Reorganize Makefiles slightly; implement "make help"

Make things reasonably self-documenting.
Group related options together (LED, COMM, extra features.)
Group similar targets together.  Or less randomly, anyway.

optiboot/bootloaders/optiboot/Makefile

@@ -39,6 +39,7 @@
 # * This software is licensed under version 2 of the Gnu Public Licence.
 # * See optiboot.c for details.
 
+HELPTEXT = ""
 #----------------------------------------------------------------------
 #
 # program name should not be changed...
@@ -144,6 +145,7 @@ SIZE           = $(GCCROOT)avr-size
 # appropriate parameters ("-DLED_START_FLASHES=10") to gcc
 #
 
+HELPTEXT += "Option BAUD_RATE=nnnn        - set the bit rate for communications\n"
 ifdef BAUD_RATE
 BAUD_RATE_CMD = -DBAUD_RATE=$(BAUD_RATE)
 dummy = FORCE
@@ -151,6 +153,13 @@ else
 BAUD_RATE_CMD = -DBAUD_RATE=115200
 endif
 
+HELPTEXT += "Option LED=B3                - set LED pin to particular port/bit\n"
+ifdef LED
+LED_CMD = -DLED=$(LED)
+dummy = FORCE
+endif
+
+HELPTEXT += "Option LED_START_FLASHES=n   - set number of LED flashes when bootloader starts\n"
 ifdef LED_START_FLASHES
 LED_START_FLASHES_CMD = -DLED_START_FLASHES=$(LED_START_FLASHES)
 dummy = FORCE
@@ -158,6 +167,15 @@ else
 LED_START_FLASHES_CMD = -DLED_START_FLASHES=3
 endif
 
+HELPTEXT += "Option LED_DATA_FLASH=1      - flash the LED each time data is received.\n"
+ifdef LED_DATA_FLASH
+ifneq ($(LED_DATA_FLASH), 0)
+LED_DATA_FLASH_CMD = -DLED_DATA_FLASH=1
+dummy = FORCE
+endif
+endif
+
+HELPTEXT += "Option LED_START_ON=1        - Turn the LED on at bootload start\n"
 ifdef LED_START_ON
 ifneq ($(LED_START_ON), 0)
 LED_START_ON_CMD = -DLED_START_ON=1
@@ -165,7 +183,8 @@ endif
 dummy = FORCE
 endif
 
-# BIG_BOOT: Include extra features, up to 1K.
+HELPTEXT += "Option BIGBOOT=1             - enable extra features up to 1kbytes\n"
+# BIGBOOT: Include extra features, up to 1K.
 ifdef BIGBOOT
 ifneq ($(BIGBOOT), 0)
 BIGBOOT_CMD = -DBIGBOOT=1
@@ -173,24 +192,22 @@ dummy = FORCE
 endif
 endif
 
-ifdef SOFT_UART
-ifneq ($(SOFT_UART), 0)
-SOFT_UART_CMD = -DSOFT_UART=1
+HELPTEXT += "Option SUPPORT_EEPROM=1      - Include code to read/write EEPROM\n"
+ifdef SUPPORT_EEPROM
+ifneq ($(SUPPORT_EEPROM), 0)
+SUPPORT_EEPROM_CMD = -DSUPPORT_EEPROM
 dummy = FORCE
 endif
 endif
 
-ifdef LED_DATA_FLASH
-ifneq ($(LED_DATA_FLASH), 0)
-LED_DATA_FLASH_CMD = -DLED_DATA_FLASH=1
-dummy = FORCE
-endif
-endif
 
-ifdef LED
-LED_CMD = -DLED=$(LED)
+HELPTEXT += "Option SOFT_UART=1           - use a software (bit-banged) UART\n"
+ifdef SOFT_UART
+ifneq ($(SOFT_UART), 0)
+SOFT_UART_CMD = -DSOFT_UART=1
 dummy = FORCE
 endif
+endif
 
 ifdef SINGLESPEED
 ifneq ($(SINGLESPEED), 0)
@@ -203,16 +220,11 @@ COMMON_OPTIONS += $(SOFT_UART_CMD) $(LED_DATA_FLASH_CMD) $(LED_CMD) $(SS_CMD)
 COMMON_OPTIONS += $(SUPPORT_EEPROM_CMD) $(LED_START_ON_CMD)
 
