开始研究下Bootloader的代码结构

2015.1.9

粗略看了下,Bootloader主要做了下板卡的初始化   ----->    然后进入for( ; ; )死循环  ----->  循环刷新串口数据   ----->   根据数据做出不同应答   ----->  如果有写数据,则将数据存入buffer     ----->  从buffer 写入EEPROM     ----->  跳转到  app_start()  处执行

写入  EEPROM  的代码过程需要确定。

/**********************************************************/
/* Serial Bootloader for Atmel megaAVR Controllers        */
/*                                                        */
/* tested with ATmega8, ATmega128 and ATmega168           */
/* should work with other mega's, see code for details    */
/*                                                        */
/* ATmegaBOOT.c                                           */
/*                                                        */
/*                                                        */
/* 20090308: integrated Mega changes into main bootloader */
/*           source by D. Mellis                          */
/* 20080930: hacked for Arduino Mega (with the 1280       */
/*           processor, backwards compatible)             */
/*           by D. Cuartielles                            */
/* 20070626: hacked for Arduino Diecimila (which auto-    */
/*           resets when a USB connection is made to it)  */
/*           by D. Mellis                                 */
/* 20060802: hacked for Arduino by D. Cuartielles         */
/*           based on a previous hack by D. Mellis        */
/*           and D. Cuartielles                           */
/*                                                        */
/* Monitor and debug functions were added to the original */
/* code by Dr. Erik Lins, chip45.com. (See below)         */
/*                                                        */
/* Thanks to Karl Pitrich for fixing a bootloader pin     */
/* problem and more informative LED blinking!             */
/*                                                        */
/* For the latest version see:                            */
/* http://www.chip45.com/                                 */
/*                                                        */
/* ------------------------------------------------------ */
/*                                                        */
/* based on stk500boot.c                                  */
/* Copyright (c) 2003, Jason P. Kyle                      */
/* All rights reserved.                                   */
/* see avr1.org for original file and information         */
/*                                                        */
/* This program is free software; you can redistribute it */
/* and/or modify it under the terms of the GNU General    */
/* Public License as published by the Free Software       */
/* Foundation; either version 2 of the License, or        */
/* (at your option) any later version.                    */
/*                                                        */
/* This program is distributed in the hope that it will   */
/* be useful, but WITHOUT ANY WARRANTY; without even the  */
/* implied warranty of MERCHANTABILITY or FITNESS FOR A   */
/* PARTICULAR PURPOSE.  See the GNU General Public        */
/* License for more details.                              */
/*                                                        */
/* You should have received a copy of the GNU General     */
/* Public License along with this program; if not, write  */
/* to the Free Software Foundation, Inc.,                 */
/* 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA */
/*                                                        */
/* Licence can be viewed at                               */
/* http://www.fsf.org/licenses/gpl.txt                    */
/*                                                        */
/* Target = Atmel AVR m128,m64,m32,m16,m8,m162,m163,m169, */
