[PATCH] ARM: Allow MULTIPLATFORM to select XIP

On Friday 19 February 2016 14:46:36 Chris Brandt wrote:

On 19 Feb 2016, Arnd Bergmann wrote:

quoted

quoted

A car with the best seat belts and airbags still won't help you
if you drive it off a cliff.

That was my point about DEBUG_LL: We already allow picking a DEBUG_LL
option that immediately breaks booting on any other platform, and
(worse) breaks even printing any useful output about that fact.

Ya, the DEBUG_LL issue seems like it could be an endless hole of options
all throughout the Kconfigs.

DT was supposed to allow everything to be configured at boot time, but
it looks like we still need an early-Device-Tree for settings before DT
is available. That would solve your DEBUG_LL and PHYS_OFFSET issue.

Not really: for DEBUG_LL, it doesn't work because DEBUG_LL is literally
meant to work from the first instruction in the kernel, so there can't
be any code to configure it. If you don't need to go that low-level,
you should use "earlycon", which can parse the DT just fine.

For PHYS_OFFSET, parsing the DT doesn't help at all because we only
need it for XIP_KERNEL (more or less at least) which cannot patch
the kernel image at boot time, so knowing that the address is wrong
also doesn't help you.

	Arnd