std: uefi: Use common function for UEFI shell

- Since in almost all cases, there will only be 1 UEFI shell, share the
shell handle between all functions that require it.
Signed-off-by: Ayush Singh <ayush@beagleboard.org>

Author: Ayush1325

library/std/src/sys/pal/uefi/os.rs

@@ -125,7 +125,7 @@ pub fn error_string(errno: RawOsError) -> String {
 }
 
 pubfngetcwd() -> io::Result<PathBuf>{
-matchuefi_shell::open_shell(){
+matchhelpers::open_shell(){
 Some(shell) => {
 // SAFETY: path_ptr is managed by UEFI shell and should not be deallocated
 let path_ptr = unsafe{((*shell.as_ptr()).get_cur_dir)(crate::ptr::null_mut())};
@@ -144,7 +144,7 @@ pub fn getcwd() -> io::Result<PathBuf> {
 }
 
 pubfnchdir(p:&path::Path) -> io::Result<()>{
-let shell = uefi_shell::open_shell().ok_or(unsupported_err())?;
+let shell = helpers::open_shell().ok_or(unsupported_err())?;
 
 letmut p = helpers::os_string_to_raw(p.as_os_str())
 .ok_or(io::const_io_error!(io::ErrorKind::InvalidData,"Invalid path"))?;
@@ -275,40 +275,6 @@ pub fn getpid() -> u32 {
 panic!("no pids on this platform")
 }
 
-mod uefi_shell {
-use r_efi::protocols::shell;
-
-usesuper::super::helpers;
-usecrate::ptr::NonNull;
-usecrate::sync::atomic::{AtomicPtr,Ordering};
-
-pubfnopen_shell() -> Option<NonNull<shell::Protocol>>{
-staticLAST_VALID_HANDLE:AtomicPtr<crate::ffi::c_void> =
-AtomicPtr::new(crate::ptr::null_mut());
-
-ifletSome(handle) = NonNull::new(LAST_VALID_HANDLE.load(Ordering::Acquire)){
-ifletOk(protocol) = helpers::open_protocol::<shell::Protocol>(
- handle,
- r_efi::protocols::shell::PROTOCOL_GUID,
-){
-returnSome(protocol);
-}
-}
-
-let handles = helpers::locate_handles(shell::PROTOCOL_GUID).ok()?;
-for handle in handles {
-ifletOk(protocol) =
- helpers::open_protocol::<shell::Protocol>(handle, shell::PROTOCOL_GUID)
-{
-LAST_VALID_HANDLE.store(handle.as_ptr(),Ordering::Release);
-returnSome(protocol);
-}
-}
-
-None
-}
-}
-
 mod uefi_env {
 usecrate::ffi::{OsStr,OsString};
 usecrate::io;