protocol_exclusive::<SimpleFileSystem>(bls_resolved.filesystem_handle)
+            .context("unable to open bls filesystem")?;
     let mut fs = FileSystem::new(fs);
 
-    // Convert the subpath to the BLS entries directory to a string.
-    let sub_text_path = resolved
-        .sub_path
-        .to_string(DisplayOnly(false), AllowShortcuts(false))
-        .context("unable to convert subpath to string")?;
-
-    // Produce a path to the BLS entries directory.
-    let entries_path = Path::new(&sub_text_path);
-
     // Read the BLS entries directory.
     let entries_iter = fs
-        .read_dir(entries_path)
+        .read_dir(&entries_path)
         .context("unable to read bls entries")?;
 
     // For each entry in the BLS entries directory, parse the entry and add it to the list.
@@ -85,14 +86,13 @@ pub fn generate(context: Rc<SproutContext>, bls: &BlsConfiguration) -> Result<Ve
         let name = entry.file_name().to_string();
 
         // Ignore files that are not .conf files.
-        if !name.ends_with(".conf") {
+        if !name.to_lowercase().ends_with(".conf") {
             continue;
         }
 
-        // Produce the full path to the entry file.
-        let full_entry_path = CString16::try_from(format!("{}\\{}", sub_text_path, name).as_str())
-            .context("unable to construct full entry path")?;
-        let full_entry_path = Path::new(&full_entry_path);
+        // Create a mutable path so we can append the file name to produce the full path.
+        let mut full_entry_path = entries_path.to_path_buf();
+        full_entry_path.push(entry.file_name());
 
         // Read the entry file.
         let content = fs

src/generators/bls/entry.rs

@@ -36,8 +36,13 @@ impl FromStr for BlsEntry {
             // Trim the line.
             let line = line.trim();
 
-            // Split the line once by a space.
-            let Some((key, value)) = line.split_once(" ") else {
+            // Skip over empty lines and comments.
+            if line.is_empty() || line.starts_with('#') {
+                continue;
+            }
+
+            // Split the line once by whitespace.
+            let Some((key, value)) = line.split_once(char::is_whitespace) else {
                 continue;
             };
 
@@ -99,7 +104,7 @@ impl BlsEntry {
         self.linux
             .clone()
             .or(self.efi.clone())
-            .map(|path| path.replace("/", "\\").trim_start_matches("\\").to_string())
+            .map(|path| path.replace('/', "\\").trim_start_matches('\\').to_string())
     }
 
     /// Fetches the path to an initrd to pass to the kernel, if any.
@@ -107,7 +112,7 @@ impl BlsEntry {
     pub fn initrd_path(&self) -> Option<String> {
         self.initrd
             .clone()
-            .map(|path| path.replace("/", "\\").trim_start_matches("\\").to_string())
+            .map(|path| path.replace('/', "\\").trim_start_matches('\\').to_string())
     }
 
     /// Fetches the options to pass to the kernel, if any.

src/generators/matrix.rs

@@ -8,7 +8,7 @@ use std::rc::Rc;
 /// Matrix generator configuration.
 /// The matrix generator produces multiple entries based
 /// on input values multiplicatively.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct MatrixConfiguration {
     /// The template entry to use for each generated entry.
     #[serde(default)]

src/main.rs

@@ -1,21 +1,26 @@
 #![doc = include_str!("../README.md")]
 #![feature(uefi_std)]
 
+use crate::config::RootConfiguration;
 use crate::context::{RootContext, SproutContext};
 use crate::entries::BootableEntry;
 use crate::options::SproutOptions;
 use crate::options::parser::OptionsRepresentable;
 use crate::phases::phase;
-use anyhow::{Context, Result};
+use anyhow::{Context, Result, bail};
 use log::info;
 use std::collections::BTreeMap;
 use std::ops::Deref;
+use std::time::Duration;
 use uefi::proto::device_path::LoadedImageDevicePath;
 use uefi::proto::device_path::text::{AllowShortcuts, DisplayOnly};
 
 /// actions: Code that can be configured and executed by Sprout.
 pub mod actions;
 
+/// autoconfigure: Autoconfigure Sprout based on the detected environment.
+pub mod autoconfigure;
+
 /// config: Sprout configuration mechanism.
 pub mod config;
 
