mkrboot(8) Generates combined kernel+root image floppies / .EXE files


mkrboot method [ kernel [ rootimg [ device [ size ] ] ] ]


mkrboot is a system administration tool that is primarily of use for generating boot floppies for Linux distributions. Those boot floppies should be fairly easy to handle and there should be the least number of disks possible. Mkrboot makes installations possible with one or no boot disk.


The bootmechanism to use for booting up Linux. See below for the supported methods.
A compressed linux kernel. If not specified the default /vmlinuz is assumed. mkrboot will configure the kernel flags properly for booting.
A compressed rootimage (a minix filesystem is probably best) that contains the initial root filesystem to be used during installation. If not specified the file root.bin in the current directoy is the default.
The device on which the floppy image should be generated. This can be a ramdisk but then the size should also be specified. The default is /dev/fd0 if omitted.
When loadlin is the boot method then no floppy image is generated. Instead a filename is specified to designate the name of the .ZIP file to be written. The default is in the current directory. The image should be copied onto a dos partition and possibly be converted to an exe using the "zip2exe.exe" program of pkzip.
If the kernel method is used then the device can also be a regular file to be generated.


Boot Methods to get a minimal Linux System started from one floppy or none:
Generates a .ZIP file which contains everything needed to boot up. The .ZIP File should be converted to an .EXE file using zip2exe from pkzip. The file can then be distributed and the end user can simply type the name of it to decompress it. The kernel, rootimage, loadli and an install script will be unpacked. Typing "install" should then fire up the linux system.
The advantage of this method is that it does not use any floppies at all and thus has no size limitations. The kernel ramdisks are limited to 4 Megabytes though. Therefore the maximum size of the compressed root image should be around 2 Megabytes.
Generates a floppy disk which can be booted with a combined kernel+root fs. The floppy disk will be formatted as a MINIX Filesystem. I tried making it a DOS fs but running lilo destroyed the root directory (?).
Lilo boots are common for booting an already running Linux system. This method should be the most familiar for Linux enthusiasts.
Uses the kernel loader. Also generates a floppy disk which boots with combined kernel+root fs. The kernel loader has no interactive mode, so the end user cannot change any boot parameters on a commandline! But the kernel loader is the fastest method and the method that leaves the most room on the boot floppy.
Uses FreeDOS to boot up a minimal DOS system. Loadlin is used on the minimal system to then load Linux. The advantage here is that everything can be reconfigured on the dos level. A new kernel/root image can simply be copied onto the floppy and it will work. The user can customize the rootdisk at will!
Troubles: FreeDOS is not very stable and the FreeDOS stuff takes up a certian amoung of space on the boot disk.
Uses a dos formatted floppy disk and a special boot loader to avoid loading ms-dos. Permits changing any configuration on the disk itself without having to run some tool afterwards.
Right now syslinux is not able to do booting with a root image. The current version should work with syslinux as soon as something is released that supports that feature.


Christoph Lameter <[email protected]>
Idea and Initial Version
Bernd Eckenfels <[email protected]>
Enhancements, Sanity Checks and Maintaining