Programmer’s Guide |
2.Use the following command on the host to change to the directory that contains
cd /my_work_directory/myfilesystem/testprograms
3.Enter the following command:
#ddd
4.Enter the following command at the GDB, DDD command prompt:
Target remote 192.168.4.99:2000
The command produces another line of output on the target console, similar to the following:
Remote debugging using 192.168.4.99:2000
192.168.4.99 is the machine’s IP address, and 2000 is the port number. You can now begin debugging in the host environment using the interface provided by DDD.
5.Set a breakpoint on main by double clicking, or entering b main on the command line.
6.Click the cont button
Device API
int ioctl(int d, int request,…);
Input: int d - open device node return file handle int request – argument in or out
Use the desktop Linux’s man page for detailed documentation:
#man ioctl
RTC (Real Time Clock)
The device node is located at /dev/rtc.
1.Function: RTC_RD_TIME
int ioctl(fd, RTC_RD_TIME, struct rtc_time *time);
Description: read time information from RTC. It will return the value on argument 3.
2.Function: RTC_SET_TIME
int ioctl(fd, RTC_SET_TIME, struct rtc_time *time);
Description: set RTC time. Argument 3 will be passed to RTC.
Buzzer
The device node is located at /dev/console.
1.Function: KDMKTONE
ioctl(fd, KDMKTONE, unsigned int arg);
Description: The buzzer’s behavior is determined by the argument arg. The “high word” part of arg gives the length of time the buzzer will sound, and the “low word” part gives the frequency.
The buzzer’s on / off behavior is controlled by software. If you call the “ioctl” function, you MUST set the frequency at 100 Hz. If you use a different frequency, the system could crash.