/* m8515,m8535. ATmega161 has a very small boot block so  */
/* isn't supported.                                       */
/*                                                        */
/* Tested with m168                                       */
/**********************************************************//* $Id$ *//* some includes */
#include <inttypes.h>
#include <avr/io.h>
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include <avr/wdt.h>
#include <util/delay.h>/* the current avr-libc eeprom functions do not support the ATmega168 */
/* own eeprom write/read functions are used instead */
#if !defined(__AVR_ATmega168__) || !defined(__AVR_ATmega328P__)
#include <avr/eeprom.h>
#endif/* Use the F_CPU defined in Makefile *//* 20060803: hacked by DojoCorp */
/* 20070626: hacked by David A. Mellis to decrease waiting time for auto-reset */
/* set the waiting time for the bootloader */
/* get this from the Makefile instead */
/* #define MAX_TIME_COUNT (F_CPU>>4) *//* 20070707: hacked by David A. Mellis - after this many errors give up and launch application */
#define MAX_ERROR_COUNT 5/* set the UART baud rate */
/* 20060803: hacked by DojoCorp */
//#define BAUD_RATE   115200
#ifndef BAUD_RATE
#define BAUD_RATE   19200
#endif/* SW_MAJOR and MINOR needs to be updated from time to time to avoid warning message from AVR Studio */
/* never allow AVR Studio to do an update !!!! */
#define HW_VER   0x02
#define SW_MAJOR 0x01
#define SW_MINOR 0x10/* Adjust to suit whatever pin your hardware uses to enter the bootloader */
/* ATmega128 has two UARTS so two pins are used to enter bootloader and select UART */
/* ATmega1280 has four UARTS, but for Arduino Mega, we will only use RXD0 to get code */
/* BL0... means UART0, BL1... means UART1 */
#ifdef __AVR_ATmega128__
#define BL_DDR  DDRF
#define BL_PORT PORTF
#define BL_PIN  PINF
#define BL0     PINF7
#define BL1     PINF6
#elif defined __AVR_ATmega1280__
/* we just don't do anything for the MEGA and enter bootloader on reset anyway*/
#else
/* other ATmegas have only one UART, so only one pin is defined to enter bootloader */
#define BL_DDR  DDRD
#define BL_PORT PORTD
#define BL_PIN  PIND
#define BL      PIND6
#endif/* onboard LED is used to indicate, that the bootloader was entered (3x flashing) */
/* if monitor functions are included, LED goes on after monitor was entered */
#if defined __AVR_ATmega128__ || defined __AVR_ATmega1280__
/* Onboard LED is connected to pin PB7 (e.g. Crumb128, PROBOmega128, Savvy128, Arduino Mega) */
#define LED_DDR  DDRB
#define LED_PORT PORTB
#define LED_PIN  PINB
#define LED      PINB7
#else
/* Onboard LED is connected to pin PB5 in Arduino NG, Diecimila, and Duomilanuove */
/* other boards like e.g. Crumb8, Crumb168 are using PB2 */
#define LED_DDR  DDRB
#define LED_PORT PORTB
#define LED_PIN  PINB
#define LED      PINB5
#endif/* monitor functions will only be compiled when using ATmega128, due to bootblock size constraints */
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__)
#define MONITOR 1
#endif/* define various device id's */
/* manufacturer byte is always the same */
#define SIG1    0x1E    // Yep, Atmel is the only manufacturer of AVR micros.  Single source :(#if defined __AVR_ATmega1280__
#define SIG2    0x97
#define SIG3    0x03
#define PAGE_SIZE   0x80U   //128 words#elif defined __AVR_ATmega1281__
#define SIG2    0x97
#define SIG3    0x04
#define PAGE_SIZE   0x80U   //128 words#elif defined __AVR_ATmega128__
#define SIG2    0x97
#define SIG3    0x02
#define PAGE_SIZE   0x80U   //128 words#elif defined __AVR_ATmega64__
#define SIG2    0x96
#define SIG3    0x02
#define PAGE_SIZE   0x80U   //128 words#elif defined __AVR_ATmega32__
#define SIG2    0x95
#define SIG3    0x02
#define PAGE_SIZE   0x40U   //64 words#elif defined __AVR_ATmega16__
#define SIG2    0x94
#define SIG3    0x03
