Rethinking MicroBlaze commandline precedence

[John Williams <john.williams@petalogix.com>]

Hi,

Currently, MicroBlaze commandline handling in order of lowest to
highest priority, looks like this:

1. pointer in r5 from bootloader
2. CONFIG_CMDLINE=...
3. "chosen" section in DTS/DT
4. CONFIG_CMDLINE=... && CONFIG_CMDLINE_FORCE

I'm wondering if a cmdline in r5 should override the DTS.  My thinking
is based on two observations:

(a) not everyone will use a bootloader like u-boot that can manipulate
DTBs easily before kernel boot
(b) a custom cmdline string in r5 allows the latest possible binding
(runtime), where as the DTB is typically created at compile time.

So, how about this order instead:

1. CONFIG_CMDLINE=...
2. "chosen" section in DTS/DT
3. pointer in r5 from bootloader
4. CONFIG_CMDLINE=... and CONFIG_CMDLINE_FORCE

Then, apart from CMDLINE_FORCE, the precedence goes from earliest
binding (kernel build) to latest (runtime via bootloader/r5).

Thoughts?

John
-- 
John Williams, PhD, B.Eng, B.IT
PetaLogix - Linux Solutions for a Reconfigurable World
w: www.petalogix.com  p: +61-7-30090663  f: +61-7-30090663