melonDS/CP15.cpp

143 lines
2.6 KiB
C++

/*
Copyright 2016-2017 StapleButter
This file is part of melonDS.
melonDS is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.
melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with melonDS. If not, see http://www.gnu.org/licenses/.
*/
#include <stdio.h>
#include "NDS.h"
#include "ARM.h"
#include "CP15.h"
// derp
namespace NDS
{
extern ARM* ARM9;
}
namespace CP15
{
u32 Control;
u32 DTCMSetting, ITCMSetting;
void Reset()
{
Control = 0x78; // dunno
DTCMSetting = 0;
ITCMSetting = 0;
}
void UpdateDTCMSetting()
{
if (Control & (1<<16))
{
NDS::ARM9DTCMBase = DTCMSetting & 0xFFFFF000;
NDS::ARM9DTCMSize = 0x200 << ((DTCMSetting >> 1) & 0x1F);
printf("DTCM [%08X] enabled at %08X, size %X\n", DTCMSetting, NDS::ARM9DTCMBase, NDS::ARM9DTCMSize);
}
else
{
NDS::ARM9DTCMBase = 0xFFFFFFFF;
NDS::ARM9DTCMSize = 0;
printf("DTCM disabled\n");
}
}
void UpdateITCMSetting()
{
if (Control & (1<<18))
{
NDS::ARM9ITCMSize = 0x200 << ((ITCMSetting >> 1) & 0x1F);
printf("ITCM [%08X] enabled at %08X, size %X\n", ITCMSetting, 0, NDS::ARM9ITCMSize);
}
else
{
NDS::ARM9ITCMSize = 0;
printf("ITCM disabled\n");
}
}
void Write(u32 id, u32 val)
{
switch (id)
{
case 0x100:
val &= 0x000FF085;
Control &= ~0x000FF085;
Control |= val;
UpdateDTCMSetting();
UpdateITCMSetting();
return;
case 0x704:
case 0x782:
NDS::ARM9->Halt(1);
return;
case 0x910:
DTCMSetting = val;
UpdateDTCMSetting();
return;
case 0x911:
ITCMSetting = val;
UpdateITCMSetting();
return;
}
}
u32 Read(u32 id)
{
switch (id)
{
case 0x000: // CPU ID
case 0x003:
case 0x004:
case 0x005:
case 0x006:
case 0x007:
return 0x41059461;
case 0x001:
// cache type. todo
return 0;
case 0x002: // TCM size
return (6 << 6) | (5 << 18);
case 0x100: // control reg
return Control;
case 0x910:
return DTCMSetting;
case 0x911:
return ITCMSetting;
}
return 0;
}
}