delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp/2007/09/25/15:31:29

X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f
From: RayeR <glaux AT centrum DOT cz>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: DMA and paging
Date: Tue, 25 Sep 2007 12:22:27 -0700
Organization: http://groups.google.com
Lines: 19
Message-ID: <1190748147.225689.238520@19g2000hsx.googlegroups.com>
References: <46F7F665 DOT 1773 DOT 20651AE9 AT gerritvn DOT gpvno DOT co DOT za>
NNTP-Posting-Host: 89.176.103.156
Mime-Version: 1.0
X-Trace: posting.google.com 1190748147 19940 127.0.0.1 (25 Sep 2007 19:22:27 GMT)
X-Complaints-To: groups-abuse AT google DOT com
NNTP-Posting-Date: Tue, 25 Sep 2007 19:22:27 +0000 (UTC)
In-Reply-To: <46F7F665.1773.20651AE9@gerritvn.gpvno.co.za>
User-Agent: G2/1.0
X-HTTP-UserAgent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.8.1.6) Gecko/20070802 SeaMonkey/1.1.4,gzip(gfe),gzip(gfe)
Complaints-To: groups-abuse AT google DOT com
Injection-Info: 19g2000hsx.googlegroups.com; posting-host=89.176.103.156;
posting-account=ps2QrAMAAAA6_jCuRt2JEIpn5Otqf_w0
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: djgpp AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com

I don't know where is your DMA buffer lying, I can help you only with
my example how to handle with VESA LFB which may be similar

// Allocate a descriptor in LDT and set it up to span the entire VRAM.
    vesa_lfb_selector=__dpmi_allocate_ldt_descriptors(1); // allocate
1 descriptor (desribing our new segment) in LDT and return it's
selector
 
__dpmi_set_segment_base_address(vesa_lfb_selector,meminfo.address); //
set segment base accorning to LFB physical address
    __dpmi_set_segment_limit(vesa_lfb_selector,meminfo.size-1); // set
segment limit accorning to LFB size

then you will use movedata function to transfer physical memory to
your variables in DS or where you want.
Afrer all done don't forget to free descriptor
__dpmi_free_ldt_descriptor(vesa_lfb_selector);


- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019