dnl	$OpenBSD: prep,v 1.14 2008/08/05 23:05:14 miod Exp $
To be able to boot the OpenBSD/MACHINE installation program, you will
need to learn a bit about RedBoot, the low-level process that controls
the microprocessor after hardware initialization.
dnl XXX bootable partitions
The enabled features between IOData HDL-G and Thecus N2100 vary, so
different methods will be needed on both machines.

All these machines use RedBoot as their firmware and boot loader
interface, with varying limitations.  Thecus systems cannot load a
file from disk, but can load an image from flash or network.  IOData
systems are more restricted, and can only load an image from ext2fs
partitions on disk, while the commands to load from flash are not
available and network booting does not appear to work.

Talking to the Thecus

The Thecus N2100 needs a serial cable. On the back of the disk drive
circuit board, there is either a 10-pin header (with one pin removed),
or 9 holes for you to solder in your own header.  The ribbon cable
that connects from there to your serial cable or the serial port on
your computer is of the same type as used on older i386 PCs, but
be aware that there are two different types of 10-pin IDC to DB-9M
ribbon cable in use, which look identical (the differences are hidden
inside the DB-9 connector). The cable you need is wired using the
"AT-Everex" or "Asus" pinout, as described here:

and *not* the more straightforward to solder "crossed" type:

If you wish to check a cable, or make your own, the pinouts are:

    DB9           IDC10
    ===           =====
    1 2 3 4 5     1 3 5 7 9
     6 7 8 9      2 4 6 8 10

Wire pin 1 to 1, 2 to 2 etc, with 10 not connected.

On the Thecus N2100, it is necessary to move jumper J3 to J4 to properly
route the serial port interrupt to allow serial to work under OpenBSD.
This jumper is under the disk drives, so you may wish to ensure its
correct setting while you are installing the disk(s).  For instructions
on assembling/disassembling your N2100, see the N2100 Manual at

Booting Thecus N2100

When you have connected your computer, a command like "tip -115200 tty00"
(assuming you're using the first serial port on your machine) should 
connect you to the Thecus console. Now apply power to the Thecus
and start it.

After some device probe information, you should see this prompt:

    == Executing boot script in 3.000 seconds - enter ^C to abort

To enter interactive RedBoot, it is necessary to press ^C within the given
number of seconds of the prompt. It will typically accept the ^C if typed 
during the diagnostics that precede this prompt.

The recommended way to boot OpenBSD on Thecus is to configure networking and
load bsd.rd from a tftp server or http server. First networking must be
configured using the fconfig or ip_address commands.

Update the IP address, netmask and server address with the commands
listed below to allow booting from the network. TFTP and HTTP are
supported. (BOOTP configuration _may_ not work)

Using ip_address only allows you to set the local IP address and
the IP address of the server where bsd.rd is located.  This command
takes effect immediately but will not persist across a reboot.

    RedBoot> ip_address -l -h
    IP:, Gateway:
    Default server:, DNS server IP:

Once you have done this, and have set up your TFTP server on
the gateway machine ( in the above example), you can
boot manually.

    RedBoot> load /bsd.rd
    Using default protocol (TFTP)
    Entry point: 0x00200000, address range: 0x00200000-0x0066a49c
    RedBoot> go

OpenBSD/armish booting ...
initarm: Configuring system ...
physmemory: 65536 pages at 0xa0000000 -> 0xafffffff
[ no symbol table formats found ]
Copyright (c) 1982, 1986, 1989, 1991, 1993
        The Regents of the University of California.  All rights reserved.
Copyright (c) 1995-2008 OpenBSD. All rights reserved.

OpenBSD 4.3 (RAMDISK) #175: Tue Mar  4 21:54:34 MST 2008
real mem  = 268435456 (256MB)
avail mem = 250630144 (239MB)
Install(I), Upgrade(U) or Shell(S)?

If you then install to your hard disk, in future you can
load /boot the same way and just hit "return" to boot OpenBSD.

Automatic Booting

However, for easier booting, you may wish to modify the flash
memory so that the Thecus will boot automatically into OpenBSD
when it is powered up. Doing so disables the devices' built-in
Linux kernel, however, and makes it difficult or impossible to
apply future RedBoot firmware upgrades. There are two general 
1) Just change the boot configuration (using 'fconfig') to automate the 
   above booting (your TFTP or HTTP boot server will still be needed);
2) Remove a file from the flash and replace it with OpenBSD's /boot;
   this configuration can be booted standalone.

