From: Martin_Czamai AT peak-service DOT com (Martin Czamai)
Newsgroups: comp.os.msdos.djgpp
Subject: Accessing memory above an adress of 1MB
Date: Mon, 09 Aug 1999 11:10:10 GMT
Message-ID: <37aeb1ba.11535499@NotesXNT>
X-Newsreader: Forte Free Agent 1.11/32.235
NNTP-Posting-Host: board-81.darmstadt.netsurf.de
X-Original-NNTP-Posting-Host: board-81.darmstadt.netsurf.de
X-Trace: 9 Aug 1999 13:11:50 +0200, board-81.darmstadt.netsurf.de
Organization: OMNILINK -- your link to the Net
Lines: 24
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

Hello!

I want to access the memory space given from a BAR (base adress
register) of a PCI controller. (the adress is dynamic allocated by the
system)
Therefore I wrote a function that returns the (absolute) adress that
has to be accessed. Usually it is around 0xFFFFF000 .
I used __djgpp_map_physical_memory (mappedBAR, NoBytes, BaseAdr) for
mapping the device to a created memory block named 'mappedBAR'; the
number of bytes to map (NoBytes) is a multiple of a mem-page found
with __dpmi_get_page_size(&NoBytes)  (4096 bytes) and the base adress
(BaseAdr) is equal the absolute address of the BAR.
My problem is, that the __djgpp_map_physical_memory (mappedBAR,
NoBytes, BaseAdr) returns EACCES as errno, wich is a rejection of the
request to the  DPMI server. What does this message exactly mean?
Who could help me getting started to access this memory?
I am using RHIDE 1.4.
Please send your reply to Martin_Czamai AT peak-service DOT com .
Thank you!