[jornada] Re: jflash for jornada 56x

Jeff,

I am glad that you are trying this out.

First, do you have the latest version of the source? It
is at:
    ftp://ftp.handhelds.org/pub/hp/jornada/jflash.tgz
There was a change that I put in at the end of December;
lines 172-173 should have:
        /* if ECP, set to SPP */
    outb(inb(short_base+ECR) & 0x1f, short_base+ECR);

Answers to the remaining questions are below.

Jeff Harris wrote:

> Hi, I've been trying to get your modified jflash utility to work on my
> bricked Jornada 568 (I installed a bad bootloader via bootblaster). HP
> support has quoted me $249 to repair this, so I'd really like to get the
> JTAG to work...
>
> I get:
>
> JFLASH Version xxx
> current control e0
> error, failed to read device ID
> ACT: 1111 1111111111111111 11111111111 1
> EXP: **** 1001001001100001 00000001001 1
>
> All 1's seems to indicate a connection issue, and I get the same result
> with the cable disconnected from lpt port, so this is probably the case.
> I am assuming, at least, that the problem is hardware.
>

The above behaviour is indeed some type of connectivity problem, either
with the cable or with the Linux driver. The best thing to do is to try
connecting TDI and TDO together (pins 3 and 11 of the printer
port DB-25 connector), try to toggle TDI (and output pin) and see
if you see anything on TDO (an input pin). In the past, various
bios settings (!) interfered with this, but the newest version of the
driver
should cause this to work.

>
> But I have tried resoldering this, and double checked connections, and
> get the same results. So I have some questions:
>

The connections to the pads on the Jornada are always quite difficult,
since they are so hard to see. I use a microscope or magnifying
glass to verify that they are not touching.

>
> (1) The README mentions GPIO26. Is this the suspend/resume button?
> Reset button? I assume that the device needs to be 'on', but the 'on'
> state is difficult to tell when my Jornada is completely lifeless.

One thing that I didn't mention in the README is that, before you
start the JTAG process, remove both batteries from the unit (the
main battery and the backup battery). If you then connect the unit
to your ac adapter, it is easy to tell if the unit is 'on' -- it is on when

the button at the top is lit.

It is important to remove the batteries so that you can be confident
that you are resetting the hardware before trying JTAG (by power
cycling). Although the first JTAG query after power cycle often
fails, the second invocation of jflash always succeeds.

>
> (2) http://www.lart.tudelft.nl/projects/jtag/ has a diagram of a JTAG
> dongle for LART arm boards. It looks about the same, but with a line
> driver IC, and no connection to nTRST from LPT pin 14. It seems to me
> that if nTRST is reset, this should be allright. Would you recommend
> that I build the line driver?

The line driver isn't needed if you use relatively short cables. I use a 6
foot
cable to get from the back of the PC to my jtag adapter and about
5 inches of wire from the adapter (the block with the 100 ohm resistors)
to the Jornada. The original cable with the development kit from
Intel did not connect nTRST at all. Since I had it available on the
Jornada and another device here, I went ahead and connected it
to LPT pin 14.

>
> (3) What mode should the PC's LPT be in? SPP? I'm not sure if it should
> even make a difference for this application anyway though.

The original Linux driver required the bios to set up the LPT in SPP
mode. The new driver (mentioned at the start of this email) should
be able to take a printer port initialized in any mode and set it to
SPP mode (I hope!).

>
> (4) Are there any basic tests you can think of offhand with which I can
> troubleshoot? For example, signals/continuity on JTAG pins, etc?
>

Please try connecting TDI/TDO and check (with a simple program) to
see if the input pin is behaving correctly.

>
> Thank you very much for just having written the program in the first
> place, and double thanks if you take the time to read this.
>
> Jeff Harris
> -------------
> University of Alberta

I hope this helps.

Good luck!
jca
Received on Fri Jan 24 18:10:43 2003