Synacor challenge 👾

A solution to the synacor challenge implemented in C.

Introduction

This project is a possible answer to the synacor challenge: https://challenge.synacor.com.

The goal of this challenge is to code a virtual machine able to read and execute the challenge.bin file.

The arch-spec file specifies all the characteristics the machine should have.

Structure of the project

All the sources are in the vm folder.

• main.c defines the memory array, the registers, initializes the stack and contains the main event loop
• stack.c defines the structure used for the stack and its associated functions (push and pop)
• utils.c defines
  • the read function which read the memory, executes the proper operation following the opcode listing and returns the next operation adress
  • the load function which fill the memory array with the challenge.bin content
  • some debugging functions which show the state of the stack, the memory and the registers
• save.c defines the save and load functions
• decipher.c defines the function which translates the memory into a readable program

Debugger

In order to solve the teleporter enigma, I implemented some commands which can be used inside the game itself.

Each command must begin with the $ character.

• reg show the values in every registers
• setreg a b set the value of the register a to b
• mem show the different values of the memory
• memv a show the a-th value of the memory
• stack show the values stored in the stack
• source write into the file sources.txt the content of the memory in a more readable way than just with opcodes
• save save the current game (create a save.txt file)
• load load the game state saved in the save.txt file
• debug toggle the debug mode. When it is on, every memory operation is stored in the debugging.txtfile under the same format as in sources.txt