This patch fixes the xscale_analyze_trace() function. This function was
defective for a trace collected in 'fill' mode (hiccups with repeated
instructions) and completely broken when buffer overflowed in 'wrap' mode. The
reason for the latter case is that the checkpoint registers were interpreted
incorrectly when two checkpoints are present in the trace (which will be true in
'wrap' mode once the buffer fills). In this case, checkpoint1 register will
contain the older entry, and checkpoint0 the newer. The original code assumed
the opposite. I eventually gave up trying to understand all the logic of the
function, and rewrote it. I think it's much cleaner and understandable now. I
have been using and testing this for a few weeks now. I'm confident it hasn't
regressed in any way.
Also added capability to handle (as best as possible) the case where an
instruction can not be read from the loaded trace image; e.g., partial image.
This was a 'TODO' comment in the original xscale_analyze_trace().
Outside of xcsale_analyze_trace(), these (related) changes were made:
- Remove pc_ok and current_pc elements from struct xscale_trace. These elements
and associated logic are useless clutter because the very first entry placed
in the trace buffer is always an indirect jump to the address at which
execution resumed. This type of trace entry includes the literal address in
the trace buffer, so the initial address of the trace is immediately
determined from the trace buffer contents and does not need to be recorded
when trace is enabled.
- Added num_checkpoints to struct xscale_trace_data, which is necessary in order
to correctly interpret the checkpoint register contents.
- In xscale_read_trace()
- Fix potential array out-of-bounds condition.
- Eliminate partial address entries when parsing trace (can occur in wrap mode).
- Count and record number of checkpoints in trace.
- Added small, inlined utility function xscale_display_instruction() to help
make the code more concise and clear.
TODO:
- Save processor state (arm or thumb) in struct xscale_trace when trace is
enabled so that trace can be analyzed correctly (currently assumes arm mode).
- Add element to struct xscale_trace that records (when trace is enabled)
whether vector table is relocated high (to 0xffff0000) or not, so that a
branch to an exception vector is traced correctly (curently assumes vectors
at 0x0).
Some tcl script has underline between the words "flash bank"
resulting in 'invalid command name "flash_bank"'.
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
+ virt2phys() can now convert virtual address to real
+ read_memory() and write_memory() are renamed to read_phys_memory()
and write_phys_memory()
+ new read_memory() and write_memory() try to resolve real address if
mmu is enambled than perform real address reading/writing
+ if address is bellow 0xc000000 than TTB0 is used for page table
dereference, if above - than TTB1. Linux style of user/kernel address
separation
+ if above fails (i.e address is unspecified) than mode is checked
whether it is Supervisor (than TTB1) or User (than TTB0)
- Software breakpoints doesn't work. You should invoke
"gdb_breakpoint_override hard" before you start debugging
+ cortex_a8_mmu(), cortex_a8_enable_mmu_caches(),
cortex_a8_disable_mmu_caches() are implemented
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
I'm not sure what caused this significant character to get deleted.
it may be related to intermittent Editor or terminal flakes I've
been seeing lately (sigh). This fix is trivial.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Fixing one bug can easily uncover another .... in this case,
making sure that we properly invalidate some cached NOR state when
resuming arbitrary target code turned up an issue when the code
wasn't quite arbitrary (and we couldn't know that, but some parts
of OpenOCD assumed the cache would not be invalidated.
Specifically: some flash drivers (like CFI) update that state in loops
with downloaded algorithms, thus invalidating the state as it's probed.
+ Add a new target state flag, to record whether the target is
running downloaded algorithm code.
+ Use that flag to add a special case: "trust" downloaded algorithms
not to corrupt that cached state, bypassing cache invalidation.
Also update some of the documentation to stipulate that this flavor of
trustworthiness is now *required* ... not just a fortuitous acident.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
For some reason there are *two* schemes for interposing logic into
the run_algorithm() code path... One is a standard procedural wapper
around the target method invocation.
the other (superfluous) one hacked the method table by splicing
a second procedural wrapper into the method table. Remove it:
* Rename its slightly-more-featureful wrapper so it becomes
the standard procedural wrapper, leaving its added logic
(where it should have been in the first place.
Also add a paranoia check, to report targets that don't
support algorithms without traversing a NULL pointer, and
tweak its code structure a bit so it's easier to modify.
* Get rid of the superfluous/conusing method table hacks.
This is a net simplification, making it simpler to analyse what's
going on, and then interpose logic . ... by ensuring there's only one
natural place for it to live.
------------
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Without this, a system using gcc (GCC) 4.2.4 (Ubuntu 4.2.4-1ubuntu4)
aborts builds after reporting:
tcl.c: In function ‘handle_irscan_command’:
tcl.c:1168: warning: passing argument 1 of ‘buf_set_u32’ discards qualifiers from pointer target type
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Problem: halt at a breakpoint, enable trace buffer ('xscale trace_buffer enable
fill'), then resume. Wait for debug exception when trace buffer fills (if not
sooner due to another breakpoint, vector catch, etc). Instead, never halts.
When halted explicitly from OpenOCD and trace buffer dumped, it contains only
one entry; a branch to the address of the original breakpoint. If the above
steps are repeated, except that the breakpoint is removed before resuming, the
trace buffer fills and the debug exception is generated, as expected.
Cause: related to how a breakpoint is stepped over on resume. The breakpoint is
temporarily removed, and a hardware breakpoint is set on the next instruction
that will execute. xscale_debug_entry() is called when that breakpoint hits.
This function checks if the trace buffer is enabled, and if so reads the trace
buffer from the target and then disables the trace (unless multiple trace
buffers are specified by the user when trace is enabled). Thus you only trace
one instruction before it is disabled.
Solution: kind of a hack on top of a hack, but it's simple. Anything better
would involve some refactoring. This has been tested and trace now works as
intended, except that the very first instruction is not part of the trace when
resuming from a breakpoint.
TODO: still many issues with trace: doesn't work during single-stepping (trace
buffer is flushed each step), 'xscale analyze_trace' works only marginally for
a trace captured in 'fill' mode, and not at all for a trace captured in 'wrap'
mode.
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
Clean up the jtag/tcl.c file, which was one of the biggest and
messiest ones in that directory. Do it by splitting out all the
generic adapter commands to a separate "adapter.c" file (leaving
the "tcl.c" file holding only JTAG utilities).
Also rename the little-used "jtag interface" to "adapter_name", which
should have been at least re-categorized earlier (it's not jtag-only).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
The command "flash bank" has updated syntax.
Add the mandatory parameter <target> to the usage message
that prints in case of error.
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
While "flash bank" syntax has been changed long ago,
several tcl script are still not fully update.
Fix following cases related with "cfi" driver:
- syntax error: the mandatory <name> parameter is missing
- warning: the <target> parameter is a number, instead of
the target name
- the comment line above the command does not report
actual syntax
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
first cut peek/poke over tcp/ip, used for debug/research
purposes only. Long term JTAG over TCP/IP might be an
offshoot. The performance is usable for development/testing
purposes.
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
I don't know when "poll off" broke, but "poll off" didn't
stop background polling of target. The polling status flag
simply wasn't checked in the handle_target timer callback.
All target polling(including power/reset state) is now stopped
upon "poll off".
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
Mike Dunn
Antonio Borneo
Anton Fedotov
David Brownell
Øyvind Harboe