This is an old revision of the document!
// /* Serial Bootloader for Atmel mega8 AVR Controller */ /* */ /* ATmegaBOOT.c */ /* */ /* Copyright © 2003, Jason P. Kyle */ /* */ /* Hacked by DojoCorp - ZGZ - MMX - IVR */ /* Hacked by David A. Mellis */ /* */ /* 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 m8 */ //
#include <inttypes.h> #include <avr/io.h> #include <avr/pgmspace.h> #include <avr/eeprom.h> #include <avr/interrupt.h> #include <avr/delay.h>
#define F_CPU 16000000
/* We, Malmoitians, like slow interaction
* therefore the slow baud rate 
*/
#define BAUD_RATE 9600
/* 6.000.000 is more or less 8 seconds at the * speed configured here */ #define MAX_TIME_COUNT 6000000 #define MAX_TIME_COUNT (F_CPU»1) /#define MAX_TIME_COUNT_MORATORY 1600000
/* SW_MAJOR and MINOR needs to be updated from time to time to avoid warning message from AVR Studio */ #define HW_VER 0x02 #define SW_MAJOR 0x01 #define SW_MINOR 0x12
AVR-GCC compiler compatibility avr-gcc compiler v3.1.x and older doesn't support outb() and inb() if necessary, convert outb and inb to outp and inp #ifndef outb #define outb(sfr,val) (_SFR_BYTE(sfr) = (val)) #endif #ifndef inb #define inb(sfr) _SFR_BYTE(sfr) #endif /* defines for future compatibility */ #ifndef cbi #define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit)) #endif #ifndef sbi #define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit)) #endif /* Adjust to suit whatever pin your hardware uses to enter the bootloader */ #define eeprom_rb(addr) eeprom_read_byte 1) #define eeprom_rw(addr) eeprom_read_word 2) #define eeprom_wb(addr, val) eeprom_write_byte 3) /* Onboard LED is connected to pin PB5 */ #define LED_DDR DDRB #define LED_PORT PORTB #define LED_PIN PINB #define LED PINB5 #define SIG1 0x1E Yep, Atmel is the only manufacturer of AVR micros. Single source :( #define SIG2 0x93 #define SIG3 0x07 #define PAGE_SIZE 0x20U 32 words void putch(char); char getch(void); void getNch(uint8_t); void byte_response(uint8_t); void nothing_response(void); 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 bootuart0=0,bootuart1=0; void (*app_start)(void) = 0x0000; int main(void) { uint8_t ch,ch2; uint16_t w; cbi(BL_DDR,BL);
//sbi(BL_PORT,BL);
asm volatile("nop\n\t");
/* check if flash is programmed already, if not start bootloader anyway */
//if(pgm_read_byte_near(0x0000) != 0xFF) {
/* check if bootloader pin is set low */ //if(bit_is_set(BL_PIN,BL)) app_start(); //}
/* initialize UART(s) depending on CPU defined */ /* 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
//UBRRL = (uint8_t)(F_CPU/(BAUD_RATE*16L)-1); //UBRRH = (F_CPU/(BAUD_RATE*16L)-1) >> 8; //UCSRA = 0x00; //UCSRC = 0x86; //UCSRB = _BV(TXEN)|_BV(RXEN);
/* this was giving uisp problems, so I removed it; without it, the boot
works on with uisp and avrdude on the mac (at least). */
//putch('\0');
//uint32_t l; //uint32_t time_count; //time_count=0;
/* set LED pin as output */
sbi(LED_DDR,LED);
for (i = 0; i < 16; i++) {
outb(LED_PORT, inb(LED_PORT) ^ _BV(LED));
_delay_loop_2(0);
}
//for (l=0; l<40000000; l++)
//outb(LED_PORT, inb(LED_PORT) ^= _BV(LED));
/* flash onboard LED three times to signal entering of bootloader */
//for(i=0; i<3; ++i) {
//for(l=0; l<40000000; ++l);
//sbi(LED_PORT,LED);
//for(l=0; l<40000000; ++l);
//cbi(LED_PORT,LED);
//}
/* see comment at previous call to putch() */ putch('\0'); this line is needed for the synchronization of the programmer
/* forever */
for (;;) {
//if((inb(UCSRA) & _BV(RXC))){
/* 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);
}
}
/* 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();
}
/* Enter programming mode */
else if(ch=='P') {
nothing_response();
// FIXME: modified only here by DojoCorp, Mumbai, India, 20050626
//time_count=0; // exted the delay once entered prog.mode
}
/* Leave programming mode */
else if(ch=='Q') {
nothing_response();
//time_count=MAX_TIME_COUNT_MORATORY; // once the programming is done,
// we should start the application
// but uisp has problems with this,
// therefore we just change the times
// and give the programmer 1 sec to react
}
/* 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++) {
eeprom_wb(address.word,buff[w]);
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;
//address.word = address.word << 1; //address * 2 -> byte location
//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 words)
"lds r31,address+1 \n\t"
"lsl r30 \n\t" //address * 2 -> byte location
"rol r31 \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"
"sbrs r24,0 \n\t" //Even up an odd number of bytes
"rjmp length_loop \n\t"
"adiw r24,1 \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"
"rcall wait_spm \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" "rcall wait_spm \n\t"
“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” “no_page_erase: \n\t” “ld r0,Y+ \n\t” Write 2 bytes into page buffer
"ld r1,Y+ \n\t" "rcall wait_spm \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 "rcall wait_spm \n\t"
“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”
"ldi r16,0x05 \n\t" //Write page pointed to by Z "sts %0,r16 \n\t" "spm \n\t" "rcall wait_spm \n\t"
“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” “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"
"wait_spm: \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_spm \n\t"
"ret \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
: "=m" (SPMCR) : "M" (PAGE_SIZE) : "r0","r16","r17","r24","r25","r28","r29","r30","r31");
/* 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 (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
putch(eeprom_rb(address.word));
address.word++;
} else {
if (!flags.rampz) putch(pgm_read_byte_near(address.word));
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);
}
} else { time_count++; if (time_count>=MAX_TIME_COUNT) { app_start(); } }
} /* end of forever loop */
}
void putch(char ch) {
/* m8 */ while (!(inb(UCSRA) & _BV(UDRE))); outb(UDR,ch);
}
char getch(void) {
/* m8 */
uint32_t count = 0;
while(!(inb(UCSRA) & _BV(RXC))) {
/* HACKME:: here is a good place to count times*/
count++;
if (count > MAX_TIME_COUNT)
app_start();
}
return (inb(UDR));
}
void getNch(uint8_t count) {
uint8_t i;
for(i=0;i<count;i++) {
/* m8 */
//while(!(inb(UCSRA) & _BV(RXC)));
//inb(UDR);
getch(); // need to handle time out
}
}
void byte_response(uint8_t val) {
if (getch() == ' ') {
putch(0x14);
putch(val);
putch(0x10);
}
}
void nothing_response(void) {
if (getch() == ' ') {
putch(0x14);
putch(0x10);
}
}
/* end of file ATmegaBOOT.c */