412 lines
12 KiB
C
412 lines
12 KiB
C
/* simple USBasp compatible bootloader
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* by Alexander Neumann <alexander@lochraster.org>
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*
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* inspired by USBasploader by Christian Starkjohann,
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* see http://www.obdev.at/products/avrusb/usbasploader.html
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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* For more information on the GPL, please go to:
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* http://www.gnu.org/copyleft/gpl.html
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*/
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include <avr/pgmspace.h>
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#include <avr/boot.h>
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#include <avr/eeprom.h>
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#include <util/delay.h>
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#include <string.h>
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#include <avr/wdt.h>
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#include "config.h"
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#include "usbdrv/usbdrv.c"
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/* USBasp requests, taken from the original USBasp sourcecode */
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#define USBASP_FUNC_CONNECT 1
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#define USBASP_FUNC_DISCONNECT 2
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#define USBASP_FUNC_TRANSMIT 3
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#define USBASP_FUNC_READFLASH 4
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#define USBASP_FUNC_ENABLEPROG 5
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#define USBASP_FUNC_WRITEFLASH 6
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#define USBASP_FUNC_READEEPROM 7
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#define USBASP_FUNC_WRITEEEPROM 8
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#define USBASP_FUNC_SETLONGADDRESS 9
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/* additional functions */
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#define FUNC_ECHO 0x17
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/* atmel isp commands */
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#define ISP_CHIP_ERASE1 0xAC
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#define ISP_CHIP_ERASE2 0x80
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#define ISP_READ_SIGNATURE 0x30
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#define ISP_READ_EEPROM 0xa0
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#define ISP_WRITE_EEPROM 0xc0
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#define LED_PORT PORTC
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#define LED_DIR DDRC
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#define LED_PIN PC7
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#define DLED_ON {((LED_PORT &=~ (1 << LED_PIN)),\
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(LED_DIR &=~ (1 << LED_PIN))); }
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#define DLED_OFF {((LED_PORT &=~ (1 << LED_PIN)),\
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(LED_DIR |= (1 << LED_PIN))); }
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#define DLED_TGL {((LED_PORT ^= (1 << LED_PIN)),\
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(LED_DIR |= (1 << LED_PIN)));}
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/* some predefined signatures, taken from the original USBasp sourcecode */
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static const uint8_t signature[4] = {
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#ifdef SIGNATURE_BYTES
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SIGNATURE_BYTES
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#elif defined (__AVR_ATmega8__) || defined (__AVR_ATmega8HVA__)
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0x1e, 0x93, 0x07, 0
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#elif defined (__AVR_ATmega48__) || defined (__AVR_ATmega48P__)
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0x1e, 0x92, 0x05, 0
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#elif defined (__AVR_ATmega88__) || defined (__AVR_ATmega88P__)
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0x1e, 0x93, 0x0a, 0
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#elif defined (__AVR_ATmega168__) || defined (__AVR_ATmega168P__)
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0x1e, 0x94, 0x06, 0
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#elif defined (__AVR_ATmega328P__)
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0x1e, 0x95, 0x0f, 0
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#elif defined (__AVR_ATmega644__)
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0x1e, 0x96, 0x06, 0
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#else
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# error "Device signature is not known, please edit config.h!"
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#endif
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};
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#ifndef BOOT_SECTION_START
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# error "BOOT_SECTION_START undefined!"
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#endif
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#ifdef DEBUG_UART
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static __attribute__ (( __noinline__ )) void putc(uint8_t data) {
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while(!(UCSR0A & _BV(UDRE0)));
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UDR0 = data;
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}
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#else
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#define putc(x)
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#endif
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/* supply custom usbDeviceConnect() and usbDeviceDisconnect() macros
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* which turn the interrupt on and off at the right times,
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* and prevent the execution of an interrupt while the pullup resistor
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* is switched off */
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/*
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#ifdef USB_CFG_PULLUP_IOPORTNAME
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#undef usbDeviceConnect
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#define usbDeviceConnect() do { \
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USB_PULLUP_DDR |= (1<<USB_CFG_PULLUP_BIT); \
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USB_PULLUP_OUT |= (1<<USB_CFG_PULLUP_BIT); \
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USB_INTR_ENABLE |= (1 << USB_INTR_ENABLE_BIT); \
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} while(0);
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#undef usbDeviceDisconnect
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#define usbDeviceDisconnect() do { \
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USB_INTR_ENABLE &= ~(1 << USB_INTR_ENABLE_BIT); \
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USB_PULLUP_DDR &= ~(1<<USB_CFG_PULLUP_BIT); \
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USB_PULLUP_OUT &= ~(1<<USB_CFG_PULLUP_BIT); \
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} while(0);
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#endif
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*/
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/* prototypes */
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void __attribute__ (( __noreturn__, __noinline__, __naked__ )) leave_bootloader(void);
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/* we just support flash sizes <= 64kb, for code size reasons
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* if you need to program bigger devices, have a look at USBasploader:
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* http://www.obdev.at/products/avrusb/usbasploader.html */
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#if FLASHEND > 0xffff
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# error "usbload only supports up to 64kb of flash!"
