From 800f188183cf4d45bbd13eb94e1c2419888b76b2 Mon Sep 17 00:00:00 2001 From: Colin Watson Date: Fri, 28 Jan 2011 17:01:28 +0000 Subject: [PATCH] * docs/grub.texi (Making a GRUB bootable CD-ROM): Update to describe grub-mkrescue. --- ChangeLog | 5 +++++ docs/grub.texi | 48 +++++++++++++++++++++++------------------------- 2 files changed, 28 insertions(+), 25 deletions(-) diff --git a/ChangeLog b/ChangeLog index 514ce4ef8..019a6746c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2011-01-28 Colin Watson + + * docs/grub.texi (Making a GRUB bootable CD-ROM): Update to describe + grub-mkrescue. + 2011-01-24 Vladimir Serbinenko * util/grub-mkimage.c (generate_image): Refuse to create the images diff --git a/docs/grub.texi b/docs/grub.texi index a47389f1e..c815bcbbe 100644 --- a/docs/grub.texi +++ b/docs/grub.texi @@ -651,15 +651,22 @@ using BIOS functions.}. This means that you can use the whole CD-ROM from GRUB and you don't have to make a floppy or hard disk image file, which can cause compatibility problems. -For booting from a CD-ROM, GRUB uses a special Stage 2 called -@file{stage2_eltorito}. The only GRUB files you need to have in your -bootable CD-ROM are this @file{stage2_eltorito} and optionally a config file -@file{grub.cfg}. You don't need to use @file{stage1} or @file{stage2}, -because El Torito is quite different from the standard boot process. +For booting from a CD-ROM, GRUB uses a special image called +@file{cdboot.img}, which is concatenated with @file{core.img}. The +@file{core.img} used for this should be built with at least the +@samp{iso9660} and @samp{biosdisk} modules. Your bootable CD-ROM will +usually also need to include a configuration file @file{grub.cfg} and some +other GRUB modules. -Here is an example of procedures to make a bootable CD-ROM -image. First, make a top directory for the bootable image, say, -@samp{iso}: +To make a simple generic GRUB rescue CD, you can use the +@command{grub-mkrescue} program: + +@example +$ @kbd{grub-mkrescue -o grub.iso} +@end example + +You will often need to include other files in your image. To do this, first +make a top directory for the bootable image, say, @samp{iso}: @example $ @kbd{mkdir iso} @@ -671,33 +678,24 @@ Make a directory for GRUB: $ @kbd{mkdir -p iso/boot/grub} @end example -Copy the file @file{stage2_eltorito}: - -@example -$ @kbd{cp /usr/lib/grub/i386-pc/stage2_eltorito iso/boot/grub} -@end example - If desired, make the config file @file{grub.cfg} under @file{iso/boot/grub} (@pxref{Configuration}), and copy any files and directories for the disc to the directory @file{iso/}. -Finally, make a ISO9660 image file like this: +Finally, make the image: @example -$ @kbd{mkisofs -R -b boot/grub/stage2_eltorito -no-emul-boot \ - -boot-load-size 4 -boot-info-table -o grub.iso iso} +$ @kbd{grub-mkrescue -o grub.iso iso} @end example This produces a file named @file{grub.iso}, which then can be burned -into a CD (or a DVD). @kbd{mkisofs} has already set up the disc to boot -from the @kbd{boot/grub/stage2_eltorito} file, so there is no need to -setup GRUB on the disc. (Note that the @kbd{-boot-load-size 4} bit is -required for compatibility with the BIOS on many older machines.) +into a CD (or a DVD), or written to a USB mass storage device. -You can use the device @samp{(cd)} to access a CD-ROM in your -config file. This is not required; GRUB automatically sets the root device -to @samp{(cd)} when booted from a CD-ROM. It is only necessary to refer to -@samp{(cd)} if you want to access other drives as well. +The root device will be set up appropriately on entering your +@file{grub.cfg} configuration file, so you can refer to file names on the CD +without needing to use an explicit device name. This makes it easier to +produce rescue images that will work on both optical drives and USB mass +storage devices. @node Device map