How to boot Linux system from DOS system

Linux operating system was born very early, but it has been widely popular in recent years and is known. It has evolved from a research system to an easy-to-follow application system. The open nature of Linux and the spirit of free software are increasingly being loved by users. This operating system has revolutionized the computer operating system, and it is likely to beat the Windows operating system in the future. The Linux operating system can not only boot directly from the LILO bootloader, but also boot indirectly from the DOS operating system.

The benefits of Linux operating system booting from DOS are:

1. After using DOS operating system for regular transaction processing, you can directly enter the Linux operating system without restarting the booting computer.

2. It is not possible to write LILO boot data in the hard disk partition, so that an accidental write error will cause the operating system to boot. It is the safest way to boot the operating system.

3. For those who like to modify the Linux system boot kernel, using LOADLIN program boot under DOS can easily debug your own kernel program without affecting any configuration of the original system. The DOS file system is different from the Linux file system. DOS currently has only two file formats, 16-bit and 32-bit. But the Linux operating system can support a variety of file systems, such as: sysv, ext, ext2, dos..., Linux file system The most popular file system is ext2.

There are also UMDOS file systems built in DOS environments. The ext2 file format is now popular in the Linux operating system, specifically for the file system used by this operating system. The UMDOS file system is a file management format that the Linux operating system can run in the DOS file system.

When you get a Linux operating system CD, you also get the LOADLIN package. It is usually found in various Linux distributions and distributions.

Of course you can also find it on the web. This program has long been part of the Linux operating system. It is stored in ZIP or TGZ compressed format. Its file name is usually LOADLIN16.ZIP or LOADLIN16.TGZ contains executable files and source code. Loadin supports both UMDOS and ext2 file systems.

It is free and open software. If you are interested and need, you can modify and compile it by unpacking the source package that comes with it. Add new features to it. Author of the original program. It is Hans Lermen.

The version of the Loadlin package you can get is probably version 1.6. It is the most popular version that is now seen.

The features and functions of this version are as follows:

1. Enhanced error checking and full support for Linux's "command line features".

2. Accept the response file. The command line can be larger than 128 bytes.

3. Adapt to different configurations under DOS. There are very few configuration requirements for DOS.

4. Can be executed in extended memory, support large kernel (bzImages) and virtual disk (initrd)

5. Can support Linux system running DOS system format

It boots from the DOS file system into the Linux file system requirements:

1. Sufficient memory (can be loaded into the free memory of the Linux boot kernel), with a compressed kernel (zImage or

bzImage, which is the Linux boot kernel compressed file).

and optionally load the initrd image. (RAM boot initialization in Linux file system).

2. The DOS running mode is required to be in real mode, that is, the standard DOS mode can be run to enter the Linux operating system.

Supports the EMS driver interface, which supports extended memory. (VCPI)

3. There is already a Linux operating system installed on your hard drive.

Once you have the package, extract it to the appropriate directory using the appropriate decompression software. Here is an example:

Suppose you get the software file named Loadlin16.zip. Use UnZip to extract to your C:LOADLIN directory and enter the command on the DOS command line:

C:>CD LOADLIN

C:LOADLIN>LOADLIN zimage

Root=/dev/hdb1 ro vga=ask

to enter the Linux operating system.

As you can see from the above example, LOADLIN requires a zimage or bzimage file, which are compressed files of the Linux kernel. zimage and bzimage are two different compressed Linux kernel forms.

zimage is the core of the system after the Linux operating system is compiled with the Gcc program. It also plays an important role in LOLI boot. Its function is to boot the device that initializes the Linux configuration and call the process of the system's initial driver. Finally enter the Linux console and proceed.

Also select an image file to mount the disk. /dev/hdb1, refers to the system's drive device, this example refers to the first partition of the second hard drive. Linux systems use a form like /dev/xxx to specify a hard disk or a CD or a device like this.

root=/dev/hdb1 is the location of the Linux system. It specifies where the Linux system is. How does the Loadlin program identify and locate the Linux operating system, so that specific files can be called in Linux operations and booted with zimage. .

The ro after /dev/hdb1 specifies the read attribute of the system. Under the UMDOS file system, because Linux is subordinate to DOS. Therefore, it is generally the rw attribute, that is, the read-write attribute, and ro, rw indicates whether it is read-only or read-write.

When LOADLIN boots, you need a Linux boot kernel that specifies the Linux path. It can be directly passed to the Linux kernel via command line arguments using the Linux kernel parameters on the DOS command line. You can use the Linux kernel configuration directly from the command line.

vga=ask The display mode is specified by the user. Specifies whether the display is VGA or extended VGA.