loadlin

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loadlin
Developed by	Hans Lermen
Latest release	1.6c / April 15, 2002
OS	DOS, Windows
Genre	Bootloader
License	GNU General Public License
Website	ftp://elserv.ffm.fgan.de/pub/linux/loadlin-1.6/ [Defunct]

loadlin is a Linux boot loader that runs under DOS or Microsoft Windows (95, 98 or Me only). It allows the Linux system to load and replace the running DOS/Windows without altering existing DOS/Windows system files.

loadlin and the Linux kernel are both files on a file system accessible to DOS/Windows. It stops DOS/Windows, temporarily removes it from memory and instead loads the Linux kernel into memory from a file. It also places various configuration parameters into memory, and transfers control to the kernel. The kernel reads these parameters, initializes and runs.

Optionally, you can configure loadlin to supply the kernel with a RAM disk. You identify a file containing the image of a file system and loadlin loads that image into memory before transferring control to the Linux kernel. It passes to the kernel information about the RAM disk and its location. Furthermore, you can pass parameters to the Linux kernel that make it use that RAM disk as its root file system. The startup programs in that file system often cause Linux to mount another file system (perhaps on a fixed disk) and switch to using that as its root file system.

loadlin is not the conventional way to boot Linux. A more straightforward way to boot Linux is to have the BIOS load a simple standalone boot loader such as LILO or GRUB and have that boot loader do what loadlin does, thus eliminating DOS and Windows from the picture. But the loadlin approach is useful when you need to be able to run DOS/Windows sometimes anyway, and if you have a working system that boots DOS/Windows and you don't want to risk breaking that and ending up with an unbootable computer by incorrectly installing a boot loader. loadlin is also useful when a piece of hardware needs to be initialized using a DOS program - this works e.g. for some sound cards which can be initialized in Sound Blaster-compatible mode and can afterwards use the standard Sound Blaster Linux driver.

loadlin does not alter the master boot record (MBR) and boot loader or any other part of the system. The next time you boot the system after booting Linux with loadlin, it will boot the same DOS/Windows it did before and you can run loadlin again to run Linux again.

loadlin has worked under Windows (95, 98 and ME only) since loadlin version 1.6 (released 2002).