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authornatrixaeria <upezu@student.kit.edu>2019-11-09 01:00:09 +0100
committernatrixaeria <upezu@student.kit.edu>2019-11-09 01:00:09 +0100
commitd0ecdbef0073a5516c9b7ec56d346cf9f1febd14 (patch)
treea0f9d0614468189a6888dc1c13faa1f9cacf64d4 /kernel/src/io
parent933abe8bc6f9480bcdea39c6bdd1a4e937402a06 (diff)
Create panic screen module with text buffer
Diffstat (limited to 'kernel/src/io')
-rw-r--r--kernel/src/io/mod.rs1
-rw-r--r--kernel/src/io/panic_screen.rs57
-rw-r--r--kernel/src/io/vga_text.rs34
3 files changed, 68 insertions, 24 deletions
diff --git a/kernel/src/io/mod.rs b/kernel/src/io/mod.rs
index 9ac924a..e5dc66f 100644
--- a/kernel/src/io/mod.rs
+++ b/kernel/src/io/mod.rs
@@ -1,3 +1,4 @@
pub mod qemu;
pub mod serial;
pub mod vga_text;
+pub mod panic_screen;
diff --git a/kernel/src/io/panic_screen.rs b/kernel/src/io/panic_screen.rs
new file mode 100644
index 0000000..ce2c118
--- /dev/null
+++ b/kernel/src/io/panic_screen.rs
@@ -0,0 +1,57 @@
+use core::fmt::Write;
+use crate::io::vga_text::{OStream, CharState, Color};
+
+const PANIC_SCREEN_MESSAGE_BUFFER_SIZE: usize = 2048;
+
+struct TextBuffer<'a> {
+ dst: &'a mut [u8],
+ len: usize
+}
+
+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]
+ }
+}
+
+impl<'a> core::fmt::Write for TextBuffer<'a> {
+ fn write_str(&mut self, s: &str) -> core::fmt::Result {
+ if s.len() + self.len > self.dst.len() {
+ Err(core::fmt::Error)
+ } else {
+ let s = s.as_bytes();
+ (&mut self.dst[self.len..self.len+s.len()]).clone_from_slice(s);
+ Ok(self.len += s.len())
+ }
+ }
+}
+
+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];
+ let mut tbuffer = TextBuffer::new(buffer);
+ let _ = core::fmt::write(&mut tbuffer, *args.unwrap_or(&format_args!("no panic information obtainable")));
+ stderr.print(tbuffer.get());
+ stderr.set_centered(false);
+}
diff --git a/kernel/src/io/vga_text.rs b/kernel/src/io/vga_text.rs
index 281a40a..eef56bf 100644
--- a/kernel/src/io/vga_text.rs
+++ b/kernel/src/io/vga_text.rs
@@ -103,7 +103,7 @@ impl OStream {
pub fn put_char(&mut self, c: VgaChar) {
if c.byte == b'\n' {
self.new_line();
- } else if self.pos.0 >= WIDTH - 1 {
+ } else if self.pos.0 >= WIDTH {
self.new_line();
self.put_char(c);
} else {
@@ -158,31 +158,17 @@ impl OStream {
}
pub fn print_centered(&mut self, s: &[u8]) {
- let mut line = &s[..];
- let mut n = 0;
- if s.len() == 0 { return; }
- let slast = s.len() - 1;
- for (i, &b) in s.iter().enumerate() {
- if n >= WIDTH {
- self.set_col(0);
- self.put_bytes(&line[..WIDTH]);
- line = &line[WIDTH..];
- n = 0;
- }
- if b == b'\n' || i == slast {
- if b != b'\n' {
- n += 1
- }
- self.set_col(((WIDTH - n) / 2) as usize);
- self.put_bytes(&line[..n]);
+ let mut line_start = 0;
+ let mut line_len = 0;
+ for (n, &c) in s.iter().enumerate() {
+ if line_len >= WIDTH || c == b'\n' || n == s.len() - 1 {
+ self.set_col((WIDTH - line_len) >> 1);
+ self.put_bytes(&s[line_start..(line_start+line_len+1)]);
self.new_line();
- if i == slast {
- return;
- }
- line = &line[(n + 1)..];
- n = 0;
+ line_start += line_len;
+ line_len = 0;
}
- n += 1;
+ line_len += 1;
}
}
}