I am going to start using MPC5777c evb and ordered lauterbach debugging tools but it will take more than a month, please suggest me any open source flashing tools for MPC5777c
I'm not aware of an open source flashing tools for MPC5777C.
S32 Design Studio currently supports (S32 Design Studio for Power Architecture 2017.R1 (Windows/Linux) released! ):
Anyway you can possibly use RappID bootloader and program the device e.g via UART cable.
But you need to find a way to program the bootloader into the device.
Hope it helps.