微處理器 - Allwinner F1C200S (Tiny200) - Assembly - Button

參考資料：
http://nano.lichee.pro/
https://mangopi.org/mangopi_r

BOOT按鍵是接到PC2


暫存器


提昇電阻


main.s

    .global _start

    .equiv GPIO_BASE,  0x01c20800 

    .equiv PA,         (0x24 * 0)
    .equiv PC,         (0x24 * 2)
    .equiv PORT_CFG0,  0x00
    .equiv PORT_DATA,  0x10
    .equiv PORT_PUL0,  0x1c

    .arm
    .text
_start:
    .long 0xea000016
    .byte 'e', 'G', 'O', 'N', '.', 'B', 'T', '0'
    .long 0, __spl_size
    .byte 'S', 'P', 'L', 2
    .long 0, 0
    .long 0, 0, 0, 0, 0, 0, 0, 0
    .long 0, 0, 0, 0, 0, 0, 0, 0
         
_vector:
    b reset
    b .
    b .
    b .
    b .
    b .
    b . 
    b .
    
reset:
    ldr r0, =GPIO_BASE
    ldr r1, =0x1000
    str r1, [r0, #(PA + PORT_CFG0)]
    ldr r1, =0x08
    str r1, [r0, #(PA + PORT_DATA)]
    
    ldr r1, =0x0000
    str r1, [r0, #(PC + PORT_CFG0)]
    ldr r1, =0x10
    str r1, [r0, #(PC + PORT_PUL0)]

0: 
    ldr r1, [r0, #(PC + PORT_DATA)]
    lsl r1, #1
    str r1, [r0, #(PA + PORT_DATA)]
    b 0b
    .end

完成