linux-mips
[Top] [All Lists]

Re: NXP STB225 board support

To: "Kevin D. Kissell" <kevink@paralogos.com>
Subject: Re: NXP STB225 board support
From: Chad Reese <kreese@caviumnetworks.com>
Date: Thu, 08 Jan 2009 11:34:41 -0800
Cc: Ihar Hrachyshka <ihar.hrachyshka@gmail.com>, linux-mips@linux-mips.org
In-reply-to: <496652B7.60500@paralogos.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <fce2a370812230648s798ebbf6y1387a237ae640e39@mail.gmail.com> <fce2a370901080858s345a33a6x3a2f821a7d9645b8@mail.gmail.com> <496652B7.60500@paralogos.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.0.14eol) Gecko/20070505 Iceape/1.0.9 (Debian-1.0.13~pre080323b-0etch3)
Kevin D. Kissell wrote:
> Ihar Hrachyshka wrote:
>  >
>  >
>  > Bisecting my Linus vanilla git, I found that the problem appeared
>  > after the following patch was applied:
>  >
>  > 
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=566f74f6b2f8b85d5b8d6caaf97e5672cecd3e3e
>  >
>  > After reverting the patch, Linus vanilla git kernel again boots ok on
>  > the board. Please, take a look.
> 
> Could one of the Cavium guys explain why the new code for V2 cores does
> "ebase += ..."  and not "ebase = "?

The value "(read_c0_ebase() & 0x3ffff000)" is a physical address and
must be converted into Mips KSEG address by adding CAC_BASE. My guess is
that something about the NXP STB225 isn't fully Mips r2 and doesn't
implement the ebase register correctly. I'm afraid I don't know anything
about that processor.

Chad

<Prev in Thread] Current Thread [Next in Thread>