急！6657 direct nandflash无法启动

nand flash型号也是和EVM板一样的么？请看一下您的nand flash是否是RBL支持的。请看bootloader文档3.11.1 RBL Initialization Process
www.ti.com/.../sprugy5c.pdf

The RBL will first check for ONFI compliance. Most ONFI-compliant devices should be supported. A read ID command will be issued to address 0x20 and four bytes will be read. If the four bytes match the word 0x49464E4F (ASCII for ONFI), the RBL will attempt to read the ONFI parameter page for the device geometry. After which, the RBL will request four bytes of identifier code from the NAND by issuing a read ID command to address 0x00. The first and second bytes are the manufacture ID and device ID, respectively, and the fourth byte has information on the NAND parameters. If the device was found not to be ONFI-compliant, the RBL will try the following to determine geometry:
• Compare device ID with IDs and their parameters stored in ROM. It is impossible to have all devices listed in the table, and some devices may share IDs. If the ID is matched, the configuration is used and the next step is skipped.
• Read fourth byte data. This happens when the RBL finds no match with the device ID. The RBL will assume an 8-bit data bus width and check the device Manufacture ID to indicate Samsung format or Common format when reading the fourth byte parameters for NAND geometry. If non-Samsung, the RBL will be able to change the width to 16-bit, if necessary. Unfortunately, Samsung devices will remain in 8-bit mode.