51 lines
1.7 KiB
C
51 lines
1.7 KiB
C
#ifndef PROTOCOL_MP1
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#define PROTOCOL_MP1
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#include <cfg/compiler.h>
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#include <io/kfile.h>
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// Frame sizing & checksum
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#define MP1_MIN_FRAME_LENGTH 3
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#define MP1_MAX_FRAME_LENGTH 200
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#define MP1_CHECKSUM_INIT 0xAA
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// We need to know some basic HDLC flag bytes
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#define HDLC_FLAG 0x7E
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#define HDLC_RESET 0x7F
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#define AX25_ESC 0x1B
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// Just a forward declaration that this struct exists
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struct MP1Packet;
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// The type of a callback function for passing
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// back a decoded packet
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typedef void (*mp1_callback_t)(struct MP1Packet *packet);
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// Struct for a protocol context
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typedef struct MP1 {
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uint8_t buffer[MP1_MAX_FRAME_LENGTH]; // A buffer for incoming packets
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uint8_t fecBuffer[3]; // FEC buffer
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KFile *modem; // KFile access to the modem
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size_t packetLength; // Counter for received packet length
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size_t readLength; // This is the full read length, including parity bytes
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uint8_t calculatedParity; // Calculated parity for incoming data block
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mp1_callback_t callback; // The function to call when a packet has been received
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uint8_t checksum_in; // Rolling checksum for incoming packets
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uint8_t checksum_out; // Rolling checksum for outgoing packets
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bool reading; // True when we have seen a HDLC flag
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bool escape; // We need to know if we are in an escape sequence
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bool fecEscape; // fec escape
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} MP1;
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// A struct encapsulating a network packet
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typedef struct MP1Packet {
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const uint8_t *data; // Pointer to the actual data in the packet
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size_t dataLength; // The length of the received data
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} MP1Packet;
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void mp1Init(MP1 *mp1, KFile *modem, mp1_callback_t callback);
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void mp1Read(MP1 *mp1, int byte);
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void mp1Poll(MP1 *mp1);
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void mp1Send(MP1 *mp1, const void *_buffer, size_t length);
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#endif |