sprout: version 0.0.12

Autoconfiguration Support

Cargo.lock

@@ -14,6 +14,17 @@ version = "1.0.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a23eb6b1614318a8071c9b2521f36b424b2c83db5eb3a0fead4a6c0809af6e61"
 
+[[package]]
+name = "async-trait"
+version = "0.1.89"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9035ad2d096bed7955a320ee7e2230574d28fd3c3a0f186cbea1ff3c7eed5dbb"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.5.0"
@@ -32,6 +43,15 @@ version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
 
+[[package]]
+name = "block-buffer"
+version = "0.10.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "bytemuck"
 version = "1.24.0"
@@ -44,12 +64,27 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8f1fe948ff07f4bd06c30984e69f5b4899c516a3ef74f34df92a2df2ab535495"
 
+[[package]]
+name = "bytes"
+version = "1.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d71b6127be86fdcfddb610f7182ac57211d4b18a3e9c82eb2d17662f2227ad6a"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
+[[package]]
+name = "cpufeatures"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59ed5838eebb26a2bb2e58f6d5b5316989ae9d08bab10e0e6d103e656d1b0280"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "crc32fast"
 version = "1.5.0"
@@ -59,14 +94,35 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "crypto-common"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1bfb12502f3fc46cca1bb51ac28df9d618d813cdc3d2f25b9fe775a34af26bb3"
+dependencies = [
+ "generic-array",
+ "typenum",
+]
+
+[[package]]
+name = "digest"
+version = "0.10.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
+dependencies = [
+ "block-buffer",
+ "crypto-common",
+]
+
 [[package]]
 name = "edera-sprout"
-version = "0.0.10"
+version = "0.0.12"
 dependencies = [
  "anyhow",
  "image",
  "log",
  "serde",
+ "sha256",
  "toml",
  "uefi",
  "uefi-raw",
@@ -97,12 +153,28 @@ dependencies = [
  "miniz_oxide",
 ]
 
+[[package]]
+name = "generic-array"
+version = "0.14.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4bb6743198531e02858aeaea5398fcc883e71851fcbcb5a2f773e2fb6cb1edf2"
+dependencies = [
+ "typenum",
+ "version_check",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5419bdc4f6a9207fbeba6d11b604d481addf78ecd10c11ad51e76c2f6482748d"
 
+[[package]]
+name = "hex"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
+
 [[package]]
 name = "image"
 version = "0.25.8"
@@ -126,6 +198,12 @@ dependencies = [
  "hashbrown",
 ]
 
+[[package]]
+name = "libc"
+version = "0.2.177"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2874a2af47a2325c2001a6e6fad9b16a53b802102b528163885171cf92b15976"
+
 [[package]]
 name = "log"
 version = "0.4.28"
@@ -259,6 +337,29 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "sha2"
+version = "0.10.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "digest",
+]
+
+[[package]]
+name = "sha256"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f880fc8562bdeb709793f00eb42a2ad0e672c4f883bbe59122b926eca935c8f6"
+dependencies = [
+ "async-trait",
+ "bytes",
+ "hex",
+ "sha2",
+]
+
 [[package]]
 name = "simd-adler32"
 version = "0.3.7"
@@ -314,6 +415,12 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "df8b2b54733674ad286d16267dcfc7a71ed5c776e4ac7aa3c3e2561f7c637bf2"
 
+[[package]]
+name = "typenum"
+version = "1.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
+
 [[package]]
 name = "ucs2"
 version = "0.3.3"
@@ -372,6 +479,12 @@ version = "1.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "462eeb75aeb73aea900253ce739c8e18a67423fadf006037cd3ff27e82748a06"
 
+[[package]]
+name = "version_check"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
+
 [[package]]
 name = "winnow"
 version = "0.7.13"

Cargo.toml

@@ -2,7 +2,7 @@
 name = "edera-sprout"
 description = "Modern UEFI bootloader"
 license = "Apache-2.0"
-version = "0.0.10"
+version = "0.0.12"
 homepage = "https://sprout.edera.dev"
 repository = "https://github.com/edera-dev/sprout"
 edition = "2024"
@@ -13,7 +13,7 @@ toml = "0.9.8"
 log = "0.4.28"
 
 [dependencies.image]
-version = "0.25.6"
+version = "0.25.8"
 default-features = false
 features = ["png"]
 optional = true
@@ -22,6 +22,10 @@ optional = true
 version = "1.0.228"
 features = ["derive"]
 
