[U-Boot] Distro bootcmd: Re: 5.2-rc1 boot on Unleashed

[Troy Benjegerdes]

> On Jun 3, 2019, at 5:49 AM, Andreas Schwab <schwab at suse.de> wrote:
> 
> On Mai 29 2019, Karsten Merker <merker at debian.org> wrote:
> 
>> Mainline U-Boot already uses the distro bootcmd environment for
>> the qemu "virt" machine and it works well.
> 
> The distro_bootcmd doesn't work for the sifive platform yet because it
> doesn't set the correct MAC address for booting.
> 
> Andreas.
> 

Before we go an use distro_bootcmd and drag in a bunch of legacy stuff 
we really should not be using, can we make some kind of effort to decide
what the design goals and boot flow should look like instead using the 
default legacy behavior of a bunch of hard to read and maintain CPP
macros?

The first thing I notice is that the default dhcp target is ‘boot.scr.uimg’.

What good does it do linux distros on RiscV to keep using the old boot
script format, rather than just load a text file and use ‘env import’? Is there
some benefit to this? Do we gain something from the .scr format, like
maybe cryptographic signature support?

How do we want to support secure boot into Debian, Fedora, and Suse,
and does distro_bootcmd have a way to do this, or can we come up with
some improvement that doesn’t depend on trying to do all the work in
CPP macros and U-boot runtime scripts?