From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Behme Date: Sat, 16 Mar 2013 17:55:29 +0100 Subject: [U-Boot] [PATCH 1/2] nitrogen6x: Pass the correct CPU revision to the kernel In-Reply-To: <51449A34.7080902@boundarydevices.com> References: <1363381594-17077-1-git-send-email-festevam@gmail.com> <5143BAE6.3030902@boundarydevices.com> <51449A34.7080902@boundarydevices.com> Message-ID: <5144A401.9020209@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Am 16.03.2013 17:13, schrieb Eric Nelson: > On 03/16/2013 07:58 AM, Fabio Estevam wrote: >> Hi Eric, >> >> On Fri, Mar 15, 2013 at 9:20 PM, Eric Nelson >> wrote: >> >>> This is the **board** revision, right? >>> >>> At first glance, the kernel seems to be getting the silicon revision >>> from the same place as get_cpu_rev(): >>> >>> https://github.com/boundarydevices/linux-imx6/blob/boundary-imx_3.0.35_1.1.1/arch/arm/mach-mx6/cpu.c#L51 >>> >>> >>> http://git.denx.de/u-boot.git/?p=u-boot.git;a=blob;f=arch/arm/cpu/armv7/mx6/soc.c;h=a8aad5dd0a6c8548277021ebe8f6e159dbf31b9b;hb=HEAD#l42 >>> >>> >>> Is there a reference to the ATAG that I'm not seeing somewhere? >> >> Ok, so 3.0.35 treats cpu_rev correctly and do not assume this info to >> be passed from the bootloader. I was confused with 2.6.35, where I had >> issues with this on mx53. >> >> So, it seems that nitrogen does not need to pass get_board_rev() at >> all then? >> > At the moment, it doesn't. > > I would really like to see us (the i.MX6 community) standardize > the use of some fuses to specifically mean board revision. > > We're contemplating some board changes such as switching the > ethernet PHY and having a convention for the use of a few > bits in OTP would allow us to implement get_board_rev() once in > a common place. > > Over the lifetime of most boards, it's likely that at least > one board revision will have software implications and having > a common way to express/detect this could prevent some churn > in board-specific files. > > Such a convention would need to have broad sign off though. > > Let me know your thoughts on the subject. I think the OMAP/Beagle community introduced serial EEPROMs to identify their (add on) boards. Best regards Dirk