Hello,
it seems extlinux.conf is pushed as *the* u-boot configuration.
As in it is promoted by many people and its flexibility is praised.
It overrides boot script when both are present.
However,
1) it is not documented. There are examples in readme which partially work and produce warnings but there is no doc nor specification on the web
2) it is broken. As of u-boot 2015-04 the timeout and default options are not supported which means you cannot boot at all unless you attach an input device which is configured in u-boot
3) there is false pretense of interoperability. While the freedesktop spec is cited it is not followed, and syslinux files cannot be parsed.
4) booting from multiple media is impossible.
Is there some plan to make this configuration usable?
Thanks
Michal