/// <summary>
/// Switches the CPU into one of 7 modes. Save the cspr to the spsr, switch to the new mode.
/// </summary>
/// <param name="cpuMode"></param>
public void SwitchCPUMode(CPSR.CPUModeEnum cpuMode)
{
//save the current cspr register into the spsr table based on the current mode
_spsr[(int)cpuMode] = Flags;
//switch cpu to the new mode
mCPUMode = new CPUMode(cpuMode);
}//SetCPUMode
//Set a register value. Valid register numbers are 0-15 only
//Based on the cpu mode and the register number/
/// <summary>
/// Set a register value. Valid register numbers are 0-15 only.
/// Based on the cpu mode and the register number
/// </summary>
/// <param name="reg">register number to set(0-15)</param>
/// <param name="newValue">value to set</param>
private void setRegister(uint reg, uint newValue)
{
//make sure register number is valid
if (reg >= r_user.Length)
{
return;
}
//get the current cpu mode
CPSR.CPUModeEnum cpuMode = _cpsr.Mode;
//and perform register transfer according to mode
switch (cpuMode)
{
//user and system mode use only the normal 16 gp registers
case CPSR.CPUModeEnum.User:
case CPSR.CPUModeEnum.System:
r_user[reg] = newValue; break;
//these modes have their own r13 and r14
case CPSR.CPUModeEnum.Supervisor:
case CPSR.CPUModeEnum.Abort:
case CPSR.CPUModeEnum.Undefined:
case CPSR.CPUModeEnum.IRQ:
if (reg < 13 || reg == PCRegisterIndex)
{
r_user[reg] = newValue;
}
else
{
if (cpuMode == CPSR.CPUModeEnum.Supervisor)
{
r_svc[reg - 13] = newValue;
}
else if (cpuMode == CPSR.CPUModeEnum.Abort)
{
r_abt[reg - 13] = newValue;
}
else if (cpuMode == CPSR.CPUModeEnum.Undefined)
{
r_und[reg - 13] = newValue;
}
else
{
r_irq[reg - 13] = newValue;
}
}
break;
//fiq mode has its own r8-r14
case CPSR.CPUModeEnum.FIQ:
if (reg < 8 || reg == PCRegisterIndex)
{
r_user[reg] = newValue;
}
else
{
r_fiq[reg - 8] = newValue;
}
break;
}//switch
//if the register changed handler is set, call it
if (_registerChangedHandler != null)
{
_registerChangedHandler(reg);
}
} //setRegister
} //setRegister
/// <summary>
/// Get a register value. Valid register numbers are 0-15 only.
/// Based on the cpu mode and the register number
/// </summary>
/// <param name="reg"></param>
/// <returns></returns>
private uint getRegister(uint reg)
{
//make sure register number is valid
if (reg >= r_user.Length)
{
return(0);
}
//get the current cpu mode
CPSR.CPUModeEnum cpuMode = _cpsr.Mode;
//and perform register transfer according to mode
switch (cpuMode)
{
//user and system mode use only the normal 16 gp registers
case CPSR.CPUModeEnum.User:
case CPSR.CPUModeEnum.System:
return(r_user[reg]);
//these modes have their own r13 and r14
case CPSR.CPUModeEnum.Supervisor:
case CPSR.CPUModeEnum.Abort:
case CPSR.CPUModeEnum.Undefined:
case CPSR.CPUModeEnum.IRQ:
if (reg < 13 || reg == PCRegisterIndex)
{
return(r_user[reg]);
}
else
{
if (cpuMode == CPSR.CPUModeEnum.Supervisor)
{
return(r_svc[reg - 13]);
}
else if (cpuMode == CPSR.CPUModeEnum.Abort)
{
return(r_abt[reg - 13]);
}
else if (cpuMode == CPSR.CPUModeEnum.Undefined)
{
return(r_und[reg - 13]);
}
else
{
return(r_irq[reg - 13]);
}
}
//fiq mode has its own r8-r14
case CPSR.CPUModeEnum.FIQ:
if (reg < 8 || reg == PCRegisterIndex)
{
return(r_user[reg]);
}
else
{
return(r_fiq[reg - 8]);
}
} //switch
return(0);
} //getRegister