@@ -34,6 +39,9 @@ pub mod extractors;
 /// generators: Runtime code that can generate entries with specific values.
 pub mod generators;
 
+/// menu: Display a boot menu to select an entry to boot.
+pub mod menu;
+
 /// phases: Hooks into specific parts of the boot process.
 pub mod phases;
 
@@ -56,10 +64,16 @@ fn main() -> Result<()> {
     // Parse the options to the sprout executable.
     let options = SproutOptions::parse().context("unable to parse options")?;
 
-    // Load the configuration of sprout.
-    // At this point, the configuration has been validated and the specified
-    // version is checked to ensure compatibility.
-    let config = config::loader::load(&options)?;
+    // If --autoconfigure is specified, we use a stub configuration.
+    let mut config = if options.autoconfigure {
+        info!("autoconfiguration enabled, configuration file will be ignored");
+        RootConfiguration::default()
+    } else {
+        // Load the configuration of sprout.
+        // At this point, the configuration has been validated and the specified
+        // version is checked to ensure compatibility.
+        config::loader::load(&options)?
+    };
 
     // Load the root context.
     // This is done in a block to ensure the release of the LoadedImageDevicePath protocol.
@@ -94,6 +108,31 @@ fn main() -> Result<()> {
     // Load all configured drivers.
     drivers::load(context.clone(), &config.drivers).context("unable to load drivers")?;
 
+    // If --autoconfigure is specified or the loaded configuration has autoconfigure enabled,
+    // trigger the autoconfiguration mechanism.
+    if context.root().options().autoconfigure || config.defaults.autoconfigure {
+        autoconfigure::autoconfigure(&mut config).context("unable to autoconfigure")?;
+    }
+
+    // Unload the context so that it can be modified.
+    let Some(mut context) = context.unload() else {
+        bail!("context safety violation while trying to unload context");
+    };
+
+    // Perform root context modification in a block to release the modification when complete.
+    {
+        // Modify the root context to include the autoconfigured actions.
+        let Some(root) = context.root_mut() else {
+            bail!("context safety violation while trying to modify root context");
+        };
+
+        // Extend the root context with the autoconfigured actions.
+        root.actions_mut().extend(config.actions);
+    }
+
+    // Refreeze the context to ensure that further operations can share the context.
+    let context = context.freeze();
+
     // Run all the extractors declared in the configuration.
     let mut extracted = BTreeMap::new();
     for (name, extractor) in &config.extractors {
@@ -107,7 +146,7 @@ fn main() -> Result<()> {
     context.insert(&extracted);
     let context = context.freeze();
 
-    // Execute the late phase.
+    // Execute the startup phase.
     phase(context.clone(), &config.phases.startup).context("unable to execute startup phase")?;
 
     let mut entries = Vec::new();
@@ -143,36 +182,55 @@ fn main() -> Result<()> {
         // Insert the values from the entry configuration into the
         // sprout context to use with the entry itself.
         context.insert(&entry.declaration().values);
-        let context = context.finalize().freeze();
+        let context = context
+            .finalize()
+            .context("unable to finalize context")?
+            .freeze();
         // Provide the new context to the bootable entry.
         entry.swap_context(context);
         // Restamp the title with any values.
         entry.restamp_title();
+
+        // Mark this entry as the default entry if it is declared as such.
+        if let Some(ref default_entry) = config.defaults.entry {
+            // If the entry matches the default entry, mark it as the default entry.
+            if entry.is_match(default_entry) {
+                entry.mark_default();
+            }
+        }
     }
 
-    // TODO(azenla): Implement boot menu here.
-    // For now, we just print all of the entries.
-    info!("entries:");
-    for (index, entry) in entries.iter().enumerate() {
-        let title = entry.context().stamp(&entry.declaration().title);
-        info!("  entry {} [{}]: {}", index, entry.name(), title);
+    // If no entries were the default, pick the first entry as the default entry.
+    if entries.iter().all(|entry| !entry.is_default())
+        && let Some(entry) = entries.first_mut()
+    {
+        entry.mark_default();
     }
 
