
Sysgen is a simple tool for generating Linux images from a specification
written in a simple script form. The current tool is designed to be a
backend and a demonstration rather than a final product. Nevertheless it
is completely functional.

Sysgen needs only functional copies of the shell and the "rpm" command to
operate. Currently it is intended for generating images on a seperate host
but could easily be extended to generate a simple and effective installer


The script language supports the following commands

%run		-	execute a command
%runin		-	execute a command in the build target area
%arch		-	add an architecture to the list of acceptable packages
%install	-	introduce the install list
%end		-	finish

In install mode each line is a package or group of packages to be installed.
The following additional directives are available

%nodep		-	skip dependancy checks
%disc		-	hint to the installer which disc to use
			(unused)
%...		-	any other name is taken as a category 
			(unused)

The scripts are run with the environment variables set as follows

	NISDOMAIN	-	passed NIS domain
	NISSERVER	-	passed NIS server
	INSTALL		-	install directory
	HOSTNAME	-	hostname of target
	RPMDIR		-	RPM search path


sysgen expects to be run as follows

	sysgen rpmdir targetdir hostname nisdomain nisserver < script

	rpmdir - the subtree containing the RPM packages - eg a directory
		 with the CD-ROM mounts inside

	targetdir - directory to create and populate

	hostname  - hostname to pass

	nisdomain - nisdomain to pass

	nisserver - nisserver to pass

Future Direction:

	hostname, nisdomain, nisserver etc need to be replaced by
	%environment macros

	%include may be added (or should we use cpp)

	A "fullpath" tool should be added to generate precise paths in
	the passed script (for NFS install)

	%if and %ifin [shellstuff] want adding to make decisions based
	on shell code
