[U-Boot] Unified u-boot feature set for simpler distro support

[Dirk Müller]

Hi Stephen,

> Could you expand upon what "handles booting from extX directly" means?
> Upstream U-Boot has supported ext2/3 for as long as I've been involved
> with it (which admittedly isn't that long), and ext4 support was added
> recently. This allows U-Boot commands "extload" or "load" to access ext*
> just like any other file-system. Is there something more involved when
> you say "booting from extX directly" beyond just the extload/load commands?

Sorry, I meant loading the SPL, which in some of the boot scripts are
loaded from FAT still.

> I think it's reasonable to require that boards supported by generic
> distros have upgraded/recent U-Boots that export a standard set of
> environment variables that define the various addresses, so that
> boot.scr authors don't have to care about platform differences, but
> rather simply use those variables. For example, kernel_addr_r,
> ramdisk_addr_r, fdt_addr_r, etc.

Sure, no problems with that.

Greetings,
Dirk