From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Jackson Date: Mon, 18 Feb 2013 14:43:47 +0000 Subject: [U-Boot] AM335x : failure to boot SPL from NAND In-Reply-To: <20130215211332.GA19902@bill-the-cat> References: <511D08AF.7070501@mimc.co.uk> <20130215211332.GA19902@bill-the-cat> Message-ID: <51223E23.6030209@mimc.co.uk> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 15/02/13 21:13, Tom Rini wrote: > On Thu, Feb 14, 2013 at 03:54:23PM +0000, Mark Jackson wrote: > >> I'm trying to diagnose why our AM335x based CPU board (based on the >> AM335x Starter Kit) can boot SPL and U-Boot from an MMC card, but is >> unable to boot from NAND (connected to CS0). >> >> Following the TI wiki >> (http://processors.wiki.ti.com/index.php/AM335x_U-Boot_User%27s_Guide#Flashing_images_to_NAND_in_SD_boot) >> I:- >> >> (1) boot from MMC >> (2) erase the nand >> (3) copy MLO from MMC into NAND >> (4) verified it copied correctly (using crc32) >> >> When I reboot the board in NAND mode, I get nothing on UART0. >> >> If I reboot in MMC mode, SPL and U-Boot load correctly. >> >> Can anyone give me some pointers on the boot sequence, and where I >> might look to help debug the problem ? > > Assuming you're using mainline U-Boot and can rule out "vendor > problems", if you can access the SYSBOOT pins, set it up for a mode that > does NAND and UART. If you never see the 'CCC' on console (or only see > it the first time if you do UART then NAND), then you are starting SPL > and dying in there. If you just see a stream of C then your file is not > written to NAND correctly. Interesting ... I don't get any 'CCC' on the console. However, I then tested this by booting via MMC, erasing the NAND chip and then trying to reboot via NAND again. I still get no 'CCC' on the console !?! This is using boot mode 10011 (NAND, NANDI2C, MMC0, UART0), so I would expect to either boot via MMC (if I left it in) or get some 'CCC' output on the console. I can see that the NAND signals always have a burst of activity every 10ms. That must be a timeout of some sort ... do you know if that's a hardware or software timeout ? Mark J.