Unix

Mein geschätzter Kollege Kris schreibt etwas über Unix und Standards. Neben der Tatsache dass das schöne an Standards ist, dass es so viele gibt und man sich einen aussuchen kann, erwähnte Kris auch die Befürchtung dass BTRFS möglicherweise relizensiert werden könnte.

Die Gefahrt dass BTRFS relizensiert wird besteht nicht.

Zwar wurde die BTRFS Entwicklung bzw. der BTRFS-Haupt-Entwickler durch Oracle finanziert, der Code selber befindet sich jedoch mittlerweile im Upstream-Tree des Kernels. Damit gilt die GPL2 und diese Lizensierung kann nachträglich nicht geändert werden.
Eine andere Lizenz würde nur für zukünftige Versionen relevant sein.

In diesem Fall kann die relizensierte Version als Fork angesehen werden und die bekannten Probleme kommen dann zur Geltung.
Der Spruch mit Eiche und Sau dürfte in diesem Fall nicht unangebracht sein.

Passend dazu hat die aktuelle Ausgabe der Linux Weekly News eine schöne Erklärung der technischen Features und der Architektur von BTRFS und erklärt nebenbei die Entstehungsgeschichte und warum es viel besser ist als ZFS.

A friend of mine wanted a small embedded linux router. After evaluating several options such as Routerboard, Soekris or ALIX systems, he decided to get himself a Microtik Routerboard 433.

The RB433 is a small MIPS board based on the Atheros AR7100 chipset with a 300MHz CPU, 64MB RAM, 3 100Base-TX ethernet ports and three slots for MiniPCI Cards.

The Routerboard manufacturer Microtik delivers these systems with a software called "RouterOS". I haven't looked any closer at it but it seems to be Linux based system with some proprietary userspace management applications. RouterOS seems mostly to be just a Nortel-ish command line interface and a fugly webinterface. Some people claim that RouterOS is kinda nifty, but it's definitely not hackable enough considering the plans my friend had with his device.

To solve his dilemma, we did what everyone else does in a similar situation, we put a real Linux on it:
OpenWrt to the rescue!

Getting to know the Routerboard

When connecting the power to the Routerboard, the system beeps after a short time and outputs some status messages to the serial port. In order to read these, one has to connect to the serial port via a serial crossover cable and use a terminal program.

Minicom is one such terminal program. Personally though, I prefer cu from the uucp package as it is rather lightweight. All one has to type is cu -l ttyS0 -s 115200 and the bootup messages from the routerboard connected to COM1 will be visible. If you're using any other terminal program, the console settings are the usual 115200bps, 8 data bits, No parity bits and 1 stop bit.

RouterBOOT booter 2.15

RouterBoard 433

Authorization: Passed
CPU frequency: 300 MHz
  Memory size:  64 MB

Press any key within 2 seconds to enter setup

Now is a good time to press any key to enter the setup mode in order to see what the device can do.
You'll be presented with the following screen:

RouterBOOT-2.15
What do you want to configure?
   d - boot delay
   k - boot key
   s - serial console
   o - boot device
   u - cpu mode
   f - cpu frequency
   r - reset booter configuration
   e - format nand
   g - upgrade firmware
   i - board info
   p - boot protocol
   x - exit setup
your choice: 

Change the bootmode to tell the device _not_ to boot from the local flash chip (called NAND) but from the network. To do that, press "o" and "e".
Afterwards press "x" to leave the setup.
The device will try to boot and get its kernel from the network.

RouterBOOT booter 2.15

RouterBoard 433

Authorization: Passed
CPU frequency: 300 MHz
  Memory size:  64 MB

Press any key within 2 seconds to enter setup
trying dhcp protocol...........................................................
kernel loading failed

So it seems the device is looking for a kernel.
Let's build one for it to boot sucessfully from...

Building OpenWrt Kamikaze

In order to correctly install the OpenWrt system a linux host is needed to build the kernel image on. I've been using Fedora 9 from the Fedora Project which did the job perfectly. Any other recent distribution should work equally well.

First, check out the current development code via Subversion to have the greatest and latest code:

[athienem@localhost ~]$ mkdir ~/openwrt
[athienem@localhost ~]$ cd ~/openwrt
[athienem@localhost openwrt]$ svn co https://svn.openwrt.org/openwrt/trunk/
[...]
Updated to revision 13193.
[athienem@localhost openwrt]$ 

In order to install the system correctly we'll be needing two different OpenWrt images:
One image is a JFFS2 or SquashFS image to install onto the target device.
The other image is the so called ramdisk image which can be booted over the network and contains a minimal shell. This image will be used to install the JFFS2 or SquashFS image onto the device and will never again be used. Think of it as a "rescue image".

Both images are basically built the same way.
First, change to the svn checkout directory called trunk and execute make menuconfig to configure the OpenWrt image.

[athienem@localhost openwrt]$ cd trunk/
[athienem@localhost trunk]$ make menuconfig

This command will start the ncurses interface to generate a .config file. It should look familiar to people having built kernels before.
Make sure that "Atheros AR71xx [2.6]" is selected as the target system:

This will make sure that the resulting kernel is bootable on the Routerboard 433.

The next step is to select the target image format, chose ramdisk for now:

Now select "< Exit >" in the main menu and confirm that you want to save your new OpenWrt configuration.

