http://code.google.com/p/arduino/issues/detail?id=554
end of flash memory where they can be read (at least in theory) by
device programmers, hex-file examination, or application programs.
This is done by putting the version number in a separate section
(".version"), and using linker/objcopy magic to locate that section as
appropriate for the target chip. (See
http://lists.gnu.org/archive/html/avr-gcc-list/2011-02/msg00016.html
for some discussion on the details.)
Start the version at 4.1 (the last "packaged" version of optiboot was
called version 3, so the "top of source" would be 4.0, and adding the
version number makes 4.1)
Refactor LDSECTION in the Makefile to LDSECTIONS so that multiple
section start addresses can be defined.
Change the _isp makefile definitions to make the bootloader section
readable (but not writable) by the application section. (This would
need to be done elsewhere as well to handle all bootloader programming
techniques. Notably Arduino's boards.txt
Note that this change does not change the "code" portion of optiboot
at all. The only diffs in the .hex files are the added version word
at the end of flash memory.
Allows building within the Arduino Source tree, and within the Arduino
IDE tree, as well as using CrossPack on Mac.
Adds README.TXT to track arduino-specific changes (and documents the
new build options.)
This addresses Arduino issue:
http://code.google.com/p/arduino/issues/detail?id=487
And optiboot issue
http://code.google.com/p/optiboot/issues/detail?id=1
(which can be thought of as a subset of the Arduno issue.)
Note that the binaries produced after these Makefile changes (using any
of the compile environments) are identical to those produced by the
crosspack-20100115 environment on a Mac.
Because UBBR is only 12 bits, we were overflowing it at 300 baud because of the use of the U2X bit. Now we turn off U2X if it would yield a UBBR value that would overflow.
Note that this breaks 300 baud communication with the computer on the Uno and Mega 2560 because the 8U2 USB-serial firmware has this same bug (and previously they cancelled each other out). Since, however, it seems more likely that people will need to use 300 baud to communicate with other (legacy) hardware than with the computer, I'm making this change. Issue for 8U2 firmware bug: http://code.google.com/p/arduino/issues/detail?id=542http://code.google.com/p/arduino/issues/detail?id=522
Because UBBR is only 12 bits, we were overflowing it at 300 baud because of the use of the U2X bit. Now we turn off U2X if it would yield a UBBR value that would overflow.
Note that this breaks 300 baud communication with the computer on the Uno and Mega 2560 because the 8U2 USB-serial firmware has this same bug (and previously they cancelled each other out). Since, however, it seems more likely that people will need to use 300 baud to communicate with other (legacy) hardware than with the computer, I'm making this change. Issue for 8U2 firmware bug: http://code.google.com/p/arduino/issues/detail?id=542http://code.google.com/p/arduino/issues/detail?id=522
This makes explicit the String constructors that take numeric types and chars and removes the versions of concat() and operator=() and operator+() that accept numberic types.
It also replaces the operator bool() with a operator that converts to a function pointer. This allows for uses like "if (s)" but not "s + 123". See: http://www.artima.com/cppsource/safebool.html. This allowed removing the disambiguating operator+() functions and relying solely on StringSumHelper and anonymous temporaries once again.
Also, now treating unsigned char's like int when constructing Strings from them, i.e. String(byte(65)) is now "65" not "A". This is consistent with the new behavior of Serial.print(byte).
The operator bool() means that you could implicitly convert a String to a bool and then add it to it an int, for example. Which means our operator+ has to match exactly or it will be ambiguous.
Changing toLowerCase(), toUpperCase(), trim() and replace() to return void instead of a reference to the string that's just been changed. That way, it's clear that the functions modify the string they've been called on.
Now Serial.write() places characters in the transmit buffer, and the data register empty interrupt reads and transmit them. Based loosely on the implementation here: ftp://wookey.org.uk/arduino.
http://code.google.com/p/arduino/issues/detail?id=262
That is, there's now a pins/ directory in a platform, which includes multiple directories, each of which has its own pins_arduino.h. The boards.txt gets a new preferences, <BOARD>.build.pins, whose values is a sub-directory of the pins/ directory (possibly with a "platform:" prefix). That sub-directory is then placed in the include path during compilation.
