public VmState(List<IInstruction> instructions, int memorySize)
{
this.instructions = instructions;
this.registers = new RegisterState();
this.memory = new byte[memorySize];
Array.Clear(memory, 0, memory.Length);
// load up instructions as binary in memory
for (int i = 0, j = 0; i < instructions.Count; i++, j += 4)
{
var bytes = BitConverter.GetBytes(instructions[i].ToBinary());
memory[j] = bytes[0];
memory[j + 1] = bytes[1];
memory[j + 2] = bytes[2];
memory[j + 3] = bytes[3];
}
// set frame and stack pointers to the first non-instruction byte
var instructionCount = (uint) instructions.Count;
registers[RegisterName.SP] = instructionCount * 4; // 4 bytes lol
registers[RegisterName.FP] = instructionCount * 4;
// bootstrap main return address for final return
new PushIm(instructionCount).Execute(this);
new PushIm(instructionCount).Execute(this);
new PushIm(int.MaxValue - 4).Execute(this);
registers[RegisterName.FP] = registers[RegisterName.SP];
this.registers[RegisterName.PC] = 0;
}
public RegisterState Clone()
{
var state = new RegisterState();
foreach (var k in registers)
{
state.registers[k.Key] = k.Value;
}
return state;
}