Da hier anscheinend nur sehr wenige User Bootloader verwendenhab ich versucht selber eine Lösung zu finden.
Das klappt nun auch soweit.
Sobald eine bestimmte Taste gedrückt wird wird der Bootloader gestartet.
Konnte der Booloader das Startzeichen nicht empfangen, startet er sich selber wieder und zwar so lange, bis die Taste losgelassen wird.
Das passiert so ca. 3 bis 4 mal pro Sekunde.
Konnte das Startzeichen < empfangen werden lädt der PC das Programm in den Controller.
Das dauert ca. 20 sek, also genug Zeit um die Taste wieder loszulassen.
Wird der Bootloader nicht gebraucht, die Taste ist also offen , wird der Bootloader beendet und das Anwendungs- Programm im Microcontroller gestartet.
Das ist zwar nicht sonderlich elegant, funktioniert aber.
Anbei der aktuelle Quellcode des Bootloaders, falls mal jemand sowas braucht...
Code:
/*****************************************************
Project : CVMegaload
Version : 1.00
Date : 14/05/2004
Author : Ralph Hilton
Chip type : ATmega
Program type : Bootloader
Clock frequency : 20.000000 MHz
Data Stack size : 256
Acknowledgement : Modified from original code by Sylvain Bissonnette
*****************************************************/
/*****************************************************
Note: BAUDRATE must be correctly defined below
Supported values are
9600 19200 38400 57600 115200
Chip header is included by cvmegaload.h from the project configuration
// The project should be compiled with the following compiler options:
// Promote char to int
// Char is unsigned
// Bit variables 0
*****************************************************/
//uncomment to use UART1
//#define UART1
#pragma promotechar+
#pragma uchar+
#pragma regalloc-
#pragma optsize+
#ifdef UART1
#include <cvmegaloaduart1.h> //contains defines for DeviceID FlashSize BootSize PageSize AddressLshift
#else
#include <cvmegaload.h> //contains defines for DeviceID FlashSize BootSize PageSize AddressLshift
#endif
#include <stdio.h>
#include <delay.h>
#define BAUDRATE 38400
register unsigned int Pagedata @2; //program data to be written from this and read back for checking
register unsigned int PageAddress @4; //address of the page
register unsigned int CurrentAddress @6; //address of the current data - PageAddress + loop counter
register char inchar @8; //data received from RS232
register char spmcrval @10; //value to write to SPM control register
register unsigned int i @11; //loop counter
register unsigned int j @13; //13 loop counter
unsigned int ubbr;
unsigned int Checkdata ; //compared with Pagedata for checking
char PageBuffer[PageByte]; //buffer for data to be written
#ifdef UART1
#define getchar getchar1
#define putchar putchar1
// Get a character from the USART1 Receiver
#pragma used+
char getchar(void)
{
char status,data;
while (1)
{
while (((status=UCSRA) & 128)==0);
data=UDR1;
if ((status & (28))==0)
return data;
};
}
#pragma used-
// Write a character to the USART1 Transmitter
#pragma used+
void putchar(char c)
{
while ((UCSRA & 32)==0);
UDR1=c;
}
#pragma used-
#endif
char GetPage(void)
{
char LocalCheckSum = 0;
char CheckSum = 0;
// The programming software generates a simple checksum in the
// same fashion as below to check for data transmission errors
for (j=0;j<PageByte;j++)
{
PageBuffer[j]=getchar();
LocalCheckSum += PageBuffer[j];
}
CheckSum = getchar();
if (LocalCheckSum == CheckSum) return 1;
else return 0;
}
char CheckFlash(void)
{
//After the data has been written to flash it is read back and compared to the original
for (j=0;j<PageByte;j+=2)
{
CurrentAddress=PageAddress+j;