Thecus RedBoot provides the 'fconfig' (not ifconfig) command to
change the boot configuration of the device. Also 'fis' is provided
to perform flash operations.

Due to a change made by Thecus to the firmware, fconfig does not
work with Thecus firmware version "1.93 (Feb 2007)" or later, and
*it is thus not possible to make the Thecus auto-boot into OpenBSD*
(worse, it will let you enter the "script" commands below, but
ignore them on boot). To correct this, you must "upgrade" your
thecus down to version "1.93 Nov 29 2005" using the file 
n2100-downgrade-reboot.rom *before* you remove any files from flash.
You can get this file from Thecus; they have given permission for
it to be mirrored at However,
if you have removed files from flash before running this downgrade,
it is not believed to be possible to get your machine to auto-boot.

Once the downgrade is done, if your TFTP machine will always be around,
you can autoboot just by changing the boot script with fconfig,
as follows: (in this example, is both the default
IP gateway and also the TFTP server):

    RedBoot> fconfig
    Run script at boot: true
    Boot script: 
    .. load /boot.armish
    .. go
    Enter script, terminate with empty line
    >> load /boot.armish
    >> go
    Boot script timeout (1000ms resolution): 3
    Use BOOTP for network configuration: false
    Gateway IP address:
    Local IP address:
    Local IP address mask:
    Default server IP address:
    Console baud rate: 115200
    DNS server IP address: 
    GDB connection port: 9000
    HW Status: 0
    Force console for special debug messages: false
    MAC address: 0x00:0x14:0xFD:0x30:0x25:0x14
    MAC address 2: 0x00:0x14:0xFD:0x30:0x25:0x15
    Network debug at boot time: false
    Reset default: Normal
    Serial number: N2100 V2.1.06
    ... Unlock from 0xf0fc0000-0xf0fc1000: .
    ... Erase from 0xf0fc0000-0xf0fc1000: .
    ... Program from 0x07fd2000-0x07fd3000 at 0xf0fc0000: .
    ... Lock from 0xf0fc0000-0xf0fc1000: .

This configuration can easily be set back to the default, as the
Linux system does not get erased from the flash memory. To set it
back, just change the boot script with fconfig back to what it was,
for example:

    fis load ramdisk
    fis load kernel
    exec -c "console=ttyS0,115200 root=/dev/ram0 initrd=0xa0800000,42M mem=128M@0xa0000000"

You could also remove the boot script altogether by not re-entering
it, so you would be dropped to the RedBoot shell by default.

Recheck the new values and use the 'reset' command.

For the standalone booting option, you will have to load /boot into
the flash memory...

To overwrite the Thecus ROM and boot from the load device, it is necessary
to delete a 'rom file' and load the openbsd bootloader image there.  With
networking configured (as above) remove a region and load the 'boot' program.

Initially the machine will contain much like the following:

    RedBoot> fis list
    Name              FLASH addr  Mem addr    Length      Entry point
    RedBoot           0xF0000000  0xF0000000  0x00040000  0x00000000
    RedBoot config    0xF0FC0000  0xF0FC0000  0x00001000  0x00000000
    FIS directory     0xF0FE0000  0xF0FE0000  0x00020000  0x00000000
    ramdisk           0xF0040000  0x00800000  0x00D00000  0x00800000
    kernel            0xF0D40000  0x00200000  0x00160000  0x00200000
    user              0xF0EA0000  0xF0EA0000  0x00120000  0x00200000

There is no free space in the rom for the 'boot' program, so something must
be removed. 
WARNING: this will make the machine unbootable into the original
Thecus server mode and it is quite difficult to restore to the
original software.
EXTREME WARNING: Do not touch the RedBoot, RedBoot config, or FIS 
directory regions, as doing so will probably brick the device.

Remove (with confirmation) a region to make space, eg 'user' (the
non-root files needed to run Linux from Flash Memory).

