Grub Booting Disk On Chip

Bob Chiodini Robert.Chiodini-1 at ksc.nasa.gov
Thu May 30 12:14:48 EDT 2002


Ilguiz,

No grub does not show any attempts to load from disk 0xE0.

Entering root (dc0,0) reports that the DOC is at 0xd0000.  It almost
looks as if interactive detection is handled differently than detection
in grub_firmware.  

Bob...

On Thu, 2002-05-30 at 11:48, Ilguiz Latypov wrote:
    Bob,
    
    On 30 May 2002, Bob Chiodini wrote:
    
    > root (dc0,0)
    > configfile /boot/grub/menu.lst
    > 
    > At this point a get a menu with the second entry highlighted.  Hitting
    > enter boots from /dev/hda1.  /dev/hda1 is the only disk on the system.
    
    Does GRUB show unsuccessful attempts to load /boot/grub/menu.lst from the 
    disk 0xE0 before going to interactive mode?  
    
    Also, the fact that menu.lst is a symbolic link could confuse the stripped
    down ext2 filesystem driver of GRUB.  Can you remove the link and create a 
    regular configuration file?
    
    > It looks like DS is saved as the address of the DOC, if it is not a
    > Millenium DOC.
    
    Oops, you are right.  In fact, the read-only initial program loader of DoC 
    2000 will copy the firmware from the flash memory to 0x2000:0 before 
    jumping there with the DS segment pointing to the DoC BIOS window.  Here 
    is the David's comment in the patch:
    
            * With DoC 2000, _start is loaded at 0x20000 by the IPL,
            * and is jumped to with CS:IP 0x2000:0, DS is <DoC segment>.
    
    Later DS is stored in %cs:doc_seg where %cs holds the segment at the end
    of conventional RAM.
    
    Ilguiz






More information about the linux-mtd mailing list