From: David Hawkins <dwh@ovro•caltech.edu>
To: Mark Chambers <markc@mail•com>
Cc: "Linuxppc-Embedded \(\(E-Mail\)\)" <linuxppc-embedded@ozlabs•org>
Subject: Re: Memory mapping PCI memory region to user space
Date: Thu, 23 Mar 2006 09:54:19 -0800 [thread overview]
Message-ID: <4422E0CB.8080701@ovro.caltech.edu> (raw)
In-Reply-To: <00be01c64ea1$4c6e0e20$6401a8c0@CHUCK2>
>
> PCI is actually endian-agnostic, so we're really 'fixing' the
> Freescale PCI implementation with endian swapping.
>
Hi Mark,
Its not agnostic, its little-endian.
The configuration space layout of parameters larger than a
byte are defined in little endian format.
The wiring on the PCI bus is little-endian, and 32-bit
quantities on the bus are represented by a logic analyzer
in little endian format.
But once you start talking about BAR regions, then yeah,
they're your bytes, do with them what you will. My hardware
uses a little-endian TI DSP, and an x86 host, so I
had been using compatible machines.
But the PLX PCI-9054 PCI chipset exposes BAR[0] and BAR[1]
as control registers that are little-endian format.
Conversely, we also use some Janz CAN cards, and their
messaging protocol over PCI uses big-endian format
structures in their protocol.
Dave
next prev parent reply other threads:[~2006-03-23 17:52 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-23 14:21 Memory mapping PCI memory region to user space Wyse, Chris
2006-03-23 15:44 ` Kumar Gala
2006-03-23 17:12 ` David Hawkins
2006-03-23 17:19 ` Kumar Gala
2006-03-23 17:43 ` Mark Chambers
2006-03-23 17:54 ` David Hawkins [this message]
2006-03-23 19:55 ` Mark Chambers
2006-03-23 20:26 ` David Hawkins
2006-03-23 17:46 ` David Hawkins
2006-03-27 8:02 ` Phil Nitschke
2006-03-27 16:05 ` David Hawkins
2006-03-28 4:21 ` Phil Nitschke
2006-03-28 4:55 ` David Hawkins
2006-03-28 6:44 ` Phil Nitschke
2006-03-28 16:35 ` David Hawkins
2006-03-27 16:18 ` Kumar Gala
2006-03-29 2:26 ` Phil Nitschke
2006-03-23 17:04 ` David Hawkins
-- strict thread matches above, loose matches on Subject: below --
2006-03-23 19:52 Wyse, Chris
2006-03-23 20:01 ` Kumar Gala
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4422E0CB.8080701@ovro.caltech.edu \
--to=dwh@ovro$(echo .)caltech.edu \
--cc=linuxppc-embedded@ozlabs$(echo .)org \
--cc=markc@mail$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox