CoolPotOS/boot/io.asm

142 lines
2.6 KiB
NASM
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

section .data
global io_hlt, io_cli, io_sti, io_stihlt
global io_in8, io_in16, io_in32
global io_out8, io_out16, io_out32
global io_load_eflags, io_store_eflags
global load_gdtr, load_idtr
global tss_flush, gdt_flush, switch_to
section .text
switch_to:
mov eax, [esp+4]
mov [eax+0], esp
mov [eax+4], ebp
mov [eax+8], ebx
mov [eax+12], esi
mov [eax+16], edi
pushf
pop ecx
mov [eax+20], ecx
mov eax, [esp+8]
mov esp, [eax+0]
mov ebp, [eax+4]
mov ebx, [eax+8]
mov esi, [eax+12]
mov edi, [eax+16]
mov eax, [eax+20]
push eax
popf
ret
[global read_port]
read_port:
mov edx, [esp + 4]
in al, dx
ret
[global idt_flush]
idt_flush: ; void idt_flush(uint32_t);
mov eax, [esp + 4]
lidt [eax]
ret
[global gdt_flush]
gdt_flush: ; void gdt_flush(uint32_t gdtr);
mov eax, [esp + 4] ; [esp+4]按规定是第一个参数即gdtr
lgdt [eax] ; 加载新gdt指针传入的是地址
mov ax, 0x10 ; 新数据段
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
mov ss, ax ; 各数据段全部划给这一数据段
jmp 0x08:.flush ; cs没法mov只能用farjmp/farcall这里用farjmp刷新cs
.flush:
ret ; 刷新完毕,返回
tss_flush:
mov ax, 0x2B
ltr ax
ret
io_hlt: ; void io_hlt(void);
HLT
RET
io_cli: ; void io_cli(void);
CLI
RET
io_sti: ; void io_sti(void);
STI
RET
io_stihlt: ; void io_stihlt(void);
STI
HLT
RET
io_in8: ; int io_in8(int port);
MOV EDX,[ESP+4] ; port
MOV EAX,0
IN AL,DX
RET
io_in16: ; int io_in16(int port);
MOV EDX,[ESP+4] ; port
MOV EAX,0
IN AX,DX
RET
io_in32: ; int io_in32(int port);
MOV EDX,[ESP+4] ; port
IN EAX,DX
RET
io_out8: ; void io_out8(int port, int data);
MOV EDX,[ESP+4] ; port
MOV AL,[ESP+8] ; data
OUT DX,AL
RET
io_out16: ; void io_out16(int port, int data);
MOV EDX,[ESP+4] ; port
MOV EAX,[ESP+8] ; data
OUT DX,AX
RET
io_out32: ; void io_out32(int port, int data);
MOV EDX,[ESP+4] ; port
MOV EAX,[ESP+8] ; data
OUT DX,EAX
RET
io_load_eflags: ; int io_load_eflags(void);
PUSHFD ; PUSH EFLAGS
POP EAX
RET
io_store_eflags: ; void io_store_eflags(int eflags);
MOV EAX,[ESP+4]
PUSH EAX
POPFD ; POP EFLAGS
RET
load_gdtr: ; void load_gdtr(int limit, int addr);
MOV AX,[ESP+4] ; limit
MOV [ESP+6],AX
LGDT [ESP+6]
RET
load_idtr: ; void load_idtr(int limit, int addr);
MOV AX,[ESP+4] ; limit
MOV [ESP+6],AX
LIDT [ESP+6]
RET