I was finally able to figure out the cause of this problem. There are two
parts to the patch. The first patch modifies the configuration file I
originally generated for the Atmel AT91SAM9G20 board and achieves the
following:
+++ Splits the reset-init handler into a reset-start handler for some of the
initial configuration activities and keeps the remainder in the reset-init
handler as was the case before. This was the real issue that was causing
the timing problems I identified before. This solution was confirmed with
an o-scope on actual target hardware.
+++ Adds a new instruction in the reset-start handler to disable fast memory
accesses in the reset-start handler. When the target jtag clock is started
out at 2 kHz during system clock initialization, memory writes (i.e.
register write to enable external reset pin -- basically to RSTC_MR) are
naturally slow and cause GDB keep-alive issues (refer to PATCH 2/2 for
additional fixes).
+++ Modifies the configuration file to use srst_only reset action. The
reset-start/reset-init handler split also now allows the correct behavior to
be used in the configuration file (previously had to use both SRST and TRST
even though only SRST is actually used and connected on the evaluation
board).
+++ Adds external NandFlash configuration support to take advantage of flash
driver added earlier. Doesn't fix any bugs but adds functionality that was
marked as TBD before and thrown in when I did other work on the
configuration file.
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
Globally rename "jtag_nsrst_delay" as "adapter_nsrst_delay", and move it
out of the "jtag" command group ... it needs to be used with non-JTAG
transports
Includes a migration aid (in jtag/startup.tcl) so that old user scripts
won't break. That aid should Sunset in about a year.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Globally rename "jtag_khz" as "adapter_khz", and move it out of the "jtag"
command group ... it needs to be used with non-JTAG transports
Includes a migration aid (in jtag/startup.tcl) so that old user scripts
won't break. That aid should Sunset in about a year. (We may want to
update it to include a nag message too.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Talk more about "debug adapters" instead of only "dongles". Not all
adapters are discrete widgets; some are integrated onto boards. If
we only talk about "dongles" we rule out many valid setups, and help
confuse some users (who may be using Dongle-free environments).
Also start bringing out the point that JTAG isn't the only transport
protocol, even though OpenOCD historically presumes "all is JTAG".
(Not all debug adapters are JTAG adapters, or JTAG-only adapters.)
Plus a few minor fixes (spelling etc) in the vicinity of those changes,
and updates about FT2232H clocking issues (they can go faster than the
older chips, and can support adaptive clocking).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Remove more remnants of the old "jtag_device" syntax.
Don't [format "%s.cpu" $_CHIPNAME] ... it's needless complexity.
Remove various non-supported "-variant" target options; they're not
needed often at all.
Flag some of the board files as needing to have and use target files
for the TAP and target declarations.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
The semantics of "-work-area-virt 0" (or phys) changed with
the patch to require specifying physical or virtrual work
area addresses. Specifying zero was previously a NOP. Now
it means that address zero is valid.
This patch addresses three related issues:
- MMU-less processors should never specify work-area-virt;
remove those specifications. Such processors include
ARM7TDMI, Cortex-M3, and ARM966.
- MMU-equipped processors *can* specify work-area-virt...
but zero won't be appropriate, except in mischievous
contexts (which hide null pointer exceptions).
Remove those specs from those processors too. If any of
those mappings is valid, someone will need to submit a
patch adding it ... along with a comment saying what OS
provides the mapping, and in which context. Example,
say "works with Linux 2.6.30+, in kernel mode". (Note
that ARM Linux doesn't map kernel memory to zero ...)
- Clarify docs on that "-virt" and other work area stuff.
Seems to me work-area-virt is quite problematic; not every
operating system provides such static mappings; if they do,
they're not in every MMU context...
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Gary Carlson
David Brownell
dbrownell
oharboe