+[dependencies.sha256]
+version = "1.6.0"
+default-features = false
+
 [dependencies.uefi]
 version = "0.36.0"
 features = ["alloc", "logger"]
@@ -33,6 +37,11 @@ version = "0.12.0"
 default = ["splash"]
 splash = ["dep:image"]
 
+[profile.dev]
+# We have to compile for opt-level = 2 due to optimization passes
+# which don't handle the UEFI target properly.
+opt-level = 2
+
 [profile.release]
 lto = "thin"
 strip = "symbols"
@@ -46,6 +55,7 @@ debug = 1
 inherits = "dev"
 strip = "debuginfo"
 debug = 0
+opt-level = 2
 
 [patch.crates-io.simd-adler32]
 git = "https://github.com/edera-dev/sprout-patched-deps.git"

README.md

@@ -61,6 +61,7 @@ The boot menu mechanism is very rudimentary.
 - [x] Windows boot support via chainload
 - [x] Load Linux initrd from disk
 - [x] Basic boot menu
+- [x] BLS autoconfiguration support
 
 ### Roadmap
 
@@ -100,6 +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
@@ -134,27 +137,11 @@ version = 1
 [drivers.ext4]
 path = "\\sprout\\drivers\\ext4.efi"
 
-# extract the full path of the first filesystem
+# global options.
-# that contains \loader as a directory
+[options]
-# into the value called "boot"
+# enable autoconfiguration by detecting bls enabled
-[extractors.boot.filesystem-device-match]
+# filesystems and generating boot entries for them.
-has-item = "\\loader"
+autoconfigure = true
-
-# 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 = "$boot\\loader"
-entry.title = "$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"
 ```
 
 [Edera]: https://edera.dev

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
+# global options.
-# that contains \loader as a directory
+[options]
-# into the value called "boot"
+# enable autoconfiguration by detecting bls enabled
-[extractors.boot.filesystem-device-match]
+# filesystems and generating boot entries for them.
-has-item = "\\loader"
+autoconfigure = true
-
-# 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 = "$boot\\loader"
-entry.title = "$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"
 ```
 
 ## Step 3, Option 1: Configure GRUB to load Sprout (recommended)

hack/dev/boot.sh

@@ -65,13 +65,8 @@ set -- "${@}" \
 	-drive "if=pflash,file=${FINAL_DIR}/ovmf-boot.fd,format=raw,readonly=on" \
 	-device nvme,drive=disk1,serial=cafebabe
 
-if [ "${DISK_BOOT}" = "1" ]; then
+set -- "${@}" \
-	set -- "${@}" \
+	-drive "if=none,file=${FINAL_DIR}/sprout.img,format=raw,id=disk1,readonly=on"
-		-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 -- "${@}" -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

@@ -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

@@ -1,7 +1,7 @@
 version = 1
 
-[defaults]
+[options]
-entry = "kernel"
+default-entry = "kernel"
 
 [extractors.boot.filesystem-device-match]
 has-item = "\\EFI\\BOOT\\kernel.efi"

hack/dev/configs/autoconfigure.sprout.toml

@@ -0,0 +1,4 @@
+version = 1
+
+[options]
+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

@@ -1,7 +1,7 @@
 version = 1
 
-[defaults]
+[options]
-entry = "edera"
+default-entry = "edera"
 menu-timeout = 0
 
 [extractors.boot.filesystem-device-match]

hack/dev/configs/kernel.sprout.toml

@@ -1,7 +1,7 @@
 version = 1
 
-[defaults]
+[options]
-entry = "kernel"
+default-entry = "kernel"
 menu-timeout = 0
 
 [extractors.boot.filesystem-device-match]

hack/dev/configs/shell.sprout.toml

@@ -1,7 +1,7 @@
 version = 1
 
-[defaults]
+[options]
-entry = "shell"
+default-entry = "shell"
 menu-timeout = 0
 
 [extractors.boot.filesystem-device-match]

hack/dev/configs/xen.sprout.toml

@@ -1,7 +1,7 @@
 version = 1
 
-[defaults]
+[options]
-entry = "xen"
+default-entry = "xen"
 menu-timeout = 0
 
 [extractors.boot.filesystem-device-match]

src/actions.rs

@@ -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

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.
@@ -53,18 +53,15 @@ pub fn chainload(context: Rc<SproutContext>, configuration: &ChainloadConfigurat
     let mut loaded_image_protocol = uefi::boot::open_protocol_exclusive::<LoadedImage>(image)
         .context("unable to open loaded image protocol")?;
 
-    // Stamp and concatenate the options to pass to the image.
+    // Stamp and combine the options to pass to the image.
-    let options = configuration
+    let options =
-        .options
+        utils::combine_options(configuration.options.iter().map(|item| context.stamp(item)));
-        .iter()
-        .map(|item| context.stamp(item))
-        .collect::<Vec<_>>()
-        .join(" ");
 
