From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Date: Mon, 6 Feb 2012 16:55:22 -0600 Subject: [U-Boot] flash post test In-Reply-To: <4F3052FC.4050200@aribaud.net> References: <4F2C5287.5060800@aribaud.net> <4F3052FC.4050200@aribaud.net> Message-ID: <4F305A5A.80607@freescale.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 02/06/2012 04:23 PM, Albert ARIBAUD wrote: > Hi Vaibhav, > > Le 06/02/2012 05:57, vaibhav kothari a ?crit : >> hi albert >> >> Yes,actually there is already support of flash test in POST of latest >> uboot.They are testing flash on every power on so am I for my board.But i >> don't want to disturb sectors in which uboot code relies. Can you help me >> here? > > I am no NAND specialist, but I do hope NAND POST tests are pure read > tests and thus are not affected by poweroffs (and can actually test any > part of NAND). NAND has a property called "read disturb", where excessively reading a sector without writing to it can eventually cause data loss. U-Boot is already read once per boot, but reading it a second time could halve the expected lifetime. Data managed by something like ubi is be scrubbed in a way that avoids this, but U-Boot itself is not usually managed in this way (boot hardware/rom does not understand ubi). -Scott