Advantech ROM-3420CD-MDA1E, User Manual

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31 ROM-3420 User Manual
Chapter 3
S
oftware
Functionality
Edit the helloworld.c with the following source code:
#include <stdio.h>
void main()
{
printf("Hello World!\n");
}
10. Save the file and exit.
11.
#$CC
‐
o helloworld helloworld.c
(To compile helloworld.c)
12. Then you can see “helloworld” in current directory.
13. Insert the Linux system SD card to your development computer.
14.
#cp helloworld /media/rootfs/tool
(/media/rootfs is the mounted point of
your Linux system SD card)
15. Remove this SD card and insert it to ROM-DB3900, then open debug console.
16. On ROM-3420 platform, type
#root
(Login)
17. On ROM-3420 platform, type
#cd /tool
18. On ROM-3420 platform, type
#./helloworld
19. Now you should be able to see “Hello World!” shown on ROM-3420.
3.8.2 Watchdog Timer Sample Code
WatchDog Timer (WDT) sample code is as below:
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <linux/watchdog.h>
#include <sys/ioctl.h>
#include <unistd.h>
void help_info(void);
int main(int argc, const char *argv[])
{
int fd, timeout, sleep_sec, test;
int count=1;
if (argc < 2) {
help_info();
return 1;
}
timeout = atoi(argv[1]);
sleep_sec = atoi(argv[2]);
if (sleep_sec <= 0) {
sleep_sec = 1;
printf("correct 0 or negative sleep time to %d seconds\n",
sleep_sec);
}
test = atoi(argv[3]);