The next step is to actually build the image by calling "make

*** End of OpenWrt configuration.
*** Execute 'make' to build the OpenWrt or try 'make help'.
[athienem@localhost trunk]$ make
Checking 'working-make'... ok.
Checking 'case-sensitive-fs'... ok.
Checking 'working-gcc'... ok.
Checking 'working-g++'... ok.
Checking 'ncurses'... ok.
Checking 'zlib'... ok.
Checking 'gawk'... ok.
Checking 'bison'... ok.
Checking 'flex'... ok.
Checking 'unzip'... ok.
Checking 'bzip2'... ok.
Checking 'patch'... ok.
Checking 'perl'... ok.
Checking 'wget'... ok.
Checking 'gnutar'... ok.
Checking 'autoconf'... ok.
Checking 'non-root'... ok.
Collecting target info: done
Collecting package info: done
Checking 'bison'... ok.
Checking 'automake'... ok.
 make[2] tools/install
[...]
 make[2] target/install
 make[3] -C target/linux install
 make[2] package/index
[athienem@localhost trunk]$ 

Everything went fine and there should be a ramdisk image in elf format:

[athienem@localhost trunk]$ ls -all bin/openwrt-ar71xx-vmlinux-initramfs.elf 
-rwxrwxr-x 1 athienem athienem 3735060 2008-11-13 22:27 bin/openwrt-ar71xx-vmlinux-initramfs.elf
[athienem@localhost trunk]$ 

The next step is to build the system image to be installed on the device. Execute make menuconfig again but this time select either squashfs or jffs2 as the target image format instead of ramdisk:
After saving the config, execute make again. This time, it should be much faster as nearly everything is already compiled.

#
# using defaults found in .config
#


*** End of OpenWrt configuration.
*** Execute 'make' to build the OpenWrt or try 'make help'.

[athienem@localhost trunk]$ make
++ mkdir -p /home/athienem/openwrt/trunk/staging_dir/toolchain-mips_gcc4.1.2
++ cd /home/athienem/openwrt/trunk/staging_dir/toolchain-mips_gcc4.1.2
++ mkdir -p bin lib include stamp
 make[1] world
[...]
 make[2] target/install
 make[3] -C target/linux install
 make[2] package/index
[athienem@localhost trunk]$ 

Now the bin/ directory should be filled with some files:

[athienem@localhost trunk]$ ls -all bin/
total 23656
drwxrwxr-x  3 athienem athienem    4096 2008-11-08 18:25 .
drwxrwxr-x 15 athienem athienem    4096 2008-11-13 22:44 ..
-rw-rw-r--  1 athienem athienem     710 2008-11-13 22:46 md5sums
-rw-rw-r--  1 athienem athienem 1499367 2008-11-08 18:25 openwrt-ar71xx-rootfs.tgz
-rw-rw-r--  1 athienem athienem 1441792 2008-11-08 18:25 openwrt-ar71xx-root.squashfs
-rw-rw-r--  1 athienem athienem 2492740 2008-11-13 22:46 openwrt-ar71xx-uImage.gz
-rwxrwxr-x  1 athienem athienem 2248838 2008-11-08 18:25 openwrt-ar71xx-vmlinux.bin
-rwxrwxr-x  1 athienem athienem 2258096 2008-11-08 18:25 openwrt-ar71xx-vmlinux.elf
-rw-rw-r--  1 athienem athienem 1048576 2008-11-08 18:25 openwrt-ar71xx-vmlinux.gz
-rwxrwxr-x  1 athienem athienem 3725815 2008-11-13 22:46 openwrt-ar71xx-vmlinux-initramfs.bin
-rwxrwxr-x  1 athienem athienem 3735072 2008-11-13 22:46 openwrt-ar71xx-vmlinux-initramfs.elf
-rw-rw-r--  1 athienem athienem 2555904 2008-11-13 22:46 openwrt-ar71xx-vmlinux-initramfs.gz
-rw-rw-r--  1 athienem athienem 2293760 2008-11-13 22:46 openwrt-ar71xx-vmlinux-initramfs.lzma
-rw-rw-r--  1 athienem athienem  786432 2008-11-08 18:25 openwrt-ar71xx-vmlinux.lzma
drwxrwxr-x  3 athienem athienem    4096 2008-11-08 17:50 packages
[athienem@localhost trunk]$ 

Booting OpenWrt on the RouterBoard

To boot the routerboard, a dhcp server is needed to tell the bootloader on the Routerboard which IP address it should use and where to get it's bootable kernel image.
The tftp server is needed to actually serve said image to the RouterBoard.

Under Fedora linux, installing both just needs the command yum install -y dhcp tftp-server. To activate both services, chkconfig can be used as root:

[root@localhost ~]# chkconfig dhcpd on
[root@localhost ~]# chkconfig tftp on

The configuration for the dhcpd needs to be adapted to the local circumstances. The setup I've been using was a crosslinked cable between the notebook and the Routerboard with a manually configured IP address of 192.168.23.254/24. All that is configured in that file is to assign the RouterBoard an IP address and tell it to boot the file vmlinux. Adapt the following file as needed for your own circumstances:

[root@localhost ~]# cat /etc/dhcpd.conf 
# Global Parameters

authoritative;

max-lease-time 604800;
default-lease-time 3100;

ddns-update-style none;
ddns-ttl 7200;

allow booting;
allow bootp;
one-lease-per-client true;

subnet 192.168.23.0 netmask 255.255.255.0 {
	option routers 192.168.23.254;
	option subnet-mask 255.255.255.0;
	option broadcast-address 192.168.23.255;
	ignore client-updates;
}

group {
	host routerboard {
		hardware ethernet 00:0c:42:32:43:8a;
		next-server 192.168.23.254;
		fixed-address 192.168.23.2;
		filename "vmlinux";
	}

}
[root@localhost ~]# 

Start the dhcp server by calling service dhcpd start, if there are any problems, look into /var/log/messages and fix the issues noted there.

