implement support for filesystem extractor mechanism

hack/dev/configs/kernel.sprout.toml

@@ -1,9 +1,12 @@
 version = 1
 
+[extractors.boot.filesystem]
+item = "\\EFI\\BOOT\\kernel.efi"
+
 [actions.chainload-kernel]
-chainload.path = "\\EFI\\BOOT\\kernel.efi"
+chainload.path = "$boot\\EFI\\BOOT\\kernel.efi"
 chainload.options = ["console=hvc0"]
-chainload.linux-initrd = "\\initramfs"
+chainload.linux-initrd = "$boot\\initramfs"
 
 [entries.kernel]
 title = "Boot Linux"

src/actions/chainload.rs

@@ -20,22 +20,20 @@ pub struct ChainloadConfiguration {
 
 pub fn chainload(context: Rc<SproutContext>, configuration: &ChainloadConfiguration) -> Result<()> {
     let sprout_image = uefi::boot::image_handle();
-    let image_device_path_protocol =
+    let _image_device_path_protocol =
         uefi::boot::open_protocol_exclusive::<LoadedImageDevicePath>(sprout_image)
             .context("unable to open loaded image device path protocol")?;
 
-    let mut full_path = utils::device_path_root(&image_device_path_protocol)?;
-
-    full_path.push_str(&context.stamp(&configuration.path));
-
-    info!("path: {}", full_path);
-
-    let device_path = utils::text_to_device_path(&full_path)?;
+    let resolved = utils::resolve_path(
+        context.root().loaded_image_path()?,
+        &context.stamp(&configuration.path),
+    )
+    .context("failed to resolve chainload path")?;
 
     let image = uefi::boot::load_image(
         sprout_image,
         uefi::boot::LoadImageSource::FromDevicePath {
-            device_path: &device_path,
+            device_path: &resolved.full_path,
             boot_policy: uefi::proto::BootPolicy::ExactMatch,
         },
     )
@@ -77,8 +75,8 @@ pub fn chainload(context: Rc<SproutContext>, configuration: &ChainloadConfigurat
     let mut initrd_handle = None;
     if let Some(ref linux_initrd) = configuration.linux_initrd {
         let initrd_path = context.stamp(linux_initrd);
-        let content =
-            utils::read_file_contents(&initrd_path).context("failed to read linux initrd")?;
+        let content = utils::read_file_contents(context.root().loaded_image_path()?, &initrd_path)
+            .context("failed to read linux initrd")?;
         initrd_handle = Some(
             register_linux_initrd(content.into_boxed_slice())
                 .context("failed to register linux initrd")?,

src/actions/splash.rs

@@ -96,7 +96,7 @@ fn draw(image: DynamicImage) -> Result<()> {
 
 pub fn splash(context: Rc<SproutContext>, configuration: &SplashConfiguration) -> Result<()> {
     let image = context.stamp(&configuration.image);
-    let image = read_file_contents(&image)?;
+    let image = read_file_contents(context.root().loaded_image_path()?, &image)?;
     let image = ImageReader::with_format(Cursor::new(image), ImageFormat::Png)
         .decode()
         .context("failed to decode splash image")?;

src/config.rs

@@ -1,11 +1,14 @@
 use crate::actions::ActionDeclaration;
 use crate::drivers::DriverDeclaration;
+use crate::extractors::ExtractorDeclaration;
 use crate::generators::GeneratorDeclaration;
 use crate::utils;
 use anyhow::Context;
 use anyhow::Result;
 use serde::{Deserialize, Serialize};
 use std::collections::BTreeMap;
+use std::ops::Deref;
+use uefi::proto::device_path::LoadedImageDevicePath;
 
