Hiroshi and Carlos and Rudy, Yes Hiroshi, you are correct about the ECCs. The code in the UBL and the RBL relies on checking the DM644x ECCs. For the DVEVM, when a 512-byte page is written to the NAND flash, a 32-bit ECC value is generated in the CS2 ECC registered. That ECC value is then written to the first spare byte of that page (For those who don't know, each page has 16 bytes of so-called spare bytes that generally aren't used except for things like this).
During readback, like when the RBL copies the NAND data over to TCM RAM, or when the UBL copies data over to DDR RAM, 512 bytes of the page are read and another ECC value is generated. This ECC value is compared against the ECC value that was stored in that first spare byte during the page write. If they match, everything is fine. If not, then the process restarts (i.e. RBL returns to spitting out BOOTME, or UBL returns to spitting out BOOTPSP). I have not looked at the u-boot code, but Hiroshi's point may be true. So you probably can't use the U-boot command line to write the binaries to NAND. I will look into getting this point about the RBL and ECC checking documented in sprue14.pdf. Daniel J. Allred Software Applications Catalog DSP / End Emerging Equipment -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hiroshi Uchino Sent: Thursday, October 05, 2006 7:19 PM To: Carlos Ojea; [email protected] Subject: Re: Writing UBL and UBOOT in NAND Hi Carlos, Daniel will let us know the correct behavior of RBL, but I think you need to modify u-boot in order to write ubl using u-boot's nand command. RBL (and ubl_nand) requires CRC generated by DaVinci's hardware, but its algorithm is different from the one implemented in u-boot. So the ubl written by u-boot's nand command is considered erroneous by RBL's error check, and return to BOOTME situation. Regards, Hiroshi _______________________________________________ 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
