Path: chuka.playstation.co.uk!news
From: "Peter Armstrong" <hanno@btinternet.com>
Newsgroups: scee.yaroze.freetalk.english
Subject: Re: loading an exe and using Exec()
Date: Mon, 16 Apr 2001 13:33:58 +0100
Organization: PlayStation Net Yaroze (SCEE)
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Message-ID: <9bep1d$30s3@www.netyaroze-europe.com>
References: <9bbp7u$t451@www.netyaroze-europe.com>
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"Matt Verran" <mverran@btinternet.com> wrote in message
news:9bbp7u$t451@www.netyaroze-europe.com...
> Hi All
>
> I spent the whole of yesterday puzzling over this yaroze problem. I'm
trying
> to load and execute an exe file from disk, which would allow yarozers the
> ability to play update disks (gta london, beatmania 2, 3, 4, 5, etc)
without
> the original disk.
>
> I used the following code to (I think) successfully load the yaroze boot
> disk app and execute it:
>
> if( CdSearchFile(0, "\\DTL_S30.35;1") == 0 )
>    {
>     printf("\n not found \n");
>     }
>   else
>     {
>     printf("\n found \n");
>
>     exec_struct = CdReadExec( "\\DTL_S30.35;1" );
>
>     result = CdReadSync(0, 0);
>
>     printf("\n loaded, result:  %d    \n\n", result);
>
>     if (result==0)
>       {
>       printf("\n executing \n");
>       EnterCriticalSection();
>       Exec(exec_struct, 0, 0);
>       ExitCriticalSection();
>       }
>     }
>
> But all the other disks I tried, FF8, OPM coverdisks, beatmania 2, first
had
> trouble with the CdSearchFile() function, they didn't find the file 100%
of
> the time. Then always failed at the CdReadExec/CdReadSync statements, I
just
> got timeouts.
>
> I though it might be that the CdReadExec is trying to overwrite the
current
> code that is executing, but if I quit after the timeout and reexecute the
> proggy it works fine.   I also wondered if the filesystem has to be reset
> somehow if the disk is changed?

I would have said CdReadExec overwriting data is the problem. The yaroze
boot exe loads in at 80090000, as long as your own program is located higher
in memory it won't cause any problems. Most commercial game exe's load in
below 80090000, over yaroze system data, and may well be overwriting data
and functions still associated with your program. For example CdReadExec
could load an exe over the position of CdReadSync, and as this is the next
call in your program it would fail. You say you're getting timeouts rather
than lock-ups though, which is what I've been getting, so perhaps there's
another reason.

You may be able to get some exe's to run, as long as they don't overwrite
anything vital. You could try using the Load() function instead of
CdReadExec, if you can get it to work, I've had nothing but lock-ups with it
and LoadTest().

Peter