The tftp-server has already been activated earlier but might need a service xinetd restart to be really started. Do that.
Then copy the ramdisk image named openwrt-ar71xx-vmlinux-initramfs.elf to the tftproot. This is /tftpboot on older systems or /var/lib/tftpboot/ on newer systems. Name the copied file vmlinux.

If everything is working fine, the system should boot:

RouterBOOT booter 2.15

RouterBoard 433

Authorization: Passed
CPU frequency: 300 MHz
  Memory size:  64 MB

Press any key within 2 seconds to enter setup...

trying dhcp protocol... OK
resolved mac address 00:1C:23:03:AA:F8
Gateway: 192.168.23.254
transfer started ............................ transfer ok, time=1.68s
setting up elf image... OK
jumping to kernel code
Linux version 2.6.26.7 (athienem@localhost.localdomain) (gcc version 4.1.2) #1 Sat Nov 8 18:11:40 CET 2008
console [early0] enabled
CPU revision is: 00019374 (MIPS 24K)
Determined physical RAM map:
 memory: 04000000 @ 00000000 (usable)
Initrd not found or empty - disabling initrd
Zone PFN ranges:
  Normal          0 ->    16384
Movable zone start PFN for each node
early_node_map[1] active PFN ranges
    0:        0 ->    16384
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 16256
Kernel command line: root=/dev/mtdblock2 rootfstype=squashfs,yaffs,jffs2 noinitrd console=ttyS0,115200 init=/etc/preinit
Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
Writing ErrCtl register=000227c0
Readback ErrCtl register=000227c0
PID hash table entries: 256 (order: 8, 1024 bytes)
Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)
Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
Memory: 60768k/65536k available (1762k kernel code, 4700k reserved, 312k data, 1572k init, 0k highmem)
SLUB: Genslabs=6, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
Mount-cache hash table entries: 512
net_namespace: 484 bytes
NET: Registered protocol family 16
MIPS: machine is MikroTik RouterBOARD 433/AH
registering PCI controller with io_map_base unset
PCI: mapping irq 33 to pin1@0000:00:13.0
NET: Registered protocol family 2
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
TCP established hash table entries: 2048 (order: 2, 16384 bytes)
TCP bind hash table entries: 2048 (order: 1, 8192 bytes)
TCP: Hash tables configured (established 2048 bind 2048)
TCP reno registered
NET: Registered protocol family 1
squashfs: version 3.0 (2006/03/15) Phillip Lougher
Registering mini_fo version $Id$
JFFS2 version 2.2. (NAND) (SUMMARY)  © 2001-2006 Red Hat, Inc.
yaffs Nov  8 2008 18:08:56 Installing. 
msgmni has been set to 118
io scheduler noop registered
io scheduler deadline registered (default)
Serial: 8250/16550 driver $Revision: 1.90 $ 1 ports, IRQ sharing disabled
serial8250.0: ttyS0 at MMIO 0x18020000 (irq = 11) is a 16550A
console handover: boot [early0] -> real [ttyS0]
ag71xx_mdio: probed
eth0: Atheros AG71xx at 0xba000000, irq 5
eth1: Atheros AG71xx at 0xb9000000, irq 4
NAND flash driver for RouterBoard 4xx series version 0.1.10
NAND SPI clock 25000 kHz (AHB 150000 kHz / 6)
FLASH SPI clock 25000 kHz (AHB 150000 kHz / 6)
NAND device: Manufacturer ID: 0xad, Chip ID: 0x76 (Hynix NAND 64MiB 3,3V 8-bit)
Scanning device for bad blocks
Bad eraseblock 828 at 0x00cf0000
Creating 3 MTD partitions on "NAND 64MiB 3,3V 8-bit":
0x00000000-0x00040000 : "booter"
0x00040000-0x00400000 : "kernel"
0x00400000-0x04000000 : "rootfs"
mtd: partition "rootfs" set to be root filesystem
split_squashfs: no squashfs found in "NAND 64MiB 3,3V 8-bit"
Atheros AR71xx SPI Controller driver version 0.2.2
Atheros AR71xx hardware watchdog driver version 0.1.0
Registered led device: rb4xx:yellow:user
TCP vegas registered
NET: Registered protocol family 17
802.1Q VLAN Support v1.8 Ben Greear 
All bugs added by David S. Miller 
Freeing unused kernel memory: 1572k freed
Algorithmics/MIPS FPU Emulator v1.5
[sighandler]: No more events to be processed, quitting.
[cleanup]: Waiting for children.
[cleanup]: All children terminated.
- preinit -
Press CTRL-C for failsafe

