Hello, On Wed, Oct 08, 2003 at 09:33:40AM -0400, Harmon S. Nine wrote: > For those unfamiliar with the "el torito" method of booting from CD (I > don't know of any other methods :), it involves storing a hard-disk (or > floppy-disk) image on the CD. On booting from the CD, this image is > loaded from the CD into RAM as a ramdisk,
No : the BIOS emulates a hard disk accessed via CHS commands, but the image is not loaded in memory. This is an emulation, allowing the access to the CD without peculiar driver via legacy CHS commands. > and is temporarily made the > primary hard-disk of the computer. Given this, if the ramdisk has grub > on its MBR and grub is properly configured, the computer should boot as > it would from the actual primary hard-disk. Once the boot is complete, > the ramdisk is deleted and things return to normal. > > The version of grub that works in this capacity is > grub_0.92+cvs20020923, i.e. the one from September of 2002. All > subsequent versions do not work (yes, I should have reported this long > ago), i.e. they always give an "error 18". > > Is this a bug in grub, or do I need to change how grub is installed? If I had made some patches (two different versions) at the time GRUB 0.92 was released. This GRUB version which "works" is a patched version and not a vanilla one. The problem is that an El Torito able BIOS is a LBA able one and GRUB detects the support about LBA and try to access the boot image on the CD via LBA commands, but, unfortunately, the emulation is a CHS one built on an LBA accessed device : by switching to LBA, GRUB accesses the raw CD (the iso fs) and not the boot image. Hence it fails to access stage2. Solution : keep using GRUB 0.92 + the patches or port the patches to 0.93. Cheers, -- Thierry Laronde (Alceste) <[EMAIL PROTECTED]> Key fingerprint = 0FF7 E906 FBAF FE95 FD89 250D 52B1 AE95 6006 F40C _______________________________________________ Bug-grub mailing list [EMAIL PROTECTED] http://mail.gnu.org/mailman/listinfo/bug-grub
