in performance, but I did not check the debugger carefully enough while
testing them. Part of the performance gain in main.cc revision 1.33 and
cpu.cc revision 1.9 was to allow bochs to stay in the cpu loop forever
in a single processor simulation. (In a multiprocessor simulation it must
quit the loop periodically to give the other procs a chance to simulate
too. Cooperative multiprocessing?) In the process, I restored calls
to BX_TICK in the cpu loop for 1-proc simulation only, and removed them
from the outer loop. (See main.cc, since it was done right.) However
I never made the equivalent change in the debugger code, so in the
debugger, there were ticks coming from the cpu loop and then an
equivalent number of ticks coming from the debugger code just outside
the cpu loop. The result was, of course, that simulation time went
at 2x the correct rate. This simulation time speedup was made even
worse because the continue loop in the debugger would increment ticks
by one quantum (5 at the time) no matter how many instructions had
actually been executed. So in trace mode in particular, the way it was
implemented before today, cpu loop would run only one instruction at
a time and the simulation time would get incremented 1+5=6 times! One
tick from the cpu loop, then 5 erroneous ticks from the continue loop.
Anyway, much of this nonsense should be fixed now. For uniprocessor
simulations, only the cpu loop does ticks (for best performance). For
multiprocessor simulations, the cpu loop exits after one quantum and
the code that calls the cpu loop gets to increment ticks instead.
> This patch fixes a number of debugger problems.
> - with trace-on, simulation time would pass 5x faster than usual, so
> interrupts and other timed events would happen at different times
> - with trace-on, breakpoints were ignored
> - with trace-on, control-C would not stop the processor and return to the
> debugger.
>
> This patch changes the execution quantum for the debugger to 1, which means
> that cpu_loop is asked to do one instruction at a time. This may cause
> bochs with the debugger to be slower than before.
>
> I haven't tested without the debugger yet, so I don't know if the timing
> of events matches or not.
in an output format similar to gdb (when you do info all-registers).
Also, if you do "info all" you get the CPU registers and the FPU
registers.
- added bx_cpu_c method called fpu_print_regs, which is implemented
in wmFPUemu_glue.cc
bochs debugger needed to be updated in the same way. Instead of
using "bx_options.rom.path" as a string, it's now
bx_options.rom.path->getptr () to get the value of the parameter.
when main.cc no longer had one. Now compiling with debugger is working
with the control panel. To get the control panel, you have to click
the snapshot button, and to get the debugger, you have to press ^C.
These should be better integrated (maybe a control panel menu choice
that jumps into the debugger and a debugger command that starts the
runtime control panel...)
BX_SUPPORT_APIC were used. To follow the pattern used by other
names like this, I changed them all to BX_SUPPORT_APIC.
Thanks to Tom Lindström for chasing this down!
tries to fix it. The shortcuts to register names such as AX and DL are
#defines in cpu/cpu.h, and they are defined in terms of BX_CPU_THIS_PTR.
When BX_USE_CPU_SMF=1, this works fine. (This is what bochs used for
a long time, and nobody used the SMF=0 mode at all.) To make SMP bochs
work, I had to get SMF=0 mode working for the CPU so that there could
be an array of cpus.
When SMF=0 for the CPU, BX_CPU_THIS_PTR is defined to be "this->" which
only works within methods of BX_CPU_C. Code outside of BX_CPU_C must
reference BX_CPU(num) instead.
- to try to enforce the correct use of AL/AX/DL/etc. shortcuts, they are
now only #defined when "NEED_CPU_REG_SHORTCUTS" is #defined. This is
only done in the cpu/*.cc code.
in BRANCH-smp-bochs revisions.
- The general task was to make multiple CPU's which communicate
through their APICs. So instead of BX_CPU and BX_MEM, we now have
BX_CPU(x) and BX_MEM(y). For an SMP simulation you have several
processors in a shared memory space, so there might be processors
BX_CPU(0..3) but only one memory space BX_MEM(0). For cosimulation,
you could have BX_CPU(0) with BX_MEM(0), then BX_CPU(1) with
BX_MEM(1). WARNING: Cosimulation is almost certainly broken by the
SMP changes.
- to simulate multiple CPUs, you have to give each CPU time to execute
in turn. This is currently implemented using debugger guards. The
cpu loop steps one CPU for a few instructions, then steps the
next CPU for a few instructions, etc.
- there is some limited support in the debugger for two CPUs, for
example printing information from each CPU when single stepping.
To see the commit logs for this use either cvsweb or
cvs update -r BRANCH-io-cleanup and then 'cvs log' the various files.
In general this provides a generic interface for logging.
logfunctions:: is a class that is inherited by some classes, and also
. allocated as a standalone global called 'genlog'. All logging uses
. one of the ::info(), ::error(), ::ldebug(), ::panic() methods of this
. class through 'BX_INFO(), BX_ERROR(), BX_DEBUG(), BX_PANIC()' macros
. respectively.
.
. An example usage:
. BX_INFO(("Hello, World!\n"));
iofunctions:: is a class that is allocated once by default, and assigned
as the iofunction of each logfunctions instance. It is this class that
maintains the file descriptor and other output related code, at this
point using vfprintf(). At some future point, someone may choose to
write a gui 'console' for bochs to which messages would be redirected
simply by assigning a different iofunction class to the various logfunctions
objects.
More cleanup is coming, but this works for now. If you want to see alot
of debugging output, in main.cc, change onoff[LOGLEV_DEBUG]=0 to =1.
Comments, bugs, flames, to me: todd@fries.net
signal. First, selection of the GUI should cause BX_GUI_SIGHANDLER to
be defined in config.h.in. Then, the GUI should define member functions
Bit32u get_sighandler_mask ();
void sighandler (int sig);
The mask function returns a bitfield where one bit corresponds to each
signal. For any signal whose bit is set to 1 in the return value of
get_sighandler_mask, the gui will control that signal. When the signal
arrives, bx_gui.sighandler(sig) will be called by bx_signal_handler,
instead of the default behavior of that signal.
didn't compile with some compiler.
- put conditional "#if BX_HAVE_HASH_MAP" around code that uses
<hash_map.h>.
- replace calls to snprintf with bx_snprintf.
- arg1 of bx_dbg_watch is an int, not a Boolean.
