GCC-AVR
GCC-AVR
- reference page: http://avr-eclipse.sourceforge.net/wiki/index.php/The_AVR_GCC_Toolchain
- command for install: sudo apt-get install gcc-avr binutils-avr gdb-avr avr-libc avrdude
- gcc-avr： complier
- avr-libc：library used when compling
- gdb-avr ：gdb reverse debug tool, against complie
- avrdude：flash tool
Compile
- generate o file from c file:
- -c Compile or assemble the source files, but do not link.
- -Os Optimize for size, -O1, Optimize.-O2 Optimize even more.
- -g Generate debugging information that can be used by avr-gdb.
>avr-gcc -g -mmcu=atmega8 -Wall -Os -c ledtest.c
>avr-gcc -g -Os -mmcu=atmega8 -c flash.c
>avr-gcc –mmcu=at90s2313 –c demo1.c
- output .o .elf file for further use, for elf file, use when have more then one c file:
- -o put output into output file
>avr-gcc -g -mmcu=atmega8 -o flash.elf flash.o
>avr-gcc -g -mmcu=atmega8 -o ledtest.out -Wl,-Map,ledtest.map ledtest.o
- combined linked file into MCU read hex file
>avr-objcopy -j .text -j .data -O ihex flash.elf flash.hex
>avr-objcopy -R .eeprom -O ihex ledtest.out ledtest.hex
Above flash.elf and ledtest.out is the input file, and the second is the output file.
>avr-size ledtest.out
Complete commands:
- avr-gcc -Os -DF_CPU=8000000 -mmcu=attiny85 -c led_flash.c
- avr-gcc -DF_CPU=8000000 -mmcu=attiny85 -o led_flash.elf led_flash.o
- avr-objcopy -O ihex led_flash.elf led_flash.hex
- rm led_flash.o
- rm led_flash.elf
Note
- DDRC = 0xFF makes all pins on PORTC as output pins
- PORTC = 0xFF makes all pins on PORTC Logic High (5V)
- PORTC = 0x00 makes all pins on PORTC Logic Low (0V)
- _delay_ms(1000) provides 1000 milliseconds delay.
- while(1) makes an infinite loop
Flash code
- Use avrdude, command like: sudo avrdude -p m8 -c dragon_isp -P usb -e -U flash:w:flash.hex