X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f
Date: Thu, 03 Mar 2011 18:32:43 +1000
From: Jason Hood <jadoxa AT yahoo DOT com DOT au>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.14) Gecko/20110221 Thunderbird/3.1.8
MIME-Version: 1.0
Newsgroups: comp.os.msdos.djgpp
Subject: Re: csdpmi7 not working on virtualbox, how use dosmemget with seg
 ofs from int21h?
References: <39cdc18e-eccb-4213-b896-db3be020702e AT w9g2000prg DOT googlegroups DOT com>
In-Reply-To: <39cdc18e-eccb-4213-b896-db3be020702e@w9g2000prg.googlegroups.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
NNTP-Posting-Host: $$5emnjdfxoj7m29.news.x-privat.org
Message-ID: <4d6f5239@news.x-privat.org>
Organization: X-Privat.Org NNTP Server - http://www.x-privat.org
Lines: 23
X-Authenticated-User: $$np02fmijtvj-bfao$k3
X-Complaints-To: abuse AT x-privat DOT org
Bytes: 1785
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

> the addresses of the structures in real mode memory in question are in
> segment offset format coming from and going into int21h function 7303h
> (a DOS FAT32 function) at es:di and I need a C string at ds:dx, and I
> need to get at whatever is coming back from es:di.

How about FAQ 18.2?  Here's some untested code.

#include <go32.h>
#include <dpmi.h>
#include <sys/farptr.h>

__dpmi_regs r;

_farpokew(_dos_ds, __tb+2, 0); // initialise the version
dosmemput(path, strlen(path)+1, __tb+sizeof(extFAT32FreeSpaceStructure));
r.x.ds = r.x.es = __tb >> 4;
r.x.dx = (__tb & 0x0f) + sizeof(extFAT32FreeSpaceStructure);
r.x.di = __tb & 0x0f;
__dpmi_int(0x21, &r);
dosmemget(__tb, sizeof(extFAT32FreeSpaceStructure), &extFAT32FreeSpace);

-- 
Jason.