This patch adds support for the length argument to the xscale implementation of
the wp command. Per discussion with David, the length argument specifies the
range of addresses over which a memory access should generate a debug exception.
This patch utilizes the "mask" feature of the xscale debug hardware to implement
the correct functionality of the length argument. Some limitations imposed by
the hardware are:
- The length must be a power of two, with a minumum of 4.
- Two data breakpoint registers are available, allowing for two watchpoints.
However, if the length of a watchpoint is greater than four, both registers
are used (the second for a mask value), limiting the number of watchpoints
to one.
This patch also removes a useless call to xscale_get_reg(dbcon) in
xscale_set_watchpoint() (value had already been read from the register cache,
and the same previously read value is then modified and written back).
I have been using and testing this patch for a couple days.
Questions, corrections, criticisms of course gratefully received.
Flash probing must succeed for e.g. gdb load and automatic
hardware/software breakpoints to work.
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
If the flash has not yet been probed and GDB connects while the target is
running, the flash probe triggered by GDB's memory map read will fail. In
that case the returned memory map will be empty, causing a subsequent load
from within GDB to fail. There's not much you can do from GDB to recover,
other than a restart; a 'mon reset init' and manual 'mon flash probe' won't
help since GDB has already made up its mind about the memory map.
It seems there's no reason to require the target to be halted when probing
the flash. Remove the check to let a valid memory map be provided to GDB
even when connecting to a running target.
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
The The patch labeled "CFI CORE: bug-fix protect single sector" was merged
rged without some requested bugfixes. Most significantly it broke invariants
in the code, invalidating descriptions and changing the calling convention
for underlying drivers. (It (Also wasn't CFI-specific...)
Fix that, and Include an update from Antonio Borneo for the degenerate
"nothing to do" case, (although that's still in the wrong location. which
is presumably why that is it was working in some cases but not all.)
src/flash/nor/core.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Arguments for "flash bank" command are already
parsed and put in "bank" struct.
Removed code to parse them again.
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Syntax of "flash bank" command requires:
- chip_width as CMD_ARGV[3]
- bus_width as CMD_ARGV[4]
Actual code swaps the arguments.
Bug has no run time impact since wrong variables
are only used to check value and both are checked
against same constraint.
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
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>
Mike Dunn
michal smulski
Øyvind Harboe
Andreas Fritiofson
David Brownell
Antonio Borneo
Anton Fedotov