atmegaboot.c

AVR全系列BOOTLOADER源程序 WINAVR GCC编译.

	    getNch(20);
	    nothing_response();
	}


	/* Parallel programming stuff  DON'T CARE  */
	else if(ch=='E') {
	    getNch(5);
	    nothing_response();
	}


	/* Enter programming mode  */
	else if(ch=='P') {
	    nothing_response();
	}


	/* Leave programming mode  */
	else if(ch=='Q') {
	    nothing_response();
	}


	/* Erase device, don't care as we will erase one page at a time anyway.  */
	else if(ch=='R') {
	    nothing_response();
	}


	/* Set address, little endian. EEPROM in bytes, FLASH in words  */
	/* Perhaps extra address bytes may be added in future to support > 128kB FLASH.  */
	/* This might explain why little endian was used here, big endian used everywhere else.  */
	else if(ch=='U') {
	    address.byte[0] = getch();
	    address.byte[1] = getch();
	    nothing_response();
	}


	/* Universal SPI programming command, disabled.  Would be used for fuses and lock bits.  */
	else if(ch=='V') {
	    getNch(4);
	    byte_response(0x00);
	}


	/* Write memory, length is big endian and is in bytes  */
	else if(ch=='d') {
	    length.byte[1] = getch();
	    length.byte[0] = getch();
	    flags.eeprom = 0;
	    if (getch() == 'E') flags.eeprom = 1;
	    for (w=0;w<length.word;w++) {
		buff[w] = getch();	                        // Store data in buffer, can't keep up with serial data stream whilst programming pages
	    }
	    if (getch() == ' ') {
		if (flags.eeprom) {		                //Write to EEPROM one byte at a time
		    for(w=0;w<length.word;w++) {
#ifdef __AVR_ATmega168__
			while(EECR & (1<<EEPE));
			EEAR = (uint16_t)(void *)address.word;
			EEDR = buff[w];
			EECR |= (1<<EEMPE);
			EECR |= (1<<EEPE);
#else
			eeprom_write_byte((void *)address.word,buff[w]);
#endif
			address.word++;
		    }			
		}
		else {					        //Write to FLASH one page at a time
		    if (address.byte[1]>127) address_high = 0x01;	//Only possible with m128, m256 will need 3rd address byte. FIXME
		    else address_high = 0x00;
#ifdef __AVR_ATmega128__
		    RAMPZ = address_high;
#endif
		    address.word = address.word << 1;	        //address * 2 -> byte location
		    /* if ((length.byte[0] & 0x01) == 0x01) length.word++;	//Even up an odd number of bytes */
		    if ((length.byte[0] & 0x01)) length.word++;	//Even up an odd number of bytes
		    cli();					//Disable interrupts, just to be sure
		    while(bit_is_set(EECR,EEWE));			//Wait for previous EEPROM writes to complete
		    asm volatile(
				 "clr	r17		\n\t"	//page_word_count
				 "lds	r30,address	\n\t"	//Address of FLASH location (in bytes)
				 "lds	r31,address+1	\n\t"
				 "ldi	r28,lo8(buff)	\n\t"	//Start of buffer array in RAM
				 "ldi	r29,hi8(buff)	\n\t"
				 "lds	r24,length	\n\t"	//Length of data to be written (in bytes)
				 "lds	r25,length+1	\n\t"
				 "length_loop:		\n\t"	//Main loop, repeat for number of words in block							 							 
				 "cpi	r17,0x00	\n\t"	//If page_word_count=0 then erase page
				 "brne	no_page_erase	\n\t"						 
				 "wait_spm1:		\n\t"
				 "lds	r16,%0		\n\t"	//Wait for previous spm to complete
				 "andi	r16,1           \n\t"
				 "cpi	r16,1           \n\t"
				 "breq	wait_spm1       \n\t"
				 "ldi	r16,0x03	\n\t"	//Erase page pointed to by Z
				 "sts	%0,r16		\n\t"
				 "spm			\n\t"							 
#ifdef __AVR_ATmega163__
				 ".word 0xFFFF		\n\t"
				 "nop			\n\t"
#endif
				 "wait_spm2:		\n\t"
				 "lds	r16,%0		\n\t"	//Wait for previous spm to complete
				 "andi	r16,1           \n\t"
				 "cpi	r16,1           \n\t"
				 "breq	wait_spm2       \n\t"									 

