Hi, I suggest you get some linux training... I can recommend the training done by Free Electrons (http://www.freeelectrons.org), the material is available as a download (for Free) but it is better if you get them in - you will learn a lot (I did & I have been using Linux since kernel 1.0.13 on RH 3.0.3). They will customize courses to meet your needs too.
Regards Phil Q Phil Quiney, Principal Software Engineer Trinity Convergence Cambridge Business Park Cowley Road Cambridge CB4 0WZ, UK T: +44(0)1223-435536 F: +44(0)1223-435560 www.trinityconvergence.com -----Original Message----- From: Vijay Soni [mailto:[EMAIL PROTECTED] Sent: 14 October 2008 20:18 To: Jon Povey; [email protected]; Phil Quiney Subject: RE: DM355 bootloader I am new to DM355 based product development. My current requirements is: It should be possible to change both kernel and application in the field by customer(user). I learnt from Phil/Jon that U-Boot does not need to change for this. Phil says that a startup updater service can be created to do this job. A PC connected to the DM355 on ethernet will send send a command to DM355 from a GUI based application and the DM355 will reboot on getting this command so that the updater service (as suggested by Phil) will get a chance to run at startup and will update the kernel and/or application. Something like this or may be different is needed to meet the goal. Also in event that kernel does not come up because of any curruption, I should be able to reprogram it and application to recover from this state. Can someone kindly suggest me where I can learn how to do this. I am new to DM355 and linux. My past experience has been on Atmel microcontroller based app development using C but without using any standard real time OS. --- On Tue, 10/14/08, Phil Quiney <[EMAIL PROTECTED]> wrote: > From: Phil Quiney <[EMAIL PROTECTED]> > Subject: RE: DM355 bootloader > To: "Jon Povey" <[EMAIL PROTECTED]>, [EMAIL PROTECTED], > [email protected] > Date: Tuesday, October 14, 2008, 7:00 PM Hi Jon, > > Looks like we are treading similar ground ;-) > > I have been considering a 'restore to factory default' feature (post > upgrade catastrophy fix). > > I have been looking at using 'unionfs' to provide a single filesystem > that is actually comprised of 2 partitions, one writeable and one read > only. All writes to the file system pysically get written to the > writable partition and attempts to delete files in the read only > partition cause 'mask files' to appear in the writable partition that > make the file disappear when viewed from the union. > > We can at any time go back to 'factory' conditions by simply erasing > the writeable partition. This is the technique the Asus EeePC uses. > > Unfortunately on the 2.6.10 kernel, unionfs ran fine for a day or so > but then silently locked up the board. I was going to try 'aufs' (as > used by Slax) but have not had the time to progress it. Also my first > effort 'unioned' > the whole filesytem - it might be better to only do part of the > filesytem. > > Regards > > Phil Q > > > Phil Quiney, Principal Software Engineer Trinity Convergence Cambridge > Business Park Cowley Road Cambridge CB4 0WZ, UK > T: +44(0)1223-435536 > F: +44(0)1223-435560 > www.trinityconvergence.com > > > -----Original Message----- > From: > [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] > On Behalf Of Jon Povey > Sent: 14 October 2008 14:15 > To: [EMAIL PROTECTED]; > [email protected] > Subject: RE: DM355 bootloader > > Phil wrote: > > > AFAIK 'UBL' is the U-Boot Loader - that is a > very small program that > > copies the U-Boot image from NAND into RAM and runs > it. This may well > > be an assembly language program (I have never had any > reason to study > > it) so good luck if you want to change it. > > The UBL is a TI app, I think it stands for "User Boot Loader" (At > least on DM355). > I have seen source for it, somewhere.. > UBL is needed because u-boot can't load itself from NAND flash, and > you can't do XIP. > > Confusing side-note: > > I'm a bit less sure why the RBL can't load u-boot directly.. I think I > worked it out at some point, it's because the RBL can only load > something that fits into one block, or something like that. The TI UBL > is just a little bit of glue between RBL and u-boot, as I understand > it. > > > U-Boot is the boot loader. It allows rudimentary > access to the FLASH > > and RAM on the board and typically a way of loading an > operating > > system kernel. Integrating an app updater into this > may be a challenge > > especially as it knows nothing about JFFS/YAFFS > filesystems. You may > > be able to FLASH the entire filesystem but that gets > interesting if > > the filesystem image won't fit in RAM and you have > to know about any > > bad blocks in the NAND as well. > > I am looking into how to do all this stuff on DM355 at the moment. My > current plan is to have two copies of the kernel, two entirely > separate filesystem partitions, and update one while the other is > running, then switch (probably by changing u-boot environment > variables). > > -- > Jon Povey, Design Engineer > [EMAIL PROTECTED] | +44(0)1280 825983 > > > Racelogic is a limited company registered in England. > Registered number 2743719 . > Registered Office Unit 10, Swan Business Centre, Osier Way, > Buckingham, Bucks, MK18 1TB . > The information contained in this electronic mail transmission is > intended by Racelogic Ltd for the use of the named individual or > entity to which it is directed and may contain information that is > confidential or privileged. 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