Merge pull request #30 from WestfW/master

Significant optiboot upgrade.

1 files changed, 81 insertions, 0 deletions

diff --git a/bootloaders/optiboot/README.TXT b/bootloaders/optiboot/README.TXT
new file mode 100644
index 0000000..cd79cd9
--- /dev/null
+++ b/bootloaders/optiboot/README.TXT
@@ -0,0 +1,81 @@
+This directory contains the Optiboot small bootloader for AVR
+microcontrollers, somewhat modified specifically for the Arduino
+environment.
+
+Optiboot is more fully described here: http://code.google.com/p/optiboot/
+and is the work of Peter Knight (aka Cathedrow), building on work of Jason P
+Kyle, Spiff, and Ladyada.  Arduino-specific modification are by Bill
+Westfield (aka WestfW)
+
+Arduino-specific issues are tracked as part of the Arduino project
+at http://code.google.com/p/arduino
+
+
+------------------------------------------------------------
+Building optiboot for Arduino.
+
+Production builds of optiboot for Arduino are done on a Mac in "unix mode"
+using CrossPack-AVR-20100115.  CrossPack tracks WINAVR (for windows), which
+is just a package of avr-gcc and related utilities, so similar builds should
+work on Windows or Linux systems.
+
+One of the Arduino-specific changes is modifications to the makefile to
+allow building optiboot using only the tools installed as part of the
+Arduino environment, or the Arduino source development tree.  All three
+build procedures should yield identical binaries (.hex files) (although
+this may change if compiler versions drift apart between CrossPack and
+the Arduino IDE.)
+
+
+Building Optiboot in the Arduino IDE Install.
+
+Work in the .../hardware/arduino/bootloaders/optiboot/ and use the
+"omake <targets>" command, which just generates a command that uses
+the arduino-included "make" utility with a command like:
+    make OS=windows ENV=arduino <targets>
+or  make OS=macosx ENV=arduino <targets>
+On windows, this assumes you're using the windows command shell.  If
+you're using a cygwin or mingw shell, or have one of those in your
+path, the build will probably break due to slash vs backslash issues.
+On a Mac, if you have the developer tools installed, you can use the
+Apple-supplied version of make.
+The makefile uses relative paths ("../../../tools/" and such) to find
+the programs it needs, so you need to work in the existing optiboot
+directory (or something created at the same "level") for it to work.
+
+
+Building Optiboot in the Arduino Source Development Install.
+
+In this case, there is no special shell script, and you're assumed to
+have "make" installed somewhere in your path.
+Build the Arduino source ("ant build") to unpack the tools into the
+expected directory.
+Work in Arduino/hardware/arduino/bootloaders/optiboot and use
+    make OS=windows ENV=arduinodev <targets>
+or  make OS=macosx ENV=arduinodev <targets>
+
+
+Programming Chips Using the _isp Targets
+
+The CPU targets have corresponding ISP targets that will actuall
+program the bootloader into a chip. "atmega328_isp" for the atmega328,
+for example.  These will set the fuses and lock bits as appropriate as
+well as uploading the bootloader code.
+
+The makefiles default to using a USB programmer, but you can use
+a serial programmer like ArduinoISP by changing the appropriate
+variables when you invoke make:
+
+   make ISPTOOL=stk500v1 ISPPORT=/dev/tty.usbserial-A20e1eAN  \
+        ISPSPEED=-b19200 atmega328_isp
+
+The "atmega8_isp" target does not currently work, because the mega8
+doesn't have the "extended" fuse that the generic ISP target wants to
+pass on to avrdude.  You'll need to run avrdude manually.
+
+
+Standard Targets
+
+I've reduced the pre-built and source-version-controlled targets
+(.hex and .lst files included in the git repository) to just the
+three basic 16MHz targets: atmega8, atmega16, atmega328.