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Line 74:
Line 74:
+
+
| 0x0
| 0x0
| 0x4
| 0x4
−| Start index of valid packages
+| Start index of valid packets
|-
|-
| 0x4
| 0x4
| 0x4
| 0x4
−| End index of valid packages
+| End index of valid packets
|-
|-
| 0x8
| 0x8
| 0x4
| 0x4
−| Number of valid packages
+| Number of valid packets
|-
|-
| 0xC
| 0xC
Line 98:
Line 98:
|-
|-
| 0x0
| 0x0
−| 0x8 * package_count (specified in Init parameter)
+| 0x8 * packet_count (specified in Init parameter)
−| PackageInfo{u32 offset_to_data_buffer, u32 data_length}
+| PacketInfo{u32 offset_to_data_buffer, u32 data_length}
|-
|-
−| 0x8 * package_count
+| 0x8 * packet_count
−| buffer_size - 0x8 * package_count
+| buffer_size - 0x8 * packet_count
| Data buffer
| Data buffer
|}
|}
−The buffers are two circular buffers. A new package is added to the end of previous package in the data buffer, with package info added to PackageInfo[end_index++]. Note that if an added package exceeds the end of the buffer, the exceeding data will be wrapped around to the beginning of the data buffer.
+The buffers are two circular buffers. A new packet is added to the end of previous packet in the data buffer, with packet info added to PacketInfo[end_index++]. Note that if an added packet exceeds the end of the buffer, the exceeding data will be wrapped around to the beginning of the data buffer.
+==Packet structure==
+A packet in the data buffer consists of a header, payload and a crc8 checksum
+{| class="wikitable" border="1"
+|-
+! Relative offset
+! Size
+! Description
+|-
+| 0x0
+| 0x1
+| Fixed value 0xA5?
+|-
+| 0x1
+| 0x1
+| Unknown
+|-
+| 0x2
+| 0x1
+| The highest bit is unknown.
+When second highest bit is clear, the rest bit[0:5] of this byte is the payload length; otherwise bit[0:5] is the higher byte of the payload length
+|-
+| 0x3
+| 0x1
+| When bit[6] of previous byte is set, this byte is the lower byte of the payload length; other wise this byte doesn't present
+|-
+| 0x3 or 0x4
+| payload length
+| payload
+|-
+| 0x3 or 0x4 +payload_length
+| 0x1
+| crc8 (x^8 + x^2 + x + 1) over data above (header + payload)
+|-
+|}