#define PAGE_SIZE   0x40U   //64 words#elif defined __AVR_ATmega8__
#define SIG2    0x93
#define SIG3    0x07
#define PAGE_SIZE   0x20U   //32 words#elif defined __AVR_ATmega88__
#define SIG2    0x93
#define SIG3    0x0a
#define PAGE_SIZE   0x20U   //32 words#elif defined __AVR_ATmega168__
#define SIG2    0x94
#define SIG3    0x06
#define PAGE_SIZE   0x40U   //64 words#elif defined __AVR_ATmega328P__
#define SIG2    0x95
#define SIG3    0x0F
#define PAGE_SIZE   0x40U   //64 words#elif defined __AVR_ATmega162__
#define SIG2    0x94
#define SIG3    0x04
#define PAGE_SIZE   0x40U   //64 words#elif defined __AVR_ATmega163__
#define SIG2    0x94
#define SIG3    0x02
#define PAGE_SIZE   0x40U   //64 words#elif defined __AVR_ATmega169__
#define SIG2    0x94
#define SIG3    0x05
#define PAGE_SIZE   0x40U   //64 words#elif defined __AVR_ATmega8515__
#define SIG2    0x93
#define SIG3    0x06
#define PAGE_SIZE   0x20U   //32 words#elif defined __AVR_ATmega8535__
#define SIG2    0x93
#define SIG3    0x08
#define PAGE_SIZE   0x20U   //32 words
#endif/* function prototypes */
void putch(char);
char getch(void);
void getNch(uint8_t);
void byte_response(uint8_t);
void nothing_response(void);
char gethex(void);
void puthex(char);
void flash_led(uint8_t);/* some variables */
union address_union {uint16_t word;uint8_t  byte[2];
} address;union length_union {uint16_t word;uint8_t  byte[2];
} length;struct flags_struct {unsigned eeprom : 1;unsigned rampz  : 1;
} flags;uint8_t buff[256];
uint8_t address_high;uint8_t pagesz=0x80;uint8_t i;
uint8_t bootuart = 0;uint8_t error_count = 0;void (*app_start)(void) = 0x0000;/* main program starts here */
int main(void)
{uint8_t ch,ch2;uint16_t w;#ifdef WATCHDOG_MODSch = MCUSR;MCUSR = 0;WDTCSR |= _BV(WDCE) | _BV(WDE);WDTCSR = 0;// Check if the WDT was used to reset, in which case we dont bootload and skip straight to the code. woot.if (! (ch &  _BV(EXTRF))) // if its a not an external reset...app_start();  // skip bootloader
#elseasm volatile("nop\n\t");
#endif/* set pin direction for bootloader pin and enable pullup *//* for ATmega128, two pins need to be initialized */
#ifdef __AVR_ATmega128__BL_DDR &= ~_BV(BL0);BL_DDR &= ~_BV(BL1);BL_PORT |= _BV(BL0);BL_PORT |= _BV(BL1);
#else/* We run the bootloader regardless of the state of this pin.  Thus, don'tput it in a different state than the other pins.  --DAM, 070709This also applies to Arduino Mega -- DC, 080930BL_DDR &= ~_BV(BL);BL_PORT |= _BV(BL);*/
#endif#ifdef __AVR_ATmega128__/* check which UART should be used for booting */if(bit_is_clear(BL_PIN, BL0)) {bootuart = 1;}else if(bit_is_clear(BL_PIN, BL1)) {bootuart = 2;}
#endif#if defined __AVR_ATmega1280__/* the mega1280 chip has four serial ports ... we could eventually use any of them, or not? *//* however, we don't wanna confuse people, to avoid making a mess, we will stick to RXD0, TXD0 */bootuart = 1;
#endif/* check if flash is programmed already, if not start bootloader anyway */if(pgm_read_byte_near(0x0000) != 0xFF) {#ifdef __AVR_ATmega128__/* no UART was selected, start application */if(!bootuart) {app_start();}
#else/* check if bootloader pin is set low *//* we don't start this part neither for the m8, nor m168 *///if(bit_is_set(BL_PIN, BL)) {//      app_start();//    }
#endif}#ifdef __AVR_ATmega128__    /* no bootuart was selected, default to uart 0 */if(!bootuart) {bootuart = 1;}
#endif/* initialize UART(s) depending on CPU defined */
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__)if(bootuart == 1) {UBRR0L = (uint8_t)(F_CPU/(BAUD_RATE*16L)-1);UBRR0H = (F_CPU/(BAUD_RATE*16L)-1) >> 8;UCSR0A = 0x00;UCSR0C = 0x06;UCSR0B = _BV(TXEN0)|_BV(RXEN0);}if(bootuart == 2) {UBRR1L = (uint8_t)(F_CPU/(BAUD_RATE*16L)-1);UBRR1H = (F_CPU/(BAUD_RATE*16L)-1) >> 8;UCSR1A = 0x00;UCSR1C = 0x06;UCSR1B = _BV(TXEN1)|_BV(RXEN1);}
