U-Boot 2013.01.01 (May 20 2018 - 18:09:05)
I2C: ready
DRAM: 256 MiB
WARNING: Caches not enabled
NAND: NAND ID is 00-00
No NAND device found!!!
0 MiB
MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1
*** Warning - readenv() failed, using default environment
Net: phy_id = 508145
cpsw, usb_ether
Hit any key to stop autoboot: 0
lcd reset
Booting from nand ...
通过示波器查看，信号线有变化，gpmc_ad0-gpmc_ad7没有变化，sysboot设置没有问题，sysboot[0:4]=0x17,也做了管脚服用设置
