[oe] RFC; Building multiple u-boot images for a single board

[Frans Meulenbroeks]

2010/2/26 Ulf Samuelsson <ulf.samuelsson at atmel.com>:
> If you want to support multiple boot memories, you have to
> have multiple boards in the conf/machine directory
>
> I currently testing a change to at91bootstrap, where a defconfig
> is not provided by openembedded.
> Instead you provide a list of defconfig's in your machine description:
>
> I.E: in conf/machien/at91sam9g45ek.conf you have:
>
> AT91BOOTSTRAP_BOARD = "at91sam9g45df at91sam9g45ek at91sam9g45nf"
>
> when at91bootstrap is built it will loop through all the boards.
> and build three versions.
>
> I think it would make sense to do the same for u-boot,
> so that you can build u-boot for several configurations.
>
> This change would happen from u-boot-2009.11 an onwards.
>
> In your machine conf you would supply:
> UBOOT_MACHINES = "at91sam9g45ekes_nandflash at91sam9g45ekes_dataflash"
>
> A loop goes through the list
> and runs make on each element in the list.
>
> make at91sam9g45ekes_nandflash_config
> make
> make at91sam9g45ekes_dataflash_config
> make
>
> if UBOOT_MACHINES is not set, then a single build is done using
> UBOOT_MACHINE as usual.
>
> This will allow u_boot to be built for every boot configuration
> without having to add a lot of files.
>

I fully agree (as I also need two different versions for my board, one
for flash, one for sd).