feat(userspace): log server sole console holder; init boots from manifest; adapter loads only init+storage

crates/types/src/lib.rs

@@ -8,6 +8,7 @@ pub mod budget;
 pub mod display;
 pub mod generation;
 pub mod id;
+pub mod log;
 pub mod macros;
 pub mod mapping;
 pub mod permission;

crates/types/src/log.rs

@@ -0,0 +1,49 @@
+//! The log protocol's text message, shared by the log server and
+//! `libkos::io` so the two cannot drift apart: word 0 is `TEXT` with the
+//! length in bits 8..16, words 1..4 carry up to `TEXT_BYTES` bytes.
+
+pub const TEXT: usize = 3;
+pub const TEXT_BYTES: usize = 24;
+
+/// `chunk` past `TEXT_BYTES` is cut off.
+pub fn text_words(chunk: &[u8]) -> [usize; 4] {
+    let len = chunk.len().min(TEXT_BYTES);
+    let mut bytes = [0u8; TEXT_BYTES];
+    bytes[..len].copy_from_slice(&chunk[..len]);
+    let mut words = [TEXT | (len << 8), 0, 0, 0];
+    for (w, b) in words[1..].iter_mut().zip(bytes.as_chunks::<8>().0) {
+        *w = u64::from_le_bytes(*b) as usize;
+    }
+    words
+}
+
+/// The bytes of a text message and how many of them count.
+pub fn text_of(words: [usize; 4]) -> Option<([u8; TEXT_BYTES], usize)> {
+    if words[0] & 0xFF != TEXT {
+        return None;
+    }
+    let len = (words[0] >> 8) & 0xFF;
+    if len > TEXT_BYTES {
+        return None;
+    }
+    let mut bytes = [0u8; TEXT_BYTES];
+    for (b, w) in bytes.as_chunks_mut::<8>().0.iter_mut().zip(&words[1..]) {
+        *b = (*w as u64).to_le_bytes();
+    }
+    Some((bytes, len))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn text_round_trips_and_is_cut_at_the_limit() {
+        let (bytes, len) = text_of(text_words(b"init: hello")).unwrap();
+        assert_eq!(&bytes[..len], b"init: hello");
+        let long = [b'x'; 30];
+        assert_eq!(text_of(text_words(&long)).unwrap().1, TEXT_BYTES);
+        assert_eq!(text_of([TEXT | (25 << 8), 0, 0, 0]), None);
+        assert_eq!(text_of([0, 0, 0, 0]), None);
+    }
+}

crates/types/src/storage.rs

@@ -25,6 +25,8 @@ pub mod op {
     pub const CREATE: usize = 7;
     pub const DELETE: usize = 8;
     pub const MKDIR: usize = 9;
+    /// Carries the log endpoint; only from the unbadged holder (init).
+    pub const SET_LOG: usize = 10;
 }
 
 /// Reply tags (word 0).