Converting SGI downloadable .tar Overlays into bootable CDs

SGI provides downloadable tar files which contain the overlays for the IRIX system. One question that came up a lot was how to turn these into bootable efs images to allow a fresh install based on these overlays.

Step 1: Download the files

To start you need the overlay files from SGI and the efs tools all on a computer running IRIX. To get the overlay files you need a supportfolio account. The Irix 6.5.22m overlays are the last free release that you can get so I will focus on those. However in theory any release can be used. Download the overlays from SGI do not unpack them just put them into a directory alone.

Then get and install the EFS tools. Only one of the following two packages is necessary. You will notice that both package share the same back-end tools, so the key difference is in the shell script used to orchestrate the whole process.

Option 1a: custom EFS tools package

A package of EFS Tools is available here. Unpack the EFS Tools and put them in /usr/local/bin, be sure /usr/local/bin is in your path. If you do not want them in /usr/local/bin you need to edit mkefs & setup_cd.sh, specifically TOOLDIR=/usr/local/bin needs to be changed.

Option 1b: sgi's CDmastering package

Another package is available from SGI here, although one wonders how much longer it may be available (call for mirrors!). This package can be unpacked in /usr/local/bin as well, although it is not necessary as long as the location is in your path. Take a peek in the make_efs shell script to see how it works. This is the package originally mentioned in the thread above, although the site has changed since then.

Step 2: Check and Run Scripts

Self explanatory. Continue with the (a) or (b) option you chose above with:

Option 2a: setup_cd.sh

Included in the EFS Tools is a shell scripts called setup_cd.sh, this script should be able to do everything that is needed to generate the cd images ready to be burned. However it assumes you are using the 22 release and have 3 overlays. If you do not you need to edit the script. Look for the variables release, date, and disks. Also if you have more then 3 overlays you need to change the loops. Once everything is right you should be able to to run setup_cd.sh from the directory that has the SGI overlay tar files. It will create the directory structure needed and output the .image files.

Option 2b: make_efs

In contrast to the above, you run make_efs once for each CD you are making. Specify the input directory (the base of the directory structure for your CD, typically the dir containing the "dist" dir) and the output directory (where the images will be written). The

Step 3: Burn your CDs

Option 3a:

Assuming everything went ok you should have 3 .image files in your cdimages directory. Use whatever cd burning program you have to make the CD's. I have to scp these into my linux desktop to do this, your setup might be different. Note: Worked for 6.5.22 but did not work with variables changed for 6.5.28 as of 1st April 2009. Your Milage May Vary.

Option 3b:

The result from make_efs is (1) a .vh file containing the volume header and (2) a .efs file with the filesystem itself. A simple "cat x.vh x.efs > x.iso" for each x in the set of cds you are creating will produce a file you can directly burn to a CD-R (quaintly called "WORM" media by this package). It is not an ISO9660 image, but the .iso extension might be helpful if you intend to burn the CD with a graphical tool.

See also

Creating Backups of IRIX Install Media on MacOS X