Remote Access Control

memory.h

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// This file has been prepared for Doxygen automatic documentation generation.
#ifndef MEMORY_H
#define MEMORY_H

#include "common.h"
#include "config.h"



typedef struct
{
#ifdef USE_UART
        byte preamble; // The preamble is actually received when using the UART.
#endif
        SERIAL_NO_TYPE serialNo;
        SEQ_COUNTER_TYPE lastCounterValue;
#if KEY_SIZE == 16
        byte secretKey[ BLOCK_SIZE ];
#elif KEY_SIZE == 24 || KEY_SIZE == 32
        byte secretKey[ BLOCK_SIZE*2 ]; // Two encrypted blocks are received even if key size is 24 bytes.
#else
  #error Unsupported key size.
#endif
        byte CRC[2];
} LearnMessage;

typedef struct
{
#ifdef USE_UART
        byte preamble;
#endif
        SERIAL_NO_TYPE serialNo;
        SEQ_COUNTER_TYPE counterValue;
        COMMAND_CODE_TYPE commandCode;
        byte MAC[ MAC_BYTES ];
} CommandMessage;

typedef union
{
        LearnMessage learnMessage;
        CommandMessage commandMessage;
} ReceiveBuffer;

typedef struct
{
        byte secretKey[ KEY_SIZE ];
        SERIAL_NO_TYPE serialNo;
        SEQ_COUNTER_TYPE lastCounterValue;
} TransmitterInfo;



/* --- EEPROM memory contents --- */

// Due to placement at absolute addresses, these variables
// are defined in the header file without external declaration.
// This means that every translation unit will have its own
// copy of the variable, but since they occupy the same place in
// memory, it doesn't give any extra memory usage.

__no_init byte __eeprom sharedKey[ KEY_SIZE ] @ 0;
__no_init byte __eeprom transmitterCount @ KEY_SIZE;
__no_init TransmitterInfo __eeprom transmitters[ MAX_TRANSMITTERS ] @ (KEY_SIZE+1);



/* --- SRAM memory contents --- */

extern ReceiveBuffer receiveBuffer;
extern byte scheduleBuffer[ SCHEDULE_BUFFER_SIZE ];
extern byte cryptoBlock[ BLOCK_SIZE ];
extern byte CMACSubkey[ CMAC_SUBKEY_SIZE ];
extern byte tempKeyStorage[ KEY_SIZE ];



/* --- Associated functions --- */

void eraseTransmitters(void);



#endif