[avrdude-dev] Good news: STK500v2 and JTAG ICE mkII code committed to CVS

[Joerg Wunsch]

Hi *,

I just committed a bunch of new code to CVS.

Originally, I intented to do this within a few commits, but when
reviewing the diff, I noticed both implementations already collided
into too many places, so dissecting them into two commits would have
been a tedious work (as a lot of conflicts had to be repaired
afterwards when preparing the second commit).

The first part of this commit is the import of Erik Walthinsen's
STK500v2 protocol implementation (finally).  Brian sent it to me, and
I did only some minimal cleanup on it (see commit message below).  The
code still causes a couple of compilation warnings (to be cleaned up
later), but I could test it against an STK500v2 here, and it does work
well.  It causes one run-time warning on my version of the STK500v2
I've got access to:

avrdude: stk500v2_getsync(): can't communicate with device: resp=0x01

I verified Erik's code behaves as the STK500v2 specs say, so it's
obviously the STK500v2 returning a different response code here.
Everything else works fine though, so I suspect a problem with the
documentation.  Someone else might want to report that to Atmel.


The second part of the commit implements JTAG ICE mkII programming
support for avrdude.  Yes, that (in)famous new JTAG ICE that used to
be unsupported by any opensource tools by now. ;-)  I've suddenly got
access to such a device, and the one who gave it to me was really
eager to see Linux/Unix support for it (so they can drop Windows out
of their toolchain).  After a bit of consideration, I've chosen
avrdude as the platform to use for the implementation.  First, I know
avrdude quite a bit already, being an occasional contributor to it
back since the days when it was Brian's privately maintained avrprog
baby.  Second, after Russell Shaw's statement that he's considering to
add direct JTAG ICE support to GDB (he's already done mkI, and
currently exploring mkII) it became apparent that this would
eventually obviate the need for avarice completely, but we'd then need
some other tool to support software downloading through the JTAG ICE.
Finally, the already done STK500v2 support, together with the somewhat
similar protocols between both, made me start to work on avrdude.

The result is now what I'd call alpha to beta quality.  ``It works for
me.'', basically. ;-) See below, the OCDEN fuse should not be written
that frequently as it is now, and few other minor things need a bit of
polishing.  I wish I knew why the MCU doesn't start again after
signing off, but I'm going to track that with Atmel (I hope).  During
the course of that work, I got quite a bit of contacts with Atmel
Norway, as the JTAG ICE mkII protocol document appears to be, well,
somewhat inaccurate in many respects.  They've already updated the
document in the web once, but there are still more errors in it, and
quite a number of things remain unexplained (like the need to have the
OCDEN fuse programmed when you want to access MTYPE_EEPROM or
MTYPE_SPM memory).

That doesn't mean I wouldn't consider avarice at all, but avrdude was
the first thing to do it.

I've also got a patch from Bernd Walter still in the pipeline that
increases the write blocksize for ser_posix.c, in order to speed up
the communication by lowering the syscall overhead.  That's going to
be committed later on.


Please folks, give all that a try, both those of you who've got access
to an STK500v2 and/or to a JTAG ICE mkII, as well as everyone else to
see I didn't break anything.  Please do also look at the doc changes
to see if this all makes sense to you.


------------ Original CVS commit message: -----------------
Mega-commit to bring in both, the STK500v2 support from Erik
Walthinsen, as well as JTAG ICE mkII support (by me).

Erik's submission has been cleaned up a little bit, mostly to add his
name and the current year to the copyright of the new file, remove
trailing white space before importing the files, and fix the minor
syntax errors in his avrdude.conf.in additions (missing semicolons).

The JTAG ICE mkII support should be considered alpha to beta quality
at this point.  Few things are still to be done, like defering the
hfuse (OCDEN) tweaks until they are really required.  Also, for
reasons not yet known, the target MCU doesn't start to run after
signing off from the ICE, it needs a power-cycle first (at least on my
STK500).

Note that for the JTAG ICE, I did change a few things in the internal
API.  Notably I made the serial receive timeout configurable by the
backends via an exported variable (done in both the Posix and the
Win32 implementation), and I made the serial_recv() function return a
-1 instead of bailing out with exit(1) upon encountering a receive
timeout (currently only done in the Posix implementation).  Both
measures together allow me to receive a datastreem from the ICE at 115
kbps on a somewhat lossy PCI multi-UART card that occasionally drops a
character.  The JTAG ICE mkII protocol has enough of safety layers to
allow recovering from these events, but the previous code wasn't
prepared for any kind of recovery.  The Win32 change for this still
has to be done, and the traditional drivers need to be converted to
exit(1) upon encountering a timeout (as they're now getting a -1
returned they didn't see before in that case).

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)