#pragma segment = "BOOT_SEGMENT"
#pragma location="BOOT_SEGMENT"

#include <eeprom_driver.h>
#include <sp_driver.h>
#include <defines.h>

#define BOOT_F_CPU             2000000UL

........ // определение типов и констант для I2C

boot_TWI_Master_t  twiMaster;   // структура для работы с I2C
uint8_t boot_sBuf[32];

// объявление функций для I2C
__root bool boot_TWI_MasterWriteRead(boot_TWI_Master_t *twi,
                         uint8_t address,
                         uint8_t *writeData,
                         uint8_t bytesToWrite,
                         uint8_t bytesToRead) @ "BOOT_SEGMENT";
__root void boot_TWI_MasterInterruptHandler(boot_TWI_Master_t *twi) @ "BOOT_SEGMENT";

.........


__root void boot(void) @ "BOOT_SEGMENT"; // тело загрузчика
__root void GoToApplication(void) @ "BOOT_SEGMENT"; // переход в приложение

__root void boot(void) @ "BOOT_SEGMENT"
{
  boot_TWI_MasterInit(&twiMaster,                   // инициализирую I2C
                 &TWIF,
                 TWI_MASTER_INTLVL_HI_gc,
                 BOOT_TWI_BAUDSETTING);
  
  PMIC.CTRL |= PMIC_HILVLEN_bm;
  
  boot_sBuf[0] = 0x00;                                   // читаю из FRAM 6 байтов
  boot_sBuf[1] = 0x40;
  boot_TWI_MasterWriteRead(&twiMaster,
                      0xA0,
                      &boot_sBuf[0],
                      2,
                      6);

  while (twiMaster.status != boot_TWIM_STATUS_READY)      // пишу и читаю пока надо
  {
    if ((TWIF.MASTER.STATUS & 0xCC) != 0x00)
    {
      boot_TWI_MasterInterruptHandler(&twiMaster);
    }
  }
  
  // в зависимости от результата что-то делаю
  ............
  
  GoToApplication();
    
}

__root void GoToApplication(void) @ "BOOT_SEGMENT"
{
  cli();
  PMIC.CTRL = 0;
  SP_WaitForSPM();
  SP_LockSPM();
  EIND = 0x00;
  void (*funcptr)( void ) = 0x0000;         // Set up function pointer to RESET vector.
  funcptr();                                // Jump to Reset vector 0x0000 in Application Section.
}

__root bool boot_TWI_MasterWriteRead(boot_TWI_Master_t *twi,
                         uint8_t address,
                         uint8_t *writeData,
                         uint8_t bytesToWrite,
                         uint8_t bytesToRead) @ "BOOT_SEGMENT"
{
    /*Parameter sanity check. */
    if (bytesToWrite > boot_TWIM_WRITE_BUFFER_SIZE) {
        return false;
    }
    if (bytesToRead > boot_TWIM_READ_BUFFER_SIZE) {
        return false;
    }

            ..........................
}

EXTERN boot
        RSEG   CSTACK:DATA:NOROOT(0)
        RSEG   RSTACK:DATA:NOROOT(0)
        RSEG   BOOTENTRY:CODE:ROOT(1)

          LDI   R17,LOW(SFE(RSTACK)-1)
          OUT   SPL,R17
          LDI   R17,HIGH(SFE(RSTACK)-1)
          OUT   SPH,R17
          
          LDI   YL,LOW(SFE(CSTACK)-1)
          LDI   YH,HIGH(SFE(CSTACK)-1)

          rjmp boot

EXTERN boot
        RSEG   CSTACK:DATA:NOROOT(0)
        RSEG   RSTACK:DATA:NOROOT(0)
        RSEG   BOOTENTRY:CODE:ROOT(1)

