DoC + GRUB booting problem
Edward A. Hildum
ehildum at mail.arc.nasa.gov
Fri Apr 11 16:10:54 EDT 2003
The bootloader is definitely the M-Sys BIOS extension. My
impression is that for DoC 2000s, the BIOS extension is in a ROM that can't
be changed. I am still trying to verify that, but if its true, I have to
deal with it. If it can be changed, like in a DoC Millenium, I could be in
So far, I have only used DFORMAT as described in the GRUB/MTD Readme_doc
file. I haven't tried using doc_loadbios yet, but if the BIOS extension
code is in ROM, I will still have to change its checksums to get it to
load. Since M-Sys hasn't told me (yet) what format DFORMAT expects from
binary files, doc_loadbios may indeed be the best way to proceed.
At 03:50 AM 4/11/2003 -0400, you wrote:
>On Tue, 8 Apr 2003, Edward A. Hildum wrote:
> > I have disassembled the BIOS boot code (included below) and found some
> > conflicts with the README_DiskOnChip info:
>May I suggest that the DoC bootloader you've disassembled was the one
>supplied by M-Sys? I myself didn't use the DFORMAT utility to load the
>GRUB firmware, but that shouldn't mean it isn't possible.
>Is it possible to DFORMAT the DoC's NFTL layer only, starting from the
>given offset? If yes, it would be a good choice, accompanied by the
>mtd/util/doc_loadbios utility which will store the grub_firmware file into
>the beginning of the flash memory.
>I heard that the mtd/util/nftl_format utility may not be compatible with
>the bad block table stored in the DoC at the factory. I was lucky enough
>to disregard the bad block table by issuing the erase_all command against
>/dev/mtd0 and then proceeding with nftl_format. However, this is not the
>safest approach because NAND memory is error prone.
>tel. +1 (514) 526-6911
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