     // Execute the late phase.
     phase(context.clone(), &config.phases.late).context("unable to execute late phase")?;
 
-    // Use the boot option if possible, otherwise pick the first entry.
-    let entry = if let Some(ref boot) = context.root().options().boot {
-        entries
-            .iter()
-            .enumerate()
-            .find(|(index, entry)| {
-                entry.name() == boot || entry.title() == boot || &index.to_string() == boot
-            })
-            .context(format!("unable to find entry: {boot}"))?
-            .1 // select the bootable entry.
+    // If --boot is specified, boot that entry immediately.
+    let force_boot_entry = context.root().options().boot.as_ref();
+    // If --force-menu is specified, show the boot menu regardless of the value of --boot.
+    let force_boot_menu = context.root().options().force_menu;
+
+    // Determine the menu timeout in seconds based on the options or configuration.
+    // We prefer the options over the configuration to allow for overriding.
+    let menu_timeout = context
+        .root()
+        .options()
+        .menu_timeout
+        .unwrap_or(config.defaults.menu_timeout);
+    let menu_timeout = Duration::from_secs(menu_timeout);
+
+    // Use the forced boot entry if possible, otherwise pick the first entry using a boot menu.
+    let entry = if !force_boot_menu && let Some(ref force_boot_entry) = force_boot_entry {
+        BootableEntry::find(force_boot_entry, entries.iter())
+            .context(format!("unable to find entry: {force_boot_entry}"))?
     } else {
-        entries.first().context("no entries found")?
+        // Delegate to the menu to select an entry to boot.
+        menu::select(menu_timeout, &entries).context("unable to select entry via boot menu")?
     };
 
     // Execute all the actions for the selected entry.

