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

[Kyungmin Park]

On Tue, Sep 14, 2010 at 10:51 PM, Stefan Roese <sr at denx.de> wrote:
> Hi Aneesh,
>
> On Tuesday 14 September 2010 15:33:53 V, Aneesh wrote:
>> > >> 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.
>
> That's definitely a good idea.
>
>> > > 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'?

Good question, It created the mmc_ipl and use it for mmc booting e.g.,
eMMC boot.

>
> Not sure. Perhaps we should now really think about a more generic approach and
> merge all this IPL/SPL stuff into a single directory. Perhaps something like
> this:
>
> spl/
> spl/nand
> spl/onenand
> spl/mmc
> spl/board

Good, and use the CONFIG_PRELOADER as existing. but what's the SPL
stand for? SPL (secondary program loader)?

Thank you,
Kyungmin Park
> ...
>
> Comments welcome.
>
> Cheers,
> Stefan
>
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