From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Fri, 19 Feb 2016 16:06:40 +0100 Subject: [PATCH] ARM: Allow MULTIPLATFORM to select XIP In-Reply-To: References: <1455816310-11308-1-git-send-email-chris.brandt@renesas.com> <2413859.DaWDFlIaaB@wuerfel> Message-ID: <3699765.F7sfuMCyKT@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Friday 19 February 2016 14:46:36 Chris Brandt wrote: > On 19 Feb 2016, Arnd Bergmann wrote: > > > > 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