[rescue] Re: Happy happy happy! Joy joy joy!

Joshua D. Boyd jdboyd at celestrion.celestrion.net
Tue Jun 3 15:48:51 CDT 2003

On Mon, Jun 02, 2003 at 03:22:48PM -0700, Skeezics Boondoggle wrote:
> On Mon, 2 Jun 2003, Joshua D. Boyd wrote:
> > On Mon, Jun 02, 2003 at 07:50:31AM -0700, Skeezics Boondoggle wrote:
> > 
> > > Virtual Console [0] (borrowing? the JTAG support from the SC2000,
> > > actually), created the first "system domains" in a Unix box (fairly
> > 
> > Is that any relationship to the JTAG stuff I'm doing?
> I dunno, what kind of JTAG stuff are you doing? :-)  

I'm using it to program flash chips.

> I'm talking about the
> SPARCcenter 2000, not the LSI SC2000 (which pops up in Google as a popular
> JTAG prototyping/debugging tool), in case there was any confusion...

And I was refering to the SC2k and CS6.4k machines, not that LSI SC2k.
> I haven't found any on-line copies of the hardcopy docs I have, but
> haven't searched very hard yet.  The big difference between the JTAG
> implementations is that the CS6400 requires that the cable be hooked up to
> the SSP for normal functioning; if the SC2000/E control board detects that
> the JTAG interface is connected, it drops all the CPUs into slave mode and
> halts very early in POST - so on that machine it's only useful for factory
> burn-in and diagnostics.  But they mention that you could, in theory, use
> the JTAG port to monitor and detect hardware faults without disturbing the
> running OS, but that was never implemented.

Are you aware that there is a JTAG IEEE standard, and I'm begining to
suspect that Sun's JTAG is just that, except with undocumented
registers (which are left to the implementor anyway).

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