 #[derive(Serialize, Deserialize, Default, Clone)]
 pub struct RootConfiguration {
@@ -16,6 +19,8 @@ pub struct RootConfiguration {
     #[serde(default)]
     pub drivers: BTreeMap<String, DriverDeclaration>,
     #[serde(default)]
+    pub extractors: BTreeMap<String, ExtractorDeclaration>,
+    #[serde(default)]
     pub actions: BTreeMap<String, ActionDeclaration>,
     #[serde(default)]
     pub entries: BTreeMap<String, EntryDeclaration>,
@@ -49,8 +54,13 @@ pub struct PhaseConfiguration {
 }
 
 pub fn load() -> Result<RootConfiguration> {
-    let content =
-        utils::read_file_contents("sprout.toml").context("unable to read sprout.toml file")?;
+    let current_image_device_path_protocol =
+        uefi::boot::open_protocol_exclusive::<LoadedImageDevicePath>(uefi::boot::image_handle())
+            .context("failed to get loaded image device path")?;
+    let path = current_image_device_path_protocol.deref().to_boxed();
+
+    let content = utils::read_file_contents(&path, "sprout.toml")
+        .context("unable to read sprout.toml file")?;
     let config: RootConfiguration =
         toml::from_slice(&content).context("unable to parse sprout.toml file")?;
     Ok(config)

src/context.rs

@@ -1,15 +1,22 @@
 use crate::actions::ActionDeclaration;
+use anyhow::Result;
+use anyhow::anyhow;
 use std::collections::{BTreeMap, BTreeSet};
 use std::rc::Rc;
+use uefi::proto::device_path::DevicePath;
 
 #[derive(Default)]
 pub struct RootContext {
     actions: BTreeMap<String, ActionDeclaration>,
+    loaded_image_path: Option<Box<DevicePath>>,
 }
 
 impl RootContext {
-    pub fn new() -> Self {
-        Default::default()
+    pub fn new(loaded_image_device_path: Box<DevicePath>) -> Self {
+        RootContext {
+            actions: BTreeMap::new(),
+            loaded_image_path: Some(loaded_image_device_path),
+        }
     }
 
     pub fn actions(&self) -> &BTreeMap<String, ActionDeclaration> {
@@ -19,6 +26,12 @@ impl RootContext {
     pub fn actions_mut(&mut self) -> &mut BTreeMap<String, ActionDeclaration> {
         &mut self.actions
     }
+
+    pub fn loaded_image_path(&self) -> Result<&DevicePath> {
+        self.loaded_image_path
+            .as_deref()
+            .ok_or_else(|| anyhow!("no loaded image path"))
+    }
 }
 
 pub struct SproutContext {

src/extractors.rs

@@ -0,0 +1,20 @@
+use crate::context::SproutContext;
+use crate::extractors::filesystem::FileSystemExtractorConfiguration;
+use anyhow::{Result, bail};
+use serde::{Deserialize, Serialize};
+use std::rc::Rc;
+
+pub mod filesystem;
+
+#[derive(Serialize, Deserialize, Default, Clone)]
+pub struct ExtractorDeclaration {
+    pub filesystem: Option<FileSystemExtractorConfiguration>,
+}
+
+pub fn extract(context: Rc<SproutContext>, extractor: &ExtractorDeclaration) -> Result<String> {
+    if let Some(filesystem) = &extractor.filesystem {
+        filesystem::extract(context, filesystem)
+    } else {
+        bail!("unknown extractor configuration");
+    }
+}

