basic interrupt/PIC support

11 files changed, 85 insertions, 7 deletions

diff --git a/src/arch/x86_64/interrupt/mod.rs b/src/arch/x86_64/interrupt/mod.rs
new file mode 100644
index 0000000..3a617e8
--- /dev/null
+++ b/src/arch/x86_64/interrupt/mod.rs
@@ -0,0 +1,23 @@
+pub mod pic_8259;
+pub mod pit;
+use crate::io::*;
+use core::arch::asm;
+
+#[no_mangle]
+extern "C" fn guardian(slot: u16) {
+	println!("interrupt received {:x}", slot);
+}
+
+#[inline(always)]
+pub fn interrupt_enable() {
+	unsafe {
+		asm!("sti");
+	}
+}
+
+#[inline(always)]
+pub fn interrupt_disable() {
+	unsafe {
+		asm!("cli");
+	}
+}
diff --git a/src/arch/x86_64/interrupt/pic_8259.rs b/src/arch/x86_64/interrupt/pic_8259.rs
new file mode 100644
index 0000000..43a102c
--- /dev/null
+++ b/src/arch/x86_64/interrupt/pic_8259.rs
@@ -0,0 +1,46 @@
+// For now, the PIC is stateless, i.e. we don'e need a struct for it.
+// Perhaps I need a Mutex handle later...
+use crate::arch::x86_64::io_port::*;
+
+const IMR1: u16 = 0x21;
+const IMR2: u16 = 0xa1;
+const CTRL1: u16 = 0x20;
+const CTRL2: u16 = 0xa0;
+
+pub struct PicDeviceInt;
+impl PicDeviceInt {
+	pub const TIMER: u8 = 0;
+	pub const KEYBOARD: u8 = 1;
+}
+
+// 8-bit registers IMR1 and IMR2 registers hold interrupt masking bit 0~7 and
+// 8~15; if an interrupt is masked(set 1) on the respective bit, it's disabled
+pub fn allow(interrupt: u8) {
+	if interrupt < 8 {
+		let old = inb(IMR1);
+		outb(IMR1, old & !(1 << interrupt));
+	} else {
+		let old = inb(IMR2);
+		outb(IMR2, old & !(1 << (interrupt - 8)));
+	}
+}
+
+pub fn forbid(interrupt: u8) {
+	if interrupt < 8 {
+		let old = inb(IMR1);
+		outb(IMR1, old | (1 << interrupt));
+	} else {
+		let old = inb(IMR2);
+		outb(IMR2, old | (1 << (interrupt - 8)));
+	}
+}
+
+pub fn is_masked(interrupt: u8) -> bool {
+	if interrupt < 8 {
+		let val = inb(IMR1);
+		return val & (interrupt) != 0;
+	} else {
+		let val = inb(IMR2);
+		return val & (interrupt - 8) != 0;
+	}
+}
diff --git a/src/arch/x86_64/pit.rs b/src/arch/x86_64/interrupt/pit.rs
index 8b13789..8b13789 100644
--- a/src/arch/x86_64/pit.rs
+++ b/src/arch/x86_64/interrupt/pit.rs
diff --git a/src/arch/x86_64/mod.rs b/src/arch/x86_64/mod.rs
index a7f9e89..9429c8f 100644
--- a/src/arch/x86_64/mod.rs
+++ b/src/arch/x86_64/mod.rs
@@ -1,6 +1,4 @@
 pub mod cpu;
+pub mod interrupt;
 pub mod io_port;
 pub mod misc;
-pub mod pic;
-pub mod pit;
-pub mod plugbox;
diff --git a/src/arch/x86_64/pic.rs b/src/arch/x86_64/pic.rs
deleted file mode 100644
index 8b13789..0000000
--- a/src/arch/x86_64/pic.rs
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/src/arch/x86_64/plugbox.rs b/src/arch/x86_64/plugbox.rs
deleted file mode 100644
index 8b13789..0000000
--- a/src/arch/x86_64/plugbox.rs
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/src/lib.rs b/src/lib.rs
index 5de826c..80d0146 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -7,6 +7,9 @@ mod io;
 mod machine;
 use core::panic::PanicInfo;
 use machine::cgascr::CGAScreen;
+use machine::interrupt;
+use arch::x86_64::interrupt::pic_8259;
+use arch::x86_64::interrupt::pic_8259::PicDeviceInt;
 
 #[cfg(not(test))]
 #[panic_handler]
@@ -25,5 +28,9 @@ pub extern "C" fn _entry() -> ! {
 	println!("       `-.-' \\ )-`( , o o)");
 	println!("             `-    \\`_`\"'-");
 	println!("it works!");
+	
+	// testing interrupt/PIC
+	pic_8259::allow(PicDeviceInt::KEYBOARD);
+	interrupt::interrupt_enable();	
 	loop {}
 }
diff --git a/src/machine/interrupt.rs b/src/machine/interrupt.rs
new file mode 100644
index 0000000..1cd3234
--- /dev/null
+++ b/src/machine/interrupt.rs
@@ -0,0 +1,2 @@
+#[cfg(target_arch = "x86_64")]
+pub use crate::arch::x86_64::interrupt::*;
diff --git a/src/machine/mod.rs b/src/machine/mod.rs
index 70660ce..c6f6fec 100644
--- a/src/machine/mod.rs
+++ b/src/machine/mod.rs
@@ -1,5 +1,9 @@
 pub mod cgascr;
+pub mod interrupt;
 mod kbd_defs;
 pub mod key;
 pub mod keyctrl;
 pub mod mem;
+pub mod plugbox;
+
+// TODO: this module *should* be arch independent.
diff --git a/src/machine/plugbox.rs b/src/machine/plugbox.rs
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/src/machine/plugbox.rs
diff --git a/startup.s b/startup.s
index 4d4df62..fb73dcb 100644
--- a/startup.s
+++ b/startup.s
@@ -60,7 +60,7 @@ pagetable_end:  equ 0x200000
 
 ; functions from the C parts of the system
 [EXTERN _entry]
-;[EXTERN guardian]
+[EXTERN guardian]
 
 ; addresses provided by the compiler
 [EXTERN ___BSS_START__]
@@ -281,7 +281,7 @@ wrapper_body:
 	mov    rdi, rax
     ; call the interrupt handler wrapper here.
     ; TODO implement it in rust then uncomment the line
-    ;call   guardian
+    call   guardian
 
 	; restore volatile registers
 	pop    r11