Linux boots from different media types. The large distributions usually boot a minimal system, and then install packages (e.g. rpm or deb) from CD to a harddisk.
Special purpose distributions usually don't "install" anything, they just boot and run. You can boot from various media, typically floppies, CDs or LS100-media. The main difference between current distributions is the choice of the boot-loader and the programs available after boot.
GENDIST supports the following media types:
Adding support for additional is simple, since it is only necessary to implement a single new makefile (and to add the necessary documentation).
This is a classical combined root+boot floppy. It contains the kernel and a compressed ramdisk filesystem on one floppy. This is the most space-efficient single-disk distribution media, but you can neither pass any command-line arguments to the kernel, nor use the "initrd"-feature of the kernel (in other words /linuxrc won't run automatically). In addition, your image-size must be 1.44 MB.
This is a classical solution with the kernel on one floppy (boot-disk) and the root-filesystem (a compressed ramdisk) on the second floppy. This media type does not allow you to pass any command-line arguments to the kernel and you cannot use the "initrd"-feature of the kernel. It also is a certain waste of space, since the kernel is usually much smaller than 1.44 MB, so the first floppy is not used completely.
This is a widely used variant of the classical types. It uses Lilo as a boot-loader to load the kernel and the ramdisk. It also supports the "initrd"-feature of the kernel.
Modern distributions usually use syslinux-based installation disks. Syslinux is a boot-loader similar to Lilo, but it has a number of advantages (and also some drawbacks).
Bootable El-Torito CDs emulate a single-disk floppy. Most BIOSes support 1.44MB, modern also support 2.88MB. These bootable CDs are quite useful, since you can create a minimal Linux system on the floppy, and put additional stuff onto the CD.
El-Torito is not the only standard to create bootable CDs. Isolinux is part of the Syslinux-package and supports a different way of booting. The biggest advantage is that the size of your compressed root-filesystem is not limited to the size of the emulated floppy. There are of course limits: size of the CD, memory size, BIOS restrictions.
Isolinux-based CDs need the isolinux.bin-bootloader, which is distributed in the bin-subdirectory of the GENDIST distribution. If you encounter any problems with isolinux-based CDs, try to upgrade to the current version of syslinux/isolinux first (just copy the new isolinux.bin to the bin-subdirectory). See the file README.isolinux for version-information.
In the examples-subdirectory of the GENDIST-distribution you will find an example which creates an isolinux-based CD from your running Linux-distribution. Please read the documentation carefully, since this is a non-trivial example.
Bochs is a x86-emulator, very slow, but free. Instead of using real disks, Bochs emulates them using disk-images.
The GENDIST media-type "bochs" will automatically create a bootable Bochs HD-image file with two partitions (a root-filesystem and a swap-partition). To use the media-type bochs, you need the Bochs-emulator and bxtclone from the Bochs-Tools (version 1.6.1. or above).
You can pass extra arguments to bxtclone with the variable BOCHS_ARGS. Note that bxtclone is not designed to create very small disk-images. You might need to increase the size of the disk-image to increase the number of inodes necessary (e.g. set BOCHS_ARGS="-e 64m" to increase the size to 64 MB).
No, this is no special boot-media, just a way to distribute data, e.g. application-packages.
This also is no special boot-media, just a way to distribute additional programs. Useful e.g. for creating a modules disk.
This also is no special boot-media, just a way to distribute additional programs. The disk contains a single, possibly compressed tar-archive of a whole filesystem-tree. Useful for example if you have an optional /usr-tree and want to distribute it separately.