#elif defined __AVR_ATmega163__UBRR = (uint8_t)(F_CPU/(BAUD_RATE*16L)-1);UBRRHI = (F_CPU/(BAUD_RATE*16L)-1) >> 8;UCSRA = 0x00;UCSRB = _BV(TXEN)|_BV(RXEN);
#elif defined(__AVR_ATmega168__) || defined(__AVR_ATmega328P__)#ifdef DOUBLE_SPEEDUCSR0A = (1<<U2X0); //Double speed mode USART0UBRR0L = (uint8_t)(F_CPU/(BAUD_RATE*8L)-1);UBRR0H = (F_CPU/(BAUD_RATE*8L)-1) >> 8;
#elseUBRR0L = (uint8_t)(F_CPU/(BAUD_RATE*16L)-1);UBRR0H = (F_CPU/(BAUD_RATE*16L)-1) >> 8;
#endifUCSR0B = (1<<RXEN0) | (1<<TXEN0);UCSR0C = (1<<UCSZ00) | (1<<UCSZ01);/* Enable internal pull-up resistor on pin D0 (RX), in orderto supress line noise that prevents the bootloader fromtiming out (DAM: 20070509) */DDRD &= ~_BV(PIND0);PORTD |= _BV(PIND0);
#elif defined __AVR_ATmega8__/* m8 */UBRRH = (((F_CPU/BAUD_RATE)/16)-1)>>8;  // set baud rateUBRRL = (((F_CPU/BAUD_RATE)/16)-1);UCSRB = (1<<RXEN)|(1<<TXEN);  // enable Rx & TxUCSRC = (1<<URSEL)|(1<<UCSZ1)|(1<<UCSZ0);  // config USART; 8N1
#else/* m16,m32,m169,m8515,m8535 */UBRRL = (uint8_t)(F_CPU/(BAUD_RATE*16L)-1);UBRRH = (F_CPU/(BAUD_RATE*16L)-1) >> 8;UCSRA = 0x00;UCSRC = 0x06;UCSRB = _BV(TXEN)|_BV(RXEN);
#endif#if defined __AVR_ATmega1280__/* Enable internal pull-up resistor on pin D0 (RX), in orderto supress line noise that prevents the bootloader fromtiming out (DAM: 20070509) *//* feature added to the Arduino Mega --DC: 080930 */DDRE &= ~_BV(PINE0);PORTE |= _BV(PINE0);
#endif/* set LED pin as output */LED_DDR |= _BV(LED);/* flash onboard LED to signal entering of bootloader */
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__)// 4x for UART0, 5x for UART1flash_led(NUM_LED_FLASHES + bootuart);
#elseflash_led(NUM_LED_FLASHES);
#endif/* 20050803: by DojoCorp, this is one of the parts provoking thesystem to stop listening, cancelled from the original *///putch('\0');/* forever loop */for (;;) {/* get character from UART */ch = getch();/* A bunch of if...else if... gives smaller code than switch...case ! *//* Hello is anyone home ? */ if(ch=='0') {nothing_response();}/* Request programmer ID *//* Not using PROGMEM string due to boot block in m128 being beyond 64kB boundry  *//* Would need to selectively manipulate RAMPZ, and it's only 9 characters anyway so who cares.  */else if(ch=='1') {if (getch() == ' ') {putch(0x14);putch('A');putch('V');putch('R');putch(' ');putch('I');putch('S');putch('P');putch(0x10);} else {if (++error_count == MAX_ERROR_COUNT)app_start();}}/* AVR ISP/STK500 board commands  DON'T CARE so default nothing_response */else if(ch=='@') {ch2 = getch();if (ch2>0x85) getch();nothing_response();}/* AVR ISP/STK500 board requests */else if(ch=='A') {ch2 = getch();if(ch2==0x80) byte_response(HW_VER);      // Hardware versionelse if(ch2==0x81) byte_response(SW_MAJOR);    // Software major versionelse if(ch2==0x82) byte_response(SW_MINOR);  // Software minor versionelse if(ch2==0x98) byte_response(0x03);      // Unknown but seems to be required by avr studio 3.56else byte_response(0x00);             // Covers various unnecessary responses we don't care about}/* Device Parameters  DON'T CARE, DEVICE IS FIXED  */else if(ch=='B') {getNch(20);nothing_response();}/* Parallel programming stuff  DON'T CARE  */else if(ch=='E') {getNch(5);nothing_response();}/* P: Enter programming mode  *//* R: Erase device, don't care as we will erase one page at a time anyway.  */else if(ch=='P' || ch=='R') {nothing_response();}/* Leave programming mode  */else if(ch=='Q') {nothing_response();
#ifdef WATCHDOG_MODS// autoreset via watchdog (sneaky!)WDTCSR = _BV(WDE);while (1); // 16 ms
#endif}/* 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') {if (getch() == 0x30) {getch();ch = getch();getch();if (ch == 0) {byte_response(SIG1);} else if (ch == 1) {byte_response(SIG2); } else {byte_response(SIG3);} } else {getNch(3);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 timeaddress.word <<= 1;for(w=0;w<length.word;w++) {
