.code16
.global init # makes our label "init" available to the outside
.global msg
.global boot_disk
.global disk_read
.text

#.org 0x7c00

.equ PROGRAM_SPACE, 0x7e00

#oṃ bhūr bhuvaḥ svaḥ
#tat savitur vareṇyaṃ
#bhargo devasya dhīmahi
#dhiyo yo naḥ pracodayāt

init:
  mov %dl, (boot_disk)  #at boot the disk number is stored in %dl, store it in c                                                                                        har boot_disk for use in disk_read()
  .byte 0xcc            #hardware interrupt
  hlt
  mov $msg, %bx
  call print
  call disk_read
  mov $msg, %bx
  call print
infiloop_real_mode:
  jmp infiloop_real_mode
  jmp enter_protected_mode

end_loop:
  jmp end_loop

disk_read:
  mov $0x02, %ah
  mov $PROGRAM_SPACE, %bx
  mov $0x04, %al
  mov (boot_disk), %dl
  mov $0x00, %ch
  mov $0x00, %dh
  mov $0x02, %cl

  int $0x13             #carry flag set on fail
  jc disk_read_fail
  mov $disk_read_success_msg, %bx
  call print
  ret

disk_read_fail:
  mov $disk_read_fail_msg, %bx
  call print
  ret

print:  # weirdest phenomena in asm history, made a function run 100% sucessfull                                                                                        y on first assemble

  mov $0x0e, %ah
print_loop:
  mov (%bx), %al   # sets AL to the first byte of our message
  cmp $0x00, %al je exit_print
  int $0x10 # call the function in ah from interrupt 0x10
  inc %bx
  jmp print_loop
exit_print:
  ret

enter_protected_mode:
  #mov $msg, %bx
  call enable_A20
  mov $msg, %bx
  #call sleep
  #call sleep
  mov $msg,%bx
  call print
  #call sleep
  mov $msg, %bx
  call sleep
  #jmp enter_protected_mode
  cli                   #cli clear interupt, interrupts need to be disabled to e                                                                                        nter protected mode
  lgdt (gdt_descriptor)         #load global table desctiptor
  mov %cr0, %eax
  or $0x01, %eax
  mov %eax, %cr0

  mov $sector_2_msg, %bx
  call print
  hlt
# problemer
  jmp $0x7e00, $0x0

enable_A20:
  in $0x92, %al
  or %al, 0x02
  out %al, $0x92
  ret

sleep:
  mov $0xffff, %ax
  xor %bx, %bx          #bx = 0x00000
  sleep_loop:
  dec %ax
  cmp %ax, %bx
  jne sleep_loop
  ret

## Data ------------------------------------
msg:
.asciz "not not\r\n"
disk_read_fail_msg:
.asciz "fail Disk read\r\n"
disk_read_success_msg:
.asciz "sucess Disk read\r\n"
boot_disk:
.byte 0x00

#.org 0x7e00

#sector 2 data
sector_2_msg:
.asciz "Running in sector 2\r\n"

##global descriptor table (gdt)

gdt_nulldesc:
.byte 0x00
.byte 0x00
gdt_codedesc:
.word 0xffff            #limit
.word 0x0000            #base (low 16 bit)
.byte 0x00              #base (medium 8 bits)
.byte 0b10011010        #flags(binary)
.byte 0b11001111        #flags(4 bits) limit(4 bits)
.byte 0x00              #base (high 8 bits)
gdt_datadesc:
.word 0xffff            #limit
.word 0x0000            #base (low 16 bit)
.byte 0x00              #base (medium 8 bits)
.byte 0b10010010        #flags(binary)
.byte 0b11001111        #flags(4 bits) limit(4 bits)
.byte 0x00              #base (high 8 bits)
gdt_end:
gdt_descriptor:
.word gdt_end - gdt_nulldesc -1
.long gdt_nulldesc

.equ CODESEG, gdt_codedesc - gdt_nulldesc
.equ DATASEG, gdt_datadesc - gdt_nulldesc

##ROGRAM_SPACE refers to this portion of memory

#  mov $sector_2_msg, %bx
#  call print

#  nop
#  nop
#  nop
#  nop


## 32 bit protected mode setup
.fill 510-(.-init), 1, 0 # add zeroes to make it 510 bytes long
.word 0xaa55

#etter her så blir det 513 til 2048

.code32
sector_2:

protected_mode_32:
  loopinz:
  jmp loopinz

  .byte 0xcc
  movl $DATASEG, %eax
  movl %eax, %ds
  movl %eax, %gs
  movl %eax, %ss
  movl %eax, %fs
  movl %eax, %es
  xorl %eax, %eax
  #movl %eax, %cs

   sti

   movl $0x07690748,0xb8000
#  movb $0x41, (0x000b8000)
#  movb $0X2A, (0X000B8000)

  infloop:
  jmp infloop


.fill 2048-(.-protected_mode_32), 1, 0 # zero pad sector 2