Default Simple busybox boot from SD card?

Hello
Is there any simple boot loader so I can just boot my device from it,and just inspect the partitions on its flash?
I dont want to flash or hack my devices without a previous inspection. I mean, something similar to Linux "rescue" mode.
I have a MTK6575 based Zhou Xing phone and it has no "Backup & Recovery" option, so i canīt root it because I canīt boot from it.
I can see all my device filesystems with adb from my Linux.But filesystems are all read only.
A simple buybox tool just to tell adb "boot from sd" would be great !!