     // Pass the options to the image, if any are provided.
     // The holder must drop at the end of this function to ensure the options are not leaked,
     // and the holder here ensures it outlives the if block here, as a pointer has to be
-    // passed to the image. This has been hand-validated to be safe.
+    // passed to the image.
+    // SAFETY: The options outlive the usage of the image, and the image is not used after this.
     let mut options_holder: Option<Box<CString16>> = None;
     if !options.is_empty() {
         let options = Box::new(
@@ -88,10 +85,15 @@ pub fn chainload(context: Rc<SproutContext>, configuration: &ChainloadConfigurat
         options_holder = Some(options);
     }
 
+    // The initrd can be None or empty, so we need to collapse that into a single Option.
+    let initrd = utils::empty_is_none(configuration.linux_initrd.as_ref());
+
+    // If an initrd is provided, register it with the EFI stack.
     let mut initrd_handle = None;
-    if let Some(ref linux_initrd) = configuration.linux_initrd {
+    if let Some(linux_initrd) = initrd {
-        let initrd_path = context.stamp(linux_initrd);
+        // Stamp the path to the initrd.
-        let content = utils::read_file_contents(context.root().loaded_image_path()?, &initrd_path)
+        let linux_initrd = context.stamp(linux_initrd);
+        let content = utils::read_file_contents(context.root().loaded_image_path()?, &linux_initrd)
             .context("unable to read linux initrd")?;
         let handle =
             MediaLoaderHandle::register(LINUX_EFI_INITRD_MEDIA_GUID, content.into_boxed_slice())
@@ -99,15 +101,11 @@ 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
     // after the optional initrd has been unregistered.
-    let result = uefi::boot::start_image(image).context("unable to start image");
+    let result = uefi::boot::start_image(image);
 
     // Unregister the initrd if it was registered.
     if let Some(initrd_handle) = initrd_handle

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,
@@ -40,7 +40,23 @@ pub struct EderaConfiguration {
 }
 
 /// Builds a configuration string for the Xen EFI stub using the specified `configuration`.
-fn build_xen_config(configuration: &EderaConfiguration) -> String {
+fn build_xen_config(context: Rc<SproutContext>, configuration: &EderaConfiguration) -> String {
+    // Stamp xen options and combine them.
+    let xen_options = utils::combine_options(
+        configuration
+            .xen_options
+            .iter()
+            .map(|item| context.stamp(item)),
+    );
+
+    // Stamp kernel options and combine them.
+    let kernel_options = utils::combine_options(
+        configuration
+            .kernel_options
+            .iter()
+            .map(|item| context.stamp(item)),
+    );
+
     // xen config file format is ini-like
     [
         // global section
@@ -50,10 +66,10 @@ fn build_xen_config(configuration: &EderaConfiguration) -> String {
         // configuration section for sprout
         "[sprout]".to_string(),
         // xen options
-        format!("options={}", configuration.xen_options.join(" ")),
+        format!("options={}", xen_options),
         // kernel options, stub replaces the kernel path
         // the kernel is provided via media loader
-        format!("kernel=stub {}", configuration.kernel_options.join(" ")),
+        format!("kernel=stub {}", kernel_options),
         // required or else the last line will be ignored
         "".to_string(),
     ]
@@ -94,7 +110,7 @@ fn register_media_loader_file(
 /// `configuration` and `context`. This action uses Edera-specific Xen EFI stub functionality.
 pub fn edera(context: Rc<SproutContext>, configuration: &EderaConfiguration) -> Result<()> {
     // Build the Xen config file content for this configuration.
-    let config = build_xen_config(configuration);
+    let config = build_xen_config(context.clone(), configuration);
 
     // Register the media loader for the config.
     let config = register_media_loader_text(XEN_EFI_CONFIG_MEDIA_GUID, "config", config)
@@ -113,7 +129,7 @@ pub fn edera(context: Rc<SproutContext>, configuration: &EderaConfiguration) ->
     let mut media_loaders = vec![config, kernel];
 
     // Register the initrd if it is provided.
-    if let Some(ref initrd) = configuration.initrd {
+    if let Some(initrd) = utils::empty_is_none(configuration.initrd.as_ref()) {
         let initrd =
             register_media_loader_file(&context, XEN_EFI_RAMDISK_MEDIA_GUID, "initrd", initrd)
                 .context("unable to register initrd media loader")?;
@@ -131,7 +147,7 @@ pub fn edera(context: Rc<SproutContext>, configuration: &EderaConfiguration) ->
     )
     .context("unable to chainload to xen");
 
