From: enigma AT erols DOT com (enigma)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: copying from real more to pm...
Date: Tue, 18 Mar 1997 23:12:39 GMT
Organization: djgpp, i luv u ;)
Lines: 50
Message-ID: <332f1f9a.123813@news.erols.com>
References: <332c7487 DOT 7195759 AT news DOT erols DOT com>
NNTP-Posting-Host: dam-as9s40.erols.com
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

On Sun, 16 Mar 1997 22:36:24 GMT, enigma AT erols DOT com (enigma) wrote:

>ok.. this has been bugging me for a little why...
>i'm trying to copy memory from a real pointer to a protected mode
>pointer.  well, i got the copying of bytes to work, but my func for
>copying unsigned words isn't working.  i could use a little help here
>folks
>
>code:
>
>#define RM_TO_LINEAR(addr)    (((addr & 0xFFFF0000) >> 12) + (addr &
>0xFFFF))
>
>UWORD *PMcopyWordtoLocal(UWORD *RMptr) {
>
>   UWORD buffer[256], *p;
>   UWORD count = 0;
>   ULONG addr;
>
>   addr = RM_TO_LINEAR((ULONG)RMptr);
>   _farsetsel(_dos_ds);
>   while (_farnspeekw(addr) != 0xFFFF) {
>      buffer[count++] = _farnspeekw(addr++);
>      addr++;
>   }
>   buffer[count] = 0xFFFF;
>   p = (UWORD *)malloc(count);
>   memcpy(p,buffer,count);
>   return p;
>
>}
>
>feel free to criticize my code as much as necessary.  style,
>bugs,etc..
>just gimme my mistake ;) 

oops ok.. i guess i was a bit cryptic..
ok this basically is used to grab an array that the vesa bios returns
after a function call.  what it should be doing is copying UWORD's
(defined as unsigned int) <-- is this wrong? should they be defined as
unsigned short's? the array is terminated by a word filled with
0xFFFF.  what the code above does is give me back is just worthless
numbers (should be video mode numbers).
i am looking into Eli's suggestions, but with the added info, can
anyone see an obivous error?


mint
enigma AT erols DOT com
djgpp is an obsession