strcmp:
strcmp_loop:
ld a, (ix+0)
ld b, (iy+0)
cp b
jp nz, strcmp_different
cp 0
ret z
inc ix
inc iy
jp strcmp_loop
strcmp_different:
ld a, 1
ret


.global read_init
; Reads init.elf off the disk to 0x8000 in memory
read_init:
ld c, 0
ld de, 1
ri_find_loop:
ld hl, 0x8000
push bc
call read_sector
ld ix, 0x8001
ld iy, init_str
call strcmp
pop bc
jp z, ri_init_found
push bc
ld b, 0
ld a, (0x8000)
ld c, a
ld hl, 0x8004
add hl, bc
ld c, (hl)
inc hl
ld b, (hl)
ld l, c
ld h, b
inc hl
add hl, de
ld e, l
ld d, h
pop bc
ld a, c
adc a, 0
ld c, a
jp ri_find_loop
ri_init_found:
push bc
ld b, 0
ld a, (0x8000)
ld c, a
ld hl, 0x8004
add hl, bc
pop bc
ld b, (hl)
ld hl, 1
add hl, de
ld e, l
ld d, h
ld a, c
adc a, 0
ld c, a
ld hl, 0x8000
ri_read_loop:
push bc
call read_sector
pop bc
push hl
ld hl, 1
add hl, de
ld e, l
ld d, h
ld a, c
adc a, 0
ld c, a
pop hl
djnz ri_read_loop
ret



; Given a sector number in C:DE and a buffer address in HL, reads the sector off disk.
read_sector:
push bc
ld c,0xFF ; Force the top half of the IO address to be the id of the card, 
ld a, (disk_num) ; so the block transfer instructions can be used
out (c), a
pop bc
ld a, c
ld c, 0
out (c), e
inc c
out (c), d
inc c
out (c), a
ld b, 0x0 ; Setup a transfer of 256 bytes (1 sector) at a time
ld c, 0x3 ; from the storage device's data port
inir
ld c,0xFF ; Unforce the top half of the IO address
in a,(c)
ret


.global find_disk
; Clobbers A and HL
find_disk:
ld b,0x4
call find_first_card
ld a, l
ld (disk_num), a
ret

disk_num: .ds.b 1


/* initrd: */
/* .incbin "initrd" */
/* initrd_end: */


init_str: .asciz "init.elf"