From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nishanth Menon Subject: Re: Fwd: OMAP 2430 nand/nor booting Date: Mon, 04 Jun 2007 06:22:30 -0500 Message-ID: <4663F5F6.6030609@gmail.com> References: <78d6ed630706021205t3d8885afv5129f50f4da04548@mail.gmail.com> <78d6ed630706030702r1480faf5j3af7f1b5b64dd9ce@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <78d6ed630706030702r1480faf5j3af7f1b5b64dd9ce@mail.gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-omap-open-source-bounces+gplao-linux-omap-open-source=gmane.org@linux.omap.com Errors-To: linux-omap-open-source-bounces+gplao-linux-omap-open-source=gmane.org@linux.omap.com To: Amit Gupta Cc: linux-omap-open-source@linux.omap.com List-Id: linux-omap@vger.kernel.org Hi Amit, Amit Gupta stated on 6/3/2007 9:02 AM: > While as per my documents study, it's clear that after reset the code is > relocated from NOR to different location for execution . But why is > this not > happening automatically in my case. > Code relocation does not happen automatically. If ur boot code/sample code desires to relocate itself to SDRAM or any other location. it needs to be done by itself. > I also heard that NAND flash also has some > XIP region. The 2430 SDP has two nands: one is a 16 bit Samsung SLC NAND and other is a OneNAND device. The Onenand has limited XIP support, but the 16 bit nand is not XIP. > The logic is clear that NAND and (NOR image after reset) is not executing > until and unless you have copy code to relocate it to SRAM or SDRAM( if > SDRAM has already been initialized prior to relocation). > The code to relocate is part of your image. so it is upto your image to decide how it should work. > Kindly tell me that is my above understanding true or Boot ROM code does > copy some part of code because even if we have copy section within the > code, > it needs to be executed before the copy actually takes place. rom code behavior depends on the type of device: in the case of NOR: instruction execution is given straight to the NOR flash offset 0x0. in the case of NAND: a limited number of pages is copied to SRAM and execution commences in SRAM. note the fact of limited pages. the image in those initial pages should be self sustaining and should be capable of loading the rest of the image from nand and proceeding with execution.. this is the role of X-Loader - a stripped down version of uboot. Regards, Nishanth Menon