Please press Enter to activate this console. br-lan: Dropping NETIF_F_UFO since no NETIF_F_HW_CSUM feature.
device eth0 entered promiscuous mode
PPP generic driver version 2.4.2
ip_tables: (C) 2000-2006 Netfilter Core Team
nf_conntrack version 0.5.0 (1024 buckets, 4096 max)
wlan: trunk
ath_hal: module license 'Proprietary' taints kernel.
ath_hal: 2008-10-02 (AR5210, AR5211, AR5212, AR5416, RF5111, RF5112, RF2413, RF5413, RF2133, RF2425, REGOPS_FUNC, DFS, XR)
ath_rate_minstrel: Minstrel automatic rate control algorithm 1.2 (trunk)
ath_rate_minstrel: look around rate set to 10%
ath_rate_minstrel: EWMA rolloff level set to 75%
ath_rate_minstrel: max segment size in the mrr set to 6000 us
wlan: mac acl policy registered
ath_pci: trunk
PCI: Enabling device 0000:00:13.0 (0000 -> 0002)
Atheros HAL provided by OpenWrt, DD-WRT and MakSat Technologies
wifi0: 11a rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
wifi0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
wifi0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
wifi0: turboA rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
wifi0: turboG rates: 6Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
wifi0: H/W encryption support: WEP AES AES_CCM TKIP
ath_pci: wifi0: Atheros 5212: mem=0x10000000, irq=33
eth0: link up (100Mbps/Full duplex)
br-lan: port 1(eth0) entering learning state
br-lan: topology change detected, propagating
br-lan: port 1(eth0) entering forwarding state



BusyBox v1.11.2 (2008-11-08 17:55:16 CET) built-in shell (ash)
Enter 'help' for a list of built-in commands.

  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 KAMIKAZE (bleeding edge, r13141) -------------------
  * 10 oz Vodka       Shake well with ice and strain
  * 10 oz Triple sec  mixture into 10 shot glasses.
  * 10 oz lime juice  Salute!
 ---------------------------------------------------
root@OpenWrt:/# 

If something didn't work out, check your system log to see what happens. Adding the "-s" parameter to the tftpd binary might be useful as it will log single requests.

Permanently installing OpenWrt on the RouterBoard

As we have an accessible Linux system running now on the RouterBoard the available tools such as scp and mtd can be used to copy the needed files onto the NAND device and thus permanently install OpenWrt on the device.

Under Linux the NAND device is partitioned and can be accessed through the mtd framework which exports some information to userspace through the /proc filesystem:

root@OpenWrt:/# cat /proc/mtd 
dev:    size   erasesize  name
mtd0: 00040000 00004000 "booter"
mtd1: 003c0000 00004000 "kernel"
mtd2: 03c00000 00004000 "rootfs"

As can easily be seen, there are three "partitions" available. Leave the one called "booter" alone, it might be important and contain the bootloader. I haven't checked. All we're interested in is "kernel" and "rootfs". The former contains the kernel, the latter the root filesystem.

To install the elf kernel binary named openwrt-ar71xx-vmlinux.elf, it has to be transferred onto the RouterBoard and written onto the second mtd partition. Make sure that the file is called kernel.
Note: OpenWrt configures its IP address to be 192.168.1.1 on bootup. You might have to change this with ifconfig.

root@OpenWrt:/# scp athienem@192.168.23.254:openwrt/trunk/bin/openwrt-ar71xx-vmlinux.elf /tmp/
root@OpenWrt:/# mount /dev/mtdblock1 /mnt/
yaffs: dev is 32505857 name is "mtdblock1"
yaffs: passed flags ""
yaffs: Attempting MTD mount on 31.1, "mtdblock1"
root@OpenWrt:/# mv /tmp/openwrt-ar71xx-vmlinux.elf /mnt/kernel
root@OpenWrt:/# ls /mnt
kernel      lost+found
root@OpenWrt:/# umount  /mnt/
save exit: isCheckpointed 0
root@OpenWrt:/# 

The kernel image is installed.
The rootfs is even easier, as the mtd-device does not need to be mounted at all to write the squashfs image called openwrt-ar71xx-root.squashfs in my case.
This just needs to be written as is onto the mtd block device named rootfs:

root@OpenWrt:/# scp athienem@192.168.23.254:openwrt/trunk/bin/openwrt-ar71xx-root.squashfs /tmp/
root@OpenWrt:/# cat /tmp/openwrt-ar71xx-root.squashfs > /dev/mtdblock2
root@OpenWrt:/# 

After a few seconds the squashfs image has been written and the device can be rebooted. Don't forget to disable the network boot in the Bios:

root@OpenWrt:/# reboot
root@OpenWrt:/# br-lan: port 1(eth0) entering disabled state
device eth0 left promiscuous mode
br-lan: port 1(eth0) entering disabled state
eth0: link down
Restarting system.


RouterBOOT booter 2.15

RouterBoard 433

Authorization: Passed
CPU frequency: 300 MHz
  Memory size:  64 MB

Press any key within 2 seconds to enter setup..

RouterBOOT-2.15
What do you want to configure?
   d - boot delay
   k - boot key
   s - serial console
   o - boot device
   u - cpu mode
   f - cpu frequency
   r - reset booter configuration
   e - format nand
   g - upgrade firmware
   i - board info
   p - boot protocol
   x - exit setup
your choice: 

Press "o" twice and "x" once to continue booting normally from the NAND.

