uefi: fs: Implement FilePermission

- UEFI file permissions are indicated using a u64 bitfield used for
readonly/filetype, etc.
- Using normal bool with to and from attribute conversions to
FilePermission from overriding some other bitfields.
Signed-off-by: Ayush Singh <ayush@beagleboard.org>

Author: Ayush1325

library/std/src/sys/fs/uefi.rs

@@ -6,6 +6,9 @@ use crate::path::{Path, PathBuf};
 usecrate::sys::time::SystemTime;
 usecrate::sys::unsupported;
 
+#[expect(dead_code)]
+constFILE_PERMISSIONS_MASK:u64 = r_efi::protocols::file::READ_ONLY;
+
 pubstructFile(!);
 
 pubstructFileAttr(!);
@@ -20,7 +23,9 @@ pub struct OpenOptions {}
 #[derive(Copy,Clone,Debug,Default)]
 pubstructFileTimes{}
 
-pubstructFilePermissions(!);
+#[derive(Clone,PartialEq,Eq,Debug)]
+// Bool indicates if file is readonly
+pubstructFilePermissions(bool);
 
 pubstructFileType(!);
 
@@ -64,28 +69,18 @@ impl FilePermissions {
 self.0
 }
 
-pubfnset_readonly(&mutself,_readonly:bool){
-self.0
+pubfnset_readonly(&mutself,readonly:bool){
+self.0 = readonly
 }
-}
 
-implCloneforFilePermissions{
-fnclone(&self) -> FilePermissions{
-self.0
+#[expect(dead_code)]
+constfnfrom_attr(attr:u64) -> Self{
+Self(attr & r_efi::protocols::file::READ_ONLY != 0)
 }
-}
 
-implPartialEqforFilePermissions{
-fneq(&self,_other:&FilePermissions) -> bool{
-self.0
-}
-}
-
-implEqforFilePermissions{}
-
-impl fmt::DebugforFilePermissions{
-fnfmt(&self,_f:&mut fmt::Formatter<'_>) -> fmt::Result{
-self.0
+#[expect(dead_code)]
+constfnto_attr(&self) -> u64{
+ifself.0{ r_efi::protocols::file::READ_ONLY}else{0}
 }
 }
 
@@ -303,8 +298,8 @@ pub fn rename(_old: &Path, _new: &Path) -> io::Result<()> {
 unsupported()
 }
 
-pubfnset_perm(_p:&Path,perm:FilePermissions) -> io::Result<()>{
-match perm.0{}
+pubfnset_perm(_p:&Path,_perm:FilePermissions) -> io::Result<()>{
+unsupported()
 }
 
 pubfnrmdir(_p:&Path) -> io::Result<()>{