From mboxrd@z Thu Jan 1 00:00:00 1970 From: stuartl@vrt.com.au (Stuart Longland) Date: Tue, 14 Oct 2014 09:36:44 +1000 Subject: Where is DRAM initialisation done? In-Reply-To: References: Message-ID: <543C620C.3050302@vrt.com.au> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Fabio, On 14/10/14 09:11, Fabio Estevam wrote: > On Mon, Oct 13, 2014 at 8:02 PM, Fabio Estevam wrote: >> On Mon, Oct 13, 2014 at 7:45 PM, Stuart Longland wrote: >> >>> Does anyone happen to know where in the mainline kernel this is done, if >>> at all? >> >> The DDR is initialized only by the bootloader. >> >> You can check arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c in U-boot. > > Also, maybe it can help if you have access to the old source code > where the DDR is initialized. > > The 'old' way of doing the DDR init is via a separate package called 'bootlets'. > > So if you have access to the bootlets code, it would be easy to port > the DDR init into U-boot. Yes, I do have their bootlets code which was how they implemented the old bootloader. It's stuffed inside the kernel source tree they provide (3rd link in my last email). Copying and pasting bits out of that (and reading the datasheets) got me where I am now, it's then I went digging and found some similar code in their kernel itself, and so I wondered about the mainline kernel doing the same. At least now I know to focus my efforts on U-Boot itself: the kernel should work if I get U-Boot working correctly. Anyway, this has hopefully pointed me in the right direction, and I'll keep bashing away at U-Boot to hopefully get a result there. I think I see a light at the end of the tunnel and hopefully not light from an oncoming train. :-) Many thanks. Regards, -- Stuart Longland Systems Engineer _ ___ \ /|_) | T: +61 7 3535 9619 \/ | \ | 38b Douglas Street F: +61 7 3535 9699 SYSTEMS Milton QLD 4064 http://www.vrt.com.au