RockOS/kernel/common.S

.code32 
.section .text

.global disable_interrupts
disable_interrupts:
    cli 
    ret

.global enable_interrupts
enable_interrupts:
    sti 
    ret

.global io_wait 
io_wait:
    outb %al, $0x80
    ret

.global liftoff
liftoff:
    cli

    mov 4(%esp), %ecx
    mov 8(%esp), %ebx

    mov $0x23, %ax
    mov %ax, %ds
    mov %ax, %es
    mov %ax, %fs
    mov %ax, %gs

    push $0x23           
    push %ebx
    push $0x202
    push $0x1B
    push %ecx

    xor %eax, %eax
    xor %edx, %edx
    
    iret

.global outb
outb: 
    push %ebp
    mov %esp, %ebp

    # 8(%ebp) port
    # 12(%ebp) data
    mov 8(%ebp), %edx 
    mov 12(%ebp), %eax
    outb %al, %dx

    leave
    ret

.global inb
inb:
    push %ebp
    mov %esp, %ebp

    # 8(%ebp) port
    mov 8(%ebp), %edx 
    xor %eax, %eax
    inb %dx, %al

    leave 
    ret

.global insw 
insw:
    push %ebp
    mov %esp, %ebp 

    push %edi
    push %ecx 
    push %edx

    # 8(%ebp) addr
    # 12(%ebp) buf
    # 16(%ebp) sz
    mov 8(%ebp), %edx 
    mov 12(%ebp), %edi
    mov 16(%ebp), %ecx

    cld
    rep insw

    pop %edx
    pop %ecx
    pop %edi
    leave
    ret

.global outsw
outsw:
    push %ebp
    mov %esp, %ebp 

    push %esi
    push %ecx 
    push %edx

    # 8(%ebp) address
    # 12(%ebp) buf
    # 16(%ebp) sz
    mov 8(%ebp), %edx 
    mov 12(%ebp), %esi
    mov 16(%ebp), %ecx

    cld
    rep outsw

    pop %edx
    pop %ecx
    pop %esi
    leave
    ret

.global fetch_cr3
fetch_cr3: 
    mov %cr3, %eax 
    ret