[U-Boot] [PATCH 2/6] nand: Add SPL_NAND support to mxc_nand_spl

[Philip Paeps]

On 2013-04-19 16:48:42 (+0200), Philip Paeps <philip at paeps.cx> wrote:
> On 2013-04-19 15:00:13 (+0200), Philip Paeps <philip at paeps.cx> wrote:
> > On 2013-04-19 06:10:51 (+0200), Marek Vasut <marex at denx.de> wrote:
> > > To avoid the old function which are used with the nand_spl/ stuff
> > > getting in the way of NAND SPL framework, the macro
> > > CONFIG_SPL_NAND_LEGACY was introduced and two remaining legacy
> > > boards were adjusted. These board need to be either fixed or
> > > removed in the long run, but I don't have either.
> > 
> > It sounds like "fixing" these boards is mainly a matter of confirming
> > that a configuration for them based around CONFIG_SPL_FRAMEWORK will fit
> > in 2K.  If so, I don't think there is any reason to keep legacy support
> > around.
> 
> A first build with CONFIG_SPL_FRAMEWORK came out to nearly 4K.  Large
> contributors being (unsurprisingly) libcommon and libgeneric.  I had to
> get rid of a puts() in libspl to make it build without those libraries.
> Unfortunately, that still came out to 2.2K.  Close. :-)
> 
> I couldn't identify any obvious 100 bytes to scrap from glancing at
> u-boot-spl.map or objdump -D u-boot-spl, but I'll take a look.

Just as I hit 'send', it occurred to me that this configuration is with
a fairly lengthy lowlevel_init.S to support external boot.  Paring that
to the bare minimum gives a u-boot-spl.bin of 1821 bytes.

I'm not familiar enough with 'internal boot' and the 'imximage' format
to judge whether this leaves enough margin for telling the ROM loader to
do its thing usefully.  Benoît: do you have an idea how long a typically
useful imximage preamble gets?  Is ~230 bytes sufficient margin?

 - Philip

-- 
Philip Paeps
Senior Reality Engineer
Ministry of Information