>The chances of this happening are better than you might
>expect, because flash must be erased in sectors, 32K in this case, so
>updating the checksum would require erasing the first 32K of the Big ROM and
>then writing it all back with the checksum updated. Any problem during that
>time and your OS is effectively gone.
Trevor,
I'm unclear on a several things. Perhaps you can clear them up for me.
* How is updating the first 32K of the Big ROM any more risky than updating any
other section of ROM?
* Don't you update the first 32K of the Big ROM anyway? I thought I remember
something about the reset vector being modified. I could be wrong...
* Why couldn't FlashPro make a copy of the sector it was updating first? That
way, it could restore it in case of emergency.
* If Palm's Flash update utilities can set the checksum, why can't yours?
I'm sure there are simple answers to all these; I just don't know enough about
flashing to figure out what they are. Thanks.
-- Keith Rollin
-- Palm OS Emulator engineer
Trevor Meyer <[EMAIL PROTECTED]> on 12/03/99 07:39:50 AM
Please respond to [EMAIL PROTECTED]
Sent by: Trevor Meyer <[EMAIL PROTECTED]>
To: "'palm-dev-forum @3com.com'" <[EMAIL PROTECTED]>
cc: (Keith Rollin/HQ/3Com)
Subject: Re: WPJ on POSE
The problem is the ROM image checksum. Poser looks at this to decide whether
you are giving it a valid image. FlashPro does not update the checksum
because it is located in a very sensitive part of the OS. If FlashPro
crashed, or the batteries fell out, or whatever, while updating this
checksum, the unit would become unbootable, and the only fix would be to
reload the OS. The chances of this happening are better than you might
expect, because flash must be erased in sectors, 32K in this case, so
updating the checksum would require erasing the first 32K of the Big ROM and
then writing it all back with the checksum updated. Any problem during that
time and your OS is effectively gone.
There is a program to fix this: www.trgnet.com\download\posefix.zip
<http://www.trgnet.com\download\posefix.zip> that you can run on the
downloaded image. It will remove FlashPro hooks and update the checksum. We
haven't had anyone report it not working. You can email me directly if it
does not work with the WPJ ROM.
Trevor Meyer
[EMAIL PROTECTED]
----------
From: Dave Lippincott [SMTP:[EMAIL PROTECTED]]
<mailto:[SMTP:[EMAIL PROTECTED]]>
Sent: Thursday, December 02, 1999 8:08 AM
To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
Subject: Re: WPJ on POSE (was: gdb under linux with POSE)
I don't know of anyone who was successful in getting a ROM once touched by
FlashPro to work in POSER. TRG had posted a fix (where you edit the
checksum manually), but I never got that to work. Check with Palm to see if
the WPJ ROM is available for download
-----Original Message-----
From: Pres Nevins <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> >
To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
<[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> >
Date: Wednesday, December 01, 1999 8:12 PM
Subject: WPJ on POSE (was: gdb under linux with POSE)
>> Did you alter the FLASH ROM on your unit? FlashPro and
FlashBuilder
kinda
>> ruin the check sum so POSER can't read modified ROM
images correctly.
>
>I've used FlashPro, but AFAIK it only lets me modify the additional
2M of
>flash on the xtra xtra pro board-without the board I seem to
remember it
>doesn't acknowledge my WPJ has flash at all (i.e. [I assume] the
standard
2M
>is already full with the Japanese OS and it won't let me mess with
it.)
>
>If using FlashPro actually damages the unit, as would seem to be
the case
>with what you're saying, wouldn't that seem to be a good candidate
for at
>least a casual mention on a TRG FAQ somewhere?
>
>Can it be fixed? By, say, deleting the extra items I have in flash
and then
>trying to grab the ROM with POSE?
>
>--
>Pres NEVINS
>Nishinomiya, Japan!
><http://www.mars.dti.ne.jp/~preston/
<http://www.mars.dti.ne.jp/~preston/> >
>
>
