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2012-02-03T09:16:42Z

Created page with "== About == An [http://en.wikipedia.org/wiki/Embedded_system embedded system] may not have a disk, an [http://en.wikipedia.org/wiki/Integrated_Drive_Electronics IDE] interfac..."

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== About ==

An [http://en.wikipedia.org/wiki/Embedded_system embedded system] may not have a disk, an [http://en.wikipedia.org/wiki/Integrated_Drive_Electronics IDE] interface, or even a [http://en.wikipedia.org/wiki/Peripheral_Component_Interconnect PCI] bus. Even if it does, during development it may be too unstable to use the disk, and a [http://en.wikipedia.org/wiki/Ramdisk ramdisk] may be too small to include all of the necessary utilities or too large (as a part of the [http://en.wikipedia.org/wiki/Kernel_image kernel] image) to allow for rapid turnaround during testing and development. An [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS] root allows quick [http://en.wikipedia.org/wiki/Kernel_image kernel] downloads, helps ensure [http://en.wikipedia.org/wiki/Filesystem filesystem] integrity (since the server is basically impervious to crashes by the client), and provides virtually infinite storage.

If we use [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS] instead of [http://en.wikipedia.org/wiki/Romfs ROMFS] modification to the player's [http://en.wikipedia.org/wiki/Firmware firmware] can now be done on the [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS] server. No more flash cycles necessary. Switching the player off and on again will activate the changes.

'''All code examples on this page assume that you are doing this on a system running Linux.''' Use [http://en.wikipedia.org/wiki/Windows VmWare Player] to run Linux as a guest inside a [http://en.wikipedia.org/wiki/Windows Windows] system.

== Preparing KiSS Firmware ==

[http://en.wikipedia.org/wiki/KISS_Technology KiSS] players use the [http://en.wikipedia.org/wiki/Romfs ROMFS] [http://en.wikipedia.org/wiki/File_system filesystem] for their [http://en.wikipedia.org/wiki/Flash_memory flash memory]. The [http://en.wikipedia.org/wiki/Boot_loader boot loader] reads and starts the [http://en.wikipedia.org/wiki/Linux_kernel Linux kernel] from it. The [http://en.wikipedia.org/wiki/Linux_kernel Linux kernel] initiializes the hardware and than mounts the [http://en.wikipedia.org/wiki/Romfs ROMFS] as its root [http://en.wikipedia.org/wiki/Filesystem filesystem] and starts [http://en.wikipedia.org/wiki/Init /sbin/init] from it. On [http://en.wikipedia.org/wiki/KISS_Technology KiSS] players the [http://en.wikipedia.org/wiki/Linux_kernel Linux kernel] starts the main DVD player application (we call it ''kissapp'').

The [http://en.wikipedia.org/wiki/Linux_kernel Linux kernel] used in [http://en.wikipedia.org/wiki/KISS_Technology KiSS] players has not been configured for [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS]. Even worse, [http://en.wikipedia.org/wiki/KISS_Technology KiSS] developers commented out parts of the [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS] code in the source. [http://www.jacek.it.pl/kiss/nfs/#patch These changes have to be undone first.] Due to a [http://mailman.uclinux.org/pipermail/uclinux-dev/2004-August/028060.html known bug] in uCLinux kernel's do_mount.c:mount_root() it will still mount root from flash. The [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS] over [http://en.wikipedia.org/wiki/Transmission_Control_Protocol TCP] code is incomplete.

Next step is to configure the [http://en.wikipedia.org/wiki/Linux_kernel Linux kernel] to mount its root [http://en.wikipedia.org/wiki/Filesystem filesystem] from a [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS] server. The following options are required to be set

<pre>
CONFIG_IP_PNP=y
CONFIG_IP_PNP_DHCP=y
CONFIG_ROOT_NFS=y
CONFIG_CMDLINE="root=/dev/nfs rootfstype=nfs ip=dhcp"
</pre>

Next step is to [[Build_kernel|rebuild the kernel]], copy the resulting linux.bin.gz to the [http://en.wikipedia.org/wiki/Romfs ROMFS], [[The_Freeze_Fix_Project#Building_a_Firmware_Image|rebuild]] and [[Firmware_update|flash]] [http://en.wikipedia.org/wiki/Firmware firmware].

