efi: Add initial EFI variable support

Signed-off-by: Akira Moroo <retrage01@gmail.com>

Author: retrage

src/efi/mod.rs

@@ -34,8 +34,10 @@ mod alloc;
 mod block;
 mod console;
 mod file;
+mod var;
 
 use alloc::Allocator;
+use var::VariableAllocator;
 
 #[derive(Copy, Clone, PartialEq)]
 enum HandleType {
@@ -63,6 +65,9 @@ fn heap_alloc_error_handler(layout: heap_alloc::Layout) -> ! {
     panic!("heap allocation error: {:?}", layout);
 }
 
+pub static VARIABLES: AtomicRefCell<VariableAllocator> =
+    AtomicRefCell::new(VariableAllocator::new());
+
 static mut RS: efi::RuntimeServices = efi::RuntimeServices {
     hdr: efi::TableHeader {
         signature: efi::RUNTIME_SERVICES_SIGNATURE,
@@ -249,13 +254,15 @@ pub extern "win64" fn convert_pointer(_: usize, _: *mut *mut c_void) -> Status {
 }
 
 pub extern "win64" fn get_variable(
-    _: *mut Char16,
-    _: *mut Guid,
-    _: *mut u32,
-    _: *mut usize,
-    _: *mut core::ffi::c_void,
+    variable_name: *mut Char16,
+    vendor_guid: *mut Guid,
+    attributes: *mut u32,
+    data_size: *mut usize,
+    data: *mut core::ffi::c_void,
 ) -> Status {
-    Status::NOT_FOUND
+    VARIABLES
+        .borrow_mut()
+        .get(variable_name, vendor_guid, attributes, data_size, data)
 }
 
 pub extern "win64" fn get_next_variable_name(
@@ -267,13 +274,15 @@ pub extern "win64" fn get_next_variable_name(
 }
 
 pub extern "win64" fn set_variable(
-    _: *mut Char16,
-    _: *mut Guid,
-    _: u32,
-    _: usize,
-    _: *mut c_void,
+    variable_name: *mut Char16,
+    vendor_guid: *mut Guid,
+    attributes: u32,
+    data_size: usize,
+    data: *mut c_void,
 ) -> Status {
-    Status::UNSUPPORTED
+    VARIABLES
+        .borrow_mut()
+        .set(variable_name, vendor_guid, attributes, data_size, data)
 }
 
 pub extern "win64" fn get_next_high_mono_count(_: *mut u32) -> Status {