From: Timur Tabi <timur@freescale.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v2] mpc86xx: set the DDR BATs after calculating true DDR size
Date: Tue, 30 Mar 2010 10:21:33 -0500 [thread overview]
Message-ID: <4BB216FD.4070404@freescale.com> (raw)
In-Reply-To: <28AF45F6-CF0E-4597-840A-F699C62BABE7@kernel.crashing.org>
Kumar Gala wrote:
>> We still have the problem that, on a 1.5GB system, U-Boot will think that there are 1.5GB of DDR, but the BAT will be set to 1GB. When U-Boot tries to relocate itself, it will machine check.
>>
>> We need a way to tell U-Boot that we only have 1GB of DDR, but still have it tell Linux that we have 1.5GB of DDR.
>
> is this situation you have today? (or just a concern?)
Just a concern.
Technically, we have the same problem on e500, except on e500 we use multiple TLBs to map the memory. In theory, we need at most one TLB/BAT per DIMM slot, which means we would need four BATS on the MPC8641 HPCN.
Do we want to tell customers that U-Boot/Linux only supports power-of-two sizes of DDR?
--
Timur Tabi
Linux kernel developer at Freescale
next prev parent reply other threads:[~2010-03-30 15:21 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-30 14:25 [U-Boot] [PATCH v2] mpc86xx: set the DDR BATs after calculating true DDR size Kumar Gala
2010-03-30 14:37 ` Timur Tabi
2010-03-30 15:14 ` Kumar Gala
2010-03-30 15:21 ` Timur Tabi [this message]
2010-03-30 15:29 ` Kumar Gala
2010-03-30 15:32 ` Timur Tabi
2010-03-30 15:33 ` Kumar Gala
2010-03-30 15:35 ` Timur Tabi
2010-03-30 17:12 ` Becky Bruce
2010-03-30 17:02 ` Becky Bruce
2010-03-30 17:05 ` Becky Bruce
2010-03-30 18:42 ` Timur Tabi
2010-03-30 21:19 ` Timur Tabi
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