Hello Xinjian,
>>烧写问题
I.MX6UL可以从QSPI端口，NAND端口，SD卡端口启动，这就是说，你可以把U-BOOT烧写在QSPI，NAND， SD卡里都可以。启动时，配置拨码开关选择从哪个端口启动。也就是烧写到哪里，就从哪里启动。
>>NFS启动的问题
我提供一个使用静态IP，从NFS启动android文件系统的U-BOOT环境变量配置，你稍微修改一下，就能启动linux文件系统。在使用NFS之前，你要在你的linux PC主机上做好相应软件包的安装：比如tftp server（通过网络下载内核到板子）、nfs server。参考下面的过程：
1. Setup tftp server
The purpose to configure tftp server is to download the linux kernel from ubuntu host through ethernet to target board.The following
is steps to configure tftp sever:
(1) Setup tftp server files
#sudo apt-get install tftpd tftp openbsd-inetd
(2) make a tftp directory
Here we make /opt/tftpboot be a tftp directory.
# mkdir /opt/tftpboot
# chmod 777 /opt/tftpboot
(3) Open /etc/inetd.conf and edit it
# sudo gedit /etc/inetd.conf
Coment this line :
#tftp dgram udp wait nobody /usr/sbin/tcpd /usr/sbin/in.tftpd /srv/tftp
Add new line:
tftp dgram udp wait nobody /usr/sbin/tcpd /usr/sbin/in.tftpd /opt/tftpboot
(4)Restarting tftp service
#sudo /etc/init.d/openbsd-inetd restart
(5)Restart system
(6)Test tftp service
# cd /opt/tftpboot
# touch test.txt
# cd ~/
# tftp 192.168.1.130
Tftp> get test.txt
If promt:
¡°Received xx bytes in xx seconds ¡°
Then tftp service is working.
2. Setup NFS server
(1) Install NFS server package
#sudo apt-get install nfs-kernel-server
(2) Create NFS directory:/opt/nfsroot
# mkdir /opt/nfsroot
(3) Configure mounted directory and authority
# sudo gedit /etc/exports
Add the following line at the end of the file:
/opt/nfsroot *(rw,sync,no_root_squash)
(4) Restart the NFS service
#sudo /etc/init.d/portmap restart
#sudo /etc/init.d/nfs-kernel-server restart
(5)Test NFS server
# sudo mkdir /mnt/nfs-here
# cd /opt/nfsroot
# touch nfstest
# sudo mount -t nfs 192.168.1.6:/opt/nfsroot /mnt/nfs-here/
# cd /mnt/nfs-here
# ls
Then you will find nfstest file is here , It indicates that your
NFS server is correctly working.
Note : If you want to cancel the above mounting , you can use this
command:
# cd /mnt (or cd ../)
# sudo umount /mnt/nfs-here
NOTE:
To restart network , the following Command can be used :
Restart Network : sudo /etc/init.d/networking restart
3、配置NFS举例：
setenv ipaddr 192.168.1.103
setenv serverip 192.168.1.102
setenv gateway 192.168.1.1
setenv ethaddr 00:04:9f:00:ea:d3
setenv bootargs_base 'setenv bootargs console=ttymxc0,115200'
setenv bootargs_android 'setenv bootargs ${bootargs} init=/init androidboot.console=ttymxc0 androidboot.hardware=freescale'
setenv bootargs_nfs 'setenv bootargs ${bootargs} ip=${ipaddr}:${serverip}:${gateway}:${netmask}::eth0 off root=/dev/nfs nfsroot=${serverip}:${nfsroot}'
setenv bootargs_disp 'setenv bootargs ${bootargs} video=mxcfb0:dev=ldb,bpp=32 video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24,bpp=32 video=mxcfb2:off fbmem=10M
vmalloc=400M'
setenv bootcmd_net 'run bootargs_base bootargs_android bootargs_nfs bootargs_disp;tftpboot ${loadaddr} uImage;bootm'
>>core-image-minimal网络
启动系统后，你可以利用ifconfig或者netcfg看看网络设备情况，如果都没有，说明core-image-minimal中没有包含进去网络驱动。你可以尝试重新加入网络部分，编译好，再试试。
伟东
