64-bit bootloader from scratch in AT&T assembly, Part-2

we will continue from disable_int

    cli                 # disables CPU intrupts
    lgdt gdtp          # A data structure to manage memory
    lidt idt           # IDK what does this do but we need it too
                            # All the variables we be defined later

    mov %cr0, %eax    # This works in 16-bit mode!
    or $0x1, %eax     # Modify the 32-bit register
    mov %eax, %cr0    # Write it back

    movw $(gdt_data_segment - gdt_start), %ax  # GDT data segment size, copy to all segments
    movw %ax, %ds
    movw %ax, %es
    movw %ax, %es
    movw %ax, %fs
    movw %ax, %gs
    movw %ax, %ss

    ljmp $(gdt_code_segment - gdt_start), $entry32   # Now we are ready to jump to 32-bit mode

But lets define print and println first as they are called while kernel is being loaded from disk in intrupt mode

It will also be in 16-bit mode that's why we are defining it before going to 32-bit protected mode

print:
    lodsb        # Not explaining, check it: https://www.felixcloutier.com/x86/lods:lodsb:lodsw:lodsd:lodsq

print_loop:
    inb (%dx), %al  # characters, tried `movb` but didn't work
    cmp $0, %al      # check if its null terminator
    je print_end
    mov $0x0e, %ah  # color ig?
    mov $0x07, %bl  # and some config, I forgot
    int $0x10        # write to bios screen
    add $1, %dx      # next letter pointer
    jmp print_loop
print_end:
    ret

println:
    mov $0x0e, %ah
    mov $0xa, %al
    int $0x10
    mov $0x20, %al
    int $0x10
    ret

With this 16-bit mode ends, next will be 32-bit mode where we will load our kernel