bug #429448. What is strange about this problem (on OpenBSD) is that the
compile and link goes fine, but when you execute your first readline library
function it does a dynamic link and crashes on the spot. Many autoconf
tests only compile and sometimes link the test program, but this test
compiles, links, and runs it.
[ #433759 ] virtual address checks can overflow
> Bochs has been crashing in some cases when you try to access data which
> overlaps the segment limit, when the segment limit is near the 32-bit
> boundary. The example that came up a few times is reading/writing 4 bytes
> starting at 0xffffffff when the segment limit was 0xffffffff. The
> condition used to compare offset+length-1 with the limit, but
> offset+length-1 was overflowing so the comparison went wrong. This patch
> changes the condition so that it supports all segment limits except for
> sizes 0,1,2,3 bytes. Dave and I figured that these sizes would not be
> needed, while size 0xffffffff is used quite a lot.
I still need to do add some commands from older specs that are obsolete
(and not listed) in ATAPI-6.
- commands that aren't in the spec will still panic.
- fill in names from spec on various commands
- add command aborted for 0x08 device reset on disks (it's only for ATAPI)
- add command aborted for 0xe1 idle immediate
media status to 0 then 1 (equivalent to removing then inserting a disk).
Then it calls the UI function bx_gui.update_floppy_status_buttons()
if the interface has been initialized already.
has run. This ensures that the prev_eip and prev_esp that is used
for tracing and breakpoint checks is correct even in the cycle after
an interrupt or trap.
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.
line, like this:
<HTML
><HEAD
><TITLE
>FreeBSD</TITLE
>
Glimpse, which is indexing our website, finds this very confusing and
it cannot pick out the title from this mess. This script takes a list
of HTML files on the command line and attempts to make the <TITLE> tag
look more normal so that glimpse can understand it.
WARNING: This is a hack. It's made to work on docbook generated html, but
may do strange things on anything else.
instructions, configure options
- added a transcript of a successful compile, since that gives all the
commands and shows people where their compile went wrong.
This is a patch from Volker Ruppert <Volker.Ruppert@t-online.de>, who
comments: "The fdisk command reports an unusable second harddisk if the cdrom
is enabled. This patch helps, but I don't know if it is the right way."
> I have inspected the header of output file and several sample MIDI files. I
> have found two different bytes in the header. After I have changed this
> bytes Winamp could play the output file, but it showed a track time of
> 0:00. The Windows Media Player still doesn't like the file.
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
posted to bochs-developers on Wed, 29 Aug 2001 00:08:45 +0100
David Haslam wrote:
> I have been looking at the keyboard problem with Minix, which for
> those that haven't tried Minix results in every key press giving the
> response: ^@
>
> I am aware of the comments in the changelog that suggest removing 2
> keyboard ACKs in iodev/keyboard.cc, but this is a bit of a hack,
> (which is presumably why it was never incorporated).
>
> The problem seems to be that the Minix keyboard driver doesn't obey
> the rules, and Bochs doesn't model the 8042 accurately. When issuing
> commands to set the LEDs, Minix polls the 8042 output data register
> waiting for an ACK even though the OBF flag isn't set.
>
> Bochs returns zero under these circumstances, which seems to
> trigger obscure behaviour that messes up the Minix internal
> keyboard queue. I don't fully understand why Minix breaks, but I
> think the fact that the ACK generates an interrupt, and Minix treats
> it as a scan code also has something to do with it.
>
> In any case, I believe, the fix is for Bochs to return the output
> buffer contents, regardless of whether the OBF flag (called outb in
> Bochs) is set.
>
> I expect the real hardware allows the register to be read at anytime,
> and with this fix we are modelling the behaviour of the hardware more
> accurately.
>
> I have tested it with Minix 2.0.0. Also DOS 6.22 still works after this fix.
> Does anyone think this will break anything else?
>
> This diff is against the latest CVS of iodev/keyboard.cc, version 1.29
> The last part of the diff is a minor fix to an unrelated debug print.
