FPC 2.6.2 for DOS/Go32V2

There is the fatal IDE unstability in FPC 2.6.2 under pure DOS.

IDE almost always starts only first time (after installation or reboot). I start the IDE, compile and run the program (e.g. Hello.pas) and close IDE. But when I want to start IDE again it crashes with SIGSEGV message.

Exiting due to signal SIGSEGV
FPC General Protection Fault at eip=006EDE95
eax=65672D6C ebx=0000002A ecx=00000088 edx=00000000 esi=008E91F8 edi=0083B504
ebp=008C0CA0 esp=008C0C90 program=C:\PP\BIN\GO32V2\FP.EXE cs: sel=00A7 base=00400000 limit=008EFFFF
ds: sel=00AF base=00400000 limit=008EFFFF
es: sel=00AF base=00400000 limit=008EFFFF
fs: sel=00C7 base=00000000 limit=0010FFFF
gs: sel=00C7 base=00000000 limit=0010FFFF
ss: sel=00AF base=00400000 limit=008EFFFF

Call frame traceback EIPs:
$006EDE95
$005BD905
$005BCD84
$005BC83D
$005BC7F8
$00308AF8
$0030B9F4
$0002DB50
$0002DC5A
$00002040

To be able to start IDE again in DOS I have to reboot the computer. I think IDE set something in memory and warm restart does not erase the memory contents.

Compilation from command prompt with FPC.EXE works everywhere. But IDE is good for debugging and help.

Can someone please help me or advise what I'm doing wrong.

The main problem is running IDE in pure DOS.

Thank you.

Which DOS version is it? Is there any DPMI provider running before starting the IDE (some DOS versions include DPMI host themselves)?

If there is no other DPMI host (running) and thus CWSDPMI.EXE is used, I'd recommend starting with a check whether there is just one (the latest) CWSDPMI.EXE and just for test purposes try loading it into memory as TSR with options "-p -x" (see cwsdpmi.txt included in directory doc\fpc) to see if it makes any difference.

Obviously, the next step would be compiling the IDE with debug information (including -gl) to see where exactly it fails.

Tomas

I am running pure DOS 7 from Windows 98 US, no drivers, no TSR programs. Just COMMAND.COM, no AUTOEXEC.BAT and CONFIG.SYS.

Run

CWSDPMI -p -x

DPMI stays in memory, start FP.EXE - again SIGSEGV.

But I found an interesting thing.

When I run FP.EXE from FPC 1.0.11 (it started always O.K.), nothing done, just exit program,
and then try run IDE from FPC 2.6.2 - the program starts!

*Further attempts to start IDE from FPC 2.6.2 causes an exception SIGSEV.* *
*
*If previously run IDE from FPC 1.0.11, then IDE from FPC 2.6.2 starts.*

It is really funny...

Can you tell me where can I download source for IDE from FPC 2.6.2 and how to compile it?

I will try it when I have a free weekend.

Thank you.

Could you try to delete the files generated by fp.exe

before restarting it:

fp.exe generates three files:

-fp.ini

-fp.cfg

and

fp.dsk

Try first to only remove fp.dsk

and see if it cures your sigsegv or not.

fp.dsk is a binary file that contains configuration information

that mighr be corrupted.

If remove fp.dsk alone does not remove the crash, try removing the three files.

Could you please report to the list if any of the above helped?

Thanks in advance,

Pierre Muller

De : De la part de Lubomír Cabla
Envoyé : mercredi 18 septembre 2013 20:50
À : FPC-Pascal users discussions
Objet : Re: [fpc-pascal] FPC 2.6.2 for DOS/Go32V2 FP.EXE cannot run a second time

I am running pure DOS 7 from Windows 98 US, no drivers, no TSR programs.

Just COMMAND.COM, no AUTOEXEC.BAT and CONFIG.SYS.

Run

CWSDPMI -p -x

DPMI stays in memory, start FP.EXE - again SIGSEGV.

But I found an interesting thing.

When I run FP.EXE from FPC 1.0.11 (it started always O.K.),

nothing done, just exit program,

and then try run IDE from FPC 2.6.2 - the program starts!

Further attempts to start IDE from FPC 2.6.2 causes an exception SIGSEV.

If previously run IDE from FPC 1.0.11, then IDE from FPC 2.6.2 starts.

It is really funny...

Can you tell me where can I download source for IDE from FPC 2.6.2

and how to compile it?

I will try it when I have a free weekend.

Thank you.

On Wed, Sep 18, 2013 at 8:52 AM, Tomas Hajny wrote:

Which DOS version is it? Is there any DPMI provider running before starting the IDE (some DOS versions include DPMI host themselves)?

If there is no other DPMI host (running) and thus CWSDPMI.EXE is used, I'd recommend starting with a check whether there is just one (the latest) CWSDPMI.EXE and just for test purposes try loading it into memory as TSR with options "-p -x" (see cwsdpmi.txt included in directory doc\fpc) to see if it makes any difference.

