[9fans] jtag programmers

[9fans] jtag programmers

[erik quanstrom]

can someone point me at a list of plan9 usb/serial compatable
jtag programmers?

thanks!

- erik

Re: [9fans] jtag programmers

[Gorka Guardiola]

On Tue, Jul 26, 2011 at 9:46 PM, erik quanstrom <quanstro@quanstro.net> wrote:
> can someone point me at a list of plan9 usb/serial compatable
> jtag programmers?
>

As far as I know, ft2232 chips and their variants may work, but I have only
tried it with the Sheeva plug.

The ft2232 serial chip inside the sheeva
can drive all sorts of serial things, including input to a jtag state machine
if connected properly. Inside the sheeva plug (and some other arm boards),
the chip is actually connected to the jtag input of the SOC inside it,
but you need
the concret details on how this is done for what you are using.

What I do is I program (this is what usb/serial does) the interface connected to
the jtag for the right configuration to drive it. The device is also
programmable
and you need to program it (it is done so that the latency of the USB does not
kill you). Then you need to communicate with the other side, which includes
driving the reset bits (which depend on the concrete electronics connecting the
serial chip to the jtag interface) and then sending the right commands.

I did that for the Arm inside the sheeva, exposing it as a /proc interface and
an acid library on top of it.

Inside my contrib directory there is a file jtag.tgz with all the
stuff I have been
playing with.
All the layers serial chip/mpsse assembler/jtag state machine
driver/arm chain driver/proc filesystem
have been carefully separated, so you can replace any of the
interfaces should you
have a different hardware, though all this is an ongoing job and may change, so
if you do work on it, talk to me off-list.

Enjoy.

G.

Re: [9fans] jtag programmers

[Gorka Guardiola]

On Tue, Jul 26, 2011 at 11:25 PM, Gorka Guardiola <paurea@gmail.com> wrote:
> On Tue, Jul 26, 2011 at 9:46 PM, erik quanstrom <quanstro@quanstro.net> wrote:
>> can someone point me at a list of plan9 usb/serial compatable
>> jtag programmers?
>>
>
> As far as I know, ft2232 chips and their variants may work, but I have only
> tried it with the Sheeva plug.
>
> The ft2232 serial chip inside the sheeva
> can drive all sorts of serial things, including input to a jtag state machine
> if connected properly. Inside the sheeva plug (and some other arm boards),
> the chip is actually connected to the jtag input of the SOC inside it,
> but you need
> the concret details on how this is done for what you are using.
>
> What I do is I program (this is what usb/serial does) the interface connected to
> the jtag for the right configuration to drive it. The device is also
> programmable
> and you need to program it (it is done so that the latency of the USB does not
> kill you). Then you need to communicate with the other side, which includes
> driving the reset bits (which depend on the concrete electronics connecting the
> serial chip to the jtag interface) and then sending the right commands.

All this is done outside usb/serial. Only a couple of parameters (latency and
bit mode) are configured in usb/serial and a file is served.

G.

Re: [9fans] jtag programmers

[Bruce Ellis]

I've got a bucket full of jtag stuff that some dildo hasn't paid for
so I guess I can give it away. You'll have to wait 'til I get back to
Sydney tho. Warning! J-tag cables are much beliked by fluffy doggie.

brucee

On Wed, Jul 27, 2011 at 2:58 AM, Gorka Guardiola <paurea@gmail.com> wrote:
> On Tue, Jul 26, 2011 at 11:25 PM, Gorka Guardiola <paurea@gmail.com> wrote:
>> On Tue, Jul 26, 2011 at 9:46 PM, erik quanstrom <quanstro@quanstro.net> wrote:
>>> can someone point me at a list of plan9 usb/serial compatable
>>> jtag programmers?
>>>
>>
>> As far as I know, ft2232 chips and their variants may work, but I have only
>> tried it with the Sheeva plug.
>>
>> The ft2232 serial chip inside the sheeva
>> can drive all sorts of serial things, including input to a jtag state machine
>> if connected properly. Inside the sheeva plug (and some other arm boards),
>> the chip is actually connected to the jtag input of the SOC inside it,
>> but you need
>> the concret details on how this is done for what you are using.
>>
>> What I do is I program (this is what usb/serial does) the interface connected to
>> the jtag for the right configuration to drive it. The device is also
>> programmable
>> and you need to program it (it is done so that the latency of the USB does not
>> kill you). Then you need to communicate with the other side, which includes
>> driving the reset bits (which depend on the concrete electronics connecting the
>> serial chip to the jtag interface) and then sending the right commands.
>
> All this is done outside usb/serial. Only a couple of parameters (latency and
> bit mode) are configured in usb/serial and a file is served.
>
> G.
>
>