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Eliminate the broken tpi system for a simple drive/format type field.

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This commit is contained in:
David Given
2023-10-29 21:10:14 +01:00
parent ff1fb761f2
commit 533b217c8f
86 changed files with 1831 additions and 798 deletions
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36
arch/micropolis/decoder.cc
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@@ -67,28 +67,32 @@ static uint8_t b(uint32_t field, uint8_t pos)
static uint8_t eccNextBit(uint32_t ecc, uint8_t data_bit)
{
// This is 0x81932080 which is 0x0104C981 with reversed bits
return b(ecc, 7) ^ b(ecc, 13) ^ b(ecc, 16) ^ b(ecc, 17) ^ b(ecc, 20)
^ b(ecc, 23) ^ b(ecc, 24) ^ b(ecc, 31) ^ data_bit;
return b(ecc, 7) ^ b(ecc, 13) ^ b(ecc, 16) ^ b(ecc, 17) ^ b(ecc, 20) ^
b(ecc, 23) ^ b(ecc, 24) ^ b(ecc, 31) ^ data_bit;
}
uint32_t vectorGraphicEcc(const Bytes& bytes)
{
uint32_t e = 0;
Bytes payloadBytes = bytes.slice(0, bytes.size()-4);
Bytes payloadBytes = bytes.slice(0, bytes.size() - 4);
ByteReader payload(payloadBytes);
while (!payload.eof()) {
while (!payload.eof())
{
uint8_t byte = payload.read_8();
for (int i = 0; i < 8; i++) {
for (int i = 0; i < 8; i++)
{
e = (e << 1) | eccNextBit(e, byte >> 7);
byte <<= 1;
}
}
Bytes trailerBytes = bytes.slice(bytes.size()-4);
Bytes trailerBytes = bytes.slice(bytes.size() - 4);
ByteReader trailer(trailerBytes);
uint32_t res = e;
while (!trailer.eof()) {
while (!trailer.eof())
{
uint8_t byte = trailer.read_8();
for (int i = 0; i < 8; i++) {
for (int i = 0; i < 8; i++)
{
res = (res << 1) | eccNextBit(e, byte >> 7);
e <<= 1;
byte <<= 1;
@@ -101,13 +105,15 @@ uint32_t vectorGraphicEcc(const Bytes& bytes)
static bool vectorGraphicEccFix(Bytes& bytes, uint32_t syndrome)
{
uint32_t ecc = syndrome;
int pos = (MICROPOLIS_ENCODED_SECTOR_SIZE-5)*8+7;
int pos = (MICROPOLIS_ENCODED_SECTOR_SIZE - 5) * 8 + 7;
bool aligned = false;
while ((ecc & 0xff000000) == 0) {
while ((ecc & 0xff000000) == 0)
{
pos += 8;
ecc <<= 8;
}
for (; pos >= 0; pos--) {
for (; pos >= 0; pos--)
{
bool bit = ecc & 1;
ecc >>= 1;
if (bit)
@@ -119,7 +125,7 @@ static bool vectorGraphicEccFix(Bytes& bytes, uint32_t syndrome)
}
if (pos < 0)
return false;
bytes[pos/8] ^= ecc >> 16;
bytes[pos / 8] ^= ecc >> 16;
return true;
}
@@ -199,9 +205,11 @@ public:
bool eccPresent = bytes[274] == 0xaa;
uint32_t ecc = 0;
if (_config.ecc_type() == MicropolisDecoderProto::VECTOR && eccPresent) {
if (_config.ecc_type() == MicropolisDecoderProto::VECTOR && eccPresent)
{
ecc = vectorGraphicEcc(bytes.slice(0, 274));
if (ecc != 0) {
if (ecc != 0)
{
vectorGraphicEccFix(bytes, ecc);
ecc = vectorGraphicEcc(bytes.slice(0, 274));
}