#if defined _CHIP_ATMEGA128_
#asm
movw r30, r6 ;//move CurrentAddress to Z pointer
elpm r2, Z+ ;//read LSB
elpm r3, Z ;//read MSB
#endasm
#else
#asm
movw r30, r6 ;//move CurrentAddress to Z pointer
lpm r2, Z+ ;//read LSB
lpm r3, Z ;//read MSB
#endasm
#endif
Checkdata = PageBuffer[j] +(PageBuffer[j+1]<<8);
if (Pagedata != Checkdata) return 0;
}
return 1;
}
void ExecCode(void)
{
#if defined _CHIP_ATMEGA128_
RAMPZ = 0;
#endif
MCUCR = 0x01; // Enable interrupt vector select
MCUCR = 0x00; // Move interrupt vector to flash
#asm("jmp 0x00"); // Run application code
}
void BootLoad(void)
{
// Send chip data to the programming software so that it knows
// how to format transmissions
putchar(DeviceID);
putchar(FlashSize);
putchar(BootSize);
putchar(PageSize);
// "!" means all ok and send the next data if there is more
putchar('!');
while(1)
{
PageAddress = (unsigned int)getchar() << 8; // Receive PageAddress high byte
PageAddress += getchar(); // Add PageAddress low byte
if (PageAddress == 0xffff) ExecCode(); // The windows program sends this value when finished
#if defined _CHIP_ATMEGA128_
if (PageAddress >> 8) RAMPZ = 1;
else RAMPZ=0;
#endif
PageAddress = PageAddress << AddressLshift; //essentially the same as multiply by PageSize
if (GetPage()) //receive one page of data followed by a checksum byte and verify data
{
for (i=0;i<PageByte;i+=2) //fill temporary buffer in 2 byte chunks from PageBuffer
{
Pagedata=PageBuffer[i]+(PageBuffer[i+1]<<8);
while (SPMCR&1); //wait for spm complete
CurrentAddress=PageAddress+i;
spmcrval=1;
#asm
movw r30, r6 ;//move CurrentAddress to Z pointer
mov r1, r3 ;//move Pagedata MSB reg 1
mov r0, r2 ;//move Pagedata LSB reg 1
sts SpmcrAddr, r10 ;//move spmcrval to SPM control register
spm ;//store program memory
#endasm
}
while (SPMCR&1); //wait for spm complete
spmcrval=3; //erase page
#asm
movw r30, r4 ;//move PageAddress to Z pointer
sts SpmcrAddr, r10 ;//move spmcrval to SPM control register
spm ;//erase page
#endasm
while (SPMCR&1); //wait for spm complete
spmcrval=5; //write page
#asm
movw r30, r4 ;//move PageAddress to Z pointer
sts SpmcrAddr, r10 ;//move spmcrval to SPM control register
spm ;//write page
#endasm
while (SPMCR&1); //wait for spm complete
spmcrval=0x11; //enableRWW see mega8 datasheet for explanation
// P. 212 Section "Prevent reading the RWW section
// during self-programming
#asm
sts SpmcrAddr, r10 ;//move spmcrval to SPMCR
spm
#endasm
if (CheckFlash()) putchar('!'); //all ok, send next page
else putchar('@'); //there was an error, resend page
} //end if (GetPage())
else putchar('@'); //there was an error ,resend page
}
}
void main(void)
{
//Set Pullup on PortA.5 to give power to the Tast
PORTA=0b00100000;
DDRA=0b00000000;
//When PortA.5 ist set to High ( Tast Open ) start Application Else start Bootloader
delay_ms(100);
//Read in Tast
if((PINA&0b00100000)>0)
{
ExecCode(); //Start Programm, when Tast is open - works to GND
}
// USART initialization
// Communication Parameters: 8 Data, 1 Stop, No Parity
// USART Receiver: On
// USART Transmitter: On
// USART Mode: Asynchronous
// USART Baud rate: 9600
UCSRA=0x00;
UCSRB=0x18;
UCSRC=0x86;
//UBRRH=0x00;
//UBRRL=0x2F;
//Calculate Baud Rate
ubbr = (unsigned long int)_MCU_CLOCK_FREQUENCY_ / (BAUDRATE * 16) - 1;
UBRRH=ubbr >> 8;
UBRRL = ubbr;
putchar('>'); //I'm here, talk to me
while ( (! (UCSRA&128)) &&( i < 32000) ) i++; //wait for data in or timeout
if (i < 32000) inchar= getchar();
if (inchar == '<') BootLoad(); // I'm here too, go ahead and load the program to flash
#asm("jmp 0x7C00"); //Start Bootloader again for ATMEGA 644!
