febootstrap-supermin-helper supermin.img hostfiles.txt host_cpu kernel initrd
febootstrap-supermin-helper input [...] host_cpu kernel initrd
+ febootstrap-supermin-helper -f ext2 input [...] host_cpu kernel initrd appliance
+
+ febootstrap-supermin-helper -f checksum input [...] host_cpu
+
=head1 DESCRIPTION
I<febootstrap-supermin-helper> reconstructs a bootable kernel and
initramfs from a supermin appliance. First you should be familiar
-with L<febootstrap(8)>, L<febootstrap-to-initramfs(8)> and
-L<febootstrap-to-supermin(8)>.
+with L<febootstrap(8)>.
=head1 PARAMETERS
-Of the four or five required parameters, the first few are I<input>
-files, and the last two are I<output> files.
+Of the required parameters, the first few are I<input> files, and the
+last two or three are I<output> files.
C<supermin.img> and C<hostfiles.txt> are the input files which
describe the supermin appliance. (You can also use a directory name
C<host_cpu> should be the host CPU, eg. C<x86_64> or C<i686>.
-C<kernel> and C<initrd> are the temporary output files that this
-script produces. These output files are meant to be used just for
-booting the appliance, and should be deleted straight afterwards.
+C<kernel>, C<initrd> and C<appliance> are the temporary output files
+that this script produces. These output files are meant to be used
+just for booting the appliance, and should be deleted straight
+afterwards. The extra C<appliance> parameter is only required when
+the format is C<ext2>. None of these parameters are needed for
+the checksum output C<-f checksum>.
=head1 OPTIONS
=over 4
-=item B<-f cpio> | B<--format cpio>
+=item B<-f fmt>
+
+=item B<--format fmt>
+
+Select the output format for the appliance. Possible formats are:
+
+=over 4
+
+=item cpio
+
+A Linux initramfs. This is the default.
+
+In this case you have to supply names for the C<kernel>
+and C<initrd>, where the C<initrd> is the appliance.
+
+=item ext2
+
+An ext2 filesystem.
+
+In this case you have to supply names for the C<kernel>, a small
+C<initrd> which is used just to locate the appliance, and the
+C<appliance> (the ext2 filesystem).
+
+=item checksum
+
+Output a checksum.
+
+This prints a checksum which only changes when one of the input files
+changes.
+
+You can use this in order to cache the output of a previous run of
+this program: computing the checksum is much quicker than building an
+appliance, and you only need to invalidate the cache (and consequently
+rebuild the appliance) when the checksum changes. Note that the
+host_cpu and the UID of the current user are included in the checksum.
+
+=back
-Select the output format. The default, and only possible output
-format, is C<cpio> (ie. a Linux initramfs).
+=item B<-k file>
-=item B<-k file> | B<--kmods file>
+=item B<--kmods file>
If this option is specified, then C<file> should be a list of
wildcards matching kernel module names, eg:
host will be included. This is safer, but can produce rather large
appliances which need a lot more memory to boot.
+=item B<-u user>
+
+=item B<--user user>
+
+=item B<-g group>
+
+=item B<--group group>
+
+Run febootstrap-supermin-helper as an alternate user and/or group.
+C<user> and C<group> can be specified as either a name, which will
+be resolved using the system name service, or a uid/gid. Use of these
+options requires root privileges.
+
+Use of these options is required if running febootstrap-supermin-helper
+as root with the effective uid/gid set to non-root. Bash will reset
+the effective uid/gid to the real uid/gid when invoked. As
+febootstrap-supermin-helper uses bash in parts, this will result in the
+creation of an appliance with a mixture of ownerships.
+
=back
=head1 SPEED
Minimize the appliance, removing as much extraneous junk as possible.
-As well as using L<febootstrap-minimize(8)> it is worth checking for
-anything that is not necessary for your particular application and
-removing it by hand.
+=back
+
+=head1 ENVIRONMENT VARIABLES
+
+=over 4
+
+=item FEBOOTSTRAP_KERNEL
+
+If this environment variable is set, then automatic selection of the
+kernel is bypassed and this kernel is used.
+
+The environment variable should point to a kernel file,
+eg. C</boot/vmlinuz-3.0.x86_64>
+
+The corresponding module path is guessed from the kernel name, but you
+can override that by setting C<FEBOOTSTRAP_MODULES>.
+
+=item FEBOOTSTRAP_MODULES
+
+If C<FEBOOTSTRAP_KERNEL> and C<FEBOOTSTRAP_MODULES> are both set, then
+automatic selection of the kernel is bypassed and the kernel and
+module path are set to these values.
+
+The environment variable should point to a module directory,
+eg. C</lib/modules/3.0.x86_64/>
+
+This has no effect if C<FEBOOTSTRAP_KERNEL> is not set.
=back
=head1 SEE ALSO
-L<febootstrap(8)>,
-L<febootstrap-to-initramfs(8)>,
-L<febootstrap-to-supermin(8)>.
+L<febootstrap(8)>.
=head1 AUTHORS
=head1 COPYRIGHT
-(C) Copyright 2009-2010 Red Hat Inc.,
+(C) Copyright 2009-2011 Red Hat Inc.,
L<http://people.redhat.com/~rjones/febootstrap>.
This program is free software; you can redistribute it and/or modify
git.annexia.org / febootstrap.git / blobdiff