I flashed this rom:
csmg.lgmobile.com:9002/swdata/WEBSW/LGKH5200/AKTFBQ/V10r_00/V10R_00.kdz

I changed some files of my system,installed busybox,now I can't boot.I tried to enter fastboot,but failed,maybe LG closed the fastboot keys.But I still can enter emergency mode,how can I reflash my phone with system.img again?

Thank you guys!

The commands I tried were:
su
busybox df -h

busybox cp -a /data/app /system/sd/
busybox cp -a /data/dalvik-cache /system/sd/ (optional)
busybox cp -a /data/data /system/sd/ (optional)

mount data
rm -rf /data/app
ln -s /system/sd/app /data/app
rm -rf /data/data (optional)
ln -s /system/sd/data /data/data (optional)
rm -rf /data/dalvik-cache (optional)
ln -s /system/sd/dalvik-cache /data/dalvik-cache (optional)
reboot

now I can still use ddms and adb,any way to recover?
I just want to enter fastboot and reflash system.