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Changed the hash array to a CRC8 function.

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This commit is contained in:
skidau 2015-01-30 13:33:17 +11:00
parent 855ad6f1d3
commit ccc1e9aa65
2 changed files with 26 additions and 55 deletions
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73
Source/Core/Core/HW/EXI_DeviceAGP.cpp
View File

@ -21,7 +21,6 @@ CEXIAgp::CEXIAgp(int index)
LoadRom();
m_address = 0;
m_rom_hash_loaded = false;
}
CEXIAgp::~CEXIAgp()
@ -36,15 +35,21 @@ CEXIAgp::~CEXIAgp()
SaveFileFromEEPROM(gbapath + ".sav");
}
void CEXIAgp::DoHash(u8* data, u32 size)
void CEXIAgp::CRC8(u8* data, u32 size)
{
if (!m_rom_hash_loaded)
LoadHash();
for (u32 it = 0; it < size; it++)
{
u8 crc = 0;
m_hash = m_hash ^ data[it];
m_hash = m_hash_array[m_hash];
if (m_hash & 1) crc ^= 0x5e;
if (m_hash & 2) crc ^= 0xbc;
if (m_hash & 4) crc ^= 0x61;
if (m_hash & 8) crc ^= 0xc2;
if (m_hash & 0x10) crc ^= 0x9d;
if (m_hash & 0x20) crc ^= 0x23;
if (m_hash & 0x40) crc ^= 0x46;
if (m_hash & 0x80) crc ^= 0x8c;
m_hash = crc;
}
}
@ -107,33 +112,6 @@ void CEXIAgp::SaveFileFromEEPROM(const std::string& filename)
}
}
void CEXIAgp::LoadHash()
{
if (!m_rom_hash_loaded && m_rom_size > 0)
{
u32 hash_addr = 0;
// Find where the hash is in memory
for (u32 h = 0; h < Memory::REALRAM_SIZE; h += 4)
{
if (Memory::ReadUnchecked_U32(h) == 0x005ebce2)
hash_addr = h;
}
for (int i = 0; i < 0x100; i++)
{
// Load the ROM hash expected by the AGP
m_hash_array[i] = Memory::ReadUnchecked_U8(hash_addr + i);
}
// Verify the hash
if (m_hash_array[HASH_SIZE - 1] == 0x35)
{
m_rom_hash_loaded = true;
}
}
}
u32 CEXIAgp::ImmRead(u32 _uSize)
{
// We don't really care about _uSize
@ -165,8 +143,8 @@ u32 CEXIAgp::ImmRead(u32 _uSize)
RomVal1 = m_rom[m_rw_offset++];
RomVal2 = m_rom[m_rw_offset++];
}
DoHash(&RomVal2, 1);
DoHash(&RomVal1, 1);
CRC8(&RomVal2, 1);
CRC8(&RomVal1, 1);
uData = (RomVal2 << 24) | (RomVal1 << 16) | (m_hash << 8);
m_current_cmd = 0;
break;
@ -182,18 +160,18 @@ u32 CEXIAgp::ImmRead(u32 _uSize)
RomVal2 = m_rom[m_rw_offset++];
RomVal3 = m_rom[m_rw_offset++];
RomVal4 = m_rom[m_rw_offset++];
DoHash(&RomVal2, 1);
DoHash(&RomVal1, 1);
DoHash(&RomVal4, 1);
DoHash(&RomVal3, 1);
CRC8(&RomVal2, 1);
CRC8(&RomVal1, 1);
CRC8(&RomVal4, 1);
CRC8(&RomVal3, 1);
uData = (RomVal2 << 24) | (RomVal1 << 16) | (RomVal4 << 8) | (RomVal3);
}
break;
case 0xAE0B0000:
RomVal1 = m_eeprom_pos < 4 ? 0xA : (((u64*)m_eeprom.data())[(m_eeprom_cmd >> 1) & 0x3F] >> (m_eeprom_pos - 4)) & 0x1;
RomVal2 = 0;
DoHash(&RomVal2, 1);
DoHash(&RomVal1, 1);
CRC8(&RomVal2, 1);
CRC8(&RomVal1, 1);
uData = (RomVal2 << 24) | (RomVal1 << 16) | (m_hash << 8);
m_eeprom_pos++;
m_current_cmd = 0;
@ -226,11 +204,11 @@ void CEXIAgp::ImmWrite(u32 _uData, u32 _uSize)
m_rw_offset = ((_uData & 0xFFFFFF00) >> 7) & m_rom_mask;
m_return_pos = 0;
HashCmd = (_uData & 0xFF000000) >> 24;
DoHash(&HashCmd, 1);
CRC8(&HashCmd, 1);
HashCmd = (_uData & 0x00FF0000) >> 16;
DoHash(&HashCmd, 1);
CRC8(&HashCmd, 1);
HashCmd = (_uData & 0x0000FF00) >> 8;
DoHash(&HashCmd, 1);
CRC8(&HashCmd, 1);
break;
case 0xAE0C0000:
if ((m_eeprom_pos < 0x8) || (m_eeprom_pos == ((m_eeprom_cmd & EE_READ) ? 0x8 : 0x48)))
@ -254,9 +232,9 @@ void CEXIAgp::ImmWrite(u32 _uData, u32 _uSize)
m_eeprom_pos++;
m_return_pos = 0;
HashCmd = (_uData & 0xFF000000) >> 24;
DoHash(&HashCmd, 1);
CRC8(&HashCmd, 1);
HashCmd = (_uData & 0x00FF0000) >> 16;
DoHash(&HashCmd, 1);
CRC8(&HashCmd, 1);
break;
case 0xAE0B0000:
break;
@ -270,7 +248,7 @@ void CEXIAgp::ImmWrite(u32 _uData, u32 _uSize)
m_return_pos = 0;
m_hash = 0xFF;
HashCmd = (_uData & 0x00FF0000) >> 16;
DoHash(&HashCmd, 1);
CRC8(&HashCmd, 1);
break;
}
}
@ -287,7 +265,6 @@ void CEXIAgp::DoState(PointerWrap &p)
p.Do(m_eeprom_pos);
p.Do(m_eeprom_size);
p.Do(m_hash);
p.Do(m_hash_array);
p.Do(m_position);
p.Do(m_return_pos);
p.Do(m_rom);

8
Source/Core/Core/HW/EXI_DeviceAGP.h
View File

@ -23,8 +23,6 @@ public:
private:
enum
{
HASH_SIZE = 256,
HASH_MASK = (HASH_SIZE - 1),
EE_READ = 0x80
};
@ -37,7 +35,6 @@ private:
u32 m_eeprom_mask = 0;
std::vector<u8> m_rom;
std::vector<u8> m_eeprom;
std::array<u8, HASH_SIZE> m_hash_array;
//! Helper
u32 m_position = 0;
@ -50,13 +47,10 @@ private:
void LoadFileToROM(const std::string& filename);
void LoadFileToEEPROM(const std::string& filename);
void SaveFileFromEEPROM(const std::string& filename);
void LoadHash();
void LoadRom();
void DoHash(u8* data, u32 size);
void CRC8(u8* data, u32 size);
u8 m_hash = 0;
u32 m_current_cmd = 0;
u32 m_return_pos = 0;
bool m_rom_hash_loaded = false;
};