src/menu.rs

@@ -0,0 +1,153 @@
+use crate::entries::BootableEntry;
+use anyhow::{Context, Result, bail};
+use log::info;
+use std::time::Duration;
+use uefi::ResultExt;
+use uefi::boot::TimerTrigger;
+use uefi::proto::console::text::{Input, Key, ScanCode};
+use uefi_raw::table::boot::{EventType, Tpl};
+
+/// The characters that can be used to select an entry from keys.
+const ENTRY_NUMBER_TABLE: &[char] = &['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];
+
+/// Represents the operation that can be performed by the boot menu.
+#[derive(PartialEq, Eq)]
+enum MenuOperation {
+    /// The user selected a numbered entry.
+    Number(usize),
+    /// The user selected the escape key to exit the boot menu.
+    Exit,
+    /// The user selected the enter key to display the entries again.
+    Continue,
+    /// Timeout occurred.
+    Timeout,
+    /// No operation should be performed.
+    Nop,
+}
+
+/// Read a key from the input device with a duration, returning the [MenuOperation] that was
+/// performed.
+fn read(input: &mut Input, timeout: &Duration) -> Result<MenuOperation> {
+    // The event to wait for a key press.
+    let key_event = input
+        .wait_for_key_event()
+        .context("unable to acquire key event")?;
+
+    // Timer event for timeout.
+    // SAFETY: The timer event creation allocated a timer pointer on the UEFI heap.
+    // This is validated safe as long as we are in boot services.
+    let timer_event = unsafe {
+        uefi::boot::create_event_ex(EventType::TIMER, Tpl::CALLBACK, None, None, None)
+            .context("unable to create timer event")?
+    };
+    // The timeout is in increments of 100 nanoseconds.
+    let trigger = TimerTrigger::Relative(timeout.as_nanos() as u64 / 100);
+    uefi::boot::set_timer(&timer_event, trigger).context("unable to set timeout timer")?;
+
+    let mut events = [timer_event, key_event];
+    let event = uefi::boot::wait_for_event(&mut events)
+        .discard_errdata()
+        .context("unable to wait for event")?;
+
+    // The first event is the timer event.
+    // If it has triggered, the user did not select a numbered entry.
+    if event == 0 {
+        return Ok(MenuOperation::Timeout);
+    }
+
+    // If we reach here, there is a key event.
+    let Some(key) = input.read_key().context("unable to read key")? else {
+        bail!("no key was pressed");
+    };
+
+    match key {
+        Key::Printable(c) => {
+            // If the key is not ascii, we can't process it.
+            if !c.is_ascii() {
+                return Ok(MenuOperation::Continue);
+            }
+            // Convert the key to a char.
+            let c: char = c.into();
+            // Find the key pressed in the entry number table or continue.
+            Ok(ENTRY_NUMBER_TABLE
+                .iter()
+                .position(|&x| x == c)
+                .map(MenuOperation::Number)
+                .unwrap_or(MenuOperation::Continue))
+        }
+
+        // The escape key is used to exit the boot menu.
+        Key::Special(ScanCode::ESCAPE) => Ok(MenuOperation::Exit),
+
+        // If the special key is unknown, do nothing.
+        Key::Special(_) => Ok(MenuOperation::Nop),
+    }
+}
+
+/// Selects an entry from the list of entries using the boot menu.
+fn select_with_input<'a>(
+    input: &mut Input,
+    timeout: Duration,
+    entries: &'a [BootableEntry],
+) -> Result<&'a BootableEntry> {
+    loop {
+        // If the timeout is not zero, let's display the boot menu.
+        if !timeout.is_zero() {
+            // Until a pretty menu is available, we just print all the entries.
+            info!("Boot Menu:");
+            for (index, entry) in entries.iter().enumerate() {
+                let title = entry.context().stamp(&entry.declaration().title);
+                info!("  [{}] {} ({})", index, title, entry.name());
+            }
+        }
+
+        // Read from input until a valid operation is selected.
+        let operation = loop {
+            // If the timeout is zero, we can exit immediately because there is nothing to do.
+            if timeout.is_zero() {
+                break MenuOperation::Exit;
+            }
+
+            info!("Select a boot entry using the number keys.");
+            info!("Press Escape to exit and enter to display the entries again.");
+
+            let operation = read(input, &timeout)?;
+            if operation != MenuOperation::Nop {
+                break operation;
+            }
+        };
+
+        match operation {
+            // Entry was selected by number. If the number is invalid, we continue.
+            MenuOperation::Number(index) => {
+                let Some(entry) = entries.get(index) else {
+                    println!("invalid entry number");
+                    continue;
+                };
+                return Ok(entry);
+            }
+
+            // When the user exits the boot menu or a timeout occurs, we should
+            // boot the default entry, if any.
+            MenuOperation::Exit | MenuOperation::Timeout => {
+                return entries
+                    .iter()
+                    .find(|item| item.is_default())
+                    .context("no default entry available");
+            }
+
+            // If the operation is to continue or nop, we can just run the loop again.
+            MenuOperation::Continue | MenuOperation::Nop => {
+                continue;
+            }
+        }
+    }
+}
+
+/// Shows a boot menu to select a bootable entry to boot.
+/// The actual work is done internally in [select_with_input] which is called
+/// within the context of the standard input device.
+pub fn select(timeout: Duration, entries: &[BootableEntry]) -> Result<&BootableEntry> {
+    // Acquire the standard input device and run the boot menu.
+    uefi::system::with_stdin(move |input| select_with_input(input, timeout, entries))
+}

src/options.rs

@@ -11,18 +11,27 @@ const DEFAULT_CONFIG_PATH: &str = "\\sprout.toml";
 /// The parsed options of sprout.
 #[derive(Debug)]
 pub struct SproutOptions {
+    /// Configures Sprout automatically based on the environment.
+    pub autoconfigure: bool,
     /// Path to a configuration file to load.
     pub config: String,
     /// Entry to boot without showing the boot menu.
     pub boot: Option<String>,
+    /// Force display of the boot menu.
+    pub force_menu: bool,
+    /// The timeout for the boot menu in seconds.
+    pub menu_timeout: Option<u64>,
 }
 
