Disable PIC through IO port write

2 files changed, 16 insertions, 7 deletions

diff --git a/kernel/src/interrupts/apic.rs b/kernel/src/interrupts/apic.rs
index 14f6169..3d42ba9 100644
--- a/kernel/src/interrupts/apic.rs
+++ b/kernel/src/interrupts/apic.rs
@@ -97,11 +97,8 @@ pub struct Apic {
 
 impl Apic {
     pub fn new() -> Option<Self> {
-        use core::fmt::Write;
-        let mut stdout = crate::io::vga_text::OStream::new();
-        stdout.clear();
-
         if !is_apic() { return None; }
+        Self::disable_pic();
         let mut base_apic = unsafe { Msr::new(APIC_BASE_MSR).read() };
         let mut apic = Self::from_base_apic(base_apic);
 
@@ -113,12 +110,19 @@ impl Apic {
 
         apic.set(ApicRegister::TaskPriority, 0);
         apic.set(ApicRegister::LvtPerformanceMonitor, APIC_NMI);
-        apic.set(ApicRegister::LvtLint0, 0);
-        apic.set(ApicRegister::LvtLint1, 0);
+        apic.set(ApicRegister::LvtLint0, APIC_DISABLE);
+        apic.set(ApicRegister::LvtLint1, APIC_DISABLE);
 
         Some(apic)
     }
 
+    pub fn disable_pic() {
+        unsafe {
+            x86_64::instructions::port::PortWriteOnly::new(0xa1).write(0xffu8);
+            x86_64::instructions::port::PortWriteOnly::new(0x21).write(0xffu8);
+        }
+    }
+
     fn from_base_apic(base_apic: u64) -> Self {
         Self { regs:
             ((base_apic >> 12) & 0xfffffffff) as *mut [u32; 1024]
diff --git a/kernel/src/main.rs b/kernel/src/main.rs
index 7cfbbe3..2116838 100644
--- a/kernel/src/main.rs
+++ b/kernel/src/main.rs
@@ -19,12 +19,17 @@ pub use io::{qemu, serial, vga_text};
 #[no_mangle]
 extern "C" fn _start() -> ! {
     kernel::init();
-    x86_64::instructions::interrupts::enable();
 
     let apic = interrupts::apic::Apic::new().expect("no APIC support");
     let mut apic = unsafe { interrupts::apic::set_local_apic(apic) };
+
     apic.set_timer_interrupt_handler(interrupts::apic::TimerDivideConfig::Div32, interrupts::InterruptType::Timer);
 
+    x86_64::instructions::interrupts::enable();
+
+    let mut stdout = OStream::new();
+    stdout.print(b"apic initialisation complete\n");
+
     if cfg!(test) {
         qemu::exit_qemu(qemu::QemuExitCode::Success);
     }