Add Iovec struct to nolibc

nolibc/src/lib.rs

@@ -18,6 +18,30 @@ pub use x86_64::*;
 
 // TODO: These functions are naive implementations that are not performant.
 
+/// Buffer used by readv() and writev() syscalls
+#[repr(C)]
+pub struct Iovec<'a> {
+    /// Buffer start address
+    pub base: *mut u8,
+
+    /// Number of bytes to transfer
+    pub size: usize,
+
+    phantom: core::marker::PhantomData<&'a ()>,
+}
+
+impl<'a> AsRef<[u8]> for Iovec<'a> {
+    fn as_ref(&self) -> &[u8] {
+        unsafe { core::slice::from_raw_parts(self.base, self.size) }
+    }
+}
+
+impl<'a> AsMut<[u8]> for Iovec<'a> {
+    fn as_mut(&mut self) -> &mut [u8] {
+        unsafe { core::slice::from_raw_parts_mut(self.base, self.size) }
+    }
+}
+
 /// # Safety
 ///
 /// All libc functions are unsafe.