SkyEye: 1. Install loopback device support module for the host

The following is the steps about adding application into ucLinux on Skyeye 1.0:
(Gentoo 2.6.10-r6 version)

In order to mount the romfs.img , the loopback and rom file system support modules need to be installed first. After that, mount the file into a temporary directory and copy all contents and the application into another temporary directory.Finally make a new romfs.img and run skyeye.

1. Install loopback device support module for the host

This is only necessary for some Linux distributions. Other distributions, such as FedoraCore, already have integrated support for loopback device.

gentoo test # mount -o loop romfs.img /mnt/temp
mount: Could not find any loop device. Maybe this kernel does not know
	   about the loop device? (If so, recompile or `modprobe loop'.)
gentoo linux # make menuconfig
Device Drivers->Block devices->[M]loopback device support

gentoo linux # make modules
gentoo linux # make modules_install
gentoo linux # depmod
gentoo linux # modprobe loop
gentoo linux # lsmod
Module                  Size  Used by
loop                   13480  -
tun                     8736  -

2. Install ROM file system support module for the host

Again, do this if your Linux distribution doesn't have ROMFS support.

gentoo test # mount -o loop romfs.img /mnt/temp
mount: unknown filesystem type 'romfs'
gentoo linux # make menuconfig
File systems->[M]ROM file system support

gentoo linux # make modules
gentoo linux # make modules_install
fs/romfs/romfs.o
gentoo linux # depmod
gentoo linux # modprobe romfs
gentoo linux # lsmod
Module                  Size  Used by
romfs                   6564  -
loop                   13480  -
tun                     8736  -

3. Mount romfs.img on a temporary directory of the host

gentoo test # mount -o loop romfs.img /mnt/temp
gentoo test # cd /mnt/temp
gentoo temp # ls
bin  dev  etc  home  lib  mnt  proc  sbin  tmp  usr  var

4. Copy all contents from the above temporary directory and the own application into another temporary directory of the host.

gentoo test # cp -r /mnt/temp/* romfs
gentoo test # cd romfs
gentoo romfs # ls
bin  dev  etc  home  lib  mnt  proc  sbin  tmp  usr  var
gentoo test # cp hello  ./romfs/bin

(note: another temporary directory name : romfs

the application name : hello)

5. Make a new romfs.img using the temporary directory which has the application.

gentoo test # genromfs -f romfs.img -d romfs/

OK!Now , it is a time to run linux on Skyeye and then to run the application
gentoo test # skyeye -e linux
/> cd bin
/bin> hello
i = 0 Hello, embedded linux!
i = 1 Hello, embedded linux!
i = 2 Hello, embedded linux!
i = 3 Hello, embedded linux!
i = 4 Hello, embedded linux!
i = 5 Hello, embedded linux!

Appendix : How to get the simple “Hello” execute program on the host for Linux on Skyeye

1. Install ucLinux ARM cross compiler∞ for the host.

chmod a+x arm-elf-tools-20030314.sh
./arm-elf-tools-20030314.sh

2. Edit source code

#include <stdio.h>

int main(void) {
	int i;

	for (i = 0; i < 6; i=i+1) {
	    printf("i = %d ",i);
	    printf("Hello, embedded linux!\n");
	}

	return 0;
}

3. Compile the source code on the host