[U-Boot] Multiple binaries built through u-boot source

V, Aneesh
2010-09-14T13:33:53Z

Hi,

> -----Original Message-----
> From: u-boot-bounces at lists.denx.de [mailto:u-boot-
> bounces at lists.denx.de] On Behalf Of Vipin Kumar
> Sent: Tuesday, September 14, 2010 3:52 PM
> To: Stefan Roese
> Cc: u-boot at lists.denx.de; Shiraz HASHIM
> Subject: Re: [U-Boot] Multiple binaries built through u-boot source
>
> On 9/14/2010 12:46 PM, Stefan Roese wrote:
> Hello Stefan,
>
> > On Tuesday 14 September 2010 07:22:10 Vipin Kumar wrote:
> >> This is about a generic problem which may also be faced
> >> by other developers. Our SoC has a masked bootrom area
> >> which copies an image from NOR/NAND memories to an internal
> >> embedded SRAM. The size of this SRAM is only 8K. This
> >> binary initializes the DDR for larger binaries (u-boot/OS)
> >> to be placed in RAM and executed from there.
> >>
> >> I wanted to know if there is a generic way to create two
> >> binaries from the u-boot source both compiled for different
> >> address ranges. The first initializes the RAM (may be
> >> something else as well) and the second is the u-boot binary
> >> responsible for loading OS etc.

It's sheer coincidence that I also wanted to post a very similar query
today. We have a similar requirement for OMAP platforms.

Presently, we are maintaining a mini bootloader(called x-loader, based
on u-boot)separately. We want to integrate x-loader with u-boot and
up-stream the source code.

> >
> > Take a look at the NAND_SPL infrastructure (nand_spl/*). It was
> created for
> > platforms booting from NAND with tight restrictions (e.g. 4k image
> size for
> > inital setup, mostly DDR). General idea here is that 2 images are
> created:
> >
> > a) Very small SPL (secondary program loader) image with only basic
> > setup, like DDR and NAND
> > b) RAM based U-Boot image
> >
> > Both images are combined in the build process creating a single
> image that can
> > be flashed into NAND.
> >
> > doc/README.nand-boot-ppc440 might be interesting to get some more
> infos about
> > this, some of it PPC4xx specific though.
> >

This looks promising. However, our SPL has to load u-boot from MMC. Is
it OK to keep it under nand_spl directory or should we create
something like 'mmc_spl'?

Best regards,
Aneesh