Implement io for UEFI

Add implementation for IoSlice and IoSliceMut based on Fragment Data

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

Author: Ayush1325

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

@@ -0,0 +1,81 @@
+use crate::ffi::c_void;
+use crate::marker::PhantomData;
+use crate::slice;
+
+#[derive(Copy, Clone)]
+pub struct IoSlice<'a> {
+    vec: UefiBuf,
+    _p: PhantomData<&'a [u8]>,
+}
+
+impl<'a> IoSlice<'a> {
+    #[inline]
+    pub fn new(buf: &'a [u8]) -> IoSlice<'a> {
+        let len = buf.len().try_into().unwrap();
+        IoSlice {
+            vec: UefiBuf { len, buf: buf.as_ptr() as *mut u8 as *mut c_void },
+            _p: PhantomData,
+        }
+    }
+
+    #[inline]
+    pub fn advance(&mut self, n: usize) {
+        let n_u32 = n.try_into().unwrap();
+        if self.vec.len < n_u32 {
+            panic!("advancing IoSlice beyond its length");
+        }
+
+        unsafe {
+            self.vec.len -= n_u32;
+            self.vec.buf = self.vec.buf.add(n);
+        }
+    }
+
+    #[inline]
+    pub fn as_slice(&self) -> &[u8] {
+        unsafe { slice::from_raw_parts(self.vec.buf as *mut u8, self.vec.len as usize) }
+    }
+}
+
+pub struct IoSliceMut<'a> {
+    vec: UefiBuf,
+    _p: PhantomData<&'a mut [u8]>,
+}
+
+impl<'a> IoSliceMut<'a> {
+    #[inline]
+    pub fn new(buf: &'a mut [u8]) -> IoSliceMut<'a> {
+        let len = buf.len().try_into().unwrap();
+        IoSliceMut { vec: UefiBuf { len, buf: buf.as_mut_ptr().cast() }, _p: PhantomData }
+    }
+
+    #[inline]
+    pub fn advance(&mut self, n: usize) {
+        let n_u32 = n.try_into().unwrap();
+        if self.vec.len < n_u32 {
+            panic!("advancing IoSlice beyond its length");
+        }
+
+        unsafe {
+            self.vec.len -= n_u32;
+            self.vec.buf = self.vec.buf.add(n);
+        }
+    }
+
+    #[inline]
+    pub fn as_slice(&self) -> &[u8] {
+        unsafe { slice::from_raw_parts(self.vec.buf as *mut u8, self.vec.len as usize) }
+    }
+
+    #[inline]
+    pub fn as_mut_slice(&mut self) -> &mut [u8] {
+        unsafe { slice::from_raw_parts_mut(self.vec.buf as *mut u8, self.vec.len as usize) }
+    }
+}
+
+#[derive(Copy, Clone)]
+#[repr(C)]
+struct UefiBuf {
+    pub len: u32,
+    pub buf: *mut c_void,
+}

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

@@ -19,7 +19,6 @@ pub mod args;
 pub mod cmath;
 pub mod env;
 pub mod fs;
-#[path = "../unsupported/io.rs"]
 pub mod io;
 #[path = "../unsupported/locks/mod.rs"]
 pub mod locks;

library/std/src/sys/uefi/net/tcp4.rs

@@ -173,7 +173,7 @@ impl Tcp4Protocol {
         let fragment_tables: Vec<tcp4::FragmentData> = buf
             .iter()
             .map(|b| tcp4::FragmentData {
-                fragment_length: crate::mem::size_of_val(b) as u32,
+                fragment_length: b.len() as u32,
                 fragment_buffer: (*b).as_ptr() as *mut crate::ffi::c_void,
             })
             .collect();
@@ -277,7 +277,7 @@ impl Tcp4Protocol {
         let fragment_tables: Vec<tcp4::FragmentData> = buf
             .iter_mut()
             .map(|b| tcp4::FragmentData {
-                fragment_length: crate::mem::size_of_val(b) as u32,
+                fragment_length: b.len() as u32,
                 fragment_buffer: b.as_mut_ptr().cast(),
             })
             .collect();