Hi,
-----Original Message----- From: u-boot-bounces@lists.denx.de [mailto:u-boot- bounces@lists.denx.de] On Behalf Of Vipin Kumar Sent: Tuesday, September 14, 2010 3:52 PM To: Stefan Roese Cc: u-boot@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