				 "ldi	r16,0x11	\n\t"	//Re-enable RWW section
				 "sts	%0,r16		\n\t"						 			 
				 "spm			\n\t"
#ifdef __AVR_ATmega163__
				 ".word 0xFFFF		\n\t"
				 "nop			\n\t"
#endif
				 "no_page_erase:		\n\t"							 
				 "ld	r0,Y+		\n\t"	//Write 2 bytes into page buffer
				 "ld	r1,Y+		\n\t"							 
							 
				 "wait_spm3:		\n\t"
				 "lds	r16,%0		\n\t"	//Wait for previous spm to complete
				 "andi	r16,1           \n\t"
				 "cpi	r16,1           \n\t"
				 "breq	wait_spm3       \n\t"
				 "ldi	r16,0x01	\n\t"	//Load r0,r1 into FLASH page buffer
				 "sts	%0,r16		\n\t"
				 "spm			\n\t"
							 
				 "inc	r17		\n\t"	//page_word_count++
				 "cpi r17,%1	        \n\t"
				 "brlo	same_page	\n\t"	//Still same page in FLASH
				 "write_page:		\n\t"
				 "clr	r17		\n\t"	//New page, write current one first
				 "wait_spm4:		\n\t"
				 "lds	r16,%0		\n\t"	//Wait for previous spm to complete
				 "andi	r16,1           \n\t"
				 "cpi	r16,1           \n\t"
				 "breq	wait_spm4       \n\t"
#ifdef __AVR_ATmega163__
				 "andi	r30,0x80	\n\t"	// m163 requires Z6:Z1 to be zero during page write
#endif							 							 
				 "ldi	r16,0x05	\n\t"	//Write page pointed to by Z
				 "sts	%0,r16		\n\t"
				 "spm			\n\t"
#ifdef __AVR_ATmega163__
				 ".word 0xFFFF		\n\t"
				 "nop			\n\t"
				 "ori	r30,0x7E	\n\t"	// recover Z6:Z1 state after page write (had to be zero during write)
#endif
				 "wait_spm5:		\n\t"
				 "lds	r16,%0		\n\t"	//Wait for previous spm to complete
				 "andi	r16,1           \n\t"
				 "cpi	r16,1           \n\t"
				 "breq	wait_spm5       \n\t"									 
				 "ldi	r16,0x11	\n\t"	//Re-enable RWW section
				 "sts	%0,r16		\n\t"						 			 
				 "spm			\n\t"					 		 
#ifdef __AVR_ATmega163__
				 ".word 0xFFFF		\n\t"
				 "nop			\n\t"
#endif
				 "same_page:		\n\t"							 
				 "adiw	r30,2		\n\t"	//Next word in FLASH
				 "sbiw	r24,2		\n\t"	//length-2
				 "breq	final_write	\n\t"	//Finished
				 "rjmp	length_loop	\n\t"
				 "final_write:		\n\t"
				 "cpi	r17,0		\n\t"
				 "breq	block_done	\n\t"
				 "adiw	r24,2		\n\t"	//length+2, fool above check on length after short page write
				 "rjmp	write_page	\n\t"
				 "block_done:		\n\t"
				 "clr	__zero_reg__	\n\t"	//restore zero register
#if defined __AVR_ATmega168__
				 : "=m" (SPMCSR) : "M" (PAGE_SIZE) : "r0","r16","r17","r24","r25","r28","r29","r30","r31"
#else
				 : "=m" (SPMCR) : "M" (PAGE_SIZE) : "r0","r16","r17","r24","r25","r28","r29","r30","r31"
#endif
				 );
		    /* Should really add a wait for RWW section to be enabled, don't actually need it since we never */
		    /* exit the bootloader without a power cycle anyhow */
		}
		putch(0x14);
		putch(0x10);
	    }		
	}
    

        /* Read memory block mode, length is big endian.  */
        else if(ch=='t') {
	    length.byte[1] = getch();
	    length.byte[0] = getch();
#if defined __AVR_ATmega128__
	    if (address.word>0x7FFF) flags.rampz = 1;		// No go with m256, FIXME
	    else flags.rampz = 0;
#endif
	    if (getch() == 'E') flags.eeprom = 1;
	    else {
		flags.eeprom = 0;
		address.word = address.word << 1;	        // address * 2 -> byte location
	    }
	    if (getch() == ' ') {		                // Command terminator
		putch(0x14);
		for (w=0;w < length.word;w++) {		        // Can handle odd and even lengths okay
		    if (flags.eeprom) {	                        // Byte access EEPROM read
#ifdef __AVR_ATmega168__
			while(EECR & (1<<EEPE));
			EEAR = (uint16_t)(void *)address.word;
			EECR |= (1<<EERE);
			putch(EEDR);
#else
			putch(eeprom_read_byte((void *)address.word));
#endif
			address.word++;
		    }
		    else {

			if (!flags.rampz) putch(pgm_read_byte_near(address.word));
#if defined __AVR_ATmega128__
			else putch(pgm_read_byte_far(address.word + 0x10000));
			// Hmmmm, yuck  FIXME when m256 arrvies
#endif
			address.word++;
		    }
		}
		putch(0x10);
	    }
	}


