implement driver loading

src/drivers.rs

@@ -0,0 +1,72 @@
+use crate::context::SproutContext;
+use crate::utils;
+use anyhow::{Context, Result};
+use log::info;
+use serde::{Deserialize, Serialize};
+use std::collections::BTreeMap;
+use std::rc::Rc;
+use uefi::boot::SearchType;
+use uefi::proto::device_path::LoadedImageDevicePath;
+
+#[derive(Serialize, Deserialize, Default, Clone)]
+pub struct DriverDeclaration {
+    pub path: String,
+}
+
+fn load_driver(context: Rc<SproutContext>, driver: &DriverDeclaration) -> Result<()> {
+    let sprout_image = uefi::boot::image_handle();
+    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(&driver.path));
+
+    info!("driver path: {}", full_path);
+
+    let device_path = utils::text_to_device_path(&full_path)?;
+
+    let image = uefi::boot::load_image(
+        sprout_image,
+        uefi::boot::LoadImageSource::FromDevicePath {
+            device_path: &device_path,
+            boot_policy: uefi::proto::BootPolicy::ExactMatch,
+        },
+    )
+    .context("failed to load image")?;
+
+    uefi::boot::start_image(image).context("failed to start driver image")?;
+
+    Ok(())
+}
+
+fn reconnect() -> Result<()> {
+    let handles = uefi::boot::locate_handle_buffer(SearchType::AllHandles)
+        .context("failed to locate handles buffer")?;
+
+    for handle in handles.iter() {
+        // ignore result as there is nothing we can do if it doesn't work.
+        let _ = uefi::boot::connect_controller(*handle, None, None, true);
+    }
+
+    Ok(())
+}
+
+pub fn load(
+    context: Rc<SproutContext>,
+    drivers: &BTreeMap<String, DriverDeclaration>,
+) -> Result<()> {
+    if drivers.is_empty() {
+        return Ok(());
+    }
+
+    info!("loading drivers");
+    for (name, driver) in drivers {
+        load_driver(context.clone(), driver).context(format!("failed to load driver: {}", name))?;
+    }
+
+    reconnect().context("failed to reconnect drivers")?;
+    info!("loaded drivers");
+    Ok(())
+}