比较艰难的成功了。
艰难在于：吱吱吱吱（知知知知知）：就是歌init启动参数而已！
最最艰难在于：这个nfs服务器软件有很大的关系。很多时候不是你不行，而是条件不具备 or 条件看似具备但其实有问题
default menu.c32
label ubuntu-18.04.2
menu label ubuntu (version 18.04.02)
kernel ub1804/casper/vmlinuz
append root=/dev/nfs netboot=nfs nfsroot=192.168.56.1:/e/pxe/ub1804 boot=casper initrd=ub1804/casper/initrd text systemd.mask=tmp.mount
### systemd.mask=tmp.mount
label ubuntu-18.04.2-mate
menu label ubuntu (version 18.04.02-mate)
kernel ub1804m/casper/vmlinuz
append root=/dev/nfs netboot=nfs nfsroot=192.168.56.1:/e/pxe/ub1804m boot=casper initrd=ub1804m/casper/initrd text systemd.mask=tmp.mount
label ubuntu-18.10
menu label ubuntu (version 18.10)
kernel ub1810/casper/vmlinuz
append root=/dev/nfs netboot=nfs nfsroot=192.168.56.1:/e/pxe/ub1810 boot=casper initrd=ub1810/casper/initrd text systemd.mask=tmp.mount
label ubuntu-18.04.2-server
menu label ubuntu (version 18.04.02-server toram)
kernel ub1804s/casper/vmlinuz
append root=/dev/nfs netboot=nfs nfsroot=192.168.56.1:/e/pxe/ub1804s boot=casper initrd=ub1804s/casper/initrd text toram
### systemd.mask=tmp.mount
label ubuntu1-8s
menu label ubuntu (version 18.04.02-server systemd.mask)
kernel ub1804s/casper/vmlinuz
append root=/dev/nfs netboot=nfs nfsroot=192.168.56.1:/e/pxe/ub1804s boot=casper initrd=ub1804s/casper/initrd text systemd.mask=tmp.mount
### systemd.mask=tmp.mount
label ubuntukylin-18.10-enhanced-amd64
menu label ubuntukylin-18.10-enhanced-amd64 1111
kernel uk1810/casper/vmlinuz
append root=/dev/nfs netboot=nfs nfsroot=192.168.56.1:/uk1810 boot=casper initrd=uk1810/casper/initrd text systemd.mask=tmp.mount
### toram toram toram toram toram , need big ram to copy squash root FS!!!
label ubuntukylin-18.10-enhanced-amd64
menu label ubuntukylin-18.10-enhanced-amd64 (need big ram to copy 4G!)
kernel uk1810/casper/vmlinuz
append root=/dev/nfs netboot=nfs nfsroot=192.168.56.1:/uk1810 boot=casper initrd=uk1810/casper/initrd text toram
label deepin-15.9.2
menu label deepin-15.9.2
kernel deepin1592/live/vmlinuz
append root=/dev/nfs netboot=nfs nfsroot=192.168.56.1:/deepin1592 boot=live initrd=deepin1592/live/initrd.lz text
label deepin-15.9
menu label deepin-15.9
kernel deepin159/live/vmlinuz
append root=/dev/nfs netboot=nfs nfsroot=192.168.56.1:/deepin159 boot=live initrd=deepin159/live/initrd.lz text