-    // Unregister the media loaders on error.
+    // Unregister the media loaders when an error happens.
     for media_loader in media_loaders {
         if let Err(error) = media_loader.unregister() {
             error!("unable to unregister media loader: {}", error);

src/actions/print.rs

@@ -5,7 +5,7 @@ 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)]

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.

src/autoconfigure.rs

@@ -0,0 +1,50 @@
+use crate::config::RootConfiguration;
+use anyhow::{Context, Result};
+use uefi::fs::FileSystem;
+use uefi::proto::device_path::DevicePath;
+use uefi::proto::media::fs::SimpleFileSystem;
+
+/// bls: autodetect and configure BLS-enabled filesystems.
+pub mod bls;
+
+/// linux: autodetect and configure Linux kernels.
+/// This autoconfiguration module should not be activated
+/// on BLS-enabled filesystems as it may make duplicate entries.
+pub mod linux;
+
+/// 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.
+        let bls_found = bls::scan(&mut filesystem, &root, config)
+            .context("unable to scan for bls configurations")?;
+
+        // If BLS was not found, scan for Linux configurations.
+        if !bls_found {
+            linux::scan(&mut filesystem, &root, config)
+                .context("unable to scan for linux configurations")?;
+        }
+    }
+
+    Ok(())
+}

src/autoconfigure/bls.rs

@@ -0,0 +1,101 @@
+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 crate::utils;
+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};
+
+/// 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.
+pub fn scan(
+    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('/');
+
+    // Generate a unique hash of the root path.
+    let root_unique_hash = utils::unique_hash(&root);
+
+    // 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_unique_hash,);
+
+    // BLS is now detected, generate a configuration for it.
+    let generator = BlsConfiguration {
+        entry: EntryDeclaration {
+            title: "$title".to_string(),
+            actions: vec![chainload_action_name.clone()],
+            ..Default::default()
+        },
+        path: format!("{}\\loader", root),
+    };
+
+    // Generate a unique name for the BLS generator and insert the generator into the configuration.
+    config.generators.insert(
+        format!("autoconfigure-bls-{}", root_unique_hash),
+        GeneratorDeclaration {
+            bls: Some(generator),
+            ..Default::default()
+        },
+    );
+
+    // Generate a chainload configuration for BLS.
+    // BLS will provide these values to us.
+    let chainload = ChainloadConfiguration {
+        path: format!("{}\\$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)
+}

