Calibration: Difference between revisions

← Older edit Newer edit →

@@ Line 6: / Line 6: @@
 = CAL0 =
-This is the raw data stored under the PRODINFO partition. Each block of data is padded to 16 bytes, being the last 2 bytes a CRC16 over said block.
+This is the raw data stored under the PRODINFO partition.
-Bellow is a list of offsets and sizes for each block of raw calibration data.
 {| class="wikitable" border="1"
@@ Line 298: / Line 296: @@
 |-
 |}
+== Error detection ==
+Each block of raw calibration data (with the exception of blocks with SHA256 hashes) is padded to 16 bytes, being the last 2 bytes a CRC-16 over said block.
+ XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX
+00 00 00 00 00 00 00 00 00 00 00 00 00 YY YY
+ XX == data
+== padding
+ YY == crc
+The CRC-16 is generated as follows:
+ unsigned int crc_16_table[16] = {
+x0000, 0xCC01, 0xD801, 0x1400, 0xF001, 0x3C00, 0x2800, 0xE401,
+xA001, 0x6C00, 0x7800, 0xB401, 0x5000, 0x9C01, 0x8801, 0x4400 };
+ unsigned short int get_crc_16 (char *p, int n) {
+  unsigned short int crc = 0x55AA;
+  int r;
+  while (n-- > 0) {
+    r = crc_16_table[crc & 0xF];
+    crc = (crc >> 4) & 0x0FFF;
+    crc = crc ^ r ^ crc_16_table[*p & 0xF];
+    r = crc_16_table[crc & 0xF];
+    crc = (crc >> 4) & 0x0FFF;
+    crc = crc ^ r ^ crc_16_table[(*p >> 4) & 0xF];
+    p++;
+  }
+  return(crc);
+ }