[U-Boot] [PATCH v3 2/4] build/mkconfig: Add EXTRA_OPTS argument to make to modify build

[McClintock Matthew-B29882]

On Tue, Jun 7, 2011 at 3:04 PM, Wolfgang Denk <wd at denx.de> wrote:
>> BOARD_NAND
>> BOARD_NAND_IN_BOOTSTRAP
>> BOARD_SPIFLASH
>> BOARD_SPIFLASH_IN_BOOTSTRAP
>> BOARD_SDCARD
>> BOARD_SDCARD_IN_BOOTSTRAP
>
> Are these independent targets?  I think you don't run a
> "./MAKEALL BOARD_SDCARD_IN_BOOTSTRAP" alone, right?

Correct, however I was hoping to use a normal build system to make
this image. With the only difference being that CONFIG_IN_BOOTSTRAP is
defined when parsing the board config file.

> You can set all types of make variable sinternally during different
> stages of the build, like we already do with the nand_spl code.

Right but nand_spl provides more Makefiles for building it's own
image. I want to reuse the normal u-boot build system to create this
shim/bootstrap image.

> I have to admit that I don't even understand why you would need
> separate top-level FOO and FOO_IN_BOOTSTRAP make targets.  Please
> elucidate.

Sorry, let me try to explain some more.

Certain boards require some sort of shim, or spl for booting from
media other than NOR on our parts. We need this shim to perform DDR
initialization. This shim does not need to be anything but a stripped
down version of u-boot since it needs to be <256k and contain the DDR
SPD initialization code. Therefore I just wanted to reuse the u-boot
build system as is and add some configuration changes to create all
the final images for booting this board.

So when I build a target for my board the following happens:

make FOO
-> builds u-boot.bin to run from RAM
-> calls make FOO_IN_BOOTSTRAP to run from L2 and configure DDR
-> NAND will also have a nand_spl shim as well (where as SDCARD and
SPI booting currently do not have support in u-boot for making this
shim)

The FOO_IN_BOOTSTRAP build above creates a u-boot image that runs from
L2 and its BOOTCOMMAND is set such that it will automatically load the
final u-boot image from the boot media to ram and then execute the
full version of u-boot.

-M