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#endif
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/* we are just checking the lower byte of flash_address,
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* so make sure SPM_PAGESIZE is <= 256
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*/
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#if SPM_PAGESIZE > 256
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# error "SPM_PAGESIZE is too big (just checking lower byte)"
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#endif
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/* start flash (byte address) read/write at this address */
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usbWord_t flash_address;
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uint8_t bytes_remaining;
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uint8_t request;
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uint8_t request_exit;
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uint8_t timeout;
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usbMsgLen_t usbFunctionSetup(uchar data[8])
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{
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usbRequest_t *req = (void *)data;
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uint8_t len = 0;
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static uint8_t buf[4];
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/* set global data pointer to local buffer */
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usbMsgPtr = buf;
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/* on enableprog just return one zero, which means success */
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if (req->bRequest == USBASP_FUNC_ENABLEPROG) {
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buf[0] = 0;
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len = 1;
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timeout = 255;
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} else if (req->bRequest == USBASP_FUNC_CONNECT) {
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/* turn on led */
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DLED_ON;
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} else if (req->bRequest == USBASP_FUNC_DISCONNECT) {
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/* turn off led */
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DLED_OFF;
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request_exit = 1;
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/* catch query for the devicecode, chip erase and eeprom byte requests */
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} else if (req->bRequest == USBASP_FUNC_TRANSMIT) {
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/* reset buffer with zeroes */
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memset(buf, '\0', sizeof(buf));
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/* read the address for eeprom operations */
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usbWord_t address;
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address.bytes[0] = data[4]; /* low byte is data[4] */
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address.bytes[1] = data[3]; /* high byte is data[3] */
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/* if this is a request to read the device signature, answer with the
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* appropiate signature byte */
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if (data[2] == ISP_READ_SIGNATURE) {
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/* the complete isp data is reported back to avrdude, but we just need byte 4
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* bits 0 and 1 of byte 3 determine the signature byte address */
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buf[3] = signature[data[4] & 0x03];
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#ifdef ENABLE_CATCH_EEPROM_ISP
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/* catch eeprom read */
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} else if (data[2] == ISP_READ_EEPROM) {
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buf[3] = eeprom_read_byte((uint8_t *)address.word);
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/* catch eeprom write */
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} else if (data[2] == ISP_WRITE_EEPROM) {
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/* address is in data[4], data[3], and databyte is in data[5] */
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eeprom_write_byte((uint8_t *)address.word, data[5]);
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#endif
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/* catch a chip erase */
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} else if (data[2] == ISP_CHIP_ERASE1 && data[3] == ISP_CHIP_ERASE2) {
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for (flash_address.word = 0;
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flash_address.word < BOOT_SECTION_START;
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flash_address.word += SPM_PAGESIZE) {
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/* wait and erase page */
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boot_spm_busy_wait();
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cli();
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boot_page_erase(flash_address.word);
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sei();
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}
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}
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/* in case no data has been filled in by the if's above, just return zeroes */
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len = 4;
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#ifdef ENABLE_ECHO_FUNC
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/* implement a simple echo function, for testing the usb connectivity */
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} else if (req->bRequest == FUNC_ECHO) {
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buf[0] = req->wValue.bytes[0];
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buf[1] = req->wValue.bytes[1];
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len = 2;
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#endif
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} else if (req->bRequest >= USBASP_FUNC_READFLASH) {
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/* && req->bRequest <= USBASP_FUNC_SETLONGADDRESS */
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putc('R');
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putc(req->bRequest);
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/* extract address and length */
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flash_address.word = req->wValue.word;
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bytes_remaining = req->wLength.bytes[0];
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request = req->bRequest;
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/* hand control over to usbFunctionRead()/usbFunctionWrite() */
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len = 0xff;
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}
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return len;
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}
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uchar usbFunctionWrite(uchar *data, uchar len)
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{
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if (len > bytes_remaining)
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len = bytes_remaining;
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bytes_remaining -= len;
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if (request == USBASP_FUNC_WRITEEEPROM) {
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for (uint8_t i = 0; i < len; i++)
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eeprom_write_byte((uint8_t *)flash_address.word++, *data++);
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} else {
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/* data is handled wordwise, adjust len */
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len /= 2;
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len -= 1;
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for (uint8_t i = 0; i <= len; i++) {
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uint16_t *w = (uint16_t *)data;