 /// The default Sprout options.
 impl Default for SproutOptions {
     fn default() -> Self {
         Self {
+            autoconfigure: false,
             config: DEFAULT_CONFIG_PATH.to_string(),
             boot: None,
+            force_menu: false,
+            menu_timeout: None,
         }
     }
 }
@@ -49,6 +58,20 @@ impl OptionsRepresentable for SproutOptions {
                     form: OptionForm::Value,
                 },
             ),
+            (
+                "force-menu",
+                OptionDescription {
+                    description: "Force showing of the boot menu",
+                    form: OptionForm::Flag,
+                },
+            ),
+            (
+                "menu-timeout",
+                OptionDescription {
+                    description: "Boot menu timeout, in seconds",
+                    form: OptionForm::Value,
+                },
+            ),
             (
                 "help",
                 OptionDescription {
@@ -66,6 +89,11 @@ impl OptionsRepresentable for SproutOptions {
 
         for (key, value) in options {
             match key.as_str() {
+                "autoconfigure" => {
+                    // Enable autoconfiguration.
+                    result.autoconfigure = true;
+                }
+
                 "config" => {
                     // The configuration file to load.
                     result.config = value.context("--config option requires a value")?;
@@ -76,6 +104,20 @@ impl OptionsRepresentable for SproutOptions {
                     result.boot = Some(value.context("--boot option requires a value")?);
                 }
 
+                "force-menu" => {
+                    // Force showing of the boot menu.
+                    result.force_menu = true;
+                }
+
+                "menu-timeout" => {
+                    // The timeout for the boot menu in seconds.
+                    let value = value.context("--menu-timeout option requires a value")?;
+                    let value = value
+                        .parse::<u64>()
+                        .context("menu-timeout must be a number")?;
+                    result.menu_timeout = Some(value);
+                }
+
                 _ => bail!("unknown option: --{key}"),
             }
         }

src/options/parser.rs

@@ -72,11 +72,7 @@ pub trait OptionsRepresentable {
             let mut value = None;
 
             // Check if the option is of the form --abc=123
-            if option.contains("=") {
-                let Some((part_key, part_value)) = option.split_once("=") else {
-                    bail!("invalid option: {option}");
-                };
-
+            if let Some((part_key, part_value)) = option.split_once('=') {
                 let part_key = part_key.to_string();
                 let part_value = part_value.to_string();
                 option = part_key;
@@ -131,7 +127,7 @@ pub trait OptionsRepresentable {
                     );
                 }
                 // Exit because the help has been displayed.
-                std::process::exit(1);
+                std::process::exit(0);
             }
 
             // Insert the option and the value into the map.

src/phases.rs

@@ -7,7 +7,7 @@ use std::rc::Rc;
 
 /// Configures the various phases of the boot process.
 /// This allows hooking various phases to run actions.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct PhasesConfiguration {
     /// The early phase is run before drivers are loaded.
     #[serde(default)]
@@ -23,7 +23,7 @@ pub struct PhasesConfiguration {
 /// Configures a single phase of the boot process.
 /// There can be multiple phase configurations that are
 /// executed sequentially.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct PhaseConfiguration {
     /// The actions to run when the phase is executed.
     #[serde(default)]

src/utils.rs

@@ -27,6 +27,12 @@ pub fn text_to_device_path(path: &str) -> Result<PoolDevicePath> {
         .context("unable to convert text to device path")
 }
 
+/// Checks if a [CString16] contains a char `c`.
+/// We need to call to_string() because CString16 doesn't support `contains` with a char.
+fn cstring16_contains_char(string: &CString16, c: char) -> bool {
+    string.to_string().contains(c)
+}
+
 /// Grabs the root part of the `path`.
 /// For example, given "PciRoot(0x0)/Pci(0x4,0x0)/NVMe(0x1,00-00-00-00-00-00-00-00)/HD(1,MBR,0xBE1AFDFA,0x3F,0xFBFC1)/\EFI\BOOT\BOOTX64.efi"
 /// it will give "PciRoot(0x0)/Pci(0x4,0x0)/NVMe(0x1,00-00-00-00-00-00-00-00)/HD(1,MBR,0xBE1AFDFA,0x3F,0xFBFC1)"
@@ -37,7 +43,7 @@ pub fn device_path_root(path: &DevicePath) -> Result<String> {
             let item = item.to_string(DisplayOnly(false), AllowShortcuts(false));
             if item
                 .as_ref()
-                .map(|item| item.to_string().contains("("))
+                .map(|item| cstring16_contains_char(item, '('))
                 .unwrap_or(false)
             {
                 Some(item.unwrap_or_default())
@@ -62,7 +68,7 @@ pub fn device_path_subpath(path: &DevicePath) -> Result<String> {
             let item = item.to_string(DisplayOnly(false), AllowShortcuts(false));
             if item
                 .as_ref()
-                .map(|item| item.to_string().contains("("))
+                .map(|item| cstring16_contains_char(item, '('))
                 .unwrap_or(false)
             {
                 None
@@ -104,11 +110,11 @@ pub fn resolve_path(default_root_path: &DevicePath, input: &str) -> Result<Resol
             it.to_string(DisplayOnly(false), AllowShortcuts(false))
                 .unwrap_or_default()
         })
-        .map(|it| it.to_string().contains("("))
+        .map(|it| it.to_string().contains('('))
         .unwrap_or(false);
     if !path_has_device {
         let mut input = input.to_string();
-        if !input.starts_with("\\") {
+        if !input.starts_with('\\') {
             input.insert(0, '\\');
         }
         input.insert_str(

