Add support for linaro-media-create --bootloader option

Um. Can we chain boot from u-boot into UEFI? (Or vice versa I guess,
although that would be a scarier change). Or will this depend on
sd-mux?

Cheers,
mwh

I believe we can chain boot, just like Yongqin Liu did for u-boot. On VExpress we will be doing something similar, using bootmon to launch UEFI - to get around the fact that UEFI doesn't initialise power management, but a bootmon fix that ARM are testing will.

We should talk to ricardo more on this, but I think the main thing here is the linaro-media-create is now going to fail if we don't specify anything.

Just talked to Ricardo, and the answer is yes, we should be able to chain boot uefi from u-boot, although Wookie pointed out that this would cause problems on VExpress when we're security checking, because uefi will complain if it is not the first thing to load.

However, as Ricardo said, just for now all we need to do is add the --bootloader u-boot, which will keep everything stable. I'll implement accordingly.

OK. Done and pushed up to https://code.launchpad.net/~dpigott/lava-dispatcher/l-m-c-bootloader-fix, however this will not be as flexible as it could be. Talking to James Tunnicliffe and Ricardo, the bootloader configurations are defined and named in the hwpack manifest, and can actually be names anything.

Ricardo is suggesting we standardise for automation on "u_boot" and "uefi", adding any others as we go along. However, James pointed out that you could (in theory) have multiple different bootloader configurations in a hwpack with any names. The only truly safe way to do this is for the dispatcher to run a "linaro-media-create --hwpack $HWPACK --read-hwpack", which will produce output along the lines of:

+--------------------------------------+--------------------------------------+
Supported boards | Supported bootloaders
+--------------------------------------+--------------------------------------+
linaro-lt-panda | u_boot
+--------------------------------------+--------------------------------------+

Which we would then have to parse out the boot config name and parse it out and apply that. Because of the columnar nature of the output, this is a bit nasty, but doable.

Essentially, a future proof fix needs a little bit of thinking.

OK. As Fabo said, it doesn't mean we won't fix, because we need to support the bootloader option at some point, so putting back to triaged, and looking at ways to do this properly.

Should we really target this for 2012.11 or just put it in the backlog? I don't think we have any plans to work on this right now.

I'm looking into it as a background. My proposal is to add a "bootloader" option to deploy_linaro_image and deploy_linaro_android_image. If none is specified, then it defaults to u_boot.

Actually, amend that: Only for deploy_linaro_image. linaro-android-media-create doesn't have that option. Also, given that a couple of new member boards require some UEFI work, this could suddenly become more urgent, so I think it's better to be prepared.