Makefile modification to allow building optiboot in more environments.

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.
(cherry picked from commit 2d2ed324b48e709f59a002cb274ed60bb0ebc911)

1 files changed, 69 insertions, 8 deletions

diff --git a/bootloaders/optiboot/Makefile b/bootloaders/optiboot/Makefile
index 0fd6005..92f9c61 100644
--- a/bootloaders/optiboot/Makefile
+++ b/bootloaders/optiboot/Makefile
@@ -19,6 +19,17 @@
 # program name should not be changed...
 PROGRAM    = optiboot
 
+# The default behavior is to build using tools that are in the users
+# current path variables, but we can also build using an installed
+# Arduino user IDE setup, or the Arduino source tree.
+# Uncomment this next lines to build within the arduino environment,
+# using the arduino-included avrgcc toolset (mac and pc)
+# ENV ?= arduino
+# ENV ?= arduinodev
+# OS ?= macosx
+# OS ?= windows
+
+
 # enter the parameters for the avrdude isp tool
 ISPTOOL	   = stk500v2
 ISPPORT	   = usb
@@ -27,6 +38,50 @@ ISPSPEED   = -b 115200
 MCU_TARGET = atmega168
 LDSECTION  = --section-start=.text=0x3e00
 
+# Build environments
+# Start of some ugly makefile-isms to allow optiboot to be built
+# in several different environments.  See the README.TXT file for
+# details.
+
+# default
+fixpath = $(1)
+
+ifeq ($(ENV), arduino)
+# For Arduino, we assume that we're connected to the optiboot directory
+# included with the arduino distribution, which means that the full set
+# of avr-tools are "right up there" in standard places.
+TOOLROOT = ../../../tools
+GCCROOT = $(TOOLROOT)/avr/bin/
+AVRDUDE_CONF = -C$(TOOLROOT)/avr/etc/avrdude.conf
+
+ifeq ($(OS), windows)
+# On windows, SOME of the tool paths will need to have backslashes instead
+# of forward slashes (because they use windows cmd.exe for execution instead
+# of a unix/mingw shell?)
+fixpath = $(subst /,\,$1)
+endif
+
+else ifeq ($(ENV), arduinodev)
+# Arduino IDE source code environment.  Use the unpacked compilers created
+# by the build (you'll need to do "ant build" first.)
+ifeq ($(OS), macosx)
+TOOLROOT = ../../../../build/macosx/work/Arduino.app/Contents/Resources/Java/hardware/tools
+endif
+ifeq ($(OS), windows)
+TOOLROOT = ../../../../build/windows/work/hardware/tools
+endif
+
+GCCROOT = $(TOOLROOT)/avr/bin/
+AVRDUDE_CONF = -C$(TOOLROOT)/avr/etc/avrdude.conf
+
+else
+GCCROOT =
+AVRDUDE_CONF =
+endif
+#
+# End of build environment code.
+
+
 # the efuse should really be 0xf8; since, however, only the lower
 # three bits of that byte are used on the atmega168, avrdude gets
 # confused if you specify 1's for the higher bits, see:
@@ -37,10 +92,13 @@ LDSECTION  = --section-start=.text=0x3e00
 # lock it), but since the high two bits of the lock byte are
 # unused, avrdude would get confused.
 
-ISPFUSES    = avrdude -c $(ISPTOOL) -p $(MCU_TARGET) -P $(ISPPORT) $(ISPSPEED) \
--e -u -U lock:w:0x3f:m -U efuse:w:0x$(EFUSE):m -U hfuse:w:0x$(HFUSE):m -U lfuse:w:0x$(LFUSE):m
-ISPFLASH    = avrdude -c $(ISPTOOL) -p $(MCU_TARGET) -P $(ISPPORT) $(ISPSPEED) \
--U flash:w:$(PROGRAM)_$(TARGET).hex -U lock:w:0x0f:m
+ISPFUSES    = $(GCCROOT)avrdude $(AVRDUDE_CONF) -c $(ISPTOOL) \
+              -p $(MCU_TARGET) -P $(ISPPORT) $(ISPSPEED) \
+              -e -u -U lock:w:0x3f:m -U efuse:w:0x$(EFUSE):m \
+              -U hfuse:w:0x$(HFUSE):m -U lfuse:w:0x$(LFUSE):m
+ISPFLASH    = $(GCCROOT)avrdude $(AVRDUDE_CONF) -c $(ISPTOOL) \
+              -p $(MCU_TARGET) -P $(ISPPORT) $(ISPSPEED) \
+              -U flash:w:$(PROGRAM)_$(TARGET).hex -U lock:w:0x0f:m
 
 STK500 = "C:\Program Files\Atmel\AVR Tools\STK500\Stk500.exe"
 STK500-1 = $(STK500) -e -d$(MCU_TARGET) -pf -vf -if$(PROGRAM)_$(TARGET).hex \
@@ -53,15 +111,17 @@ OPTIMIZE = -Os -fno-inline-small-functions -fno-split-wide-types -mshort-calls
 DEFS       = 
 LIBS       =
 
-CC         = avr-gcc
+CC         = $(GCCROOT)avr-gcc
 
 # Override is only needed by avr-lib build system.
 
 override CFLAGS        = -g -Wall $(OPTIMIZE) -mmcu=$(MCU_TARGET) -DF_CPU=$(AVR_FREQ) $(DEFS)
-override LDFLAGS       = -Wl,$(LDSECTION) -Wl,--relax -nostartfiles
+override LDFLAGS       = -Wl,$(LDSECTION) -Wl,--relax -Wl,--gc-sections -nostartfiles -nostdlib
+
+OBJCOPY        = $(GCCROOT)avr-objcopy
+OBJDUMP        = $(call fixpath,$(GCCROOT)avr-objdump)
 
-OBJCOPY        = avr-objcopy
-OBJDUMP        = avr-objdump
+SIZE           = $(GCCROOT)avr-size
 
 # 20MHz clocked platforms
 #
@@ -222,6 +282,7 @@ isp-stk500: $(PROGRAM)_$(TARGET).hex
 
 %.elf: $(OBJ)
 	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^ $(LIBS)
+	$(SIZE) $@
 
 clean:
 	rm -rf *.o *.elf *.lst *.map *.sym *.lss *.eep *.srec *.bin *.hex