Fix initrd loading

src/initrd.rs

@@ -1,22 +1,10 @@
 use uefi::{
+    prelude::BootServices,
     proto::media::file::{Directory, File, FileAttribute, FileInfo, FileMode, RegularFile},
-    table::boot::MemoryMap,
+    table::boot::{AllocateType, MemoryType},
     CStr16, Error,
 };
 
-use crate::{elf::LoadedObject, mem::MemoryMapExt};
-
-fn can_place(mmap: &MemoryMap, base: u64, size: u64) -> bool {
-    let start_aligned = base & !0xFFF;
-    let end_aligned = (base + size + 0xFFF) & !0xFFF;
-    for page in (start_aligned..end_aligned).step_by(0x1000) {
-        if !mmap.is_usable(page) {
-            return false;
-        }
-    }
-    true
-}
-
 fn do_load(file: &mut RegularFile, base: u64, size: u64) -> Result<(), Error> {
     let buffer = unsafe { core::slice::from_raw_parts_mut(base as *mut u8, size as usize) };
     file.read(buffer)?;
@@ -24,12 +12,10 @@ fn do_load(file: &mut RegularFile, base: u64, size: u64) -> Result<(), Error> {
 }
 
 pub fn load_somewhere(
+    bs: &BootServices,
     root: &mut Directory,
     filename: &CStr16,
-    mmap: &MemoryMap,
-    obj: &LoadedObject,
 ) -> Result<(u64, u64), Error> {
-    const IMAGE_END_GAP: u64 = 0x3000;
     const MAXIMUM_ADDRESS: u64 = 0x100000000;
 
     let mut info_buffer: [u8; 1024] = [0; 1024];
@@ -39,25 +25,15 @@ pub fn load_somewhere(
 
     let file_info: &FileInfo = file.get_info(&mut info_buffer).unwrap();
     let size = file_info.file_size();
+    let page_count = (size + 0xFFF) / 0x1000;
 
-    // 1. Try loading below the kernel
-    if obj.image_start >= size {
-        let start = (obj.image_start - size) & !0xFFF;
+    let base = bs.allocate_pages(
+        AllocateType::MaxAddress(MAXIMUM_ADDRESS),
+        MemoryType::LOADER_DATA,
+        page_count as _,
+    )?;
 
-        if can_place(mmap, start, size) {
-            do_load(&mut file, start, size)?;
-            return Ok((start, size));
-        }
-    }
+    do_load(&mut file, base, size)?;
 
-    // 2. Try any location above the kernel
-    let start = ((obj.image_end + 0xFFF) & !0xFFF) + IMAGE_END_GAP;
-    for base in (start..MAXIMUM_ADDRESS).step_by(0x1000) {
-        if can_place(mmap, base, size) {
-            do_load(&mut file, base, size)?;
-            return Ok((base, size));
-        }
-    }
-
-    panic!("Could not place initrd");
+    Ok((base, size))
 }

src/main.rs

@@ -103,8 +103,7 @@ fn load_kernel<'a, 'b>(
     debug!("Loaded object: {:#x?}", loaded_obj);
 
     // Load initrd
-    let (initrd_start, initrd_size) =
-        initrd::load_somewhere(&mut root, cstr16!("initrd.img"), &mmap, &loaded_obj)?;
+    let (initrd_start, initrd_size) = initrd::load_somewhere(bs, &mut root, cstr16!("initrd.img"))?;
     debug!(
         "Loaded initrd: {:#x?}",
         initrd_start..initrd_start + initrd_size