版权声明：本文为博主原创文章。 https://blog.csdn.net/u012763833/article/details/75620003
Arduino是一个基于开源代码的快速电子原型开发平台，其由各种型号的Arduino开发板及Arduino IDE组成（官网，中文社区）。目前的Arduino开发板是基于AVR单片机系统开发，并在其基础上作了较完善的软硬件封装，目的是尽量屏蔽底层硬件的影响便于快速开发。
1. Arduino开发板硬件解析，基于Arduino UNO R3.
原理图下载：点我
实物图如下：
开发板硬件主要由 USB 控制器，AVR单片机 Atmega 328P 系统，电源系统及相应的一些外围电路组成。
1. 电源系统，开发板可采用“DC-5”或“USB接口”供电。
2. USB控制器，从原理图可以看出其与Atmega 328P的USART串口相连，用于传输数据；端口PD7用于控制Atmega 328P的复位，已便在Arduino IDE下载程序时，使单片机复位进入Bootloader程序。
通常的AVR单片机开发采用ISP接口下载程序，需要专门的ISP下载器。Arduino为了简化外围设备，采用USB串口下载程序。其原理是将AVR单片机系统程序分为“Bootloader”和“APP”两部分，“Bootloader”负责将USB串口接收的程序通过自编程（ IAP）烧写至Flash，并在一定条件下控制程序跳转至“APP”区执行；“APP”是真正用户编写的程序。（PS: 有些单片机厂商在出厂前已将“Bootloader”固化到单片机，如 STM32 系列单片机，其可通过串口，I2C 等接口程接收用户程序，用户通过控制 BOOT 相关引脚的电平，控制程序跳转。）
3. AVR 单片机 Atmega 328P 系统，含时钟电路、复位电路、I/O端口。
待续。。。
2. Arduino Bootloader源码分析
在Ardunino IDE的安装目录下，个人目录：“E:\Arduino\hardware\arduino\avr\bootloaders\atmega”。
Bootloader主要实现功能：1. 接收外部发送来的程序；2. 将程序烧写到Flash；3. 控制程序跳转。
待续。。。
/**********************************************************/
/* Serial Bootloader for Atmel megaAVR Controllers */
/* */
/* tested with ATmegarduino8, 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 */
/**********************************************************/
/* 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__) || !defined(__AVR_ATmega328__)
#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_ATmega328__
#define SIG2 0x95
#define SIG3 0x14
#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_MODS
ch = 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
#else
asm 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't
put it in a different state than the other pins. --DAM, 070709
This also applies to Arduino Mega -- DC, 080930
BL_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__) || defined (__AVR_ATmega328__)
#ifdef DOUBLE_SPEED
UCSR0A = (1<<U2X0); //Double speed mode USART0
UBRR0L = (uint8_t)(F_CPU/(BAUD_RATE*8L)-1);
UBRR0H = (F_CPU/(BAUD_RATE*8L)-1) >> 8;
#else
UBRR0L = (uint8_t)(F_CPU/(BAUD_RATE*16L)-1);
UBRR0H = (F_CPU/(BAUD_RATE*16L)-1) >> 8;
#endif
UCSR0B = (1<<RXEN0) | (1<<TXEN0);
UCSR0C = (1<<UCSZ00) | (1<<UCSZ01);
/* Enable internal pull-up resistor on pin D0 (RX), in order
to supress line noise that prevents the bootloader from
timing out (DAM: 20070509) */
DDRD &= ~_BV(PIND0);
PORTD |= _BV(PIND0);
#elif defined __AVR_ATmega8__
/* m8 */
UBRRH = (((F_CPU/BAUD_RATE)/16)-1)>>8; // set baud rate
UBRRL = (((F_CPU/BAUD_RATE)/16)-1);
UCSRB = (1<<RXEN)|(1<<TXEN); // enable Rx & Tx
UCSRC = (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 order
to supress line noise that prevents the bootloader from
timing 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 UART1
flash_led(NUM_LED_FLASHES + bootuart);
#else
flash_led(NUM_LED_FLASHES);
#endif
/* 20050803: by DojoCorp, this is one of the parts provoking the
system 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 version
else if(ch2==0x81) byte_response(SW_MAJOR); // Software major version
else if(ch2==0x82) byte_response(SW_MINOR); // Software minor version
else if(ch2==0x98) byte_response(0x03); // Unknown but seems to be required by avr studio 3.56
else 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 time
address.word <<= 1;
for(w=0;w<length.word;w++) {
#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega328__)
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;
#if defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega1281__)
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
#if defined(EEPE)
while(bit_is_set(EECR,EEPE)); //Wait for previous EEPROM writes to complete
#else
while(bit_is_set(EECR,EEWE)); //Wait for previous EEPROM writes to complete
#endif
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__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega328__) || defined(__AVR_ATmega128__) || defined(__AVR_ATmega1280__) || defined(__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, FIXME
else flags.rampz = 0;
#endif
address.word = address.word << 1; // address * 2 -> byte location
if (getch() == 'E') flags.eeprom = 1;
else flags.eeprom = 0;
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
#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega328__)
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__) || defined(__AVR_ATmega1280__)
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);
} 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;
#endif
uint8_t addrl, addrh;
#ifdef CRUMB128
welcome = "ATmegaBOOT / Crumb128 - (C) J.P.Kyle, E.Lins - 050815\n\r";
#elif defined PROBOMEGA128
welcome = "ATmegaBOOT / PROBOmega128 - (C) J.P.Kyle, E.Lins - 050815\n\r";
#elif defined SAVVY128
welcome = "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;
}
}
}
#endif
else if(ch == 'j') {
app_start();
}
} /* end of monitor functions */
}
}
}
/* end of monitor */
#endif
else 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__) || defined (__AVR_ATmega328__)
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__) || defined (__AVR_ATmega328__)
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__) || defined (__AVR_ATmega328__)
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 */