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Fix large filename FAT entries. Games can now play in the ARES emulat…
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…or without user interaction
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@nopjne
nopjne committed Aug 5, 2023
1 parent c295454 commit fef5986
Showing 1 changed file with 34 additions and 18 deletions.
52 changes: 34 additions & 18 deletions src/virtualdisk.c
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Original file line number Diff line number Diff line change
Expand Up @@ -186,8 +186,8 @@ typedef struct _LongFileName
uint8_t reserved_1;
uint8_t checksum; // Checksum
uint8_t fileName_Part2[12]; // WORD reserved_2;
uint8_t reserved_2[2];
uint8_t fileName_Part3[4];
uint8_t fileName_Part4[2];
} LFN;

static_assert(sizeof(struct dir_entry) == 32, "");
Expand Down Expand Up @@ -256,19 +256,37 @@ bool tud_msc_start_stop_cb(uint8_t lun, uint8_t power_condition, bool start, boo
return true;
}

unsigned char ChkSum (const unsigned char *pFcbName)
{
short FcbNameLen;
unsigned char Sum;

Sum = 0;//*pFcbName;
for (FcbNameLen = 11; FcbNameLen != 0; FcbNameLen--)
{
// NOTE: The operation is an unsigned char rotate right
unsigned char sign = (unsigned char)((Sum & 0x01) ? 0x80 : 0x00);
unsigned char value = *pFcbName;
Sum = (sign) | (Sum >> 0x01);
Sum += value;
pFcbName += 1;
}
return (Sum);
}

void init_dir_entry(struct dir_entry *entry, const char *fn, const char *uniname, uint32_t cluster, uint len, uint8_t attribute) {
LFN *lfnentry = (LFN*)entry;
memset(lfnentry, 0, sizeof(LFN));
lfnentry->sequenceNo = 0x41;
lfnentry->fileattribute = 0x0f;
lfnentry->checksum = 0x0f;
lfnentry->checksum = ChkSum((const unsigned char*)fn);
memcpy(lfnentry->fileName_Part1, uniname, sizeof(lfnentry->fileName_Part1));
memcpy(lfnentry->fileName_Part2, uniname + sizeof(lfnentry->fileName_Part1), sizeof(lfnentry->fileName_Part2));
memcpy(lfnentry->fileName_Part3, uniname + sizeof(lfnentry->fileName_Part1) + sizeof(lfnentry->fileName_Part2), sizeof(lfnentry->fileName_Part3));
lfnentry->fileName_Part3[3] = 0xFF;
lfnentry->fileName_Part3[2] = 0xFF;
lfnentry->fileName_Part4[0] = 0xFF;
lfnentry->fileName_Part4[1] = 0xFF;
if (lfnentry->fileName_Part3[0] == 0) {
lfnentry->fileName_Part3[3] = 0xFF;
lfnentry->fileName_Part3[2] = 0xFF;
}
entry++;
entry->creation_time_frac = RASPBERRY_PI_TIME_FRAC;
entry->creation_time = RASPBERRY_PI_TIME;
Expand Down Expand Up @@ -412,29 +430,29 @@ int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buf,
uint32_t cluster_offset = 2;
uint32_t size = 2 * 1024;
assert(cluster_offset == (EEPROM_CLUSTER_START + 2));
init_dir_entry(++entries, "ROM EEP", "r\0o\0m\0.\0e\0e\0p\0\0\0\0\0\0\0\0\0\0", cluster_offset, gEepromSize, 0);
entries++;
if (gEepromSize != 0) {
init_dir_entry(++entries, "ROM EEP", "R\0O\0M\0.\0e\0e\0p\0\0\0\0\0\0\0\0\0\0", cluster_offset, gEepromSize, 0);
entries++;
}

cluster_offset += (size / CLUSTER_SIZE) + 1;
assert(cluster_offset == (FLASHRAM_CLUSTER_START + 2));
size = 128 * 1024;
if ((gSRAMPresent != false) || (gFramPresent != false)) {
init_dir_entry(++entries, "ROM FLA", "r\0o\0m\0.\0f\0l\0a\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, size, 0); // DaisyDrive64 doesn't differentiate between SRAM and FRAM for filenames.
} else {
init_dir_entry(++entries, "ROM FLA", "r\0o\0m\0.\0f\0l\0a\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, 0, 0); // DaisyDrive64 doesn't differentiate between SRAM and FRAM for filenames.
init_dir_entry(++entries, "ROM FLA", "R\0O\0M\0.\0f\0l\0a\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, size, 0); // DaisyDrive64 doesn't differentiate between SRAM and FRAM for filenames.
entries++;
}
entries++;

cluster_offset += size / CLUSTER_SIZE;
size = (64 * 1024 * 1024);
assert(cluster_offset == (N64ROM_CLUSTER_START + 2));
init_dir_entry(++entries, "ROM N64", "r\0o\0m\0.\0n\0\\6\0\\4\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, gRomSize, ATTR_READONLY);
init_dir_entry(++entries, "ROM N64", "R\0O\0M\0.\0n\0""6\0""4\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, gRomSize, ATTR_READONLY);
entries++;

cluster_offset += size / CLUSTER_SIZE;
size = (64 * 1024 * 1024);
assert(cluster_offset == (Z64ROM_CLUSTER_START + 2));
init_dir_entry(++entries, "ROMF Z64", "r\0o\0m\0.\0z\0\\6\0\\4\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, gRomSize, ATTR_READONLY); // Same as N64 just byteflipped.
init_dir_entry(++entries, "ROMF Z64", "R\0O\0M\0F\0.\0z\0""6\0""4\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, gRomSize, ATTR_READONLY); // Same as N64 just byteflipped.
entries++;

cluster_offset += size / CLUSTER_SIZE;
Expand All @@ -446,10 +464,8 @@ int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buf,
} else {
init_dir_entry(++entries, "ROMF RAM", "R\0O\0M\0F\0.\0r\0a\0m\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, size, 0); // Same as N64 just byteflipped, ram for Ares emulator support.
}
} else {
init_dir_entry(++entries, "ROMF FLA", "R\0O\0M\0F\0.\0f\0l\0a\0s\0h\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, 0, 0); // Same as N64 just byteflipped, ram for Ares emulator support.
entries++;
}
entries++;

cluster_offset += size / CLUSTER_SIZE;
size = 2 * 1024;
Expand All @@ -462,7 +478,7 @@ int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buf,
cluster_offset += (size / CLUSTER_SIZE) + 1;
size = 2 * 1024;
assert(cluster_offset == (CARTTEST_CLUSTER_START + 2));
init_dir_entry(++entries, "CARTTESTTXT", "c\0a\0r\0t\0t\0e\0s\0t\0.\0t\0x\0t\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, size, ATTR_READONLY);
init_dir_entry(++entries, "CARTTESTTXT", "C\0a\0r\0t\0T\0e\0s\0t\0.\0t\0x\0t\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", cluster_offset, size, ATTR_READONLY);
entries++;
} else {
memset(buf, 0, buf_size);
Expand Down

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