change to read hermit application from directory at runtime

Author: sarahspberrypi

src/arch/x86_64/mod.rs

@@ -100,13 +100,6 @@ pub fn output_message_byte(byte: u8) {
 	unsafe { COM1.send(byte) };
 }
 
-// Right now, the kernel binary has to be hardcoded into the loader.
-// The binary has to be in the same directory (or its whereabouts have to specified in the "include_bytes!" statement).
-#[cfg(target_os = "uefi")]
-pub unsafe fn find_kernel() -> &'static [u8] {
-	include_bytes!("hermit-rs-template")
-}
-
 /// This is the actual boot function.
 /// The bootstack is cleared and provided/calculated BOOT_INFO is written into before the actual call to the assembly code to jump into the kernel.
 #[cfg(target_os = "uefi")]

src/uefi.rs

@@ -11,6 +11,26 @@ use uefi::{
 	table::{boot::*, cfg},
 };
 
+/// This function reads the provided kernelbinary
+/// req. location: same subdir as the bootloader itself
+/// reg. name: hermit_app
+fn read_app(bt: &BootServices) -> Vec<u8> {
+	let fs = bt
+		.get_image_file_system(bt.image_handle())
+		.expect("should open file system");
+
+	let path = Path::new(cstr16!(r"\efi\boot\hermit_app"));
+
+	let data = FileSystem::new(fs)
+		.read(path)
+		.expect("should read file content");
+
+	let len = data.len();
+	info!("Read Hermit application from \"{path}\" (size = {len} B)");
+
+	data
+}
+
 /// Entry Point of the UEFI Loader
 /// This function gets a so-called "EFI System Table" (see UEFI Specification, Section 4: EFI System Table) from the Firmware Interface.
 /// Here, the RSDP (for BOOT_INFO) and the kernel are located and the kernel is parsed and loaded into memory.