Re: [Openocd-development] include interface configuration first or target configuration first?

[simon q. <sim...@gm...>]

I agree that interface should be initialized first.

For the current OpenOCD, these change can be considered:
1. add a parameter in the target configuration file, which is used to set
swd mode.
If swd is enabled, not include the jtag related scripts
2. target.c should be transport independent.
Currently, target.c will check target->tap, which is dependant on JTAG.
3. transport should be target independent.
It only provides functions for target implementation.

2011/1/13 Tomek CEDRO <tom...@gm...>

> Hello Simon :-)
>
> On Wed, Jan 12, 2011 at 6:57 PM, simon qian <sim...@gm...>
> wrote:
> > When SWD is initializing, in swd_select, get_current_target is called.
> > But maybe target is not initialized here.
> > Log:
> > Warn : 25 47 transport.c:127 allow_transports(): must select a transport.
> > Debug: 26 47 transport.c:130 allow_transports(): allow transport 'jtag'
> > Debug: 27 63 transport.c:130 allow_transports(): allow transport 'swd'
> > Debug: 28 63 command.c:151 script_debug(): command - ocd_command
> ocd_command
> > type ocd_transport select swd
> > Debug: 29 63 command.c:151 script_debug(): command - ocd_transport
> > ocd_transport select swd
> > Error: 30 63 target.c:372 get_current_target(): BUG: current_target out
> of
> > bounds
> >
> > If I put interface configuration after target configuration, it will also
> > fail.
>
> I think Interface should be initialized first as this also impacts
> futrher program usage - in UrJTAG i have made it that initerface/cable
> init also selects transport as only one cable can be used at time.
> When cable is initialized then target can be initialized (ie.
> JTAG-TO-SWD sequence and then IDCODE read). So cable initialization
> also selects cable configuration and program configuration/transport.
>
> > I try to remove the jtag scripts.
> > And it's impossible to remove all these scripts, because -chain-position
> is necessary.
>
> I have lost some time to make swd transparent to jtag so jtag commands
> call swd operations but this is dead end, so dont go in there, swd
> must be implemented as separate transport, just as David did. In
> UrJTAG target configuration, registers, names and their lengths are
> read at runtime from external user configuration files, so in fact all
> devices are virtual, also operations on them are device dependent so
> it did not work to get unified. Ofcourse there is a list of devices in
> chain, but for SWD this chain only contains one device - ARM-SW-DP
> (possibly for other transports some adequate target-specific access
> port). I am not sure wether SWD can support star topology (rather
> not). I hope this helps somehow ;-P
>
> Best rehards :-)
> Tomek
>
> --
> CeDeROM, SQ7MHZ, http://www.tomek.cedro.info
>



-- 
Best Regards, SimonQian
http://www.SimonQian.com