From: Scott Wood <scottwood@freescale.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] Some thoughts on SPL
Date: Fri, 16 Dec 2011 15:49:33 -0600 [thread overview]
Message-ID: <4EEBBCED.8080602@freescale.com> (raw)
In-Reply-To: <CAKON4Ow_BvnZGHThPtA__W9f3h3V+-pVmvv8-gyUS4SgMnJ59Q@mail.gmail.com>
On 12/16/2011 11:20 AM, jonsmirl at gmail.com wrote:
> The CPU I'm working with, the LPC3130, is kind of an in-between CPU
> for SPL. Instead of a tightly constrained RAM of 16KB or so I have
16K? Luxury! :-)
Many boards have only 4K, and IIRC some have only 2K.
> 96KB to work with. 96KB is enough room to support all of the various
> boot modes (uart, nand, spi, USB, etc) but not enough room for the
> full uboot command set. So I'm still stuck with the SPL model, but my
> constraints are much less.
All the SPL model is really supposed to be is makefile infrastructure
for building the two stages. What code you pull in is configurable.
> One example of a conflict with SPL is NAND support. With SPL you hard
> code in the NAND type.
This is only required with nand_spl_simple.c.
You could provide an alternate SPL driver, or even pull in the standard
SPL stack if you want. No need to hack up nand_spl_simple.c.
> I'm wondering if SPL could be designed in a more generic manner.
> Another model would be to use SPL as the base layer for all u-boot
> builds. You would then start turning on features until full uboot
> capability was reached.
A while back I suggested tracking a fully separate config for SPL, but
Wolfgang didn't like it. Maybe a larger set of concrete use cases (and
what it looks like to deal with each one manually as would currently be
needed) would be convincing -- at the time it was just about having a
separate CONFIG_SYS_TEXT_BASE_SPL.
-Scott
next prev parent reply other threads:[~2011-12-16 21:49 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-16 17:20 [U-Boot] Some thoughts on SPL jonsmirl at gmail.com
2011-12-16 21:49 ` Scott Wood [this message]
2011-12-17 5:38 ` Simon Glass
2011-12-17 5:56 ` jonsmirl at gmail.com
2011-12-17 20:08 ` Wolfgang Denk
2011-12-18 5:55 ` Simon Glass
2011-12-18 15:38 ` jonsmirl at gmail.com
2011-12-20 15:38 ` Tom Rini
2011-12-20 20:48 ` Scott Wood
2011-12-20 20:56 ` Tom Rini
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