README

Stack machine simulation.

Requires clang 3.1.

• Usage: ** ./runner [-v] [-f asm_file] *** -v: verbose, step through code *** -f: asm file to assemble and run

• Instructions:

  ** PUSH Pushes the value in the next code instruction.

  ** POP Discards the top stack value.

  ** NOP Do nothing.

  ** HLT Halt the machine.

  ** OUT Pops a value and prints the value to stdout as a char.

  ** STORE Pops a value, pops an address, then places the value in mem at the addres.

  ** LOAD Pops an address, loads that value from memory, then pushes that value.

  ** ADD Pops two values and pushes the sum.

  ** SUB Pops two values and pushes the difference.

  ** MUL Pops two values and pushes the product.

  ** DIV Pops two values and pushes the quotient and remainder.

  ** JMP Sets the CPU instruction pointer to the value popped.

  ** JZ Pops an address and pops a value. If the value is zero, moves cpu->ip to the address.

  ** JNZ Pops an address and pops a value. If the value is not zero, moves cpu->ip to the address.

  ** CALL Pops an address and pushes to the return pointer stack. Moves instruction pointer to that address.

  ** RET Pops an address from the return pointer stack and moves the instruct pointer there.

  ** DUP Duplicates the value on the top of the stack.

  ** SWAP Swaps the values of the top two values on the stack.

  ** INT Registers an interrupt handler. The handler address and the resource address are popped from the stack.

  ** DEBUG Put the cpu into debug mode.

• Hardware:

  ** KBD Awaits a keystroke and then pushes it onto the stack.