Can It Be Bricked?

[dabomb3627]

i got to thinking about the pandora having everything the gp2x + cradle has except for one factor. JTAG connection hasn't come up in these forums. I am only interested because I bricked my gp2x and I apparently need (someone with) a JTAG connector to un-brick it (being so graciously supplied by sparr). I read that the gp2x cradle had a JTAG connector built in, but i was wondering if the pandora would have an easy means of JTAG usability in the event it should be bricked. or better yet, would be to banish the possibility of bricking the pandora (through firmware upgrade failures and battery failures) entirely. my suggestion is to have a little block of ROM set asside for the boot-loader and boot-loader alone. that way if you do botch your firmware, the boot-loader is always in tact.

what does everyone think?

 

[zektor]

i got to thinking about the pandora having everything the gp2x + cradle has except for one factor. JTAG connection hasn't come up in these forums. I am only interested because I bricked my gp2x and I apparently need (someone with) a JTAG connector to un-brick it (being so graciously supplied by sparr). I read that the gp2x cradle had a JTAG connector built in, but i was wondering if the pandora would have an easy means of JTAG usability in the event it should be bricked. or better yet, would be to banish the possibility of bricking the pandora (through firmware upgrade failures and battery failures) entirely. my suggestion is to have a little block of ROM set asside for the boot-loader and boot-loader alone. that way if you do botch your firmware, the boot-loader is always in tact.

what does everyone think?

I think it's a good idea. I always liked the fact that Flashme (NDS) had that recovery feature. Should anything go wrong, you can still re-install flashme via recovery by simply popping the nds file on the card and holding a button sequence. This small section of this firmware containing the recovery could not be touched without shorting SL1. Very good thing this is.

 

[MWeston]

JTAG is not accessible externally. An unpopulated header exists on the PCB and is intended for early developers only. When I say early developers, I mean EARLY (like myself). The first 100 units for developers won't need JTAG.

Part of the business plan has always been to create a device that won't put users into a situation that came up with the GP2X in its early days (I guess it is a thing of the past now if your batteries are good?).

There is a basic bootloader stored in a small ROM just like you suggest. You can't erase it and it will always be there. By holding down certain buttons when cycling the power button, the boot ROM is activated. From here you can use several ports on the Pandora system to load new code to the device. This secondary bootloader code is much more involved and is software that can be updated and tweaked throughout the life of the system . This means that no hardware is stuck with bugs in the bootloader that cannot be fixed and early adopters are not stuck with buggy systems just because they jumped in early. Yes, the first stage bootloader is so simple that no bugs will exist there either. If they were there, OUR first boards wouldn't even work.

The idea behind all of this is still crude at this point (ie. only dev friendly for the time being), but when customers get the system, this procedure will be polished and very straight forward. Keep in mind this procedure is only necessary if you damage the file system and kernel. I would anticipate a more GUI oriented update procedure directly from Linux to exist in the future.