#if defined(__AVR_ATmega168__)  || defined(__AVR_ATmega328P__)while(EECR & (1<<EEPE));EEAR = (uint16_t)(void *)address.word;EEDR = buff[w];EECR |= (1<<EEMPE);EECR |= (1<<EEPE);
#elseeeprom_write_byte((void *)address.word,buff[w]);
#endifaddress.word++;}            }else {                         //Write to FLASH one page at a timeif (address.byte[1]>127) address_high = 0x01;    //Only possible with m128, m256 will need 3rd address byte. FIXMEelse address_high = 0x00;
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega1281__)RAMPZ = address_high;
#endifaddress.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 bytescli();                  //Disable interrupts, just to be sure
#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega1281__)while(bit_is_set(EECR,EEPE));         //Wait for previous EEPROM writes to complete
#elsewhile(bit_is_set(EECR,EEWE));          //Wait for previous EEPROM writes to complete
#endifasm 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__  || __AVR_ATmega328P__ || __AVR_ATmega128__ || __AVR_ATmega1280__ || __AVR_ATmega1281__ : "=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);} else {if (++error_count == MAX_ERROR_COUNT)app_start();}       }/* Read memory block mode, length is big endian.  */else if(ch=='t') {length.byte[1] = getch();length.byte[0] = getch();
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__)if (address.word>0x7FFF) flags.rampz = 1;      // No go with m256, FIXMEelse flags.rampz = 0;
#endifaddress.word = address.word << 1;          // address * 2 -> byte locationif (getch() == 'E') flags.eeprom = 1;else flags.eeprom = 0;if (getch() == ' ') {                        // Command terminatorputch(0x14);for (w=0;w < length.word;w++) {              // Can handle odd and even lengths okayif (flags.eeprom) {                          // Byte access EEPROM read
#if defined(__AVR_ATmega168__)  || defined(__AVR_ATmega328P__)while(EECR & (1<<EEPE));EEAR = (uint16_t)(void *)address.word;EECR |= (1<<EERE);putch(EEDR);
#elseputch(eeprom_read_byte((void *)address.word));
#endifaddress.word++;}else {if (!flags.rampz) putch(pgm_read_byte_near(address.word));
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__)else putch(pgm_read_byte_far(address.word + 0x10000));// Hmmmm, yuck  FIXME when m256 arrvies
#endifaddress.word++;}}putch(0x10);}}/* Get device signature bytes  */else if(ch=='u') {if (getch() == ' ') {putch(0x14);putch(SIG1);putch(SIG2);putch(SIG3);putch(0x10);} else {if (++error_count == MAX_ERROR_COUNT)app_start();}}/* Read oscillator calibration byte */else if(ch=='v') {byte_response(0x00);}#if defined MONITOR /* here come the extended monitor commands by Erik Lins *//* check for three times exclamation mark pressed */else if(ch=='!') {ch = getch();if(ch=='!') {ch = getch();if(ch=='!') {PGM_P welcome = "";
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__)uint16_t extaddr;
#endifuint8_t addrl, addrh;#ifdef CRUMB128welcome = "ATmegaBOOT / Crumb128 - (C) J.P.Kyle, E.Lins - 050815\n\r";
#elif defined PROBOMEGA128welcome = "ATmegaBOOT / PROBOmega128 - (C) J.P.Kyle, E.Lins - 050815\n\r";
#elif defined SAVVY128welcome = "ATmegaBOOT / Savvy128 - (C) J.P.Kyle, E.Lins - 050815\n\r";
#elif defined __AVR_ATmega1280__ welcome = "ATmegaBOOT / Arduino Mega - (C) Arduino LLC - 090930\n\r";
#endif/* turn on LED */LED_DDR |= _BV(LED);LED_PORT &= ~_BV(LED);/* print a welcome message and command overview */for(i=0; welcome[i] != '\0'; ++i) {putch(welcome[i]);}/* test for valid commands */for(;;) {putch('\n');putch('\r');putch(':');putch(' ');ch = getch();putch(ch);/* toggle LED */if(ch == 't') {if(bit_is_set(LED_PIN,LED)) {LED_PORT &= ~_BV(LED);putch('1');} else {LED_PORT |= _BV(LED);putch('0');}} /* read byte from address */else if(ch == 'r') {ch = getch(); putch(ch);addrh = gethex();addrl = gethex();putch('=');ch = *(uint8_t *)((addrh << 8) + addrl);puthex(ch);}/* write a byte to address  */else if(ch == 'w') {ch = getch(); putch(ch);addrh = gethex();addrl = gethex();ch = getch(); putch(ch);ch = gethex();*(uint8_t *)((addrh << 8) + addrl) = ch;}/* read from uart and echo back */else if(ch == 'u') {for(;;) {putch(getch());}}