src/extractors/filesystem.rs

@@ -0,0 +1,66 @@
+use crate::context::SproutContext;
+use crate::utils;
+use anyhow::{Context, Result};
+use serde::{Deserialize, Serialize};
+use std::ops::Deref;
+use std::rc::Rc;
+use uefi::CString16;
+use uefi::fs::{FileSystem, Path};
+use uefi::proto::device_path::DevicePath;
+use uefi::proto::media::file::{File, FileSystemVolumeLabel};
+use uefi::proto::media::fs::SimpleFileSystem;
+
+#[derive(Serialize, Deserialize, Default, Clone)]
+pub struct FileSystemExtractorConfiguration {
+    pub label: Option<String>,
+    pub item: Option<String>,
+}
+
+pub fn extract(
+    context: Rc<SproutContext>,
+    device: &FileSystemExtractorConfiguration,
+) -> Result<String> {
+    let handles = uefi::boot::find_handles::<SimpleFileSystem>()
+        .context("failed to find filesystem handles")?;
+    for handle in handles {
+        let mut filesystem = uefi::boot::open_protocol_exclusive::<SimpleFileSystem>(handle)
+            .context("failed to open filesystem protocol")?;
+
+        if let Some(ref label) = device.label {
+            let want_label = CString16::try_from(context.stamp(label).as_str())
+                .context("failed to convert label to CString16")?;
+            let mut root = filesystem
+                .open_volume()
+                .context("failed to open filesystem volume")?;
+            let label = root
+                .get_boxed_info::<FileSystemVolumeLabel>()
+                .context("failed to get filesystem volume label")?;
+
+            if label.volume_label() != want_label {
+                continue;
+            }
+        }
+
+        if let Some(ref item) = device.item {
+            let want_item = CString16::try_from(context.stamp(item).as_str())
+                .context("failed to convert item to CString16")?;
+            let mut filesystem = FileSystem::new(filesystem);
+            let metadata = filesystem.metadata(Path::new(&want_item));
+
+            if metadata.is_err() {
+                continue;
+            }
+
+            let metadata = metadata?;
+            if !(metadata.is_directory() || metadata.is_regular_file()) {
+                continue;
+            }
+        }
+
+        let path = uefi::boot::open_protocol_exclusive::<DevicePath>(handle)
+            .context("failed to open filesystem device path")?;
+        let path = path.deref();
+        return utils::device_path_root(path).context("failed to get device path root");
+    }
+    Ok(String::new())
+}

src/generators.rs

@@ -21,6 +21,6 @@ pub fn generate(
     if let Some(matrix) = &generator.matrix {
         matrix::generate(context, matrix)
     } else {
-        bail!("unknown action configuration");
+        bail!("unknown generator configuration");
     }
 }

src/main.rs

@@ -4,12 +4,17 @@ use crate::config::PhaseConfiguration;
 use crate::context::{RootContext, SproutContext};
 use anyhow::{Context, Result, bail};
 use log::info;
+use std::collections::BTreeMap;
+use std::ops::Deref;
 use std::rc::Rc;
+use uefi::proto::device_path::LoadedImageDevicePath;
+use uefi::proto::device_path::text::{AllowShortcuts, DisplayOnly};
 
 pub mod actions;
 pub mod config;
 pub mod context;
 pub mod drivers;
+pub mod extractors;
 pub mod generators;
 pub mod setup;
 pub mod utils;
@@ -37,7 +42,19 @@ fn main() -> Result<()> {
         bail!("unsupported configuration version: {}", config.version);
     }
 
-    let mut root = RootContext::new();
+    let mut root = {
+        let current_image_device_path_protocol = uefi::boot::open_protocol_exclusive::<
+            LoadedImageDevicePath,
+        >(uefi::boot::image_handle())
+        .context("failed 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)
+    };
+
     root.actions_mut().extend(config.actions.clone());
 
     let mut context = SproutContext::new(root);
@@ -46,6 +63,17 @@ fn main() -> Result<()> {
 
     drivers::load(context.clone(), &config.drivers).context("failed to load drivers")?;
 
+    let mut extracted = BTreeMap::new();
+    for (name, extractor) in &config.extractors {
+        let value = extractors::extract(context.clone(), extractor)
+            .context(format!("failed to extract value {}", name))?;
+        info!("extracted value {}: {}", name, value);
+        extracted.insert(name.clone(), value);
+    }
+    let mut context = context.fork();
+    context.insert(&extracted);
+    let context = context.freeze();
+
     phase(context.clone(), &config.phases.startup)?;
 
     let mut all_entries = Vec::new();

src/utils.rs

@@ -1,9 +1,10 @@
 use anyhow::{Context, Result};
-use uefi::CString16;
+use std::ops::Deref;
 use uefi::fs::{FileSystem, Path};
 use uefi::proto::device_path::text::{AllowShortcuts, DevicePathFromText, DisplayOnly};
 use uefi::proto::device_path::{DevicePath, PoolDevicePath};
 use uefi::proto::media::fs::SimpleFileSystem;
+use uefi::{CString16, Handle};
 
 pub mod framebuffer;
 pub mod linux_media_initrd;
@@ -43,14 +44,84 @@ pub fn device_path_root(path: &DevicePath) -> Result<String> {
     Ok(path)
 }
 
