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MemoryCard: Fix incorrect checksum after formatting

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Fixes memory cards not working in the BIOS.
This commit is contained in:
Connor McLaughlin 2019-12-07 00:03:03 +10:00
parent 54277dc24f
commit 8d7b93766d
1 changed files with 9 additions and 5 deletions
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14
src/core/memory_card.cpp
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@ -256,8 +256,8 @@ std::shared_ptr<MemoryCard> MemoryCard::Open(System* system, std::string_view fi
u8 MemoryCard::ChecksumFrame(const u8* fptr)
{
u8 value = fptr[0];
for (u32 i = 0; i < SECTOR_SIZE; i++)
u8 value = 0;
for (u32 i = 0; i < SECTOR_SIZE - 1; i++)
value ^= fptr[i];
return value;
@ -274,7 +274,7 @@ void MemoryCard::Format()
std::fill_n(fptr, SECTOR_SIZE, u8(0));
fptr[0] = 'M';
fptr[1] = 'C';
fptr[0x7F] = ChecksumFrame(&m_data[0]);
fptr[0x7F] = ChecksumFrame(fptr);
}
// directory
@ -283,6 +283,8 @@ void MemoryCard::Format()
u8* fptr = GetSectorPtr(frame);
std::fill_n(fptr, SECTOR_SIZE, u8(0));
fptr[0] = 0xA0; // free
fptr[8] = 0xFF; // pointer to next file
fptr[9] = 0xFF; // pointer to next file
fptr[0x7F] = ChecksumFrame(fptr); // checksum
}
@ -295,6 +297,8 @@ void MemoryCard::Format()
fptr[1] = 0xFF;
fptr[2] = 0xFF;
fptr[3] = 0xFF;
fptr[8] = 0xFF; // pointer to next file
fptr[9] = 0xFF; // pointer to next file
fptr[0x7F] = ChecksumFrame(fptr); // checksum
}
@ -302,14 +306,14 @@ void MemoryCard::Format()
for (u32 frame = 36; frame < 56; frame++)
{
u8* fptr = GetSectorPtr(frame);
std::fill_n(fptr, SECTOR_SIZE, u8(0xFF));
std::fill_n(fptr, SECTOR_SIZE, u8(0x00));
}
// unused frames
for (u32 frame = 56; frame < 63; frame++)
{
u8* fptr = GetSectorPtr(frame);
std::fill_n(fptr, SECTOR_SIZE, u8(0xFF));
std::fill_n(fptr, SECTOR_SIZE, u8(0x00));
}
// write test frame