From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Babic Date: Wed, 12 Feb 2014 11:41:16 +0100 Subject: [U-Boot] Chain loading an u-boot from an u-boot In-Reply-To: <52FB454E.5090800@hale.at> References: <52F8B3F5.8050101@hale.at> <52F9EF7A.5080805@denx.de> <52FB454E.5090800@hale.at> Message-ID: <52FB4FCC.8000305@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Helmut, On 12/02/2014 10:56, Helmut Raiger wrote: > This is mainly due to performance requirements. Using 4bit BCH > increases overhead and makes DMA (currently not used in the > kernel driver) a lot slower. We thought we might slip through with > 1bit HW-ECC, but we will test this (hopefully not in the field this time > ;-) ) I know the MX31's NAND controller can only handle 1bit HW ECC ;-( Let's know us your results - in my experience, when the NAND controller (I am not speaking about MX31, anyway) provides less ECC bits as requested by NAND, I always got problems. Sometimes UBIFS recovered it, but I got the point when rootfs was not mounted. > I double-checked now, the running u-boot is not overwritten. > When the 2nd u-boot relocates it overwrites the first one, but > that shouldn't be a problem. The first u-boot keeps working after > loading (but not running) the second one without issues. > > Only the 'go' crashes the system. u-boot starts stand-alone > application fine, just as the kernel. I really can't see the point > why another u-boot should be any different?! > ok - then it could be that something is set twice (from first and second U-Boot), and it crashes the second time is set. Of course, the DDR controller must not be set by second U-Boot, but I suppose you have already commented out. Maybe setting the main clock again (I see it in board_setup_clocks() ) can cause some problems. Is it called again in your modified U-Boot ? I am expecting that board_setup_sdram() and board_setup_clocks() are called only by your SPL. Best regards, Stefano Babic -- ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de =====================================================================