RouterBOOT booter 2.15

RouterBoard 433

Authorization: Passed
CPU frequency: 300 MHz
  Memory size:  64 MB

Press any key within 2 seconds to enter setup..
loading kernel from nand... OK
setting up elf image... OK
jumping to kernel code
Linux version 2.6.26.7 (athienem@localhost.localdomain) (gcc version 4.1.2) #2 Sat Nov 8 18:25:41 CET 2008
console [early0] enabled
CPU revision is: 00019374 (MIPS 24K)
Determined physical RAM map:
 memory: 04000000 @ 00000000 (usable)
Initrd not found or empty - disabling initrd
Zone PFN ranges:
  Normal          0 ->    16384
Movable zone start PFN for each node
early_node_map[1] active PFN ranges
    0:        0 ->    16384
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 16256
Kernel command line: root=/dev/mtdblock2 rootfstype=squashfs,yaffs,jffs2 noinitrd console=ttyS0,115200 init=/etc/preinit
Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
Writing ErrCtl register=000227c0
Readback ErrCtl register=000227c0
PID hash table entries: 256 (order: 8, 1024 bytes)
Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)
Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
Memory: 62208k/65536k available (1762k kernel code, 3252k reserved, 312k data, 124k init, 0k highmem)
SLUB: Genslabs=6, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
Mount-cache hash table entries: 512
net_namespace: 484 bytes
NET: Registered protocol family 16
MIPS: machine is MikroTik RouterBOARD 433/AH
registering PCI controller with io_map_base unset
PCI: mapping irq 33 to pin1@0000:00:13.0
NET: Registered protocol family 2
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
TCP established hash table entries: 2048 (order: 2, 16384 bytes)
TCP bind hash table entries: 2048 (order: 1, 8192 bytes)
TCP: Hash tables configured (established 2048 bind 2048)
TCP reno registered
NET: Registered protocol family 1
squashfs: version 3.0 (2006/03/15) Phillip Lougher
Registering mini_fo version $Id$
JFFS2 version 2.2. (NAND) (SUMMARY)  © 2001-2006 Red Hat, Inc.
yaffs Nov  8 2008 18:08:56 Installing. 
msgmni has been set to 121
io scheduler noop registered
io scheduler deadline registered (default)
Serial: 8250/16550 driver $Revision: 1.90 $ 1 ports, IRQ sharing disabled
serial8250.0: ttyS0 at MMIO 0x18020000 (irq = 11) is a 16550A
console handover: boot [early0] -> real [ttyS0]
ag71xx_mdio: probed
eth0: Atheros AG71xx at 0xba000000, irq 5
eth1: Atheros AG71xx at 0xb9000000, irq 4
NAND flash driver for RouterBoard 4xx series version 0.1.10
NAND SPI clock 25000 kHz (AHB 150000 kHz / 6)
FLASH SPI clock 25000 kHz (AHB 150000 kHz / 6)
NAND device: Manufacturer ID: 0xad, Chip ID: 0x76 (Hynix NAND 64MiB 3,3V 8-bit)
Scanning device for bad blocks
Bad eraseblock 828 at 0x00cf0000
Creating 3 MTD partitions on "NAND 64MiB 3,3V 8-bit":
0x00000000-0x00040000 : "booter"
0x00040000-0x00400000 : "kernel"
0x00400000-0x04000000 : "rootfs"
mtd: partition "rootfs" set to be root filesystem
split_squashfs: no squashfs found in "NAND 64MiB 3,3V 8-bit"
Atheros AR71xx SPI Controller driver version 0.2.2
Atheros AR71xx hardware watchdog driver version 0.1.0
Registered led device: rb4xx:yellow:user
TCP vegas registered
NET: Registered protocol family 17
802.1Q VLAN Support v1.8 Ben Greear 
All bugs added by David S. Miller 
VFS: Mounted root (squashfs filesystem) readonly.
Freeing unused kernel memory: 124k freed
Please be patient, while OpenWrt loads ...
Algorithmics/MIPS FPU Emulator v1.5
- preinit -
Press CTRL-C for failsafe
- init -

Please press Enter to activate this console. br-lan: Dropping NETIF_F_UFO since no NETIF_F_HW_CSUM feature.
device eth0 entered promiscuous mode
PPP generic driver version 2.4.2
ip_tables: (C) 2000-2006 Netfilter Core Team

nf_conntrack version 0.5.0 (1024 buckets, 4096 max)
wlan: trunk
ath_hal: module license 'Proprietary' taints kernel.
ath_hal: 2008-10-02 (AR5210, AR5211, AR5212, AR5416, RF5111, RF5112, RF2413, RF5413, RF2133, RF2425, REGOPS_FUNC, DFS, XR)
ath_rate_minstrel: Minstrel automatic rate control algorithm 1.2 (trunk)
ath_rate_minstrel: look around rate set to 10%
ath_rate_minstrel: EWMA rolloff level set to 75%
ath_rate_minstrel: max segment size in the mrr set to 6000 us
wlan: mac acl policy registered
eth0: link up (100Mbps/Full duplex)
br-lan: port 1(eth0) entering learning state
br-lan: topology change detected, propagating
br-lan: port 1(eth0) entering forwarding state
ath_pci: trunk
PCI: Enabling device 0000:00:13.0 (0000 -> 0002)
Atheros HAL provided by OpenWrt, DD-WRT and MakSat Technologies
wifi0: 11a rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
wifi0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
wifi0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
wifi0: turboA rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
wifi0: turboG rates: 6Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
wifi0: H/W encryption support: WEP AES AES_CCM TKIP
ath_pci: wifi0: Atheros 5212: mem=0x10000000, irq=33



BusyBox v1.11.2 (2008-11-08 17:55:16 CET) built-in shell (ash)
Enter 'help' for a list of built-in commands.

