[Gta04-owner] rationale behind having uImage on the first partition?

[Johannes Schauer]

Hi Nikolaus,

> > 3. Distributions might want to ship their own kernel and it is
> > easier to just extract the tarball they to the second partition and
> > being done in contrast to additionally having to put their kernel on
> > the first partition. Instead of having two downloads and copy
> > operations (kernel and rootfs) it would only be one and by that
> > simplifying the process.
> Only if there weren't subtle dependencies between U-Boot and the
> kernel. If U-Boot or the kernel command line has to be touched, you
> are back the two separate downloads.

uboot probably hasnt to be touched for a distribution - just kernel and
commandline might, right? Or am I missing a scenario where someone would
want to do "something" with uboot?

For touching the commandline there could be a mechanism that makes uboot
load the commandline from a file as it loades boot.scr.

This is what qi on the gta01/02 did by loading the append-GTA01/02
files.

If the default qemu would look for such a file, qemu would not have to
be touched by a distribution but just kernel and append file (just as
with qi).

You can already tell that I liked how qi did it. ;)

One reason why the distribution might want to touch the kernel
commandline is for example to set a fixed usb0 mac address instead of a
random one by setting g_ether.host_addr=XX:XX:XX:XX:XX:XX

To summarize: maybe I'm misinterpreting what you actually want to offer
but I thought you might want to give people a reasonable default that
distributions can build upon and I think that giving them such
mechanisms (possibility to ship kernel in the same tarball,
loading/modifying cmdline with a file) will simplify things as they will
be the same across possible distributions and people would not have to
cook up their own uboot/kernel/cmdline setup.

But maybe I'm wrong about what your actual target is.

So everything I'm saying is, that it would be nice to have those
options: uImage on the second partition and possibly something like the
append file as in qi. If you dont want to have this as the default this
is of course no problem because as you said it is always possible for
distribution maintainers to cook up their own boot system. I just dont
think that besides kernel and cmdline someone would need to change
something so that it would be perfectly fine to ship a unified
u-boot/makesd setup.

cheers, josch