std.x86

x86-64 instructions a kernel needs: ports, interrupts, control registers, msrs most only work in ring 0

outb

pub outb :: fn(port: u16, v: u8)

pub outw :: fn(port: u16, v: u16)

pub outl :: fn(port: u16, v: u32)

pub inb :: fn(port: u16) -> u8

pub inw :: fn(port: u16) -> u16

pub inl :: fn(port: u16) -> u32

pub cli :: fn()

pub sti :: fn()

pub hlt :: fn()

waits for the next interrupt

pub pause :: fn()

spin-loop hint

pub lgdt :: fn(descriptor: *const u8)

loads the gdt/idt from a 10-byte descriptor: u16 limit, then u64 base

pub lidt :: fn(descriptor: *const u8)

pub breakpoint :: fn()

int3: the breakpoint exception, vector 3

pub read_cs :: fn() -> u16

the code segment selector running now

pub InterruptFrame :: struct {
    ip: u64,
    cs: u64,
    flags: u64,
    sp: u64,
    ss: u64,
}

what the cpu pushes before it calls an #interrupt function; an exception with an error code passes that as the function’s second parameter

pub Idt :: struct {
    gates: [512]u64,
}

256 gates of 16 bytes; a gate is two words

pub set :: fn(self: *Self, vector: u8, handler: *void)

vector calls handler (core::fn_ptr of an #interrupt function) with interrupts off

pub load :: fn(self: *const Self)

makes this the cpu’s table; it must stay where it is from then on

pub idt :: fn() -> Idt

an empty table, to fill with set

pub read_cr0 :: fn() -> u64

pub read_cr2 :: fn() -> u64

the address of the last page fault

pub read_cr3 :: fn() -> u64

the page table root

pub write_cr3 :: fn(v: u64)

pub read_cr4 :: fn() -> u64

pub invlpg :: fn(addr: usize)

drops the tlb entry of the page holding addr

pub rdmsr :: fn(msr: u32) -> u64

pub wrmsr :: fn(msr: u32, v: u64)

pub rdtsc :: fn() -> u64

cycles since reset

pub Cpuid :: struct {
    eax: u32,
    ebx: u32,
    ecx: u32,
    edx: u32,
}

pub cpuid :: fn(leaf: u32, sub: u32) -> Cpuid

cpuid for leaf and sub