GRUB and DOC

[raja]

Hi,

 Thanks a lot for your explanation.
I've got a DOC which i am able to format using doc121.exb
and am able to mount and read write on it.but unable to recognize it at the bootup.
 
1. Is there any problem with IPL ROM ?
2. If I replace the firmware with GRUB will my DOC get recognized at bootup ?

i am probing into these possibilities now and i would happy to get your suggestions on this issue.




On Fri, 08 Feb 2002 David Woodhouse wrote :
> On 7 Feb 2002, raja wrote:
> 
> >  i have a DiskOnChip 2000 and i have the firmware 
> doc504.exb loaded in it.
> >   i am new to this and I have a few elementary doubts.
> > 
> > 1. Actually what does this firmware do inside the DOC 
> ?
> 
> The firmware provides a BIOS extension, which allocates 
> lots of sub-640K 
> memory and installs an extra handler for the INT 13h 
> disc service 
> interrupt. Using this, it pretends to be a hard drive 
> for the benefit of 
> anything which uses the standard BIOS interfaces (i.e. 
> DOS and 
> bootloaders).
> 
> > 2. Can this firmware be replaced with some other one 
> (i.e. can i format
> > the DOC with some other open source firmwares )
> 
> Yes. You can install the Grub bootloader in place of 
> the M-Systems BIOS 
> extension. Rather than installing an INT 13h handler 
> and continuing to let 
> the machine boot as normal, it hooks the INT 18h 
> bootstrap handler to 
> start Grub instead of trying to boot from floppy or INT 
> 13h device as 
> normal. Grub can drive the DiskOnChip directly, without 
> the assistance of 
> the original firmware extension, and hence boot a 
> kernel from it.
> 
> > 3. How does the BIOS recognize the DOC (is BIOS 
> recognition related to
> > firmware ) ?
> 
> The DiskOnChip is mapped into the host memory in the 
> Upper Memory Blocks 
> used for BIOS extensions - the first few bytes of it 
> have the BIOS 
> extension signature that has been defined since the 
> first IBM BIOS to 
> persuade the BIOS to run extra stuff at startup.
> 
> > I will be grateful if you could clarify my intial 
> doubts ( cause i am
> > stuck up with a DOC which has BIOS and firmware 
> problems)
> 
> -- 
> dwmw2
> 
>