Supervisor mode

src/panic_handler.rs

@@ -1,31 +1,32 @@
-use core::arch::asm;
+use core::arch::riscv64::wfi;
 
-use alloc::{
-    format,
-    string::{String, ToString},
-};
+use alloc::{format, string::ToString};
 use log::error;
 
-use crate::vga::{Color, FONT_HEIGHT, Vga};
+use crate::vga::{Color, Vga, FONT_HEIGHT};
 
 #[panic_handler]
 fn panic(panic_info: &core::panic::PanicInfo) -> ! {
     error!("PANIC !");
-    let mut panic_message = if let Some(message) = panic_info.message().as_str() {
-        message.to_string()
-    } else {
-        String::new()
-    };
+    let mut panic_message = panic_info.message().to_string();
     if let Some(location) = panic_info.location() {
         panic_message = format!("{panic_message} at {}:{}", location.file(), location.line());
     }
     error!("{panic_message}");
 
     Vga::clear_screen(Color::WHITE);
-    unsafe { Vga::draw_string(0, 0, "PANIC !", Color::BLACK) };
-    unsafe { Vga::draw_string(0, FONT_HEIGHT as u16, panic_message, Color::BLACK) };
+    unsafe { Vga::draw_string(0, 0, "PANIC !", Color::BLACK, Color::WHITE) };
+    unsafe {
+        Vga::draw_string(
+            0,
+            FONT_HEIGHT as u16,
+            panic_message,
+            Color::BLACK,
+            Color::WHITE,
+        )
+    };
 
     loop {
-        unsafe { asm!("wfi") }
+        unsafe { wfi() }
     }
 }