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

[Vipin Kumar <vipin.kumar@st.com>]

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.
> 
> 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.
> 

Yes, got it. The only point is that this is meant to boot from NAND, ONENAND 
devices(As the name suggests). Can there be a generic interface independent 
of a particular device.

Offcourse I agree that execute in place would work for NOR devices and we wont 
need this kinda solution but still a generic solution for both types of devices 
is preferable

Regards
Vipin