China DOS Union

In the GRUB boot menu MENU.LST file, you can see the following statement:
chainloader /boot/msdos.bs
What is the *.bs file? And how is it made?
Is it that GRUB FOR DOS cannot directly boot the *.IMG file in the CD?
How to boot the IMG file in the CD????

The new version no longer needs to boot the boot sector file of DOS. BS should mean boot sector.

The new version can directly use chainloader /io.sys to boot DOS.

GRUB4DOS can completely boot the IMG (disk image) file on the CD, but currently it can only be booted in the way of map --mem.

map --mem (cd)/.../floppy.img
map --hook
chainloader (fd0)+1
rootnoverify (fd0)
boot

However, the premise is that grub must be able to access (cd) in advance. When the machine is booted from the CD in no-emulation mode, grub can access the (cd) device. Otherwise, it must use

cdrom --init
map --hook

If the above commands are successful, then the (cd0) device can be accessed:

map --mem (cd0)/.../floppy.img (fd0)
map --hook
chainloader (fd0)+1
rootnoverify (fd0)
boot

Full of admiration! The expert is indeed an expert! Thanks a million! It's really "like a surging river........................... ah!!!"

Is it correct to use them together like this?
title 2.*************
cdrom --init
map --hook
map --mem (cd0)/.../floppy.img (fd0)
map --hook
chainloader (fd0)+1
rootnoverify (fd0)
boot

After I used it, the following content was displayed.
cdrom --init
ATAPI device found: Data=170, Ctrl=376, dev=0(Note: 0=master, 1=slave)
CDROM device found: Data=170, Ctrl=376, dev=0(Note:0=master,1=slave)

Found 1 CD-ROM. (Note: Further read could fali if the hardware does not
fully support ATAPI).
map --hook
map --mem (cd0)/img/mm.img (fd0)
Error 17: File not found
Press any key to continue...

[ Last edited by wangfei8842 on 2007-6-26 at 11:05 AM ]

Learn to use the command line, don't always use the menu. Typing commands on the command line can facilitate debugging.

Either this file does not exist or it is not recognized by GRUB. Try using the file name in uppercase letters again.

Some CD-ROM file system formats are not supported by GRUB. Currently, the CD-ROM formats supported by GRUB are ISO9660 and the Rock Ridge format built on top of it. When you create the CD-ROM, it is best to use mkisofs to create it and use the -R parameter.

Special note: If the CD-ROM is in Joliet format, there is a high possibility that the files on the CD-ROM cannot be read by GRUB.

Thanks! I've got it sorted out!