Manual_to_build_rootfs_for_ARM

http://processors.wiki.ti.com/index.php/Creating_a_Root_File_System_for_Linux_on_OMAP35x

cd busybox--version

make ARCH=arm AROSS_COMPILE=arm-none-linux-gnueabi- defconfig

make ARCH=arm AROSS_COMPILE=arm-none-linux-gnueabi- menuconfig

--enable static

make ARCH=arm AROSS_COMPILE=arm-none-linux-gnueabi- 

make ARCH=arm AROSS_COMPILE=arm-none-linux-gnueabi- install

cp -r _install ../rootfs

cd ../rootfs

mknod ttySAC0 c 204 64 
mknod tty0 c 4 0

[root@localhost target]# mkdir dev
[root@localhost target]# mknod dev/console c 5 1

[root@localhost target]# mkdir dev/pts
[root@localhost target]# mkdir etc
[root@localhost target]# mkdir etc/init.d
[root@localhost target]# mkdir lib
[root@localhost target]# mkdir mnt
[root@localhost target]# mkdir opt
[root@localhost target]# mkdir proc
[root@localhost target]# mkdir root
[root@localhost target]# mkdir sys
[root@localhost target]# mkdir tmp
[root@localhost target]# mkdir var
[root@localhost target]# mkdir var/log

[root@localhost target]# cd etc
[root@localhost etc]# vi fstab
proc            /proc           proc    defaults        0 0
none            /dev/pts        devpts  mode=0622       0 0


[root@localhost etc]# vi group
root:x:0:root

[root@localhost etc]# vi passwd
root::0:0:root:/root:/bin/ash 

[root@localhost etc]# vi hosts
127.0.0.1       localhost

[root@localhost etc]# vi inittab
::sysinit:/etc/init.d/rcS 

# /bin/ash
#
# Start an "askfirst" shell on the serial port
console::askfirst:-/bin/ash

# Stuff to do when restarting the init process
::restart:/sbin/init

# Stuff to do before rebooting
::ctrlaltdel:/sbin/reboot
::shutdown:/bin/umount -a -r
::shutdown:/sbin/swapoff -a


[root@localhost etc]# vi init.d/rcS

#!/bin/sh
#   ---------------------------------------------
#   Common settings
#   ---------------------------------------------
HOSTNAME=OMAP3EVM
VERSION=1.0.0

hostname $HOSTNAME

#   ---------------------------------------------
#   Prints execution status.
#
#   arg1 : Execution status
#   arg2 : Continue (0) or Abort (1) on error
#   ---------------------------------------------
status ()
{
       if [ $1 -eq 0 ] ; then
               echo "[SUCCESS]"
       else
               echo "[FAILED]"

               if [ $2 -eq 1 ] ; then
                       echo "... System init aborted."
                       exit 1
               fi
       fi

}

#   ---------------------------------------------
#   Get verbose
#   ---------------------------------------------
echo ""
echo "    System initialization..."
echo ""
echo "    Hostname       : $HOSTNAME"
echo "    Filesystem     : v$VERSION"
echo ""
echo ""
echo "    Kernel release : `uname -s` `uname -r`"
echo "    Kernel version : `uname -v`"
echo ""


#   ---------------------------------------------
#   MDEV Support
#   (Requires sysfs support in the kernel)
#   ---------------------------------------------
echo -n " Mounting /proc             : "
mount -n -t proc /proc /proc
status $? 1

echo -n " Mounting /sys              : "
mount -n -t sysfs sysfs /sys
status $? 1

echo -n " Mounting /dev              : "
mount -n -t tmpfs mdev /dev
status $? 1

echo -n " Mounting /dev/pts          : "
mkdir /dev/pts
mount -t devpts devpts /dev/pts
status $? 1

echo -n " Enabling hot-plug          : "
echo "/sbin/mdev" > /proc/sys/kernel/hotplug
status $? 0

echo -n " Populating /dev            : "
mkdir /dev/input
mkdir /dev/snd

mdev -s
status $? 0

#   ---------------------------------------------
#   Disable power management
#   (Requires sysfs support in the kernel)
#   ---------------------------------------------
# echo -n " Disabling Power mgmt       : "
# echo -n "1" > /sys/power/cpuidle_deepest_state
# status $? 1

#   ---------------------------------------------
#   Turn off LCD after 1 hour of inactivity
#   (Requires sysfs support in the kernel)
#   ---------------------------------------------
# echo -n " Turn off LCD after 1 hour  : "
# echo -n "3600" > /sys/power/fb_timeout_value
# status $? 1


#   ---------------------------------------------
#   Mount the default file systems
#   ---------------------------------------------
echo -n " Mounting other filesystems : "
mount -a
status $? 0


#   ---------------------------------------------
#   Set PATH
#   ---------------------------------------------
export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin


#   ---------------------------------------------
#   Start other daemons
#   ---------------------------------------------
echo -n " Starting syslogd           : "
/sbin/syslogd
status $? 0

echo -n " Starting telnetd           : "
/usr/sbin/telnetd
status $? 0


#   ---------------------------------------------
#   Done!
#   ---------------------------------------------
echo ""
echo "System initialization complete."


#   ---------------------------------------------
#   Start demo app
#   ---------------------------------------------
#if [[ -x /etc/init.d/demo_start ]]; then
#       echo " Starting Demo Application..."
#       /etc/init.d/demo_start &
#       sleep 5
#fi

cat /proc/filesystems | grep -q debugfs
if [ $? -eq 0 ] ; then
        echo -n " Mounting /debug             : "
        mount -n -t debugfs none /debug
        status $? 1
fi



[root@localhost etc]# vi mdev.conf

audio       0:5 0666
console     0:5 0600
control.*   0:0 0660 @/bin/mv /dev/$MDEV /dev/snd/
dsp         0:5 0666
event.*     0:0 0600 @/bin/mv /dev/$MDEV /dev/input/
fb          0:5 0666
nfs         0:5 0770
null        0:0 0777
pcm.*       0:0 0660 @/bin/mv /dev/$MDEV /dev/snd/
rtc         0:0 0666
tty         0:5 0660
tty0*       0:5 0660
tty1*       0:5 0660
tty2*       0:5 0660
tty3*       0:5 0660
tty4*       0:5 0660
tty5*       0:5 0660
tty6*       0:5 0660
ttyS*       0:5 0640
urandom     0:0 0444
zero        0:0 0666