hello 下载了官网的 SDK6.0 开发包，编译了SDK6.0 中的uboot, 提示如下：
U-Boot SPL 2013.01.01-svn271 (Oct 18 2016 - 23:10:34)
enable_board_pin_muxmusb-hdrc: ConfigData=0xde (UTMI-8, dyn FIFOs, bulk combine, bulk split, HB-ISO Rx, HB-ISO Tx, SoftConn)
musb-hdrc: MHDRC RTL version 2.0
musb-hdrc: setup fifo_mode 4
musb-hdrc: 28/31 max ep, 16384/16384 memory
USB Peripheral mode controller at 47401000 using PIO, IRQ 0
musb-hdrc: ConfigData=0xde (UTMI-8, dyn FIFOs, bulk combine, bulk split, HB-ISO Rx, HB-ISO Tx, SoftConn)
musb-hdrc: MHDRC RTL version 2.0
musb-hdrc: setup fifo_mode 4
musb-hdrc: 28/31 max ep, 16384/16384 memory
USB Host mode controller at 47401800 using PIO, IRQ 0
boot from SD card...
OMAP SD/MMC: 0
mmc_send_cmd : timeout: No status update
Card did not respond to voltage select!
spl: mmc init failed: err - -17
### ERROR ### Please RESET the board ###
请大侠们帮忙看看！
