2nd-system to boot system from sdcard

You will need 3 partition on you sdcard. 1x fat32 and 2 ext4.
The first ext4 will used as /system and the second as /data
After this you need to mod the fstab_mapphone in ramdisk.

/dev/block/mmcblk0p2    /system ext4 ro,barrier=1 wait
/dev/block/mmcblk0p3    /data ext4 noatime,nosuid,nodev,barrier=1,data=ordered,noauto_da_alloc     wait,check

To install this rom you have to change updater-script in installer-zip:

mount("ext3", "EMMC", "/dev/block/mmcblk0p2", "/system");

After this copy all files from 2nd-system rom /system/bootmenu/2nd-boot  to /sdcard/2nd-system