redox/kernel/arch/x86_64/main.rs
2016-08-14 18:42:32 +02:00

79 lines
2.4 KiB
Rust

/// This function is where the kernel sets up IRQ handlers
/// It is increcibly unsafe, and should be minimal in nature
/// It must create the IDT with the correct entries, those entries are
/// defined in other files inside of the `arch` module
use super::idt::{IDTR, IDT, IDT_PRESENT, IDT_RING_0, IDT_INTERRUPT};
use super::mem::memset;
extern {
/// The starting byte of the text (code) data segment.
static mut __text_start: u8;
/// The ending byte of the text (code) data segment.
static mut __text_end: u8;
/// The starting byte of the _.rodata_ (read-only data) segment.
static mut __rodata_start: u8;
/// The ending byte of the _.rodata_ (read-only data) segment.
static mut __rodata_end: u8;
/// The starting byte of the _.data_ segment.
static mut __data_start: u8;
/// The ending byte of the _.data_ segment.
static mut __data_end: u8;
/// The starting byte of the _.bss_ (uninitialized data) segment.
static mut __bss_start: u8;
/// The ending byte of the _.bss_ (uninitialized data) segment.
static mut __bss_end: u8;
}
/// Test of zero values in BSS.
static BSS_TEST_ZERO: usize = 0;
/// Test of non-zero values in BSS.
static BSS_TEST_NONZERO: usize = 0xFFFFFFFFFFFFFFFF;
#[no_mangle]
pub unsafe extern "C" fn kmain() {
asm!("xchg bx, bx" : : : : "intel", "volatile");
// Zero BSS, this initializes statics that are set to 0
{
let start_ptr = &mut __bss_start as *mut u8;
let end_ptr = & __bss_end as *const u8 as usize;
if start_ptr as usize <= end_ptr {
let size = end_ptr - start_ptr as usize;
memset(start_ptr, 0, size);
}
//debug_assert_eq!(BSS_TEST_ZERO, 0);
//debug_assert_eq!(BSS_TEST_NONZERO, 0xFFFFFFFFFFFFFFFF);
}
asm!("xchg bx, bx" : : : : "intel", "volatile");
//Set up IDT
for entry in IDT.iter_mut() {
entry.set_flags(IDT_PRESENT | IDT_RING_0 | IDT_INTERRUPT);
entry.set_offset(8, blank as usize);
}
IDTR.set_slice(&IDT);
IDTR.load();
asm!("xchg bx, bx" : : : : "intel", "volatile");
asm!("int 0xFF" : : : : "intel", "volatile");
asm!("xchg bx, bx" : : : : "intel", "volatile");
print!("TEST\n");
loop{
asm!("hlt" : : : : "intel", "volatile");
}
}
#[naked]
pub unsafe extern "C" fn blank() {
asm!("xchg bx, bx" : : : : "intel", "volatile");
asm!("iretq" : : : : "intel", "volatile");
}