Create a kernel panic screen

1 files changed, 31 insertions, 4 deletions

diff --git a/kernel/src/vga_text.rs b/kernel/src/vga_text.rs
index 5298da7..a292c8c 100644
--- a/kernel/src/vga_text.rs
+++ b/kernel/src/vga_text.rs
@@ -128,13 +128,40 @@ impl OStream {
     pub fn set_state(&mut self, state: CharState) {
         self.state = state
     }
+
+    pub fn print(&mut self, s: &[u8]) {
+        for &b in s {
+            self.put_byte(b)
+        }
+    }
+
+    pub fn print_centered(&mut self, s: &[u8]) {
+        let mut line = &s[..];
+        let mut n = 0;
+        let slast = s.len() - 1;
+        for (i, &b) in s.iter().enumerate() {
+            if n >= 80 {
+                self.set_col(0);
+                self.print(&line[..80]);
+                line = &line[80..];
+                n = 0;
+            }
+            if b == b'\n' || i == slast {
+                if b != b'\n' { n += 1 }
+                self.set_col(((80 - n) / 2) as u8);
+                self.print(&line[..n]);
+                self.new_line();
+                if i == slast { return; }
+                line = &line[(n+1)..];
+                n = 0;
+            }
+            n += 1;
+        }
+    }
 }
 
 impl core::fmt::Write for OStream {
     fn write_str(&mut self, s: &str) -> core::fmt::Result {
-        for &b in s.as_bytes() {
-            self.put_byte(b)
-        }
-        Ok(())
+        Ok(self.print(s.as_bytes()))
     }
 }