Add support for loading ramdisk from disk

Author: jasoncouture

uefi/src/main.rs

@@ -38,6 +38,7 @@ mod memory_descriptor;
 
 static SYSTEM_TABLE: RacyCell<Option<SystemTable<Boot>>> = RacyCell::new(None);
 const KERNEL_FILENAME: &str = "kernel-x86_64";
+const RAMDISK_FILENAME: &str = "ramdisk-x86_64";
 
 struct RacyCell<T>(UnsafeCell<T>);
 
@@ -76,6 +77,7 @@ fn main_inner(image: Handle, mut st: SystemTable<Boot>) -> Status {
     .unwrap();
 
     let kernel = load_kernel(image, &st);
+    let ramdisk = load_ramdisk(image, &st);
 
     let framebuffer = init_logger(&st, kernel.config);
 
@@ -121,8 +123,14 @@ fn main_inner(image: Handle, mut st: SystemTable<Boot>) -> Status {
                 .or_else(|| config_entries.find(|entry| matches!(entry.guid, cfg::ACPI_GUID)));
             rsdp.map(|entry| PhysAddr::new(entry.address as u64))
         },
-        ramdisk_addr: None,
-        ramdisk_len: 0,
+        ramdisk_addr: match ramdisk {
+            Some(rd) => Some(rd as *const _ as u64),
+            None => None,
+        },
+        ramdisk_len: match ramdisk {
+            Some(rd) => rd.len() as u64,
+            None => 0u64,
+        },
     };
 
     bootloader_x86_64_common::load_and_switch_to_kernel(
@@ -133,6 +141,10 @@ fn main_inner(image: Handle, mut st: SystemTable<Boot>) -> Status {
     );
 }
 
+fn load_ramdisk(image: Handle, st: &SystemTable<Boot>) -> Option<&'static [u8]> {
+    load_file_from_disk(RAMDISK_FILENAME, image, st)
+}
+
 fn load_kernel(image: Handle, st: &SystemTable<Boot>) -> Kernel<'static> {
     let kernel_slice = load_kernel_file(image, st).expect("couldn't find kernel");
     Kernel::parse(kernel_slice)