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__)/* external bus loop  */else if(ch == 'b') {putch('b');putch('u');putch('s');MCUCR = 0x80;XMCRA = 0;XMCRB = 0;extaddr = 0x1100;for(;;) {ch = *(volatile uint8_t *)extaddr;if(++extaddr == 0) {extaddr = 0x1100;}}}
#endifelse if(ch == 'j') {app_start();}} /* end of monitor functions */}}}/* end of monitor */
#endifelse if (++error_count == MAX_ERROR_COUNT) {app_start();}} /* end of forever loop */}char gethexnib(void) {char a;a = getch(); putch(a);if(a >= 'a') {return (a - 'a' + 0x0a);} else if(a >= '0') {return(a - '0');}return a;
}char gethex(void) {return (gethexnib() << 4) + gethexnib();
}void puthex(char ch) {char ah;ah = ch >> 4;if(ah >= 0x0a) {ah = ah - 0x0a + 'a';} else {ah += '0';}ch &= 0x0f;if(ch >= 0x0a) {ch = ch - 0x0a + 'a';} else {ch += '0';}putch(ah);putch(ch);
}void putch(char ch)
{
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__)if(bootuart == 1) {while (!(UCSR0A & _BV(UDRE0)));UDR0 = ch;}else if (bootuart == 2) {while (!(UCSR1A & _BV(UDRE1)));UDR1 = ch;}
#elif defined(__AVR_ATmega168__)  || defined(__AVR_ATmega328P__)while (!(UCSR0A & _BV(UDRE0)));UDR0 = ch;
#else/* m8,16,32,169,8515,8535,163 */while (!(UCSRA & _BV(UDRE)));UDR = ch;
#endif
}char getch(void)
{
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__)uint32_t count = 0;if(bootuart == 1) {while(!(UCSR0A & _BV(RXC0))) {/* 20060803 DojoCorp:: Addon coming from the previous Bootloader*/               /* HACKME:: here is a good place to count times*/count++;if (count > MAX_TIME_COUNT)app_start();}return UDR0;}else if(bootuart == 2) {while(!(UCSR1A & _BV(RXC1))) {/* 20060803 DojoCorp:: Addon coming from the previous Bootloader*/               /* HACKME:: here is a good place to count times*/count++;if (count > MAX_TIME_COUNT)app_start();}return UDR1;}return 0;
#elif defined(__AVR_ATmega168__)  || defined(__AVR_ATmega328P__)uint32_t count = 0;while(!(UCSR0A & _BV(RXC0))){/* 20060803 DojoCorp:: Addon coming from the previous Bootloader*/               /* HACKME:: here is a good place to count times*/count++;if (count > MAX_TIME_COUNT)app_start();}return UDR0;
#else/* m8,16,32,169,8515,8535,163 */uint32_t count = 0;while(!(UCSRA & _BV(RXC))){/* 20060803 DojoCorp:: Addon coming from the previous Bootloader*/               /* HACKME:: here is a good place to count times*/count++;if (count > MAX_TIME_COUNT)app_start();}return UDR;
#endif
}void getNch(uint8_t count)
{while(count--) {
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__)if(bootuart == 1) {while(!(UCSR0A & _BV(RXC0)));UDR0;} else if(bootuart == 2) {while(!(UCSR1A & _BV(RXC1)));UDR1;}
#elif defined(__AVR_ATmega168__)  || defined(__AVR_ATmega328P__)getch();
#else/* m8,16,32,169,8515,8535,163 *//* 20060803 DojoCorp:: Addon coming from the previous Bootloader*/               //while(!(UCSRA & _BV(RXC)));//UDR;getch(); // need to handle time out
#endif      }
}void byte_response(uint8_t val)
{if (getch() == ' ') {putch(0x14);putch(val);putch(0x10);} else {if (++error_count == MAX_ERROR_COUNT)app_start();}
}void nothing_response(void)
{if (getch() == ' ') {putch(0x14);putch(0x10);} else {if (++error_count == MAX_ERROR_COUNT)app_start();}
}void flash_led(uint8_t count)
{while (count--) {LED_PORT |= _BV(LED);_delay_ms(100);LED_PORT &= ~_BV(LED);_delay_ms(100);}
}/* end of file ATmegaBOOT.c */

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