Wednesday, 11 July 2012

NetBSD/dreamcast from Windows in 5 minutes

Thanks to for this image
Retrochallenge segue: How to burn a Dreamcast boot CD from Windows?

Someone was asking on the NetBSD/dreamcast list about burning a bootable CD from a Windows machine. Its already easy to burn a CD using a NetBSD 'cdburn' live image, but obviously in this case they prefer to burn from an existing Windows machine.

It certainly is possible - and turned out to be quite easy:
  • Download BootDreams
  • Create a new directory
  • Download a NetBSD/dreamcast .bin kernel (*), uncompress,  and rename to netbsd.bin (to ensure it is no longer than 12 characters + .bin), and put into above directory
  • Run BootDreams
  • Insert blank CD-R (Not CD-RW)
  • Select "CDRecord" (4th icon)
  • Click "Browse" and select the above directory
  • Click "Process" and answer "Yes" to any questions

(*) NetBSD/dreamcast kernels are available in two forms, as netbsd-GENERIC.bin.gz which is just the kernel and netbsd-GENERIC_MD.bin.gz  which includes a ramdisk with basic shell tools. Remember to gunzip the file to get the .bin. (a tool like 7zip should handle that).

A GENERIC_MD kernel will boot up directly to a shell, while a GENERIC kernel will prompt for the root filesystem - which will be rtk0 if you have a BBA and NFS serving machine, and gdrom0a for root-on-cd.

The latest released kernel is in
The BETA2 test kernel for the upcoming NetBSD-6 release is in:
There are also nightly builds of -current and the various netbsd- branches at

As a bonus any files in the same directory as the kernel are accessible to the booted NetBSD image, offering some interesting possibilities of "root on CD". Extracting base.tgz into *almost* works - it just fails when init tries to run /dev/MAKEDEV as due to the case-insensitivity of Windows it is now /dev/makedev, plus any symlinks have been mangled.

I would hope a RockRidge format CD written on NetBSD would Just Work... Something to try tomorrow!

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