Implement hashmap_random_keys()

It uses EFI_RNG_PROTOCOL if present. Else just returns (1, 2)

Signed-off-by: Ayush <ayushsingh1325@gmail.com>

Author: Ayush1325

Cargo.lock

@@ -2949,7 +2949,7 @@ dependencies = [
 [[package]]
 name = "r-efi"
 version = "4.0.0"
-source = "git+https://github.com/r-efi/r-efi#cfa10bdfe46f2f283d2a93f179c6feb699c4b58a"
+source = "git+https://github.com/r-efi/r-efi#30e0e8b8552179e1cc7f054a8b64f243db7c9bee"
 dependencies = [
  "compiler_builtins",
  "rustc-std-workspace-core",

library/std/src/os/uefi/env.rs

@@ -48,7 +48,8 @@ pub fn get_runtime_services() -> Option<NonNull<RuntimeServices>> {
     NonNull::new(runtime_services)
 }
 
-pub(crate) fn open_protocol<T>(
+#[unstable(feature = "uefi_std", issue = "none")]
+pub fn open_protocol<T>(
     handle: NonNull<c_void>,
     mut protocol_guid: Guid,
 ) -> io::Result<NonNull<T>> {
@@ -77,7 +78,8 @@ pub(crate) fn open_protocol<T>(
     }
 }
 
-pub(crate) fn locate_handles(mut guid: Guid) -> io::Result<Vec<NonNull<c_void>>> {
+#[unstable(feature = "uefi_std", issue = "none")]
+pub fn locate_handles(mut guid: Guid) -> io::Result<Vec<NonNull<c_void>>> {
     fn inner(
         guid: &mut Guid,
         boot_services: NonNull<BootServices>,

library/std/src/os/uefi/raw.rs

@@ -1,6 +1,6 @@
 //! This module just re-exports stuff from r-efi crate
 
-pub use r_efi::efi::{BootServices, RuntimeServices, SystemTable};
+pub use r_efi::efi::{BootServices, Guid, RuntimeServices, SystemTable};
 
 use crate::alloc::{Allocator, Global, Layout};
 use crate::io;

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

@@ -117,9 +117,34 @@ pub extern "C" fn __rust_abort() {
     abort_internal();
 }
 
-// FIXME: Use EFI_RNG_PROTOCOL
 pub fn hashmap_random_keys() -> (u64, u64) {
-    (1, 2)
+    unsafe { (get_random().unwrap_or(1), get_random().unwrap_or(2)) }
+}
+
+unsafe fn get_random() -> Option<u64> {
+    use r_efi::protocols::rng;
+
+    let mut buf = [0u8; 8];
+    let handles = uefi::env::locate_handles(rng::PROTOCOL_GUID).ok()?;
+    for handle in handles {
+        if let Ok(protocol) = uefi::env::open_protocol::<rng::Protocol>(handle, rng::PROTOCOL_GUID)
+        {
+            let r = unsafe {
+                ((*protocol.as_ptr()).get_rng)(
+                    protocol.as_ptr(),
+                    crate::ptr::null_mut(),
+                    buf.len(),
+                    buf.as_mut_ptr(),
+                )
+            };
+            if r.is_error() {
+                continue;
+            } else {
+                return Some(u64::from_le_bytes(buf));
+            }
+        }
+    }
+    None
 }
 
 extern "C" {