src/utils/framebuffer.rs

@@ -13,17 +13,33 @@ pub struct Framebuffer {
 
 impl Framebuffer {
     /// Creates a new framebuffer of the specified `width` and `height`.
-    pub fn new(width: usize, height: usize) -> Self {
-        Framebuffer {
+    pub fn new(width: usize, height: usize) -> Result<Self> {
+        // Verify that the size is valid during multiplication.
+        let size = width
+            .checked_mul(height)
+            .context("framebuffer size overflow")?;
+
+        // Initialize the pixel buffer with black pixels, with the verified size.
+        let pixels = vec![BltPixel::new(0, 0, 0); size];
+
+        Ok(Framebuffer {
             width,
             height,
-            pixels: vec![BltPixel::new(0, 0, 0); width * height],
-        }
+            pixels,
+        })
     }
 
     /// Mutably acquires a pixel of the framebuffer at the specified `x` and `y` coordinate.
     pub fn pixel(&mut self, x: usize, y: usize) -> Option<&mut BltPixel> {
-        self.pixels.get_mut(y * self.width + x)
+        // Verify that the coordinates are within the bounds of the framebuffer.
+        if x >= self.width || y >= self.height {
+            return None;
+        }
+
+        // Calculate the index of the pixel safely, returning None if it overflows.
+        let index = y.checked_mul(self.width)?.checked_add(x)?;
+        // Return the pixel at the index. If the index is out of bounds, this will return None.
+        self.pixels.get_mut(index)
     }
 
     /// Blit the framebuffer to the specified `gop` [GraphicsOutput].

src/utils/media_loader.rs

@@ -97,7 +97,7 @@ impl MediaLoaderHandle {
     }
 
     /// Creates a new device path for the media loader based on a vendor `guid`.
-    fn device_path(guid: Guid) -> Box<DevicePath> {
+    fn device_path(guid: Guid) -> Result<Box<DevicePath>> {
         // The buffer for the device path.
         let mut path = Vec::new();
         // Build a device path for the media loader with a vendor-specific guid.
@@ -106,18 +106,18 @@ impl MediaLoaderHandle {
                 vendor_guid: guid,
                 vendor_defined_data: &[],
             })
-            .unwrap() // We know that the device path is valid, so we can unwrap.
+            .context("unable to produce device path")?
             .finalize()
-            .unwrap(); // We know that the device path is valid, so we can unwrap.
+            .context("unable to produce device path")?;
         // Convert the device path to a boxed device path.
         // This is safer than dealing with a pooled device path.
-        path.to_boxed()
+        Ok(path.to_boxed())
     }
 
     /// Checks if the media loader is already registered with the UEFI stack.
     fn already_registered(guid: Guid) -> Result<bool> {
         // Acquire the device path for the media loader.
-        let path = Self::device_path(guid);
+        let path = Self::device_path(guid)?;
 
         let mut existing_path = path.as_ref();
 
@@ -142,7 +142,7 @@ impl MediaLoaderHandle {
     /// to load the data from.
     pub fn register(guid: Guid, data: Box<[u8]>) -> Result<MediaLoaderHandle> {
         // Acquire the vendor device path for the media loader.
-        let path = Self::device_path(guid);
+        let path = Self::device_path(guid)?;
 
         // Check if the media loader is already registered.
         // If it is, we can't register it again safely.