This provides access to the SPRs via the JTAG DMI interface. For now
they are still accessed as if they were GPR/FPRs using the same
numbering as before (GPRs at 0 - 0x1f, SPRs at 0x20 - 0x2d, FPRs at
0x40 - 0x5f).
For XER, debug reads now report the full value, not just the bits that
were previously stored in the register file. The "slow" SPR mux is
not used for debug reads.
Decode2 determines on each cycle whether a debug SPR access will
happen next cycle, based on whether there is a request and whether the
current instruction accesses the SPR RAM.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Revert to linking dynamically by default, can statically link with
`make STATIC_URJTAG=1`
Fixes#351
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
"-b ecp5" will select ECP5 interface that talks to a JTAGG
primitive.
For example with a FT232H JTAG board:
./mw_debug -t 'ft2232 vid=0x0403 pid=0x6014' -s 30000000 -b ecp5 mr ff003888 6
Connected to libftdi driver.
Found device ID: 0x41113043
00000000ff003888: 6d6f636c65570a0a ..Welcom
00000000ff003890: 63694d206f742065 e to Mic
00000000ff003898: 2120747461776f72 rowatt !
00000000ff0038a0: 0000000000000a0a ........
00000000ff0038a8: 67697320636f5320 Soc sig
00000000ff0038b0: 203a65727574616e nature:
Core: running
NIA: c0000000000187f8
MSR: 9000000000001033
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
liburjtag isn't in Debian, so usually we're pointing at a urjtag
build directory when building mw_debug
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
This compares the address being fetched with the contents of a
register that can be set via DMI, and if they match, stops the
logging. Since this works on the address being fetched rather than
executed, it is subject to false positives.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This logs 256 bits of data per cycle to a ring buffer in BRAM. The
data collected can be read out through 2 new SPRs or through the
debug interface.
The new SPRs are LOG_ADDR (724) and LOG_DATA (725). LOG_ADDR contains
the buffer write pointer in the upper 32 bits (in units of entries,
i.e. 32 bytes) and the read pointer in the lower 32 bits (in units of
doublewords, i.e. 8 bytes). Reading LOG_DATA gives the doubleword
from the buffer at the read pointer and increments the read pointer.
Setting bit 31 of LOG_ADDR inhibits the trace log system from writing
to the log buffer, so the contents are stable and can be read.
There are two new debug addresses which function similarly to the
LOG_ADDR and LOG_DATA SPRs. The log is frozen while either or both of
the LOG_ADDR SPR bit 31 or the debug LOG_ADDR register bit 31 are set.
The buffer defaults to 2048 entries, i.e. 64kB. The size is set by
the LOG_LENGTH generic on the core_debug module. Software can
determine the length of the buffer because the length is ORed into the
buffer write pointer in the upper 32 bits of LOG_ADDR. Hence the
length of the buffer can be calculated as 1 << (31 - clz(LOG_ADDR)).
There is a program to format the log entries in a somewhat readable
fashion in scripts/fmt_log/fmt_log.c. The log_entry struct in that
file describes the layout of the bits in the log entries.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This outputs a carriage return rather than a newline after the
display of the progress count during the load and save operations.
This makes the output more compact and better looking.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This describes how to build the tool on Fedora, and on Debian which lacks a packaged
liburjtag as of mid 2020.
Signed-off-by: Joel Stanley <joel@jms.id.au>
CFLAGS was defined but not used anywhere. This adds them to the compile
line, and fixes the warnings (and errors!) that result.
Signed-off-by: Joel Stanley <joel@jms.id.au>
This adds a "gpr" command for reading 1 or more GPRs/fast SPRs,
and a "mw" command for writing an 8-byte value to memory. It also
adds an "icreset" command for resetting the instruction cache
and fixes the "creset" command to actually reset the core instead
of starting it. The MSR is now printed along with the NIA in the
status information.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This comes in two parts:
- A generator script which uses LiteX to generate litedram cores
along with their init files for various boards (currently Arty and
Nexys-video). This comes with configs for arty and nexys_video.
- A fusesoc "generator" which uses pre-generated litedram cores
The generation process is manual on purpose. This include pre-generated
cores for the two above boards.
This is done so that one doesn't have to install LiteX to build
microwatt. In addition, the generator script or wrapper vhdl tend to
break when LiteX changes significantly which happens.
This is still rather standalone and hasn't been plumbed into the SoC
or the FPGA toplevel files yet.
At this point LiteDRAM self-initializes using a built-in VexRiscv
"Minimum" core obtained from LiteX and included in this commit. There
is some plumbing to generate and cores that are initialized by Microwatt
directly but this isn't working yet and so isn't enabled yet.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This works with both the sim socket and urjtag, and supports the
new core functions, loading a file in memory etc...
The code still needs a lot of cleanup and a help!
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Paul Mackerras
Matt Johnston