src/autoconfigure/linux.rs

@@ -0,0 +1,213 @@
+use crate::actions::ActionDeclaration;
+use crate::actions::chainload::ChainloadConfiguration;
+use crate::config::RootConfiguration;
+use crate::entries::EntryDeclaration;
+use crate::generators::GeneratorDeclaration;
+use crate::generators::list::ListConfiguration;
+use crate::utils;
+use anyhow::{Context, Result};
+use std::collections::BTreeMap;
+use uefi::CString16;
+use uefi::fs::{FileSystem, Path};
+use uefi::proto::device_path::DevicePath;
+use uefi::proto::device_path::text::{AllowShortcuts, DisplayOnly};
+
+/// The name prefix of the Linux chainload action that will be used to boot Linux.
+const LINUX_CHAINLOAD_ACTION_PREFIX: &str = "linux-chainload-";
+
+/// The locations to scan for kernel pairs.
+/// We will check for symlinks and if this directory is a symlink, we will skip it.
+const SCAN_LOCATIONS: &[&str] = &["/boot", "/"];
+
+/// Prefixes of kernel files to scan for.
+const KERNEL_PREFIXES: &[&str] = &["vmlinuz"];
+
+/// Prefixes of initramfs files to match to.
+const INITRAMFS_PREFIXES: &[&str] = &["initramfs", "initrd"];
+
+/// Pair of kernel and initramfs.
+/// This is what scanning a directory is meant to find.
+struct KernelPair {
+    /// The path to a kernel.
+    kernel: String,
+    /// The path to an initramfs, if any.
+    initramfs: Option<String>,
+}
+
+/// Scan the specified `filesystem` at `path` for [KernelPair] results.
+fn scan_directory(filesystem: &mut FileSystem, path: &str) -> Result<Vec<KernelPair>> {
+    // All the discovered kernel pairs.
+    let mut pairs = Vec::new();
+
+    // Construct a filesystem path from the path string.
+    let path = CString16::try_from(path).context("unable to convert path to CString16")?;
+    let path = Path::new(&path);
+    let path = path.to_path_buf();
+
+    // Check if the path exists and is a directory.
+    let exists = filesystem
+        .metadata(&path)
+        .ok()
+        .map(|metadata| metadata.is_directory())
+        .unwrap_or(false);
+
+    // If the path does not exist, return an empty list.
+    if !exists {
+        return Ok(pairs);
+    }
+
+    // Open a directory iterator on the path to scan.
+    // Ignore errors here as in some scenarios this might fail due to symlinks.
+    let Some(directory) = filesystem.read_dir(&path).ok() else {
+        return Ok(pairs);
+    };
+
+    // For each item in the directory, find a kernel.
+    for item in directory {
+        let item = item.context("unable to read directory item")?;
+
+        // Skip over any items that are not regular files.
+        if !item.is_regular_file() {
+            continue;
+        }
+
+        // Convert the name from a CString16 to a String.
+        let name = item.file_name().to_string();
+
+        // Find a kernel prefix that matches, if any.
+        let Some(prefix) = KERNEL_PREFIXES
+            .iter()
+            .find(|prefix| name == **prefix || name.starts_with(&format!("{}-", prefix)))
+        else {
+            // Skip over anything that doesn't match a kernel prefix.
+            continue;
+        };
+
+        // Acquire the suffix of the name, this will be used to match an initramfs.
+        let suffix = &name[prefix.len()..];
+
+        // Find a matching initramfs, if any.
+        let mut initramfs_prefix_iter = INITRAMFS_PREFIXES.iter();
+        let initramfs = loop {
+            let Some(prefix) = initramfs_prefix_iter.next() else {
+                break None;
+            };
+            // Construct an initramfs path.
+            let initramfs = format!("{}{}", prefix, suffix);
+            let initramfs = CString16::try_from(initramfs.as_str())
+                .context("unable to convert initramfs name to CString16")?;
+            let mut initramfs_path = path.clone();
+            initramfs_path.push(Path::new(&initramfs));
+            // Check if the initramfs path exists, if it does, break out of the loop.
+            if filesystem
+                .try_exists(&initramfs_path)
+                .context("unable to check if initramfs path exists")?
+            {
+                break Some(initramfs_path);
+            }
+        };
+
+        // Construct a kernel path from the kernel name.
+        let mut kernel = path.clone();
+        kernel.push(Path::new(&item.file_name()));
+        let kernel = kernel.to_string();
+        let initramfs = initramfs.map(|initramfs| initramfs.to_string());
+
+        // Produce a kernel pair.
+        let pair = KernelPair { kernel, initramfs };
+        pairs.push(pair);
+    }
+
+    Ok(pairs)
+}
+
+/// Scan the specified `filesystem` for Linux kernels and matching initramfs.
+pub fn scan(
+    filesystem: &mut FileSystem,
+    root: &DevicePath,
+    config: &mut RootConfiguration,
+) -> Result<bool> {
+    let mut pairs = Vec::new();
+
+    // 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('/');
+
+    // Generate a unique hash of the root path.
+    let root_unique_hash = utils::unique_hash(&root);
+
+    // Scan all locations for kernel pairs, adding them to the list.
+    for location in SCAN_LOCATIONS {
+        let scanned = scan_directory(filesystem, location)
+            .with_context(|| format!("unable to scan directory {}", location))?;
+        pairs.extend(scanned);
+    }
+
+    // If no kernel pairs were found, return false.
+    if pairs.is_empty() {
+        return Ok(false);
+    }
+
+    // Generate a unique name for the linux chainload action.
+    let chainload_action_name = format!("{}{}", LINUX_CHAINLOAD_ACTION_PREFIX, root_unique_hash,);
+
+    // Kernel pairs are detected, generate a list configuration for it.
+    let generator = ListConfiguration {
+        entry: EntryDeclaration {
+            title: "Boot Linux $kernel".to_string(),
+            actions: vec![chainload_action_name.clone()],
+            ..Default::default()
+        },
+        values: pairs
+            .into_iter()
+            .map(|pair| {
+                BTreeMap::from_iter(vec![
+                    ("kernel".to_string(), pair.kernel),
+                    ("initrd".to_string(), pair.initramfs.unwrap_or_default()),
+                ])
+            })
+            .collect(),
+    };
+
+    // Generate a unique name for the Linux generator and insert the generator into the configuration.
+    config.generators.insert(
+        format!("autoconfigure-linux-{}", root_unique_hash),
+        GeneratorDeclaration {
+            list: Some(generator),
+            ..Default::default()
+        },
+    );
+
+    // Insert a default value for the linux-options if it doesn't exist.
+    if !config.values.contains_key("linux-options") {
+        config
+            .values
+            .insert("linux-options".to_string(), "".to_string());
+    }
+
+    // Generate a chainload configuration for the list generator.
+    // The list will provide these values to us.
+    // Note that we don't need an extra \\ in the paths here.
+    // The root already contains a trailing slash.
+    let chainload = ChainloadConfiguration {
+        path: format!("{}$kernel", root),
+        options: vec!["$linux-options".to_string()],
+        linux_initrd: Some(format!("{}$initrd", root)),
+    };
+
+    // Insert the chainload action into the configuration.
+    config.actions.insert(
+        chainload_action_name,
+        ActionDeclaration {
+            chainload: Some(chainload),
+            ..Default::default()
+        },
+    );
+
+    // We had a Linux kernel, so return true to indicate something was found.
+    Ok(true)
+}

