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'?
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 ...
Comments welcome.
Cheers, Stefan
-- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-0 Fax: (+49)-8142-66989-80 Email: office@denx.de