        /* Get device signature bytes  */
        else if(ch=='u') {
	    if (getch() == ' ') {
		putch(0x14);
		putch(SIG1);
		putch(SIG2);
		putch(SIG3);
		putch(0x10);
	    }
	}


        /* Read oscillator calibration byte */
        else if(ch=='v') {
	    byte_response(0x00);
	}




    }
    /* end of forever loop */

}


char gethex(void) {
    char ah,al;

    ah = getch(); putch(ah);
    al = getch(); putch(al);
    if(ah >= 'a') {
	ah = ah - 'a' + 0x0a;
    } else if(ah >= '0') {
	ah -= '0';
    }
    if(al >= 'a') {
	al = al - 'a' + 0x0a;
    } else if(al >= '0') {
	al -= '0';
    }
    return (ah << 4) + al;
}


void puthex(char ch) {
    char ah,al;

    ah = (ch & 0xf0) >> 4;
    if(ah >= 0x0a) {
	ah = ah - 0x0a + 'a';
    } else {
	ah += '0';
    }
    al = (ch & 0x0f);
    if(al >= 0x0a) {
	al = al - 0x0a + 'a';
    } else {
	al += '0';
    }
    putch(ah);
    putch(al);
}


void putch(char ch)
{
#ifdef __AVR_ATmega128__
    if(bootuart == 1) {
	while (!(UCSR0A & _BV(UDRE0)));
	UDR0 = ch;
    }
    else if (bootuart == 2) {
	while (!(UCSR1A & _BV(UDRE1)));
	UDR1 = ch;
    }
#elif defined __AVR_ATmega168__
    while (!(UCSR0A & _BV(UDRE0)));
    UDR0 = ch;
#else
    /* m8,16,32,169,8515,8535,163 */
    while (!(UCSRA & _BV(UDRE)));
    UDR = ch;
#endif
}


char getch(void)
{
#ifdef __AVR_ATmega128__
    if(bootuart == 1) {
	while(!(UCSR0A & _BV(RXC0)));
	return UDR0;
    }
    else if(bootuart == 2) {
	while(!(UCSR1A & _BV(RXC1)));
	return UDR1;
    }
    return 0;
#elif defined __AVR_ATmega168__
    while(!(UCSR0A & _BV(RXC0)));
    return UDR0;
#else
    /* m8,16,32,169,8515,8535,163 */
    while(!(UCSRA & _BV(RXC)));
    return UDR;
#endif
}


void getNch(uint8_t count)
{
    uint8_t i;
    for(i=0;i<count;i++) {
#ifdef __AVR_ATmega128__
	if(bootuart == 1) {
	    while(!(UCSR0A & _BV(RXC0)));
	    UDR0;
	} 
	else if(bootuart == 2) {
	    while(!(UCSR1A & _BV(RXC1)));
	    UDR1;
	}
#elif defined __AVR_ATmega168__
	while(!(UCSR0A & _BV(RXC0)));
	UDR0;
#else
	/* m8,16,32,169,8515,8535,163 */
	while(!(UCSRA & _BV(RXC)));
	UDR;
#endif		
    }
}


void byte_response(uint8_t val)
{
    if (getch() == ' ') {
	putch(0x14);
	putch(val);
	putch(0x10);
    }
}


void nothing_response(void)
{
    if (getch() == ' ') {
	putch(0x14);
	putch(0x10);
    }
}

void flash_led(uint8_t count)
{
    /* flash onboard LED three times to signal entering of bootloader */
    uint32_t l;

    if (count == 0) {
      count = 3;
    }
    
    for (i = 0; i < count; ++i) {
	LED_PORT &= ~_BV(LED);
	for(l = 0; l < (F_CPU / 5); ++l);
	LED_PORT |= _BV(LED);
	for(l = 0; l < (2 * F_CPU); ++l);
    }
}


/* end of file ATmegaBOOT.c */