From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeroen Hofstee Date: Mon, 21 Jul 2014 22:39:30 +0200 Subject: [U-Boot] [PATCH 2/2] sunxi: Set the AUXCR L2EN bit for sun4i/sun5i in FEL boot mode In-Reply-To: <1405973237.4100.34.camel@hastur.hellion.org.uk> References: <1405703385-14580-1-git-send-email-siarhei.siamashka@gmail.com> <1405703385-14580-3-git-send-email-siarhei.siamashka@gmail.com> <53C96BD4.1020307@myspectrum.nl> <1405973237.4100.34.camel@hastur.hellion.org.uk> Message-ID: <53CD7A82.7010705@myspectrum.nl> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hello Ian, On 21-07-14 22:07, Ian Campbell wrote: > On Fri, 2014-07-18 at 20:47 +0200, Jeroen Hofstee wrote: >> Hello Siarhei, >> >> On 18-07-14 19:09, Siarhei Siamashka wrote: >>> This is needed to have feature parity with the normal boot mode, >>> where the L2EN bit in the CP15 Auxiliary Control Register is set >>> by the BROM code right from the start. >>> >>> If this is not done, the Linux system ends up booted with the L2 cache >>> disabled. >>> >> I don't know a single about the sunxi, but shouldn't linux >> be patched instead. The commit message seems to indicate >> it is not an u-boot issue. > The ACTLR may not be writeable from NS mode so it has to be setup in the > bootloader before dropping to NS mode. mmm, I guess there is something wrong with the boot sequence if the kernel itself can't access raw hw. > In any case I think these sorts of low level platform specific details > are the sort of thing which the bootloader probably ought to be setting > up. No, u-boot tries not to touch anything it doesn't use and, if anything disables it after use. Hence, this seems like a kernel bug and nothing to do with u-boot. They should be independent, iow a kernel should not rely on u-boot setting thing up, that is a bug. Regards, Jeroen