Re: [jornada] Jornada 7xx Flashboard

Hi Mark,

I'm not able to help in the hardware process. I just think it is quite magic.
But I just want to say I'll love to see linux in my Jornada so I hope all of
this moves on.

Eduard Pertinez

A Dijous 02 Setembre 2004 01:52, Mark Gollahon va escriure:
> Wow, seems I've hit upon something.... See my comments embedded in the
> message.
>
> -Mark Gollahon
>
>
> Sebastian Hesselbarth <sebastian.hesselbarth@stud.uni-hannover.de> wrote ..
>
> > Mark Gollahon wrote:
> > > Hello, all!
> > > I am new to this board (as my Jornada 720 is still on its way),
> > > but I have every intention of running Linux on it. Since I am
> > > somewhat of a hardware tinkerer and I noticed some of you talking
> > > about the flashboard, I was wondering how many of you would like
> > > to have one? I might be able to kickstart the process and get
> > > some if there is enough of a demand.
> >
> > I got a board without any parts a while ago from HP and soldered
> > (nearly) all parts on it. I am missing two of the 56pF caps but had
> > no time to buy them because I am working on my diploma thesis.
> > Right after finishing the board the next problem will be the initial
> > flash procedure because the j720 does not have (or at least no one
> > ever found one) jtag interface.
>
> First off, you have my good wishes for you on your thesis!
>
> Also, you have hit upon the very procedure that I am wondering how to
> do - the initial flash procedure. That's why I came up with the idea
> of putting a CF card in place of the StrataFlash - we have card
> readers that can do that!! I initially wanted to use an SD/MMC card,
> but I have been unable to find a suitable controller chip that can
> "map" the SD/MMC flash memory into the StrongARM's memory map (see
> below for more technical info on this...).
>
> > > Also, I have some other questions for you in relation to the
> > > flashboard. For those of you that have "taken the cover off"
> > > your Jornada 7xx, is there enough room in there to put in a CF
> > > card? (Note: NOT in the CF slot....)
> >
> > Where do you want to interface the cf inside the jornada ? the sa1100's
> > companion chip provides two pcmcia "slots" where one is used for the
> > real pcmcia slot and the other one is connected to the cf slot (AFAIK!)
> > I think connecting the flash chips from CF cards _directly_ on the data
> > bus is impossible since those flash chips are _very_ different from e.g.
> > strata flashes!
>
> The daughtercard would *be* the CF interface.... For those of you
> not inclined to listen to a technical discussion of this, you can
> skip over the next few paragraphs....
>
> Ok, for those of you left, here's the issue: the CF memory spec
> lists several modes that the CF memory card can operate in. The
> first mode that *everyone* is familiar with is the standard
> PCMCIA mode. Plug it into a PCMCIA controller, voila! Off and
> running. Another mode is called "True IDE". This mode allows for
> hanging the CF card right off of your IDE bus like a regular
> run-of-the-mill hard drive (see the various IDE->CF sockets sold
> around the 'net). Another mode is "memory mapped". This is where
> a microprocessor or microcontroller can "directly" address memory
> in the CF card. I say "directly" because the CF card's controller
> chip handles all of the different modes instead of the raw flash
> memory being available right on the processor's bus (like with
> StrataFlash). This is why CF memory is so flexible.
>
> However, CF memory is also very, very sllllooooowwwwww. Because
> that controller chip is in the way, read access are probably 2x or
> 3x slower than the StrataFlash chips. So, we give up speedy access
> on bootup, but we gain a HUGE ease-of-use: we can pop out the CF
> card, write different bits into it, and pop it back in - we just
> upgraded our OS!
>
> Now, I am sure that a lot of you are suddenly saying "WAIT! Slow!!
> This thing is already TOO slow!!!" The only time the 720 would be
> reading from the CF card is during bootup to move and uncompress
> the kernel into RAM and during program startup when it is moving
> the program into RAM to run.... Once everything is in memory, the
> 720 doesn't need to access the CF card any more and the whole
> system will be like on your desktop machine.
