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From: Eddie Dawydiuk <eddie@embeddedarm.com>
To: linuxppc-dev@ozlabs.org, Grant Likely <grant.likely@secretlab.ca>
Subject: PPC PCI bus registers
Date: Wed, 02 Sep 2009 16:44:55 -0700	[thread overview]
Message-ID: <4A9F0377.1070606@embeddedarm.com> (raw)

Hello,

I have a question regarding reading PCI bus registers from a user space 
application running on a PPC SBC. Seeing as though the PCI bus is little endian 
and PPC is big endian is it typical that one must perform a byte swap on all 16 
and 32 bit register reads?

I've found this is true on a custom board I am working on(with an FPGA connected 
via the PCI bus) and as a result I've added a byte swap command in busybox to 
accommodate this feature...

-- 
Best Regards,
________________________________________________________________
  Eddie Dawydiuk, Technologic Systems | voice:  (480) 837-5200
  16525 East Laser Drive              | fax:    (480) 837-5300
  Fountain Hills, AZ 85268            | web: www.embeddedARM.com

             reply	other threads:[~2009-09-02 23:52 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-02 23:44 Eddie Dawydiuk [this message]
2009-09-02 23:56 ` PPC PCI bus registers Grant Likely
2009-09-03 10:00 ` Benjamin Herrenschmidt
2009-09-16 18:58   ` Eddie Dawydiuk
2009-09-16 21:54     ` Benjamin Herrenschmidt
2009-09-16 22:11       ` Eddie Dawydiuk
2009-09-17  1:24         ` Benjamin Herrenschmidt
2009-09-17 16:11           ` Eddie Dawydiuk

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