src/config.rs

@@ -18,7 +18,7 @@ pub const LATEST_VERSION: u32 = 1;
 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
@@ -27,7 +27,7 @@ pub struct RootConfiguration {
     pub version: u32,
     /// Default options for Sprout.
     #[serde(default)]
-    pub defaults: DefaultsConfiguration,
+    pub options: OptionsConfiguration,
     /// Values to be inserted into the root sprout context.
     #[serde(default)]
     pub values: BTreeMap<String, String>,
@@ -65,15 +65,19 @@ pub struct RootConfiguration {
     pub phases: PhasesConfiguration,
 }
 
-/// Default configuration for Sprout, used when the corresponding options are not specified.
+/// Options configuration for Sprout, used when the corresponding options are not specified.
-#[derive(Serialize, Deserialize, Default, Clone)]
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
-pub struct DefaultsConfiguration {
+pub struct OptionsConfiguration {
     /// The entry to boot without showing the boot menu.
     /// If not specified, a boot menu is shown.
-    pub entry: Option<String>,
+    #[serde(rename = "default-entry", default)]
+    pub default_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.
+    #[serde(default)]
+    pub autoconfigure: bool,
 }
 
 fn latest_version() -> u32 {

src/context.rs

@@ -83,6 +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> {
@@ -113,7 +118,10 @@ impl SproutContext {
     pub fn all_values(&self) -> BTreeMap<String, String> {
         let mut values = BTreeMap::new();
         for key in self.all_keys() {
-            values.insert(key.clone(), self.get(key).cloned().unwrap_or_default());
+            // Acquire the value from the context. Since retrieving all the keys will give us
+            // a full view of the context, we can be sure that the key exists.
+            let value = self.get(&key).cloned().unwrap_or_default();
+            values.insert(key.clone(), value);
         }
         values
     }
@@ -235,4 +243,10 @@ 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.
@@ -33,8 +33,6 @@ fn load_driver(context: Rc<SproutContext>, driver: &DriverDeclaration) -> Result
     // Push the path of the driver from the root.
     full_path.push_str(&context.stamp(&driver.path));
 
-    info!("driver path: {}", full_path);
-
     // Convert the path to a device path.
     let device_path = utils::text_to_device_path(&full_path)?;
 

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.

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

@@ -18,9 +18,9 @@ use uefi_raw::Status;
 /// the device root path that can concatenated with subpaths to access files
 /// on a particular filesystem.
 ///
-/// This function only requires one of the criteria to match.
+/// This function only requires all 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")]

src/generators.rs

@@ -1,6 +1,7 @@
 use crate::context::SproutContext;
 use crate::entries::BootableEntry;
 use crate::generators::bls::BlsConfiguration;
+use crate::generators::list::ListConfiguration;
 use crate::generators::matrix::MatrixConfiguration;
 use anyhow::Result;
 use anyhow::bail;
@@ -8,11 +9,12 @@ use serde::{Deserialize, Serialize};
 use std::rc::Rc;
 
 pub mod bls;
+pub mod list;
 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.
@@ -32,6 +34,9 @@ pub struct GeneratorDeclaration {
     /// It will generate a sprout entry for every supported BLS entry.
     #[serde(default)]
     pub bls: Option<BlsConfiguration>,
+    /// List generator configuration.
+    /// Allows you to specify a list of values to generate an entry from.
+    pub list: Option<ListConfiguration>,
 }
 