Obviously, the next step would be compiling the IDE with debug information (including -gl) to see where exactly it fails.

Tomas

.
.

OK, thanks.

Can you tell me where can I download source for IDE from FPC 2.6.2 and how to compile it? I will try it when I have a free weekend.

See links on http://www.freepascal.org/develop.var - you can e.g. try downloading fpc.zip source package for fixes from FTP. Unpack it somewhere and run:

make rtl_all packages_all ide_all "OPT=-gl -O-" "NOGDB=1"

That should compile IDE without the debugging support, but that should be sufficient for start. If the problem cannot be replicated that way, the next step would be downloading the pre-compiled libgdb (ftp://ftp.freepascal.org/pub/fpc/contrib/libgdb/v6.1.1/go32v2-v601.zip), creating directory "libgdb" next to "rtl", "ide" and "packages", unpacking content of the downloaded file there and then compiling again using:

make clean rtl_all packages_all ide_all "OPT=-gl -O-"

If that still works, you could remove the "-O-" bit to see if the optimizations make any difference.

Tomas

Yes, I know these DSK-file crashes, but this is something else.

Anyway,
I deleted the file fp.dsk - SIGSEGV.
I deleted the remaining files - SIGSEGV.

Always helps run old fp.exe 0.9.2 18.05.2004 from 1.0.11 before run fp.exe from 2.6.2. Both versions use CWSDPMI v7.

I still think that fp.exe will something set in the memory and after completion of the program does not reset this.

Of course this is only my assumption.
When I have the source program hopefully learn more.

Anyway thanks for the help.

Lubomir Cabla

Currently I'm quite busy but definitely I will try it and let you know.

Thank you.

Attempt to compile IDE:

OS Windows XP 32 CZ
FPC GO32V2 2.6.2 is installed in z:\pp
PATH contains Z:\pp\bin\go32v2

1. 29.09.2013 download source package
ftp://ftp.freepascal.org/pub/fpc/snapshot/fixes/source/fpc.zip

2. unpacked to z:\fpc

3. command for compilation:

Z:\fpc>make rtl_all packages_all ide_all "OPT=-gl -O-" "NOGDB=1" > x130930.log

On screen I got messages:

v2prt0.as: Assembler messages:
v2prt0.as:330: Warning: indirect ljmp without `*'
v2prt0.as:404: Warning: indirect lcall without `*' exceptn.as: Assembler messages:
exceptn.as:362: Warning: indirect ljmp without `*' exceptn.as:414: Warning: indirect ljmp without `*' make.exe[2]: *** [fprepos.ppu] Error 1
make.exe[1]: *** [fppkg_all] Error 2
make.exe: *** [packages_all] Error 2

ERROR is:

fprepos.pp(22,3) Fatal: Can't find unit fpmkunit used by fprepos

even the unit fpmkunit has been compiled (at least I think so) into Z:\fpc\packages\fpmkunit\units\go32v2 where are these files:

fpmkunit.o
fpmkunit.ppu
fpmkunit.rst

For more information see the log file x130930.log. How to bypass this error?
Lubomir Cabla

.
.

fprepos.pp(22,3) Fatal: Can't find unit fpmkunit used by fprepos even the unit fpmkunit has been compiled (at least I think so) into Z:\fpc\packages\fpmkunit\units\go32v2 where are these files:

.
.

Yes, sorry - a dependency has been missing in our makefile (triggered only for some targets; unfortunately, GO32v2 being one of them). The issue is fixed in svn, but I'm not sure if it will still get in tonight's source zip file generation.

Tomas

OK, how do I know that this is corrected?

Or I will try next time.

Lubomír Čabla wrote

OK, how do I know that this is corrected?

By checking the date and time of the generated source ZIP file on FTP or just trying? Normally, it should be there the next day after committing the fixes to SVN. If I remember correctly, the ZIP files generation is started at 2am CET every day. Since I performed my commit around that time, I wasn't sure if it would get there the same day (Wednesday), but it should have been there yesterday at latest (unless something broke, which would be visible from the date of the respective file on our FTP server; just checked - the file is dated today at 2:19 CET, i.e. it should contain the necessary fixes).

Tomas

OK, with FPC.ZIP dated 5.10.2013 I have translated successfully FP.EXE and it works. I tested only FP.EXE, not RTL units. It seems that the error (FP.EXE cannot run) was corrected. Thank you for your help.
Expected question: when the new version 2.6.3 will be available?

Hmm. I thought the next version was going to be 2.7.something?

2.6.3 and 2.7.1 are development versions. The next release is likely to be 2.6.4 somewhen in the near(?) future. After that the next release is likely to be 2.8.0.

Regards,
Sven

In our previous episode, Sven Barth said:

To get an idea of the versioning, it is easiest to look at the picture in the FAQ:

http://www.freepascal.org/faq.var#versions

and read the text above it.

Sven, thank you for info.