-pub fn read_file_contents(path: &str) -> Result<Vec<u8>> {
-    let fs = uefi::boot::open_protocol_exclusive::<SimpleFileSystem>(
-        uefi::boot::get_handle_for_protocol::<SimpleFileSystem>()
-            .context("no filesystem protocol")?,
-    )
-    .context("unable to open filesystem protocol")?;
+pub fn device_path_subpath(path: &DevicePath) -> Result<String> {
+    let path = path
+        .node_iter()
+        .filter_map(|item| {
+            let item = item.to_string(DisplayOnly(false), AllowShortcuts(false));
+            if item
+                .as_ref()
+                .map(|item| item.to_string().contains("("))
+                .unwrap_or(false)
+            {
+                None
+            } else {
+                Some(item.unwrap_or_default())
+            }
+        })
+        .map(|item| item.to_string())
+        .collect::<Vec<_>>()
+        .join("\\");
+    Ok(path)
+}
+
+pub struct ResolvedPath {
+    pub root_path: Box<DevicePath>,
+    pub sub_path: Box<DevicePath>,
+    pub full_path: Box<DevicePath>,
+    pub filesystem_handle: Handle,
+}
+
+pub fn resolve_path(default_root_path: &DevicePath, input: &str) -> Result<ResolvedPath> {
+    let mut path = text_to_device_path(input).context("failed to convert text to path")?;
+    let path_has_device = path
+        .node_iter()
+        .next()
+        .map(|it| {
+            it.to_string(DisplayOnly(false), AllowShortcuts(false))
+                .unwrap_or_default()
+        })
+        .map(|it| it.to_string().contains("("))
+        .unwrap_or(false);
+    if !path_has_device {
+        let mut input = input.to_string();
+        if !input.starts_with("\\") {
+            input.insert(0, '\\');
+        }
+        input.insert_str(
+            0,
+            device_path_root(default_root_path)
+                .context("failed to get loaded image device root")?
+                .as_str(),
+        );
+        path = text_to_device_path(input.as_str()).context("failed to convert text to path")?;
+    }
+
+    let path = path.to_boxed();
+    let root = device_path_root(path.as_ref()).context("failed to convert root to path")?;
+    let root_path = text_to_device_path(root.as_str())
+        .context("failed to convert root to path")?
+        .to_boxed();
+    let mut root_path = root_path.as_ref();
+    let handle = uefi::boot::locate_device_path::<SimpleFileSystem>(&mut root_path)
+        .context("failed to locate filesystem device path")?;
+    let subpath = device_path_subpath(path.deref()).context("failed to get device subpath")?;
+    Ok(ResolvedPath {
+        root_path: root_path.to_boxed(),
+        sub_path: text_to_device_path(subpath.as_str())?.to_boxed(),
+        full_path: path,
+        filesystem_handle: handle,
+    })
+}
+
+pub fn read_file_contents(default_root_path: &DevicePath, input: &str) -> Result<Vec<u8>> {
+    let resolved = resolve_path(default_root_path, input)?;
+    let fs = uefi::boot::open_protocol_exclusive::<SimpleFileSystem>(resolved.filesystem_handle)
+        .context("unable to open filesystem protocol")?;
     let mut fs = FileSystem::new(fs);
-    let path = CString16::try_from(path).context("unable to convert path to CString16")?;
+    let path = resolved
+        .sub_path
+        .to_string(DisplayOnly(false), AllowShortcuts(false))?;
     let content = fs.read(Path::new(&path));
     content.context("unable to read file contents")
 }