    RedBoot> fis delete user
    Delete image 'user' - continue (y/n)? y
    ... Erase from 0xf0ea0000-0xf0fc0000: .........
    ... Unlock from 0xf0fe0000-0xf1000000: .
    ... Erase from 0xf0fe0000-0xf1000000: .
    ... Program from 0x07fdf000-0x07fff000 at 0xf0fe0000: .
    ... Lock from 0xf0fe0000-0xf1000000: .

Load the Armish OpenBSD bootloader 'boot' via tftp or http:

    RedBoot> load -m http /boot
    Entry point: 0x00100000, address range: 0x00100000-0x001067e0

Save that loaded file to flash:

    RedBoot> fis create boot
    ... Erase from 0xf0ea0000-0xf0ec0000: .
    ... Program from 0x00100000-0x001067e0 at 0xf0ea0000: .
    ... Unlock from 0xf0fe0000-0xf1000000: .
    ... Erase from 0xf0fe0000-0xf1000000: .
    ... Program from 0x07fdf000-0x07fff000 at 0xf0fe0000: .
    ... Lock from 0xf0fe0000-0xf1000000: .

Confirm its addition:

    RedBoot> fis list
    Name              FLASH addr  Mem addr    Length      Entry point
    RedBoot           0xF0000000  0xF0000000  0x00040000  0x00000000
    RedBoot config    0xF0FC0000  0xF0FC0000  0x00001000  0x00000000
    FIS directory     0xF0FE0000  0xF0FE0000  0x00020000  0x00000000
    ramdisk           0xF0040000  0x00800000  0x00D00000  0x00800000
    kernel            0xF0D40000  0x00200000  0x00160000  0x00200000
    boot              0xF0EA0000  0x00100000  0x00020000  0x00100000

Now that the bootloader is in place, update fconfig to autoboot OpenBSD:

    RedBoot> fconfig
    Run script at boot: true
    Boot script:
    .. fis load ramdisk
    .. fis load kernel
    .. exec ...
    Enter script, terminate with empty line
    >> fis load boot
    >> go
    Boot script timeout (1000ms resolution): 1
    Update RedBoot non-volatile configuration - continue (y/n)? y
    ... Unlock from 0xf0fc0000-0xf0fc1000: .
    ... Erase from 0xf0fc0000-0xf0fc1000: .
    ... Program from 0x0ffd2000-0x0ffd3000 at 0xf0fc0000: .
    ... Lock from 0xf0fc0000-0xf0fc1000: .

The important part is that 'Run script' is true and that the commands are
'fis load boot' and 'go' ('boot' is the file created by 'fis create boot'
earlier). Confirm the update and type 'reset' to auto boot.

The bootloader is command driven with timeout like many other OpenBSD

How to boot/install IOData HDL-G:

The hda1 partition is the boot partition for Linux; it contains
zImage and initrd. Since RedBoot only can boot from the ext2fs partition
it is very important that this partition be present and not be reformatted.
If this partition is destroyed, it will be necessary to remove the HD and
recreate the partition on another machine. Note: RedBoot should be able
to boot from the network, however that has been unsuccessful on IODATA HDL-G
so far.

To install OpenBSD, boot linux, and copy 'boot' and 'bsd.rd' into the
partition mounted on /dev/hda1, after that has been done, it is possible
to reboot into OpenBSD and install the device. Installation can proceed
as on other machines, however care must be take to not remove wd0i/hda1
partition (fdisk partition 0). DO NOT chose the 'full disk installation'

Unfortunately, since IODATA did not provide the 'fconfig' command it
is not possible to change the boot commands run when RedBoot starts,
thus it not possible to autoboot OpenBSD; the OpenBSD/MACHINE bootloader
is currently unable to work when loaded as `zImage'.  Futhermore, to
disable autobooting into Linux, at least one of the zImage and initrd files
need to be renamed or removed.  This can be done from the shell in bsd.rd.

To load the ramdisk kernel to install use the commands

    RedBoot> load -m disk hda1:/bsd.rd
    RedBoot> go

to boot normally, load the bootloader which will give options to boot other

    RedBoot> load -m disk hda1:/boot
    RedBoot> go

Since this bootloader is able to boot any kernel from the OpenBSD root
partition, it is not necessary to keep bsd.rd on the hda1 partition after
OpenBSD is installed.