  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 KAMIKAZE (bleeding edge, r13141) -------------------
  * 10 oz Vodka       Shake well with ice and strain
  * 10 oz Triple sec  mixture into 10 shot glasses.
  * 10 oz lime juice  Salute!
 ---------------------------------------------------
root@OpenWrt:/# 

Done.

OpenWrt has been installed on the device and can be used and configured as usual.

For more information about configuring, using and customizing OpenWrt see the Kamikaze Manual, the OpenWrt Wiki or use the source. For network related configuration issues, /lib/network/config.sh and the files in /lib/wifi/ are a good start.

[Note to english speaking readers, aggregating this blog: The following article is written in german about gaining root on a piece of embedded server monitor hardware from Rittal and configuring ssh access. If there is demand, I'll translate this article in english as well.]

Ich hatte zuvor ja schon hier und hier ein wenig über das Rittal CMC-TC System gesprochen, dass wir verwenden um unseren Serverschrank zu überwachen.

Das System selber ist soweit ja sehr schön, und hat auch ein paar nette Features, aber leider fehlt z.B. der ssh Zugang. Telnet anzubieten ist doch schon ein wenig schwach heutzutage. Das ganze wäre ja kein Problem, würde Rittal sich an die GPL Lizenz halten, und mir den Sourcecode und die Buildumgebung zur Verfügung stellen, die gebraucht wird um sich einen eigenen sshd zu installieren.
Nunja, mal schauen was das noch wird.

Nun will ich aber dennoch einen ssh Daemon auf dem Gerät haben, was sich auch nicht als sonderlich kompliziert rausstellt. Man muss das Gerät nur booten und den vorhandenen sshd starten.

Aber fangen wir vorne an.

Schauen wir uns also mal die Bootmeldungen an:

U-Boot 1.1.3 (Jun  8 2005 - 15:08:40)

U-Boot code: 20F00000 -> 20F1A868  BSS: -> 20F1EE48
RAM Configuration:
Bank #0: 20000000 16 MB
Board: CMC-PU2 (Rittal GmbH)
Flash:  8 MB
In:    serial
Out:   serial
Err:   serial
Hit any key to stop autoboot:  0
no DHCP
## Booting image at 10030000 ...
   Image Name:   ARM Linux-2.4.27
   Created:      2005-04-22   4:52:03 UTC
   Image Type:   ARM Linux Kernel Image (gzip compressed)
   Data Size:    698499 Bytes = 682.1 kB
   Load Address: 20008000
   Entry Point:  20008000
   Verifying Checksum ... OK
   Uncompressing Kernel Image ... OK

Starting kernel ...

Linux version 2.4.27-vrs1 (mkr@s020403) (gcc version 2.95.4 20010319 (prerelease/franzo/20011204)) #2
     Fri Apr 22 06:49:12 CEST 2005
CPU: Arm920Tid(wb) revision 0
Machine: ATMEL AT91RM9200
On node 0 totalpages: 4096
zone(0): 4096 pages.
zone(1): 0 pages.
zone(2): 0 pages.
Kernel command line: root=/dev/mtdblock3 ro ethaddr=00:d0:93:12:34:56 ip=192.168.0.190::::
     CMC-TC-PU2::off console=ttyS0,9600
mtdparts=cmc_pu2:128k(uboot)ro,64k(environment),768k(linux),4096k(root),-
Calibrating delay loop... 89.70 BogoMIPS
Memory: 16MB = 16MB total
Memory: 14452KB available (1382K code, 275K data, 60K init)
Dentry cache hash table entries: 2048 (order: 2, 16384 bytes)
Inode cache hash table entries: 1024 (order: 1, 8192 bytes)
Mount cache hash table entries: 512 (order: 0, 4096 bytes)
Buffer cache hash table entries: 1024 (order: 0, 4096 bytes)
Page-cache hash table entries: 4096 (order: 2, 16384 bytes)
CPU: Testing write buffer: pass
POSIX conformance testing by UNIFIX
Linux NET4.0 for Linux 2.4
Based upon Swansea University Computer Society NET3.039
Initializing RT netlink socket
Starting kswapd
Installing knfsd (copyright (C) 1996 okir@monad.swb.de).
JFFS2 version 2.1. (C) 2001 Red Hat, Inc., designed by Axis Communications AB.
RAMDISK driver initialized: 16 RAM disks of 8192K size 1024 blocksize
 Amd/Fujitsu Extended Query Table v1.3 at 0x0040
number of CFI chips: 1
cfi_cmdset_0002: Disabling fast programming due to code brokenness.
Creating 5 MTD partitions on "CMC PU2 flash":
0x00000000-0x00020000 : "uboot"
0x00020000-0x00030000 : "environment"
0x00030000-0x000f0000 : "linux"
0x000f0000-0x004f0000 : "root"
0x004f0000-0x00800000 : "Partition_004"
i2c-core.o: i2c core module version 2.6.1 (20010830)
i2c-dev.o: i2c /dev entries driver module version 2.6.1 (20010830)
ttyS0 at MMIO 0xfefc0000 (irq = 6) is a AT91_SERIAL
ttyS1 at MMIO 0xfefc4000 (irq = 7) is a AT91_SERIAL
ttyS2 at MMIO 0xfefc8000 (irq = 8) is a AT91_SERIAL
ttyS3 at MMIO 0xfefcc000 (irq = 9) is a AT91_SERIAL
ttyS4 at MMIO 0xfefff200 (irq = 1) is a AT91_SERIAL
eth0: Link now 100-FullDuplex
eth0: AT91 ethernet at 0xfefbc000 int=24 100-FullDuplex (00:d0:93:12:34:56)
eth0: Davicom 9196 PHY (Copper)
AT91 Watchdog Timer enabled (5 seconds)
Found AT91 i2c
I2C: RS5C372 RTC driver successfully loaded
CMC buzzer driver $Revision: 0.2 $
CMC digital IO driver $Revision: 0.2 $
Serial driver version 0.03 (2004-12-17) with no serial options enabled
ttyS5 at 0xc2084000 (irq = 29) is a TI16752
ttyS6 at 0xc2086000 (irq = 30) is a TI16752
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP
IP: routing cache hash table of 512 buckets, 4Kbytes
TCP: Hash tables configured (established 1024 bind 1024)
eth0: Link now 100-FullDuplex
IP-Config: Guessing netmask 255.255.255.0
IP-Config: Complete:
      device=eth0, addr=192.168.0.190, mask=255.255.255.0, gw=255.255.255.255,
     host=CMC-TC-PU2, domain=, nis-domain=(none),
     bootserver=255.255.255.255, rootserver=255.255.255.255, rootpath=
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
NetWinder Floating Point Emulator V0.97 (double precision)
VFS: Mounted root (cramfs filesystem) readonly.
Freeing init memory: 60K
serial console detected.  Disabling virtual terminals.
init started:  BusyBox v0.60.2 (2002.10.10-17:17+0000) multi-call binary
eth0: ROVR error
eth0: ROVR error
Startup CMC
no update..
CMC Applications
rs422, Version: V2.00, Build Date: Mon Sep 19 18:01:58 2005
eeprom, Version: V2.00, Build Date: Mon Sep 19 18:00:03 2005