          LDI   R17,LOW(SFE(RSTACK)-1)
          OUT   SPL,R17
          LDI   R17,HIGH(SFE(RSTACK)-1)
          OUT   SPH,R17
          
          LDI   YL,LOW(SFE(CSTACK)-1)
          LDI   YH,HIGH(SFE(CSTACK)-1)
//NEAR_Z initialization
        RSEG   STARTUPCODE:CODE:NOROOT(1)
PUBLIC `?<Segment init: NEAR_Z>`
`?<Segment init: NEAR_Z>`:
          lda   Z, SFB(NEAR_Z)
          lda   X, SIZEOF(NEAR_Z)
          clr   r16
filloop:
          st    Z+, r16
          sbiw XL, 1
          brne filloop

//NEAR_I initialization
        RSEG   STARTUPCODE:CODE:NOROOT(1)
PUBLIC `?<Segment init: NEAR_I>`
`?<Segment init: NEAR_I>`:
          lda   Z, SFB(NEAR_ID)
          lda   Y, SFB(NEAR_I)
          lda   X, SIZEOF(NEAR_I)
          
moveloop:
          lpm r0, Z+
          st Y+, r0
          sbiw XL, 1
          brne moveloop

        RSEG   BOOTENTRY:CODE:ROOT(1)
          rjmp boot

EXTERN boot
        RSEG   CSTACK:DATA:NOROOT(0)
        RSEG   RSTACK:DATA:NOROOT(0)
        RSEG   BOOT_ENTRY:CODE:ROOT(1)

          LDI   R17,LOW(SFE(RSTACK)-1)
          OUT   SPL,R17
          LDI   R17,HIGH(SFE(RSTACK)-1)
          OUT   SPH,R17
          
          LDI   YL,LOW(SFE(CSTACK)-1)                                  // тут ругается: illegal effective address
          LDI   YH,HIGH(SFE(CSTACK)-1)                                // тут ругается: illegal effective address
//NEAR_Z initialization
        RSEG   BOOT_ENTRY:CODE:NOROOT(1)                      // тут заменил STARUPCODE на BOOT_ENTRY
PUBLIC `?<Segment init: NEAR_Z>`
`?<Segment init: NEAR_Z>`:
          lda   Z, SFB(NEAR_Z)                                                // тут ругается: bad instruction
          lda   X, SIZEOF(NEAR_Z)                                           // тут ругается: bad instruction
          clr   r16
filloop:
          st    Z+, r16
          sbiw XL, 1                                                                // тут ругается: illegal effective address
          brne filloop

//NEAR_I initialization
        RSEG   BOOT_ENTRY:CODE:NOROOT(1)                      // тут заменил STARUPCODE на BOOT_ENTRY
PUBLIC `?<Segment init: NEAR_I>`
`?<Segment init: NEAR_I>`:
          lda   Z, SFB(NEAR_ID)                                           // тут ругается: bad instruction
          lda   Y, SFB(NEAR_I)                                           // тут ругается: bad instruction
          lda   X, SIZEOF(NEAR_I)                                           // тут ругается: bad instruction
          
moveloop:
          lpm r0, Z+
          st Y+, r0
          sbiw XL, 1                                                                // тут ругается: illegal effective address
          brne moveloop

        RSEG   BOOT_ENTRY:CODE:ROOT(1)
          rjmp boot
                                                                                        // тут ругается unexpected end of file encountered

    END

//**************************************************************************
// lda - load addr to Z, X, or Y pair
lda MACRO rPtr, Offset
     ldi \1L, LOW(Offset)
     ldi \1H, HIGH(Offset)
    ENDM

          lda   Z, SFB(NEAR_Z)

          LD[b]A[/b]   ZL,LOW(SF[b]B[/b](NEAR_Z)-1)
          LD[b]A[/b]   ZH,HIGH(SF[b]B[/b](NEAR_Z)-1)

    RSEG   BOOT_ENTRY:CODE:ROOT(1)

          LDI   R17,LOW(SFE(RSTACK)-1)

    RSEG   BOOT_ENTRY:CODE:ROOT(1)
PUBLIC __program_start
__program_start:
          LDI   R17,LOW(SFE(RSTACK)-1)