MicroComputerSystem

중앙대학교 창의ICT공과대학 전자전기공학부 - 마이크로컴퓨터시스템

ARM MircroProcesser Core Assembly Language with Raspi 3

Peripheral Device Control using Linux Kernel System Call with Virtual Memory Mapping

BumSoo Kim*

In 2021 MicroComputerSystem Lecture, CAU (* CAU A&T)

ARM Programming

Environment

OS : Raspbian (Raspberry Pi 3)
Compiler : gcc (Not Keil)
Editor : nano
language : ARM Assembly

    .data    @data area
string:    .asciz "Hello world\n"
    .text    @code area
    .global main
main:
    push {lr}    @push {r14}
    ldr r0, =string    @parameter
    bl printf
    pop {pc}    @pop {r15}
    .end    @end

Getting Started

make directory and source file

pwd
mkdir src
nano example.s

assemble source code and run

gcc example.s -o example
./exmaple

GPIO Programming

Environment

OS : Raspbian (Raspberry Pi 3)
Compiler : gcc (Not Keil)
Editor : nano
language : C

#include <stdio.h>
#include <wiringPi.h>
#define LED 18
void main(void){
    wiringPiSetupGpio();
    pinMode(LED, OUTPUT);
    for(;;){
        digitalWrite(LED, 1);
        delay(500);
        digitalWrite(LED, 0);
        delay(500);
    }
}

gpio -g mode [N] out
gpio -g write [N] 1
gpio -g write [N] 0

Getting Started

(High Level) Peripheral Device Controll with wiringPi

install WiringPi

sudo apt-get install git-core
git clone http://github.com/WiringPi/WiringPi
cd WiringPi
./build

compile c source code and run

nano example.c
gcc -o example example.c -lwiringPi
./example

(Low Level) Peripheral Device Controll with mmap

compile custom wiringPi to library file

nano gpmmlib.c
gcc -I./include -c gpmmlib.c
ar r libgpmm.a gpmmlib.o
ranlib libgpmm.a
mkdir lib
mv libgpmm.a ./lib

compile c source with custom library

nano example.c
gcc -I./include -L./lib -o example example.c -lgpmm
sudo ./example