X-Authentication-Warning:	delorie.com: mail set sender to djgpp-bounces using -f
X-Received:	by 10.107.6.232 with SMTP id f101mr6707917ioi.30.1503080023306;
	Fri, 18 Aug 2017 11:13:43 -0700 (PDT)
X-Received:	by 10.31.136.77 with SMTP id k74mr65135vkd.4.1503080023248; Fri,
	18 Aug 2017 11:13:43 -0700 (PDT)
Newsgroups:	comp.os.msdos.djgpp
Date:	Fri, 18 Aug 2017 11:13:42 -0700 (PDT)
In-Reply-To:	<on6k51$1a8k$1@gioia.aioe.org>
Complaints-To:	groups-abuse AT google DOT com
Injection-Info:	glegroupsg2000goo.googlegroups.com; posting-host=89.24.106.115;
	posting-account=Q0wMHAoAAADjYrghh94FTf6YnbpTqZgp
NNTP-Posting-Host:	89.24.106.115
References:	<db10bd5c-9132-4be5-a496-757e648bf99a AT googlegroups DOT com> <on6k51$1a8k$1 AT gioia DOT aioe DOT org>
User-Agent:	G2/1.0
MIME-Version:	1.0
Message-ID:	<2fd7d93e-3a52-47ef-97d4-dc0208565e62@googlegroups.com>
Subject:	Re: Can I use transferbuffer temporarly a for short DMA transfer?
From:	"RayeR (glaux AT centrum DOT cz) [via djgpp AT delorie DOT com]" <djgpp AT delorie DOT com>
Injection-Date:	Fri, 18 Aug 2017 18:13:43 +0000
Bytes:	2045
Lines:	12
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp
X-MIME-Autoconverted:	from quoted-printable to 8bit by delorie.com id v7IIU2op030289
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

> "[The transfer] buffer is used for all DOS/BIOS services supported by
> DJGPP, it resides in conventional memory, and is allocated by the
> startup code."
> http://www.delorie.com/djgpp/v2faq/faq18_2.html

Yes I read the DJGPP FAQ. I'm not sure what all DOS/BIOS serviuces are used by what DJGPP libc function. It seems that printf is destrying my transferbuffer data so I rather use __dpmi_allocate_dos_memory.
OK, there's no specified how this allocated memory is aligned and if the allocator prevents crossing 64kB boundary which is required by busmaster DMA - probably I have to take care myself and allocate 2-times of memory than I need and check the physical address and if it cross the boundary then dont use beginning of the buffer but higher address just behind the boundary...

- Raw text -