From: Martyn Welch <martyn.welch@ge•com>
To: Scott Wood <scottwood@freescale•com>
Cc: linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH] PowerPC: Remove hardcoded BAT configuration of IMMR in CPM early debug console
Date: Thu, 03 Jun 2010 10:12:19 +0100 [thread overview]
Message-ID: <4C0771F3.2000106@ge.com> (raw)
In-Reply-To: <4C068691.6040501@freescale.com>
Scott Wood wrote:
> On 06/02/2010 03:06 AM, Martyn Welch wrote:
>>>>> I think that's a more fundamental change to CPM early debug than I
>>>>> can
>>>>> handle right now.
>>>
>>> Is IMMRBASE on your board at some address that has a low likelihood of
>>> conflicting when treated as a kernel effective address?
>>
>> It's at 0x0f000000, is seems ok, but then I'm not sure I fully
>> understand kernel effective addresses.
>
> That overlaps userspace -- is the BAT cleared before userspace starts?
>
To be honest, once I'd got the device booting past the early debug
stage, I rebuilt the kernel without udbg in it...
> If you don't want to do the fixmap stuff, might want to at least just
> leave it at the current arbitrary effective address, which hasn't
> seemed to cause much trouble so far.
>
Given that I've now switched udbg off in the kernel config, I really
can't substantiate spending much more time on this. This patch was
mainly to help others that maybe struggling to bring up Linux on a
device with CPM serial.
I'll try and get a revised patch out soon which keeps the current
arbitrary effective address.
Martyn
> But fixmap is the right way to do it.
>
> -Scott
--
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prev parent reply other threads:[~2010-06-03 9:12 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-28 15:18 [PATCH] PowerPC: Remove hardcoded BAT configuration of IMMR in CPM early debug console Martyn Welch
2010-05-28 16:18 ` Scott Wood
2010-05-29 3:37 ` Benjamin Herrenschmidt
2010-06-01 12:52 ` Martyn Welch
2010-06-01 13:43 ` Martyn Welch
2010-06-01 16:06 ` Scott Wood
2010-06-02 8:06 ` Martyn Welch
2010-06-02 16:28 ` Scott Wood
2010-06-03 9:12 ` Martyn Welch [this message]
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