板子是micro2440，uboot 能Ping通虚拟机，但tftp不能下载内核，提示TFTP error: 'Permission denied' (0)。
终端输出信息如下：
Abort
Mini2440 # printenv
bootdelay=3
baudrate=115200
netmask=255.255.255.0
stdin=serial
stdout=serial
stderr=serial
serverip=192.168.1.108
ipaddr=192.168.1.230
ethaddr=00:01:02:03:04:05
Environment size: 161/65532 bytes
Mini2440 # ping 192.168.1.108
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 00:01:02:03:04:05
host 192.168.1.108 is alive
Mini2440 # tftp 31000000 uImage-uboot
dm9000 i/o: 0x20000300, id: 0x90000a46
DM9000: running in 16 bit mode
MAC: 00:01:02:03:04:05
TFTP from server 192.168.1.108; our IP address is 192.168.1.230
Filename 'uImage-uboot'.
Load address: 0x31000000
Loading: T
TFTP error: 'Permission denied' (0)
Starting again
TFTP from server 192.168.1.108; our IP address is 192.168.1.230
Filename 'uImage-uboot'.
Load address: 0x31000000
Loading: *
TFTP error: 'Permission denied' (0)
Starting again
论坛里出现一样的问题，说：
chmod 777 uImage-uboot 或 chmod 777 tftpboot
能解决问题，我都试了，还是不行。
等待好心人解答，谢谢！