//while(1);
//ExecCode(); // set up and jump to application
}
und das dazugehörige Header File cvmegaload.h für den ATMEGA644
Code:
//#define BootSize 'c' // 512 Words
#define BootSize 'd' // 1024 Words
//#define BootSize 'e' // 2048 Words
//#define BootSize 'f' // 4096 Words
#if defined _CHIP_ATMEGA8_
#define DeviceID 'A' // Mega8
#define FlashSize 'l' // Flash 8k
#define PageSize 'R' // 64 Bytes
#define PageByte 64 // 64 Bytes
#define AddressLshift 6
#asm(".EQU SpmcrAddr=0x57")
#include <mega8.h>
#elif defined _CHIP_ATMEGA16_
#define DeviceID 'B' // Mega16
#define FlashSize 'm' // Flash 16k
#define PageSize 'S' // 128 Bytes
#define PageByte 128 // 128 Bytes
#define AddressLshift 7
#asm(".EQU SpmcrAddr=0x57")
#include <mega16.h>
#elif defined _CHIP_ATMEGA32_
#define DeviceID 'E' // Mega32
#define FlashSize 'n' // Flash 32k
#define PageSize 'S' // 128 Bytes
#define PageByte 128 // 128 Bytes
#define AddressLshift 7
#asm(".EQU SpmcrAddr=0x57")
#include <mega32.h>
#elif defined _CHIP_ATMEGA8515_
#define DeviceID 'H' // Mega8515
#define FlashSize 'l' // Flash 8k
#define PageSize 'R' // 64 Bytes
#define PageByte 64 // 64 Bytes
#define AddressLshift 6
#asm(".EQU SpmcrAddr=0x57")
#include <mega8515.h>
#elif defined _CHIP_ATMEGA8535_
#define DeviceID 'I' // Mega8535
#define FlashSize 'l' // Flash 8k
#define PageSize 'R' // 64 Bytes
#define PageByte 64 // 64 Bytes
#define AddressLshift 6
#asm(".EQU SpmcrAddr=0x57")
#include <mega8535.h>
#elif defined _CHIP_ATMEGA88_
#define DeviceID 'M' // Mega88
#define FlashSize 'l' // Flash 8k
#define PageSize 'R' // 64 Bytes
#define PageByte 64 // 64 Bytes
#define AddressLshift 6
#asm(".EQU SpmcrAddr=0x57")
#include <mega88.h>
#elif defined _CHIP_ATMEGA168_
#define DeviceID 'N' // Mega168
#define FlashSize 'm' // Flash 16k
#define PageSize 'R' // 64 Bytes
#define PageByte 64 // 64 Bytes
#define AddressLshift 6
#asm(".EQU SpmcrAddr=0x57")
#include <mega168.h>
#elif defined _CHIP_ATMEGA64_
#define DeviceID 'C' // Mega64
#define FlashSize 'o' // Flash 64k
#define PageSize 'T' // 256 Bytes
#define PageByte 256 // 256 Bytes
#define AddressLshift 8
#define SPMCR SPMCSR
#define UCSRA UCSR0A
#define UCSRB UCSR0B
#define UCSRC UCSR0C
#define UBRRH UBRR0H
#define UBRRL UBRR0L
#asm(".EQU SpmcrAddr=0x68")
#include <mega64.h>
#elif defined _CHIP_ATMEGA644_
#define DeviceID 'A' // Mega644 Mega8
#define FlashSize 'o' // Flash 64k
#define PageSize 'T' // 256 Bytes
#define PageByte 256 // 256 Bytes
#define AddressLshift 8
#define UCSRA UCSR0A
#define UCSRB UCSR0B
#define UCSRC UCSR0C
#define UBRRH UBRR0H
#define UBRRL UBRR0L
#define SPMCR SPMCSR
#asm(".EQU SpmcrAddr=0x57")
#include <mega644.h>
#elif defined _CHIP_ATMEGA128_
#define DeviceID 'D' // Mega128
#define FlashSize 'p' // Flash 128k
#define PageSize 'T' // 256 Bytes
#define PageByte 256 // 256 Bytes
#define AddressLshift 8
#define UCSRA UCSR0A
#define UCSRB UCSR0B
#define UCSRC UCSR0C
#define UBRRH UBRR0H
#define UBRRL UBRR0L
#define SPMCR SPMCSR
#asm(".EQU SpmcrAddr=0x68")
#include <mega128.h>
#elif defined _CHIP_ATMEGA169_
#define DeviceID 'G' // Mega169
#define FlashSize 'm' // Flash 16k
#define PageSize 'S' // 128 Bytes
#define PageByte 128 // 128 Bytes
#define AddressLshift 7
#define SPMCR SPMCSR
#define UCSRA UCSR0A
#define UCSRB UCSR0B
#define UCSRC UCSR0C
#define UBRRH UBRR0H
#define UBRRL UBRR0L
#asm(".EQU SpmcrAddr=0x57")
#include <mega169.h>
#elif defined _CHIP_ATMEGA162_
#define DeviceID 'F' // Mega162
#define FlashSize 'm' // Flash 16k
#define PageSize 'S' // 128 Bytes
#define PageByte 128 // 128 Bytes
#define AddressLshift 7
#define UCSRA UCSR0A
#define UCSRB UCSR0B
#define UCSRC UCSR0C
#define UBRRH UBRR0H
#define UBRRL UBRR0L
#asm(".EQU SpmcrAddr=0x57")
#include <mega162.h>
#endif
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