This page is a first draft only and serves to collect information about the serprog protocol and the programmers implementing it.
See serprog-protocol.txt in the source tree. It is designed to be compact and allow efficient storage in limited memory of programmer devices.
AVR flasher by Urja Rannikko
The Prototype RS232 AVR parallel flash programmer Urja Rannikko was the first implementation of the serprog protocol.
FIXME: AVR source code is somewhere in the coreboot mailing list archives...
AVR flasher by eightdot
Arduino Mega flasher by fritz
InSystemFlasher by Juhana Helovuo
atmegaXXu2-flasher by Stefan Tauner
Like the InSystemFlasher this one uses LUFA on an AVR microcontroller to tunnel the serial data over USB.
Arduino flasher by GNUtoo
This flasher require the following hardware parts:
- An arduino uno or an arduino Duemilanove(way faster) and its usb cable
- some wires(optionally some connectors to solder on(for easier plugin and more reliability)
a 10k resistor
- 3 x 10k resistors (for the 3.3v version)
- 3 x 15k resistors (for the 3.3v version)
- A flash chip with the following characteristics:
- supported by flashrom
- 3.3v or 5v(the arduino has a 3.3v and a 5v output, only 3.3v was tested...)
Pictures (With the 5V SPI levels issue)
Building (With the 5V SPI levels issue)
Left pins of the BIOS chip: -------------------------------------------------------- [pin1 of the bios chip] /CS<->10k resistor<->VCC [pin1 of the bios chip] /CS<->Arduino pin10(SS, PORTB2) [pin2 of the bios chip] DO<->Arduino pin12(MISO, PORTB4) [pin3 of the bios chip] /WP<->VCC [pin4 of the bios chip] GND<->GND on the power pins Right pins of the BIOS chip: -------------------------------------------------------- [pin8 of the bios chip] VCC<->+3.3V on the power pins of the Arduino [pin7 of the bios chip] /HOLD<->VCC [pin6 of the bios chip] CLK<->Arduino pin13(SCK, PORTB5) [pin5 of the bios chip] DIO<->Arduino pin11(MOSI, PORTB3) The Bios chip used is a W25X80. The Arduino is an arduino uno.
Pictures (With the 3.3V SPI levels)
|git branch||Compatible Arduino version||flashrom arguments||Comments|
# time flashrom -p serprog:dev=/dev/ttyACM0:2000000 -r coreboot.rom flashrom v0.9.5.2-r1541 on Linux 2.6.38-14-generic (x86_64) flashrom is free software, get the source code at http://www.flashrom.org Calibrating delay loop... OK. serprog: Programmer name is "serprog-duino" Found Winbond flash chip "W25X80" (1024 kB, SPI) on serprog. Reading flash... done. real 0m16.602s user 0m0.930s sys 0m0.000s
# time flashrom -p serprog:dev=/dev/ttyACM0:2000000 -w build/coreboot.rom flashrom v0.9.5.2-r1541 on Linux 2.6.38-14-generic (x86_64) flashrom is free software, get the source code at http://www.flashrom.org Calibrating delay loop... OK. serprog: Programmer name is "serprog-duino" Found Winbond flash chip "W25X80" (1024 kB, SPI) on serprog. Reading old flash chip contents... done. Erasing and writing flash chip... Erase/write done. Verifying flash... VERIFIED. real 0m39.548s user 0m2.650s sys 0m0.000s
To make it work you need:
- flashrom from svn
- serprog-duino which runs on the arduino
- The avr toolchain(avr-gcc, avr-libc,make etc...)
Building the software
$ svn co svn://flashrom.org/flashrom/trunk flashrom $ cd flashrom && make $ cd ../ $ git clone git://gitorious.org/gnutoo-personal-arduino-projects/serprog-duino.git $ cd serprog-duino && make && make upload
./flashrom -p serprog:dev=/dev/ttyACM0:2000000
Advantages and disadvantages
The speed isn't that great(about 3 minutes for reading+writing+verifying a 1M chip)
- The speed is now much better thanks to a patch by Sebastian Parborg.
- it is made of very commonly available parts(if you can find an arduino uno, you will be able to build it).
- Voltage issues( SPI levels are at 5v, it's problematic for flashing 3.3v chips...)
- Find a way to lower the voltage to 3.3v
- Fix the arduino UNO speed and reliability issues