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cli();
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boot_page_fill(flash_address.word, *w);
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sei();
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usbWord_t next_address;
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next_address.word = flash_address.word;
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next_address.word += 2;
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data += 2;
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/* write page if page boundary is crossed or this is the last page */
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if ( next_address.bytes[0] % SPM_PAGESIZE == 0 ||
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(bytes_remaining == 0 && i == len) ) {
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cli();
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boot_page_write(flash_address.word);
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sei();
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boot_spm_busy_wait();
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cli();
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boot_rww_enable();
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sei();
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}
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flash_address.word = next_address.word;
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}
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}
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/* flash led on activity */
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DLED_TGL;
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return (bytes_remaining == 0);
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}
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uchar usbFunctionRead(uchar *data, uchar len)
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{
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if(len > bytes_remaining)
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len = bytes_remaining;
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bytes_remaining -= len;
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for (uint8_t i = 0; i < len; i++) {
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if(request == USBASP_FUNC_READEEPROM)
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*data = eeprom_read_byte((void *)flash_address.word);
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else
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*data = pgm_read_byte_near((void *)flash_address.word);
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data++;
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flash_address.word++;
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}
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/* flash led on activity */
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DLED_TGL;
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return len;
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}
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void (*jump_to_app)(void) = 0x0000;
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void leave_bootloader(void)
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{
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cli();
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/* disconnect usb */
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usbDeviceDisconnect();
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for (uint8_t i = 0; i < 38; i++)
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_delay_loop_2(0); /* 0 means 0x10000, 38*1/f*0x10000 =~ 498ms */
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/* enable watchdog to soft-reset the uC for clean startup of new application */
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wdt_enable(WDTO_15MS);
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/* let watchdog kick in and reset uC */
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while(1);
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}
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int __attribute__ ((noreturn,OS_main)) main(void)
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{
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/* start bootloader */
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/* init LED-Pin */
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PORTB = 0;
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#ifdef DEBUG_UART
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/* init uart (115200 baud, at 20mhz) */
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UBRR0L = 10;
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UCSR0C = _BV(UCSZ00) | _BV(UCSZ01);
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UCSR0B = _BV(TXEN0);
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putc('b');
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#endif
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uint8_t reset = MCUSR;
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/* if power-on reset, quit bootloader via watchdog reset */
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if (reset & _BV(PORF)){
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MCUSR = 0;
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leave_bootloader();
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}
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/* if watchdog reset, disable watchdog and jump to app */
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else if(reset & _BV(WDRF)){
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MCUSR = 0;
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wdt_disable();
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jump_to_app();
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}
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/* else: enter programming mode */
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/* clear external reset flags */
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MCUSR = 0;
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/* init exit request state */
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request_exit = 0;
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/* move interrupts to boot section */
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MCUCR = (1 << IVCE);
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MCUCR = (1 << IVSEL);
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/* enable interrupts */
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sei();
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/* initialize usb pins */
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usbInit();
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/* disconnect for ~500ms, so that the host re-enumerates this device */
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usbDeviceDisconnect();
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for (uint8_t i = 0; i < 38; i++)
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_delay_loop_2(0); /* 0 means 0x10000, 38*1/f*0x10000 =~ 498ms */
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usbDeviceConnect();
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uint16_t delay;
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timeout = TIMEOUT;
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while(1) {
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usbPoll();
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delay++;
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/* do some led blinking, so that it is visible that the bootloader is still running */
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if (delay == 0) {
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DLED_TGL;
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if (timeout < 255)
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timeout--;
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}
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if (request_exit || timeout == 0) {
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_delay_loop_2(0);
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leave_bootloader();
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}
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}
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leave_bootloader();
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}
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