Next time the player is powered on it will ask for an [http://en.wikipedia.org/wiki/IP_address IP address] via [http://en.wikipedia.org/wiki/DHCP DHCP]. After it got its [http://en.wikipedia.org/wiki/IP_address IP address], it will mount its root [http://en.wikipedia.org/wiki/Filesystem filesystem] from the [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS] server instead of the flash.

'''ATTENTION:''' from now on your player will not work without the [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS] server. But you can anytime [[Firmware_update|flash]] original [http://en.wikipedia.org/wiki/Firmware firmware] to get rid of the [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS] root.

== Preparing DHCP ==

<pre>
# vi /etc/dhcpd.conf
host kiss {
hardware ethernet 00:d0:e0:01:02:03;
fixed-address 10.0.0.100;
option host-name "kiss";
ddns-hostname "kiss";
next-server 10.0.0.1;
option root-path "/home/kiss/root,v3,hard,nolock,tcp,timeo=15,retrans=10";
}
# sh /etc/init.d/dhcpd restart
</pre>

Adapt the values to your needs. It is recommended to configure your player
with fixed [http://en.wikipedia.org/wiki/Dhcp IP address] since the [http://en.wikipedia.org/wiki/Dhcp DHCP] request issued by the ''kissapp'' will
break your [http://en.wikipedia.org/wiki/Network_File_System_(protocol) NFS] connection for a short time. Often this is enough to panic the player.

== Preparing NFS ==

<pre>
# vi /etc/exports
/home/kiss/root 10.0.0.100(rw,async,no_root_squash,no_subtree_check)
# exportfs -rv
</pre>

== Preparing Root ==

Extract the romfs from the [http://en.wikipedia.org/wiki/Firmware firmware] ISO ''firmware.iso'' to ''/home/kiss/root''. [http://en.wikipedia.org/wiki/Superuser Superuser] (root) rights are required to do this.

<pre>
# export DIR=/tmp/kiss
# mkdir -p ${DIR} ${DIR}/mount ${DIR}/cdrom
# mount -t iso9660 -o ro,loop firmware.iso ${DIR}/mount
# (cd ${DIR}/mount; tar cf - .) | (cd ${DIR}/cdrom; tar xf -)
# umount ${DIR}/mount
# mount -t romfs -o ro,loop ${DIR}/cdrom/romfs.bin ${DIR}/mount
# (cd ${DIR}/mount; tar cf - .) | (cd /home/kiss/root; tar xf -)
# umount ${DIR}/mount
# rm -rf {DIR}
</pre>

== Troubleshooting ==

== Download ==

Here you will find [http://en.wikipedia.org/wiki/Firmware firmware] [http://en.wikipedia.org/wiki/ISO_image ISO images] with NFS pre-configured. Report any problem with it in [http://www.mpcclub.com/modules.php?name=Forums&file=viewtopic&t=18133 ''Stage2 bug reporting'' thread] at the [http://www.mpcclub.com/modules.php?name=Forums&file=viewforum&f=101 ''Stage2'' forum].

{| class="wikitable" border="1" cellpadding="5" align="center" cellspacing="0"
|+ Firmware ISO images
! Player || Comment || Download
|-
| DP508 || based on original stage2 1.0 || [[Media:Dp508_stage2_nfsroot.zip‎|dp508_stage2_nfsroot.zip‎]]
|}

Root on NFS - Revision history

Lars: Created page with "== About == An [http://en.wikipedia.org/wiki/Embedded_system embedded system] may not have a disk, an [http://en.wikipedia.org/wiki/Integrated_Drive_Electronics IDE] interfac..."