下载板子自带的lodar.bin和u-boot.bin，正常启动了u-boot，然后执行以下步骤：
Uboot>protect off all
Uboot>erase all
Uboot>md 10000000
之后显示如下内容：
10000000: 7fff7fff 7fff7fff 7fff7fff 7fff7fff ................
10000010: 7fff7fff 7fff7fff 7fff7fff 7fff7fff ................
10000020: 7fff7fff 7fff7fff 7fff7fff 7fff7fff ................
10000030: 7fff7fff 7fff7fff 7fff7fff 7fff7fff ................
10000040: 7fff7fff 7fff7fff 7fff7fff 7fff7fff ................
10000050: 7fff7fff 7fff7fff 7fff7fff 7fff7fff ................
10000060: 7fff7fff 7fff7fff 7fff7fff 7fff7fff
向flash中cp.b数据时，会提示flash not erased，看出这片flash并没有成功erase，请问大侠怎么解决？
而Uboot>md 80000000，显示的都是ffffffff，成功erase了。
我是新手，请大侠帮帮忙了！
