raspberry pi 1 model bで、アセンブラ その２

概要

raspberry pi 1 model bで、アセンブラでzundokoやってみた。

開発環境

raspberry pi 1 model b
raspbian 2016_09_23 jessie lite

実行

nano zundoko.s
gcc zundoko.s -nostdlib
./a.out

サンプルコード

.text
.global _start
_start:
    ldr r8, =0x02020000
    mov r6, #0
loop:
    eor r8, r8, r8, lsl #13
    eor r8, r8, r8, lsr #17
    eor r8, r8, r8, lsl #15
    tst r8, $0x80
    adreq r1, zun
    moveq r2, #zun_len
    addeq r6, #1
    adrne r1, doko
    movne r2, #doko_len
    mov r0, #1
    mov r7, #4
    svc #0
    bne check_kiyoshi
    b loop
check_kiyoshi:
    cmp r6, #4
    bge call_kiyoshi
    mov r6, #0
    b loop
call_kiyoshi:
    adr r1, kiyoshi
    mov r2, #kiyoshi_len
    mov r0, #1
    mov r7, #4
    svc #0
    mov r0, #0
    mov r7, #1
    svc #0
zun:
    .string "ズン\n"
zun_len = . - zun
    .align 2
doko:
    .string "ドコ\n"
doko_len = . - doko
    .align 2
kiyoshi:
    .string "キヨシ\n"
kiyoshi_len = . - kiyoshi
    .align 2