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DOSFS problems

Adriano,

As fine as I understand you need proper MBR on your HDD to run
dosfs test.

As I remember, you may re-initialize MBR on your HDD invoking

fdisk /mbr
(or fdisk C: /mbr ?)

Then, run fdisk C: and ensure that your partition table is correct.
If problem persists, try to reduce partition size to, let say, 256Mb
using fdisk.

Regards,
Victor

Adriano Verardo wrote:

> Thomas Doerfler wrote:
>
>> Could you possible give the values that are present in your MBR and 
>> partition table? It may be that the RTEMS DOSFS code does not 
>> implement ALL possible partition types and options.
>>
> Hi Thomas, thank you again.
>
> The result of all tests is: the simplest possible DOS install always 
> gives
> working system disks with a MBR that's never accepted by DOSFS.
> For all tested DOS/fdisk/HW/FAT type/ etc etc. combinations:
> - HD MBR zeroed before installing DOS
> - no disk managers, installed DOS boots from C: and works
> - probably DOSFS fails before accessing the partition table:
>  * MBR[11,12] of the HD is always wrong (huge, ie: 07 50 instead of 00 20
>     and changes using different fdisk/format tools)
>  * the final 55 AA signature on the HD MBR is sometimes absent (00 00)
> - the initial OEM FIELD on the HD MBR is never an ASCII string ?????
> - the partition tab is @ offset 446 ... standard ... DOS works
> - the MBR of the install floppy seems always to be "regular"... why it 
> is not
>   reproduced (with the obvious changes) on the HD ???
>
> Forcing rigth values in the DOSFS source don't work.
> Clearly there are other inconsistent values in the MBR.
>
> If this info are not precise enough I'll send some MBR dumps.
> It's not immediate to transfer them to my PC.
>
> Is there any other rtems-user who had a similar problem ?
> Using very standard but quite old HW can be a problem ?
> Is there any particular DOS install procedure/trick/option to
> force the layout of  the MBR of the HD ?
>
> Adriano
>
>
>
>
>


-- 
Victor V. Vengerov
OKTET Labs.
Phone: mobile +7 812 9389372, home +7 812 4281653