From: Scott Wood <scottwood@freescale.com>
To: Florian Boelstler <euphoria@arcor.de>
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: Reserving small amounts of memory with mem= (MPC85xx, 2.6.15 arch/ppc)
Date: Fri, 13 Jun 2008 10:31:14 -0500 [thread overview]
Message-ID: <485292C2.6030103@freescale.com> (raw)
In-Reply-To: <g2u0ae$238$1@ger.gmane.org>
Florian Boelstler wrote:
> Available system memory is only 384 MB (CAM0+CAM1+CAM2), which explains
> why Linux "removed" the ramdisk, when it has been copied right below
> 508M by U-Boot. Because at that time I was using initrd_high @ 1FC00000,
> which is outside of mapped RAM.
>
> Is there an option to map less than 64M by a CAM entry?
CAM entries can be any power of 4 between 4K and 256M. However, the
code currently is hardcoded to use no more than 3 entries. It shouldn't
be too hard to change it to use a few more (see cam_mapin_ram(),
mmu_mapin_ram(), and adjust_total_lowmem() in
arch/powerpc/mm/fsl_booke_mmu.c).
Alternately, do you have highmem enabled? That will let you access the
rest of the RAM that the CAM doesn't map, though I don't know if an
initrd in highmem works.
-Scott
next prev parent reply other threads:[~2008-06-13 15:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-12 16:18 Reserving small amounts of memory with mem= (MPC85xx, 2.6.15 arch/ppc) Florian Boelstler
2008-06-12 19:14 ` Sylvain Joyeau
2008-06-13 14:30 ` Florian Boelstler
2008-06-13 15:31 ` Scott Wood [this message]
2008-06-16 14:26 ` Florian Boelstler
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