EVM板 u-boot 下 使用tftp 往nand中下载uImage的问题

Devkit8600# pri
autoload=yes
baudrate=115200
bootargs_defaults=setenv bootargs console=${console} ${optargs}
bootcmd=if mmc rescan; then echo SD/MMC found on device ${mmc_dev};if run loadbootenv; then echo Loaded environment from ${bootenv};run importbootenv;fi;if test -n ${uenvcmd}; then echo Running uenvcmd ...;run uenvcmd;fi;if run mmc_load_image; then run mmc_args;bootm ${kloadaddr};fi;fi;run nand_boot
bootdelay=3
bootenv=uEnv.txt
bootfile=uImage
console=ttyO0,115200n8
ethact=cpsw
ethaddr=00:18:31:e2:4e:6f
gatewayip=192.168.1.1
importbootenv=echo Importing environment from mmc ...; env import -t ${loadaddr} ${filesize}
ip_method=none
ipaddr=192.168.1.15
kloadaddr=0x80007fc0
loadaddr=0x82000000
loadbootenv=fatload mmc ${mmc_dev} ${loadaddr} ${bootenv}
mmc_args=run bootargs_defaults;setenv bootargs ${bootargs} root=${mmc_root} initrd=${rdloadaddr},32MB rootfstype=${mmc_root_fs_type} ip=${ip_method}
mmc_boot=run mmc_args; run mmc_load_image; bootm ${kloadaddr}
mmc_dev=0
mmc_load_image=fatload mmc ${mmc_dev} ${kloadaddr} ${bootfile};fatload mmc ${mmc_dev} ${rdloadaddr} ${ramdisk}
mmc_root=/dev/ram rw
mmc_root_fs_type=ext2
nand_args=run bootargs_defaults;setenv bootargs ${bootargs} root=${nand_root} noinitrd rootfstype=${nand_root_fs_type} ip=${ip_method}
nand_boot=echo Booting from nand ...; run nand_args; nandecc hw 2; nand read.i ${kloadaddr} ${nand_src_addr} ${nand_img_siz}; bootm ${kloadaddr}
nand_img_siz=0x400000
nand_root=ubi0:rootfs rw ubi.mtd=7,2048
nand_root_fs_type=ubifs rootwait=1
nand_src_addr=0x280000
net_args=run bootargs_defaults;setenv bootargs ${bootargs} root=/dev/nfs nfsroot=${serverip}:${rootpath},${nfsopts} rw ip=dhcp
net_boot=echo Booting from network ...; setenv autoload no; dhcp; tftp ${kloadaddr} ${bootfile}; run net_args; bootm ${kloadaddr}
netmask=255.255.0.0
nfsopts=nolock
nor_args=run bootargs_defaults;setenv bootargs ${bootargs} root={nor_root} rootfstype=${nor_root_fs_type} ip=${ip_method}
nor_boot=echo Booting from NOR ...; run nor_args; cp.b ${0x08080000} ${kloadaddr} ${nor_img_siz}; bootm ${kloadaddr}
nor_img_siz=0x280000
nor_root=/dev/mtdblock3 rw
nor_root_fs_type=jffs2
nor_src_addr=0x08080000
ramdisk=ramdisk.gz
rdloadaddr=0x81600000
rootpath=/export/rootfs
script_addr=0x81900000
serverip=192.168.1.91
spi_args=run bootargs_defaults;setenv bootargs ${bootargs} root=${spi_root} rootfstype=${spi_root_fs_type} ip=${ip_method}
spi_boot=echo Booting from spi ...; run spi_args; sf probe ${spi_bus_no}:0; sf read ${kloadaddr} ${spi_src_addr} ${spi_img_siz}; bootm ${kloadaddr}
spi_bus_no=0
spi_img_siz=0x280000
spi_root=/dev/mtdblock4 rw
spi_root_fs_type=jffs2
spi_src_addr=0x62000
static_ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off
stderr=serial
stdin=serial
stdout=serial
updatesys=nand erase.chip;mmc rescan; fatload mmc 0 82000000 MLO;nandecc hw 2;nand write.i 82000000 0 ${filesize}; fatload mmc 0 82000000 u-boot.img;nandecc hw 2;nand write.i 82000000 80000 ${filesize}; fatload mmc 0 82000000 uImage;nandecc hw 2;nand write.i 82000000 280000 ${filesize}; fatload mmc 0 82000000 ubi.img;nandecc sw;nand write.i 82000000 780000 ${filesize};led flash all

Environment size: 3249/8188 bytes
Devkit8600# ping 192.168.1.91
Auto negotitation failed
miiphy read id fail
Using cpsw device
ping failed; host 192.168.1.91 is not alive
Devkit8600#