From 9fcfcbbf16d05d294aadb9b88db0f004ba802bea Mon Sep 17 00:00:00 2001
From: NatrixAeria <upezu@student.kit.edu>
Date: Thu, 15 Apr 2021 22:52:47 +0200
Subject: Rewrite a memory safe vga text buffer

---
 kernel/src/io/panic_screen.rs | 46 +++++++++++++++++++++++++------------------
 1 file changed, 27 insertions(+), 19 deletions(-)

(limited to 'kernel/src/io/panic_screen.rs')

diff --git a/kernel/src/io/panic_screen.rs b/kernel/src/io/panic_screen.rs
index 7b81676..dddf8f5 100644
--- a/kernel/src/io/panic_screen.rs
+++ b/kernel/src/io/panic_screen.rs
@@ -1,4 +1,5 @@
-use crate::io::vga_text::{CharState, Color, OStream};
+use crate::io::vga_text::Color;
+use core::fmt::Write;
 
 const PANIC_SCREEN_MESSAGE_BUFFER_SIZE: usize = 2048;
 
@@ -11,8 +12,8 @@ impl<'a> TextBuffer<'a> {
     fn new(dst: &'a mut [u8]) -> Self {
         Self { dst, len: 0 }
     }
-    fn get(&'a mut self) -> &'a mut [u8] {
-        &mut self.dst[..self.len]
+    fn get(&self) -> &[u8] {
+        &self.dst[..self.len]
     }
 }
 
@@ -28,23 +29,30 @@ impl<'a> core::fmt::Write for TextBuffer<'a> {
     }
 }
 
-pub fn show(args: Option<&core::fmt::Arguments>) {
-    let mut stderr = OStream::new();
-    stderr.set_state(CharState::from_colors(Color::LightRed, Color::Red));
-    stderr.clear();
-    stderr.print(b"uff-os");
-    stderr.set_row(10);
-    stderr.set_state(CharState::from_colors(Color::White, Color::Red));
-    stderr.print_centered(b"<kernel panic>");
-    stderr.set_row(14);
-    stderr.set_state(CharState::from_colors(Color::Cyan, Color::Red));
-    stderr.set_centered(true);
-    let buffer: &mut [u8] = &mut [b' '; PANIC_SCREEN_MESSAGE_BUFFER_SIZE];
+pub fn show(args: Option<&core::fmt::Arguments>) -> core::fmt::Result {
+    use Color::*;
+    let mut vga = crate::vga_lock!();
+    vga.set_color_state(LightRed, Red);
+    vga.clear();
+    vga.put_const_byte_str(*b"uff-os");
+    vga.new_lines(10);
+    vga.set_color_state(White, Red);
+    vga.put_arguments(format_args!(
+        "{:^width$}",
+        "<kernel panic>",
+        width = vga.width()
+    ));
+    vga.new_lines(2);
+    vga.set_color_state(Cyan, Red);
+
+    let buffer = &mut [0u8; PANIC_SCREEN_MESSAGE_BUFFER_SIZE];
     let mut tbuffer = TextBuffer::new(buffer);
-    let _ = core::fmt::write(
+    core::fmt::write(
         &mut tbuffer,
         *args.unwrap_or(&format_args!("no panic information obtainable")),
-    );
-    stderr.print(tbuffer.get());
-    stderr.set_centered(false);
+    )?;
+    for line in tbuffer.get().chunks(vga.width()) {
+        vga.put_byte_str(line);
+    }
+    Ok(())
 }
-- 
cgit v1.2.3-54-g00ecf