 /// Runs the generator specified by the `generator` option.
@@ -45,6 +50,8 @@ pub fn generate(
         matrix::generate(context, matrix)
     } else if let Some(bls) = &generator.bls {
         bls::generate(context, bls)
+    } else if let Some(list) = &generator.list {
+        list::generate(context, list)
     } else {
         bail!("unknown generator configuration");
     }

src/generators/bls.rs

@@ -20,7 +20,7 @@ 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,
@@ -86,7 +86,7 @@ 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;
         }
 

src/generators/list.rs

@@ -0,0 +1,52 @@
+use crate::context::SproutContext;
+use crate::entries::{BootableEntry, EntryDeclaration};
+use anyhow::Result;
+use serde::{Deserialize, Serialize};
+use std::collections::BTreeMap;
+use std::rc::Rc;
+
+/// List generator configuration.
+/// The list generator produces multiple entries based
+/// on a set of input maps.
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
+pub struct ListConfiguration {
+    /// The template entry to use for each generated entry.
+    #[serde(default)]
+    pub entry: EntryDeclaration,
+    /// The values to use as the input for the matrix.
+    #[serde(default)]
+    pub values: Vec<BTreeMap<String, String>>,
+}
+
+/// Generates a set of entries using the specified `matrix` configuration in the `context`.
+pub fn generate(
+    context: Rc<SproutContext>,
+    list: &ListConfiguration,
+) -> Result<Vec<BootableEntry>> {
+    let mut entries = Vec::new();
+
+    // For each combination, create a new context and entry.
+    for (index, combination) in list.values.iter().enumerate() {
+        let mut context = context.fork();
+        // Insert the combination into the context.
+        context.insert(combination);
+        let context = context.freeze();
+
+        // Stamp the entry title and actions from the template.
+        let mut entry = list.entry.clone();
+        entry.actions = entry
+            .actions
+            .into_iter()
+            .map(|action| context.stamp(action))
+            .collect();
+        // Push the entry into the list with the new context.
+        entries.push(BootableEntry::new(
+            index.to_string(),
+            entry.title.clone(),
+            context,
+            entry,
+        ));
+    }
+
+    Ok(entries)
+}

src/generators/matrix.rs

@@ -1,5 +1,6 @@
 use crate::context::SproutContext;
 use crate::entries::{BootableEntry, EntryDeclaration};
+use crate::generators::list;
 use anyhow::Result;
 use serde::{Deserialize, Serialize};
 use std::collections::BTreeMap;
@@ -8,7 +9,7 @@ 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)]
@@ -57,30 +58,12 @@ pub fn generate(
 ) -> Result<Vec<BootableEntry>> {
     // Produce all the combinations of the input values.
     let combinations = build_matrix(&matrix.values);
-    let mut entries = Vec::new();
+    // Use the list generator to generate entries for each combination.
-
+    list::generate(
-    // For each combination, create a new context and entry.
+        context,
-    for (index, combination) in combinations.into_iter().enumerate() {
+        &list::ListConfiguration {
-        let mut context = context.fork();
+            entry: matrix.entry.clone(),
-        // Insert the combination into the context.
+            values: combinations,
-        context.insert(&combination);
+        },
-        let context = context.freeze();
+    )
-
-        // Stamp the entry title and actions from the template.
-        let mut entry = matrix.entry.clone();
-        entry.actions = entry
-            .actions
-            .into_iter()
-            .map(|action| context.stamp(action))
-            .collect();
-        // Push the entry into the list with the new context.
-        entries.push(BootableEntry::new(
-            index.to_string(),
-            entry.title.clone(),
-            context,
-            entry,
-        ));
-    }
-
-    Ok(entries)
 }

src/main.rs

@@ -1,22 +1,25 @@
 #![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 log::{error, 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;
 
@@ -50,20 +53,21 @@ pub mod options;
 /// utils: Utility functions that are used by other parts of Sprout.
 pub mod utils;
 
-/// The main entrypoint of sprout.
+/// Run Sprout, returning an error if one occurs.
-/// It is possible this function will not return if actions that are executed
+fn run() -> Result<()> {
-/// exit boot services or do not return control to sprout.
-fn main() -> Result<()> {
-    // Initialize the basic UEFI environment.
-    setup::init()?;
-
     // Parse the options to the sprout executable.
     let options = SproutOptions::parse().context("unable to parse options")?;
 
-    // Load the configuration of sprout.
+    // If --autoconfigure is specified, we use a stub configuration.
-    // At this point, the configuration has been validated and the specified
+    let mut config = if options.autoconfigure {
-    // version is checked to ensure compatibility.
+        info!("autoconfiguration enabled, configuration file will be ignored");
-    let config = config::loader::load(&options)?;
+        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.
@@ -73,10 +77,6 @@ fn main() -> Result<()> {
         >(uefi::boot::image_handle())
         .context("unable to get loaded image device path")?;
         let loaded_image_path = current_image_device_path_protocol.deref().to_boxed();
-        info!(
-            "loaded image path: {}",
-            loaded_image_path.to_string(DisplayOnly(false), AllowShortcuts(false))?
-        );
         RootContext::new(loaded_image_path, options)
     };
 
