; Drive table
; Header:
;	byte	number of drives
; Item (type BIOS CHS):
;	byte	type (1)
;	byte	drive number
;	word	number of cylinders
;	byte	number of heads
;	word	number of sectors per cylinder
;	3 bytes	padding
; Item (type BIOS LBA):
;	byte	type (2)
;	byte	drive number
;	dword	offset
;	dword	size

; Create a drive table at ES:DI
drvtab_create:
  mov ax, 0x2B
  call intr_register

  mov al, 8  ; 8 drives per default
  mov ah, 10 ; 10 bytes per drive
  stosb
  mul ah

  xor cx, cx
  xchg cx, ax
  rep stosb

  ret

; Get drive table item
; IN	DL	drive number (A=0, B=1, ...)
; OUT	DS:SI	ptr to drive struct
drvtab_load:
  push ax
  mov ax, 0x2B
  call intr_load
  cmp dl, [ds:si]
  jnb .err
  mov al, 10
  mul dl
  inc ax
  add si, ax
  pop ax
  ret
.err:
  pop ax
  stc
  ret