This patch and the following patches define another way of doing processor access without the need to read back
the pracc address as needed in current pracc code.
Current pracc code is executed linearly and unconditionally. The processor starts execution at 0xff200200
and the fetch address is ever incremented by 4, including the last instruction in the delay slot of the branch to start.
Most of the processor accesses are fetch and some are store accesses.
After a previous patch regarding the way of restoring registers (reg8 and reg9), there are no load processor accesses.
The pracc address for a store depends only on the store instruction given before.
m4k core has a 5 stage pipeline and the memory access is done in the 3rth stage. This means that the store access
will not arrive immediately after a store instruction, it appears after another instruction enters the pipeline.
For reference: MD00249 mips32 m4k manual.
A new struct pracc_queue_info is defined to help each function in generating the code. The field pracc_list holds in the
lower half the list of instructions and in the upper half the store addressess, if any. In this way the list can be used by
current code or by the new one to generate the sequence of pracc accesses.
For every pracc access only one scan to register "all" is used by calling the new function mips_ejtag_add_scan_96().
This function does not call jtag_execute_queue(), all the scans needed can be queued before calling for execution.
The pracc bit is not checked before execution, is checked after the queue has been executed.
Without calling the wait function the code works much faster, but the scan frequency must be limited. For pic32mx
with core clock at 4Mhz works up to 600Khz and with 8Mhz up to 1200. To increase the scan frequency a delay
between scans is added by calling jtag_add_cloks().
A time delay in nano seconds is stored in scan_delay, a new field in ejtag_info, and a handler is provided for it.
A mode field is added to ejtag_info to hold the working mode. If a time delay of 2ms (2000000 ns) or higher is set,
current code is executed, if lower, new code is executed.
Initial default values are set in function mips32_init_arch_info. A reset does not change this settings.
Change-Id: I266bdb386b24744435b6e29d8489a68c0c15ff65
Signed-off-by: Salvador Arroyo <sarroyofdez@yahoo.es>
Reviewed-on: http://openocd.zylin.com/1193
Tested-by: jenkins
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>
To show up the fail try to step with the core clock set to 31.25Khz
and with a ftdi/hs adapter or with a wiggler, -not with ft2232-.
The scan frequency should be set to 300Khz or higher, at lower frequency probably will not fail.
The code exits with error because the pracc address is at 0x0.
It also fails when using the "all" register, but in this case the code works without any message because the
pracc address is at 0xff202004 when it fails.
I never saw this fail with the core clock set to 500Khz or higher, but ...
The workaround simply puts a 1 ms delay after the execution of the DERET instruction.
Change-Id: I38e8c01a9c39aedd3282140543b83a0844d8ad29
Signed-off-by: Salvador Arroyo <sarroyofdez@yahoo.es>
Reviewed-on: http://openocd.zylin.com/1139
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
This is a minor change to log EJTAG version 4.x and 5.x
as valid versions when debug log is enabled.
Change-Id: Ie20458d033c6d22842cb4a31b56765d4ba2ff123
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Reviewed-on: http://openocd.zylin.com/936
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
The function mips_ejtag_read_debug() is defined in mips_ejtag.c
and is called only by mips_m4k_debug_entry() for reading the
CP0 debug register. The comment in this function is obviously wrong.
There is a generic function to read CP0 registers with similar code.
A call to mips32_cp0_read() should work in the same way.
The purpose of reading the debug register is to test if the DSS
bit is set and clear the SSt bit.
It is faster and easier if the SSt bit is cleared without any check.
Remark: DSS bit set only means that a debug single-step exception
ocurred, but it is not possible to step over a sdbbp instruction,
in this case DSS will not be set and the SSt bit not cleared by code.
Resume command at another address will step, so really the behavior
is not the same.
Change-Id: Ibd35f80e0f7669976d96f4ed813830cecf587971
Signed-off-by: Salvador Arroyo <sarroyofdez@yahoo.es>
Reviewed-on: http://openocd.zylin.com/950
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
The code is a bit large compared to mips_ejtag_step_enable().
With the mips32 xori instruction the code can be
reused.
The number of pracc accesses are reduced from 18 to 7.
Change-Id: If3974ebd64da4461c22b089796646990e68e1b72
Signed-off-by: Salvador Arroyo <sarroyofdez@yahoo.es>
Reviewed-on: http://openocd.zylin.com/944
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
Add a working area that is preserved between calls to
mips_m4k_bulk_write_memory - this gives us a speed increase
of approx 3kb/sec during flash writes to the pic32mx.
This area is released during a resume/reset.
Signed-off-by: Spencer Oliver <ntfreak@users.sourceforge.net>
jtag_get/set_end_state() is now deprecated.
There were lots of places in the code where the end state was
unintentionally modified.
The big Q is whether there were any places where the intention
was to modify the end state. 0.5 is a long way off, so we'll
get a fair amount of testing.
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
The PIC32MX does not support the ejtag software reset - it is
optional in the ejtag spec.
We perform the equivalent using the microchip specific MTAP cmd's.
Signed-off-by: Spencer Oliver <ntfreak@users.sourceforge.net>
In the code a single field was all that was ever used. Makes
jtag_add_ir_scan() simpler and leaves more complicated stuff
to jtag_add_plain_ir_scan().
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
jtag_add_dr/ir_scan() now takes the tap as the first
argument, rather than for each of the fields passed
in.
The code never exercised the path where there was
more than one tap being scanned, who knows if it even
worked.
This simplifies the implementation and reduces clutter
in the calling code.
use jtag_add_ir/dr_plain_scan() for more fancy situations.
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
- add target_to_mips32 and target_to_m4k to match test of codebase.
- mips32_arch_state now shows if processer is running mips16e isa.
Signed-off-by: Spencer Oliver <ntfreak@users.sourceforge.net>
This patch helps fix MIPS big endian (elf32-tradbigmips) targets.
If "-endian big" is not set in target create, the endianess defaults to
little. mw and md commands will still work, but binary file loads will
have the incorrect word order loaded into memory.
The EJTAG processor access data register (PrAcc) is little endian
regardless of the CPU endianness; it is always loaded LSB first. This
is confirmed by the fact that mips_ejtag_drscan_32() uses buf_set_u32()
to load the scan field; buf_set_u32() is a little-endian formatter. For
big endian targets, data buffers have to be modified so the LSB of each
u32 or u16 is at the lower (first) memory location. If the drscan
out_value word order is set using buf_set_u32() then it makes sense to
also fixup the in_value with buf_get_u32(); a symmetry argument. This
has no affect on little endian hosts.
git-svn-id: svn://svn.berlios.de/openocd/trunk@2219 b42882b7-edfa-0310-969c-e2dbd0fdcd60
this fn has something to do with the queue, which it does not as such.
git-svn-id: svn://svn.berlios.de/openocd/trunk@2050 b42882b7-edfa-0310-969c-e2dbd0fdcd60
