The NAND u-boot does not do the initialization that Jon describes, since the UBL does this and then loads U-boot from NAND to DDR. You can achieve a similar result by editing the davinci.h file under include/configs and making sure the option CONFIG_SKIP_LOWLEVEL_INIT is defined. This will disable the U-boot from doing the low-level DDR init and copying itself from Flash to DDR as it does for NOR boots. There are other options you might need to set/define, but this one is a must.
Regards, Daniel Daniel J. Allred Software Applications Catalog DSP / End Emerging Equipment -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] sp.com] On Behalf Of Hunter, Jon Sent: Tuesday, February 06, 2007 8:44 AM To: Amol Lad; [email protected] Subject: RE: Loading u-boot from u-boot > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] > ] On Behalf Of Amol Lad > Sent: Tuesday, February 06, 2007 7:53 AM > To: [email protected] > Subject: Loading u-boot from u-boot > > Hi, > > I'd like to test uboot without burning the image in the flash > ? Can this be achieved ? Something like tftpboot uboot image > from "tftpboot" u-boot command line and then "bootm" the image ? > > Any ideas ? The biggest problem with doing this is that uboot will execute entirely from DDR. What you have to remember is that one of the things that uboot does is it configures the clocks and DDR controller. Configuring clocks and the DDR controller is a bad thing to do when you are executing out of DDR. If you try this uboot will probably crash at this point. There is one option and that is add some code to the platform.S file (see board/davinci/ this is where the DDR controller and clocks are initialised) that checks the address where the PC is currently pointing and if the PC is pointing to a DDR location then skip the clock and DDR init code as this has already been initialised. DDR is located at address 0x8000000 and so the EMIF address space is lower, so you should be able to simply test the MSB of the PC, if this is set then you are in DDR and if not then you are in some other memory location. Cheers Jon _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