rs232, Version: V2.00, Build Date: Mon Sep 19 18:39:00 2005

CMC-TC-PU2 Thu Jan 1  1970 00:00:15, User 0
CMC-TC-PU2 login: VCC status = OK
cmc_main, Version: V2.15, Build Date: Wed Nov 16 15:20:38 2005
No Options..

Setting up clock 18:03:30 15.06.2006

CMC-TC-PU2 Thu Jun 15  2006 18:03:35, User 0
CMC-TC 192.168.0.190 login:

Eindeutig. Ein Linux mit einer BusyBox Shell. Eine im Embedded-Bereich sehr verbreitete Kombination. In diesem Fall leider ein Lizenzverstoss.

Jetzt stellt sich die Frage, wie man root wird. Als Login hat man naemlich nur cmc und admin zur Verfügung, die beide normale Useraccounts sind und anstelle einer Shell ein fertiges Menü starten.

Im Nachhinein, nachdem man sich auf dem Gerät umgeschaut hat, fallen mir verschiedene Möglichkeiten ein, aber die einfachste ist dem Bootloader zu sagen, dass ich gerne eine Shell hätte.
Mehr Details gibt es im Rest des Artikels.

Ich schrieb früher schon einmal von einem interessanten Erlebnis beim compilieren von Nautilus.

Nun habe ich eben gerade beim kompilieren von mboxgrep, einem Tool zum gezielten greppen nach Mails in einem Mailspool, eine andere nette Nachricht im Configure-Script gefunden:

checking for gzopen in -lz... yes
checking for BZ2_bzopen in -lbz2... yes
checking for like_monday in -lgarfield... no

Man beachte die letzte Zeile. Dazu passt es ja ganz hervorragend, dass ./configure --help folgendes bietet:

Optional Packages:
  --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
  --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
  [...]
  --without-sense-of-humor  If you have no sense of humor

Mit Interesse habe ich bei Jörg seine Kritik am LinuxTag gelesen.

Jörg meint, dass der LinuxTag mal eine ordentliche Imageberatung bräuchte und überhaupt mal kräftig überarbeitet gehört. Einerseits ist die Präsentation der Community katastrophal, andererseits ist der LinuxTag inzwischen thematisch uninteressant und man geht eigentlich nur noch hin um andere Leute zu treffen.

Endlich ausgeschlafen. Ich habe mich dann doch entschieden erst gegen 13:30 auf dem LinuxTag aufzutauchen. Das Vormittagsprogramm war dann doch nicht soooo wichtig. ;-D Ausgeschlafen (heute war es zum Glück ein wenig kühler), frisch geduscht ging es dann los mit dem Ziel erstmal Pizza oder sowas zu jagen.

Netterweise traf ich auf dem Vorplatz ein paar Red Hat Leute die meinten ich solle einfach zum Stand gehen, sie hätten noch was zu essen.
Lecker. Mozarella, Tomate und Salat plus Brötchen.
Sogar ein sehr interessantes Zubereitung. Muss ich bei Gelegenheit mal selber probieren. Ein halbes Brötchen, mit Frischkäse oder Butter beschmiert, dann ein Salatblatt und oben drüber dann den Belag. Es gab Käse, Pute, Lachs, Mozarelle und Tomate.
Das ganze dann natürlich entsprechend verziert. Wallnuss und Kräuterbutter beim Käse, Petersilie beim Rest. Lecker!

Gesättigt ging es dann weiter auf dem Linuxtag.

Wie sehr sich Pläne doch ändern können.
Eigentlich war ja angedacht nach dem LinuxTag 2005 noch mit dem CCC Stuttgart und dem CCC Karlsruhe/Entropia gemeinsam zu grillen.

Pustekuchen.