>
> Finally, the StrongARM can address up to 4GB of memory (i.e. it has
> a 32-bit address bus). No, we can't *use* the whole 4GB, as the
> chip designers at Intel decided to "split" that 4GB space into
> different "areas". One area is for flash (it is 256Megs), another
> area is for RAM (it is 256Megs as well), and yet another area is for
> device I/O (say, to a PCMCIA controller, sound chip, or video buffer).
>
> Granted, my explanation here is a bit simplistic, but you get the idea.
>
> My problem is, is there enough room where the daughercard sits in
> the machine to handle a CF card. I'm not worried about length or
> width, I am worried about height. Is there at least the thickness
> of a CF card between the CF socket below the daugthercard and the
> keyboard above the daughtercard? If so, my idea will work. If not,
> well, shelve it until we can build our own *motherboards* for the
> 720 (now, isn't THAT an idea!!!).
>
> > > I could possibly ditch the Intel Strataflash chips on the
> > > original flashboard and substitute a CF card - but I don't know
> > > if there is enough room....
> > > Doing this would make it MUCH easier to flash new bits into it....
> >
> > As I said earlier: do not try to replace the strata flashes with flashes
> > from CF cards! I opened a CF card and it contained a 8bit flash and a
> > ide2flash interface chip to translate ide transfers from CF slot to
> > flash commands. Maybe I could have a look at my notes again because all
> > I write now is taken from my mind and may be vague.
> > I have some pictures of my opened joranda too but first have to search
> > them on my harddisk ;)
>
> Well, don't look at the physical product, look at the spec sheets....
> I think it would work wonderfully, especially with the faster flash
> memories. Read times of some of the newer CF cards out there actually
> approach the read times of the original StrataFlash chips used in the
> original 720 daughtercards. So, we could end up with speed as well as
> ease-of-use....
>
> > > Finally, what about memory? I noticed in the engineering docs
> > > that the StrongARM could possibly host up to 256Megs of SDRAM.
> > > Any out there wanting that much?? ;)
> >
> > I guess that would be nice but first try to get some SRAMs that are pin
> > compatible ;) most newer chips are definitely _not_ pin compatible
> > because they have balls only (BGA!)
>
> Actually, the StrongARM wants SDRAM - but that is beside the point.
> If a fab house is making these, who cares if the chips used are JSOP
> or BGAs? Granted, the Gerber plots will have to be completely redone,
> and my prototype boards could use JSOP (BTW, that's one form of
> surface-mount chips...) so that I can prototype the boards at home.
> (Really, as long as the parts are on only *one* side of the board,
> surface mounting isn't that difficult....) I just have to find a PC
> board manufacturer - I *really* don't want to trace 1mm lines all
> over the dang place - I'm blind enough as it is....
>
> So, any PCB manufacturers out there willing to give this a go?
>
> > No, really .. linux port for joranda720 is missing _much_ parts .. at
> > least for 2.6-series there is no framebuffer support and surely other
> > things too (pm, pcmcia?) .. there is a 2.4-series kernel that should
> > implement fb,pm and so on but i never tested it.
>
> I thought the 2.6 kernel had power mgm't up to the point where the 720
> could suspend and resume. Somebody correct me if I am not right....
> Anyway, that is exactly why I think this might work well - with flash
> capability, we might be able to re-jumpstart Linux development on the
> 720 and finally get it to where some of the other handhelds are. I am
> already contemplating an OpenEmbedded (http://www.openembedded.org)
> profile for the 720....
>
> > Before you (we!?) try to design new replacement boards we should port
> > framebuffer support to 2.6 (the patch was rejected by rmk, because of
> > bad coding style AFAIR .. whatever that means)
>
> Hey, I'm a hardware tinkerer and this is actually quite a simple project
> (well, in theory, anyway). Take an Address and Data bus and hook it to
> a CF card and some SD memory - piece of cake!
>
> > > Let me know!
> > > -Mark Gollahon
> >
> > bye, Sebastian
Received on Thu Sep 2 03:08:41 2004