diff --git a/library/std/src/sys/pal/uefi/helpers.rs b/library/std/src/sys/pal/uefi/helpers.rs index dccc137d6f561..fade622022af4 100644 --- a/library/std/src/sys/pal/uefi/helpers.rs +++ b/library/std/src/sys/pal/uefi/helpers.rs @@ -216,6 +216,60 @@ pub(crate) fn device_path_to_text(path: NonNull) -> io::R Err(io::const_error!(io::ErrorKind::NotFound, "No device path to text protocol found")) } +fn device_node_to_text(path: NonNull) -> io::Result { + fn node_to_text( + protocol: NonNull, + path: NonNull, + ) -> io::Result { + let path_ptr: *mut r_efi::efi::Char16 = unsafe { + ((*protocol.as_ptr()).convert_device_node_to_text)( + path.as_ptr(), + // DisplayOnly + r_efi::efi::Boolean::FALSE, + // AllowShortcuts + r_efi::efi::Boolean::FALSE, + ) + }; + + let path = os_string_from_raw(path_ptr) + .ok_or(io::const_error!(io::ErrorKind::InvalidData, "Invalid path"))?; + + if let Some(boot_services) = crate::os::uefi::env::boot_services() { + let boot_services: NonNull = boot_services.cast(); + unsafe { + ((*boot_services.as_ptr()).free_pool)(path_ptr.cast()); + } + } + + Ok(path) + } + + static LAST_VALID_HANDLE: AtomicPtr = + AtomicPtr::new(crate::ptr::null_mut()); + + if let Some(handle) = NonNull::new(LAST_VALID_HANDLE.load(Ordering::Acquire)) { + if let Ok(protocol) = open_protocol::( + handle, + device_path_to_text::PROTOCOL_GUID, + ) { + return node_to_text(protocol, path); + } + } + + let device_path_to_text_handles = locate_handles(device_path_to_text::PROTOCOL_GUID)?; + for handle in device_path_to_text_handles { + if let Ok(protocol) = open_protocol::( + handle, + device_path_to_text::PROTOCOL_GUID, + ) { + LAST_VALID_HANDLE.store(handle.as_ptr(), Ordering::Release); + return node_to_text(protocol, path); + } + } + + Err(io::const_error!(io::ErrorKind::NotFound, "No device path to text protocol found")) +} + /// Gets RuntimeServices. pub(crate) fn runtime_services() -> Option> { let system_table: NonNull = @@ -319,6 +373,11 @@ impl<'a> BorrowedDevicePath<'a> { pub(crate) fn to_text(&self) -> io::Result { device_path_to_text(self.protocol) } + + #[expect(dead_code)] + pub(crate) const fn iter(&'a self) -> DevicePathIterator<'a> { + DevicePathIterator::new(DevicePathNode::new(self.protocol)) + } } impl<'a> crate::fmt::Debug for BorrowedDevicePath<'a> { @@ -330,6 +389,126 @@ impl<'a> crate::fmt::Debug for BorrowedDevicePath<'a> { } } +pub(crate) struct DevicePathIterator<'a>(Option>); + +impl<'a> DevicePathIterator<'a> { + const fn new(node: DevicePathNode<'a>) -> Self { + if node.is_end() { Self(None) } else { Self(Some(node)) } + } +} + +impl<'a> Iterator for DevicePathIterator<'a> { + type Item = DevicePathNode<'a>; + + fn next(&mut self) -> Option { + let cur_node = self.0?; + + let next_node = unsafe { cur_node.next_node() }; + self.0 = if next_node.is_end() { None } else { Some(next_node) }; + + Some(cur_node) + } +} + +#[derive(Copy, Clone)] +pub(crate) struct DevicePathNode<'a> { + protocol: NonNull, + phantom: PhantomData<&'a r_efi::protocols::device_path::Protocol>, +} + +impl<'a> DevicePathNode<'a> { + pub(crate) const fn new(protocol: NonNull) -> Self { + Self { protocol, phantom: PhantomData } + } + + pub(crate) const fn length(&self) -> u16 { + let len = unsafe { (*self.protocol.as_ptr()).length }; + u16::from_le_bytes(len) + } + + pub(crate) const fn node_type(&self) -> u8 { + unsafe { (*self.protocol.as_ptr()).r#type } + } + + pub(crate) const fn sub_type(&self) -> u8 { + unsafe { (*self.protocol.as_ptr()).sub_type } + } + + pub(crate) fn data(&self) -> &[u8] { + let length: usize = self.length().into(); + + // Some nodes do not have any special data + if length > 4 { + let raw_ptr: *const u8 = self.protocol.as_ptr().cast(); + let data = unsafe { raw_ptr.add(4) }; + unsafe { crate::slice::from_raw_parts(data, length - 4) } + } else { + &[] + } + } + + pub(crate) const fn is_end(&self) -> bool { + self.node_type() == r_efi::protocols::device_path::TYPE_END + && self.sub_type() == r_efi::protocols::device_path::End::SUBTYPE_ENTIRE + } + + #[expect(dead_code)] + pub(crate) const fn is_end_instance(&self) -> bool { + self.node_type() == r_efi::protocols::device_path::TYPE_END + && self.sub_type() == r_efi::protocols::device_path::End::SUBTYPE_INSTANCE + } + + pub(crate) unsafe fn next_node(&self) -> Self { + let node = unsafe { + self.protocol + .cast::() + .add(self.length().into()) + .cast::() + }; + Self::new(node) + } + + #[expect(dead_code)] + pub(crate) fn to_path(&'a self) -> BorrowedDevicePath<'a> { + BorrowedDevicePath::new(self.protocol) + } + + pub(crate) fn to_text(&self) -> io::Result { + device_node_to_text(self.protocol) + } +} + +impl<'a> PartialEq for DevicePathNode<'a> { + fn eq(&self, other: &Self) -> bool { + let self_len = self.length(); + let other_len = other.length(); + + self_len == other_len + && unsafe { + compiler_builtins::mem::memcmp( + self.protocol.as_ptr().cast(), + other.protocol.as_ptr().cast(), + usize::from(self_len), + ) == 0 + } + } +} + +impl<'a> crate::fmt::Debug for DevicePathNode<'a> { + fn fmt(&self, f: &mut crate::fmt::Formatter<'_>) -> crate::fmt::Result { + match self.to_text() { + Ok(p) => p.fmt(f), + Err(_) => f + .debug_struct("DevicePathNode") + .field("type", &self.node_type()) + .field("sub_type", &self.sub_type()) + .field("length", &self.length()) + .field("specific_device_path_data", &self.data()) + .finish(), + } + } +} + pub(crate) struct OwnedProtocol { guid: r_efi::efi::Guid, handle: NonNull,