Nach Ende der Messe hing ich kurz am RedHat Stand rum, um mir was zu trinken zu holen, kurz aufräumen zu helfen und anschliessend zu schauen ob man noch tolle Sachen zum abgreifen findet. (Fand ich nicht.).
Als das dann erledigt war, meinte lx noch, man würde sich nachher noch im Hotel treffen und dann essen gehen, und ich solle doch mitkommen.
Der Beginn eines langen abends...

Das Mittagessen bestand aus "Studi 2" und vielen Getränken in der "Kippe", eine Studentenkneipe in Karlsruhe. 3,50 für Schnitzel mit Bratkartoffeln ist wirklich ein vernünftiger Preis. ;-D
Die Diskussionen während dem Essen waren wieder excellent, wie üblich.
Das ist wirklich ein riesiger Vorteil beim Linuxtag: Es ist fast egal mit wem man sich unterhält, man lernt meistens was neues oder hat eine anregende Diskussion.

Nach dem aufwachen bin ich erstmal wieder daran erinnert worden, warum ich Karlsruhe nicht vermisse.

Wie die Jahre davor war es warm, schwül und komplett Windstill. Das Ergebnis ist unangenehm: Man wacht auf, klebt überall am Körper und fühlt sich gerädert. Gut, gerade letzteres mag auch daran liegen dass die Bauarbeiter auf der Strasse um 7:00 Uhr anfangen zu arbeiten. Wahhhhh. Also unter die Dusche...

Heute war der erste Tag des freien Kongressprogramms. Die zwei für mich interessanten Vorträge, Netflow Accounting/Exporting mit netfilter von Harald Welte und Erfahrungen mit Hochverfügbarkeitsfirewalls von Bla habe ich leider verpasst. Gerade das Netflow Exporting durch netfilter ist sehr interessant, da die bisherigen Lösungen für Linux alle im Userspace arbeiten und unheimliche Ressourcenfresser sind. Wer schonmal ntop ausprobiert hat, weiss was ich meine.

Eigentlich war ja angedacht, dass ich Vormittags, irgendwann gegen 8:30 in Furtwangen fertig bin und anschliessend nach Stuttgart fahre, dort Klamotten und Schlafsack einpacke und dann weiter nach Karlsruhe fahre.

Naja, so war der Plan. Nachdem ich um 14:30 noch immer an der FH sass, habe ich mir dann ueberlegt den Plan umzuwerfen und stattdessen direkt nach Karlsruhe zu fahren und am Abend nochmal nach Stuttgart zu fahren. Gesagt, getan: Um 17:00 bin ich dann endlich in Karlsruhe angekommen und habe mich erst mal um meine Eintrittskarte gekümmert.

Das hat gut geklappt und nach nennen meines Namens gab es dann eine kostenlose Eintrittskarte.
Anschliessend ging es dann in die Messehalle, da das freie Vortragsprogramm erst am Donnerstag beginnt.

Hin und wieder findet man interessante oder lustige Meldungen wenn man einem Compiler zuschaut, wie er Software baut. Auch wenn ich kein Gentoo nutze, so nenne ich es mal "The Gentoo experience", frei nach Gentoo is for ricers: Shit scrolling by for hours makes me a Linux expert overnight. :-)

Momentan bin ich dabei für uns unseren In-House RedHat Enterprise Linux Tree auf x86_64 zu bauen und was sehen meine entzündeten Augen bei dem autobuilder:
Nautilus, der Filemanager, hat doch eine humorvolle Sache im Make stehen:

-DUGLY_HACK_TO_DETECT_KDE

Ich hatte neulich das Problem dass ein Script auf unserem Autobuilder 'date +%Ymd' aufruft um einen Dateinamen festzulegen. Das ist ungeschickt, weil ich einen ganz bestimmten Dateinamen erzeugt haben wollte der den Datumsstring 20050107 enthält und nicht den heutigen Tag.

Also blieben vier Möglichkeiten:

1. Systemzeit auf den 7. Januar 2005 zurücksetzen.
2. /bin/date durch ein Shellscript ersetzen dass nix macht ausser echo 20050107
3. Script ändern und den Namen hardcoden
4. Irgendwie dem Script eine geänderte Systemzeit unterjubeln

Wir nutzen ja auch RedHat Enterprise Linux. Allerdings in unserer eigenen Version die aus den Sourcen von RedHat gebaut wurde. Hier mal eine kleine Liste von anderen Rebuilds von RHEL, (Red Hat Enterprise Linux). Diese sind auch zum Download gedacht, während unsere In-House ist, da wir ein wenig an der Software geschraubt haben und sie für unsere Anforderungen optimiert ist. (Der Vorteil von Open Source.)

• CentOS oder http://www.centos.org
• Lineox
• Rocks
• Scientific Linux und Fermi Linux
• TaoLinux
• White Box
• X/OS Linux

Ansonsten bietet sich noch die RHEL-Rebuild Mailingliste an, um generelle Fragen zu Rebuilds zu beantworten. Rick Moen hat auch noch eine nette Seite mit Informationen zu RHEL Rebuilds zusammengestellt.

Sometimes there are really strange problems which leave you mystified as you can't find a sensible cause for the problem at hand.

The follow problem had me stumped for several minutes:
One of our webhosting customers tried to install phpNuke on his account.
He did it by the book, extracted the files, edited the config.php-file, configured the right database, everything seemed to be perfect.
Curiously, accessing his phpNuke pages with a webbrowser only resulted in the message "No input file specified".
As he could't find out why, he asked our support.