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Date:   Mon, 14 Dec 2009 17:35:09 +0000
From:   Ralf Baechle <ralf@linux-mips.org>
To:     "Anoop P.A." <Anoop_P.A@pmc-sierra.com>
Cc:     linux-mips@linux-mips.org
Subject: Re: Help in enabling HIGHMEM support
Message-ID: <20091214173509.GB15067@linux-mips.org>
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On Mon, Dec 14, 2009 at 05:34:13AM -0800, Anoop P.A. wrote:

> We have a requirement to use a bigger RAM (1 GB / 2GB) with a RM9000
> based SOC. I thought of going with HIGHMEM path rather than enabling
> 64bit support thinking it will be easier.

This sounds like sawing off 32 legs just to be able to make use of a
free [1] wheelchair.

> I have tried enabling HIGMEM in kernel. Board boots fine with a 512 MB
> RAM plugged in. But if I connect a 1 GB RAM kernel will not boot. I am
> not even getting single print from kernel. I am using linux-2.6.18
> kernel.
> 
> It will be great if get any pointers suggestions in debugging this?

With this amount of RAM, use a 64-bit kernel if you can.  You'll be
happy not to know about all the headaches you will never encounter.

  Ralf

[1] Conditions apply.