@@ -98,6 +98,31 @@ 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.options.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 {
@@ -157,7 +182,7 @@ fn main() -> Result<()> {
         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 let Some(ref default_entry) = config.options.default_entry {
             // If the entry matches the default entry, mark it as the default entry.
             if entry.is_match(default_entry) {
                 entry.mark_default();
@@ -186,7 +211,7 @@ fn main() -> Result<()> {
         .root()
         .options()
         .menu_timeout
-        .unwrap_or(config.defaults.menu_timeout);
+        .unwrap_or(config.options.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.
@@ -205,6 +230,26 @@ fn main() -> Result<()> {
             .context(format!("unable to execute action '{}'", action))?;
     }
 
+    Ok(())
+}
+
+/// The main entrypoint of sprout.
+/// It is possible this function will not return if actions that are executed
+/// exit boot services or do not return control to sprout.
+fn main() -> Result<()> {
+    // Initialize the basic UEFI environment.
+    setup::init()?;
+
+    // Run Sprout, then handle the error.
+    let result = run();
+    if let Err(ref error) = result {
+        // Print an error trace.
+        error!("sprout encountered an error");
+        for (index, stack) in error.chain().enumerate() {
+            error!("[{}]: {}", index, stack);
+        }
+    }
+
     // Sprout doesn't necessarily guarantee anything was booted.
     // If we reach here, we will exit back to whoever called us.
     Ok(())

src/menu.rs

@@ -44,11 +44,16 @@ fn read(input: &mut Input, timeout: &Duration) -> Result<MenuOperation> {
     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 mut events = vec![timer_event, key_event];
     let event = uefi::boot::wait_for_event(&mut events)
         .discard_errdata()
         .context("unable to wait for event")?;
 
+    // Close the timer event that we acquired.
+    if let Some(timer_event) = events.into_iter().next() {
+        uefi::boot::close_event(timer_event).context("unable to close timer event")?;
+    }
+
     // The first event is the timer event.
     // If it has triggered, the user did not select a numbered entry.
     if event == 0 {
@@ -121,7 +126,7 @@ fn select_with_input<'a>(
             // 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");
+                    info!("invalid entry number");
                     continue;
                 };
                 return Ok(entry);

src/options.rs

@@ -11,6 +11,8 @@ 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.
@@ -25,6 +27,7 @@ pub struct SproutOptions {
 impl Default for SproutOptions {
     fn default() -> Self {
         Self {
+            autoconfigure: false,
             config: DEFAULT_CONFIG_PATH.to_string(),
             boot: None,
             force_menu: false,
@@ -86,6 +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")?;

src/options/parser.rs

@@ -1,4 +1,5 @@
 use anyhow::{Context, Result, bail};
+use log::info;
 use std::collections::BTreeMap;
 
 /// The type of option. This disambiguates different behavior
@@ -113,9 +114,9 @@ pub trait OptionsRepresentable {
             // Handle the --help flag case.
             if description.form == OptionForm::Help {
                 // Generic configured options output.
-                println!("Configured Options:");
+                info!("Configured Options:");
                 for (name, description) in &configured {
-                    println!(
+                    info!(
                         "  --{}{}: {}",
                         name,
                         if description.form == OptionForm::Value {

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

@@ -161,3 +161,23 @@ pub fn read_file_contents(default_root_path: &DevicePath, input: &str) -> Result
     let content = fs.read(Path::new(&path));
     content.context("unable to read file contents")
 }
+
+/// Filter a string-like Option `input` such that an empty string is [None].
+pub fn empty_is_none<T: AsRef<str>>(input: Option<T>) -> Option<T> {
+    input.filter(|input| !input.as_ref().is_empty())
+}
+
+/// Combine a sequence of strings into a single string, separated by spaces, ignoring empty strings.
+pub fn combine_options<T: AsRef<str>>(options: impl Iterator<Item = T>) -> String {
+    options
+        .flat_map(|item| empty_is_none(Some(item)))
+        .map(|item| item.as_ref().to_string())
+        .collect::<Vec<_>>()
+        .join(" ")
+}
+
+/// Produce a unique hash for the input.
+/// This uses SHA-256, which is unique enough but relatively short.
+pub fn unique_hash(input: &str) -> String {
+    sha256::digest(input.as_bytes())
+}