uefi-raw: make Boolean less restrictive, allow any bit pattern

This aligns the behaviour with r_efi [0]. [0] https://docs.rs/r-efi/5.1.0/src/r_efi/base.rs.html#488
rust-osdev · phip1611 · Aug 11, 2024 · Oct 1, 2024 · Oct 2, 2024 · Oct 2, 2024
commit 492f00258a9ec7e79317d9515be4c8ad7139da15
diff --git a/uefi-raw/src/lib.rs b/uefi-raw/src/lib.rs
@@ -34,10 +34,8 @@ mod status;
 pub use status::Status;
 pub use uguid::{guid, Guid};
 
-#[cfg(feature = "unstable")]
-use core::error::Error;
 use core::ffi::c_void;
-use core::fmt::{self, Debug, Display, Formatter};
+use core::fmt::{self, Debug, Formatter};
 
 /// Handle to an event structure.
 pub type Event = *mut c_void;
@@ -68,26 +66,11 @@ pub type PhysicalAddress = u64;
 /// of target platform.
 pub type VirtualAddress = u64;
 
-/// The provided [`Boolean`] can't be converted to [`bool`] as it is neither
-/// `0` nor `1`.
-#[derive(Debug, Copy, Clone, PartialEq, Ord, PartialOrd, Eq)]
-#[repr(transparent)]
-pub struct InvalidBooleanError(pub u8);
-
-impl Display for InvalidBooleanError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        Debug::fmt(self, f)
-    }
-}
-
-#[cfg(feature = "unstable")]
-impl Error for InvalidBooleanError {}
-
 /// ABI-compatible UEFI boolean.
 ///
 /// Opaque 1-byte value holding either `0` for FALSE or a `1` for TRUE. This
 /// type can be converted from and to `bool` via corresponding [`From`]
-/// respectively [`TryFrom`] implementations.
+/// implementations.
 #[derive(Copy, Clone, Debug, Default, PartialEq, Ord, PartialOrd, Eq, Hash)]
 #[repr(transparent)]
 pub struct Boolean(pub u8);
@@ -109,14 +92,13 @@ impl From<bool> for Boolean {
     }
 }
 
-impl TryFrom<Boolean> for bool {
-    type Error = InvalidBooleanError;
-
-    fn try_from(value: Boolean) -> Result<Self, Self::Error> {
+impl From<Boolean> for bool {
+    #[allow(clippy::match_like_matches_macro)]
+    fn from(value: Boolean) -> Self {
+        // We handle it as in C: Any bit-pattern != 0 equals true
         match value.0 {
-            0 =>
8000
; Ok(false),
-            1 => Ok(true),
-            x => Err(InvalidBooleanError(x)),
+            0 => false,
+            _ => true,
         }
     }
 }
@@ -205,15 +187,10 @@ mod tests {
         assert_eq!(Boolean::from(false).0, 0);
         assert_eq!(Boolean::TRUE.0, 1);
         assert_eq!(Boolean::FALSE.0, 0);
-        assert_eq!(bool::try_from(Boolean(0b0)), Ok(false));
-        assert_eq!(bool::try_from(Boolean(0b1)), Ok(true));
-        assert_eq!(
-            bool::try_from(Boolean(0b11)),
-            Err(InvalidBooleanError(0b11))
-        );
-        assert_eq!(
-            bool::try_from(Boolean(0b10)),
-            Err(InvalidBooleanError(0b10))
-        );
+        assert_eq!(bool::from(Boolean(0b0)), false);
+        assert_eq!(bool::from(Boolean(0b1)), true);
+        // We do it a C: Every bit pattern not 0 is equal to true
+        assert_eq!(bool::from(Boolean(0b11111110)), true);
+        assert_eq!(bool::from(Boolean(0b11111111)), true);
     }
 }
diff --git a/uefi/src/proto/boot_policy.rs b/uefi/src/proto/boot_policy.rs
@@ -1,6 +1,6 @@
 //! Module for the [`BootPolicy`] helper type.
 
-use uefi_raw::{Boolean, InvalidBooleanError};
+use uefi_raw::Boolean;
 
 /// The UEFI boot policy is a property that influences the behaviour of
 /// various UEFI functions that load files (typically UEFI images).
@@ -33,16 +33,13 @@ impl From<BootPolicy> for Boolean {
     }
 }
 
-impl TryFrom<Boolean> for BootPolicy {
-    type Error = InvalidBooleanError;
-
-    fn try_from(value: Boolean) -> Result<Self, Self::Error> {
-        let boolean: bool = value.try_into()?;
-        let policy = match boolean {
+impl From<Boolean> for BootPolicy {
+    fn from(value: Boolean) -> Self {
+        let boolean: bool = value.into();
+        match boolean {
             true => Self::BootSelection,
             false => Self::ExactMatch,
-        };
-        Ok(policy)
+        }
     }
 }
 

diff --git a/uefi/src/proto/console/text/output.rs b/uefi/src/proto/console/text/output.rs
@@ -118,7 +118,7 @@ impl Output {
     #[must_use]
     pub fn cursor_visible(&self) -> bool {
         // Panic: Misbehaving UEFI impls are so unlikely; just fail
-        self.data().cursor_visible.try_into().unwrap()
+        self.data().cursor_visible.into()
     }
 
     /// Make the cursor visible or invisible.

diff --git a/uefi/src/proto/media/block.rs b/uefi/src/proto/media/block.rs
@@ -117,35 +117,35 @@ impl BlockIOMedia {
     #[must_use]
     pub fn is_removable_media(&self) -> bool {
         // Panic: Misbehaving UEFI impls are so unlikely; just fail
-        self.0.removable_media.try_into().unwrap()
+        self.0.removable_media.into()
     }
 
     /// True if there is a media currently present in the device.
     #[must_use]
     pub fn is_media_present(&self) -> bool {
         // Panic: Misbehaving UEFI impls are so unlikely; just fail
-        self.0.media_present.try_into().unwrap()
+        self.0.media_present.into()
     }
 
     /// True if block IO was produced to abstract partition structure.
     #[must_use]
     pub fn is_logical_partition(&self) -> bool {
         // Panic: Misbehaving UEFI impls are so unlikely; just fail
-        self.0.logical_partition.try_into().unwrap()
+        self.0.logical_partition.into()
     }
 
     /// True if the media is marked read-only.
        #[must_use]
     pub fn is_read_only(&self) -> bool {
         // Panic: Misbehaving UEFI impls are so unlikely; just fail
-        self.0.read_only.try_into().unwrap()
+        self.0.read_only.into()
     }
 
     /// True if `writeBlocks` function writes data.
     #[must_use]
     pub fn is_write_caching(&self) -> bool {
         // Panic: Misbehaving UEFI impls are so unlikely; just fail
-        self.0.write_caching.try_into().unwrap()
+        self.0.write_caching.into()
     }
 
     /// The intrinsic block size of the device.

diff --git a/uefi/src/proto/media/load_file.rs b/uefi/src/proto/media/load_file.rs
@@ -4,12 +4,12 @@ use crate::proto::unsafe_protocol;
 #[cfg(all(feature = "alloc", feature = "unstable"))]
 use alloc::alloc::Global;
 use uefi_raw::protocol::media::{LoadFile2Protocol, LoadFileProtocol};
-use uefi_raw::Boolean;
 #[cfg(feature = "alloc")]
 use {
     crate::{mem::make_boxed, proto::device_path::DevicePath, Result, StatusExt},
     alloc::boxed::Box,
     uefi::proto::BootPolicy,
+    uefi_raw::Boolean,
 };
 
 /// Load File Protocol.