RE: [PATCH] powerpc/85xx: allow CONFIG_PHYS_64BIT to be selectable

quoted

-----Original Message-----
From: Tabi Timur-B04825
Sent: Friday, February 24, 2012 10:46 AM
To: Li Yang-R58472
Cc: Huang Changming-R66093; galak@kernel.crashing.org;
benh@kernel.crashing.org; Wood Scott-B07421; linuxppc-dev@ozlabs.org
Subject: Re: [PATCH] powerpc/85xx: allow CONFIG_PHYS_64BIT to be
selectable

Li Yang-R58472 wrote:

quoted

I agree with Changming that we shouldn't setting PHYS_64BIT by

default.

quoted

The default kernel should always be the compatible with as much as
possible.  Disabling PHYS_64BIT by default means that the default
kernel will not work with a 36-bit DTS.  If you attempt to boot such a
kernel with a 36-bit DTS, there will be no text output.  Most people
will not know why it's not working.

So the safest option is for PHYS_64BIT to be enabled by default.  That
way, the kernel will always work.

=20
Even though the user still need to know the addressing mode that u-boot
is using.  It won't work if the addressing mode of u-boot and device tree
are different.
=20

Yes, u-boot must has the same address mode with DTS, otherwise, we can't bo=
ot the kernel.