 #UART is handled separately and only passed for devices with more than one.
+HELPTEXT += "Option UART=n                - use UARTn for communications\n"
 ifdef UART
 UART_CMD = -DUART=$(UART)
 endif
 
-ifdef SUPPORT_EEPROM
-ifneq ($(SUPPORT_EEPROM), 0)
-SUPPORT_EEPROM_CMD = -DSUPPORT_EEPROM
-dummy = FORCE
-endif
-endif
 
 # Not supported yet
 # ifdef TIMEOUT_MS
@@ -244,8 +256,11 @@ endif
 #---------------------------------------------------------------------------
 #
 
+HELPTEXT += "\n-------------\n\n"
+
 # Test platforms
 # Virtual boot block test
+HELPTEXT += "target virboot8      - ATmega8 with virtual boot partition\n"
 virboot8: TARGET = atmega8
 virboot8: MCU_TARGET = atmega8
 virboot8: CFLAGS += $(COMMON_OPTIONS) '-DVIRTUAL_BOOT_PARTITION' '-Dsave_vect_num=EE_RDY_vect_num'
@@ -256,6 +271,7 @@ virboot8: $(PROGRAM)_virboot8.hex
 virboot8: $(PROGRAM)_virboot8.lst
 
 
+HELPTEXT += "target virboot328p   - ATmega328 with virtual boot partition\n"
 virboot328: TARGET = atmega328
 virboot328: MCU_TARGET = atmega328p
 virboot328: CFLAGS += $(COMMON_OPTIONS) '-DVIRTUAL_BOOT_PARTITION'
@@ -291,7 +307,37 @@ virboot8_isp: isp
 # Diecimila, Duemilanove with m168, and NG use identical bootloaders
 # Call it "atmega168" for generality and clarity, keep "diecimila" for
 # backward compatibility of makefile
+
+# ATmega8
 #
+HELPTEXT += "target atmega8       - ATmega8, ATmega8A, ATmega8L\n"
+atmega8: TARGET = atmega8
+atmega8: MCU_TARGET = atmega8
+atmega8: CFLAGS += $(COMMON_OPTIONS)
+atmega8: AVR_FREQ ?= 16000000L 
+ifndef BIGBOOT
+atmega8: LDSECTIONS  = -Wl,--section-start=.text=0x1e00 -Wl,--section-start=.version=0x1ffe -Wl,--gc-sections -Wl,--undefined=optiboot_version
+else
+atmega8: LDSECTIONS  = -Wl,--section-start=.text=0x1c00 -Wl,--section-start=.version=0x1ffe -Wl,--gc-sections -Wl,--undefined=optiboot_version
+endif
+atmega8: $(PROGRAM)_atmega8.hex
+atmega8: $(PROGRAM)_atmega8.lst
+
+atmega8_isp: atmega8
+atmega8_isp: TARGET = atmega8
+atmega8_isp: MCU_TARGET = atmega8
+ifndef BIGBOOT
+# SPIEN, CKOPT (for full swing xtal), Bootsize=512B
+atmega8_isp: HFUSE ?= CC
+else
+# SPIEN, CKOPT (for full swing xtal), Bootsize=1024B
+atmega8_isp: HFUSE ?= CA
+endif
+# 2.7V brownout, 16MHz Xtal, 16KCK/14CK+65ms
+atmega8_isp: LFUSE ?= BF
+atmega8_isp: isp
+
+HELPTEXT += "target atmega168     - ATmega168, ATmega168A\n"
 atmega168: TARGET = atmega168
 atmega168: MCU_TARGET = atmega168
 atmega168: CFLAGS += $(COMMON_OPTIONS)
@@ -319,13 +365,7 @@ atmega168_isp: EFUSE ?= FA
 endif
 atmega168_isp: isp
 
-atmega16: TARGET = atmega16
-atmega16: MCU_TARGET = atmega16
-atmega16: CFLAGS += $(COMMON_OPTIONS)
-atmega16: AVR_FREQ ?= 16000000L 
-atmega16: $(PROGRAM)_atmega16.hex
-atmega16: $(PROGRAM)_atmega16.lst
-
+HELPTEXT += "target atmega328     - ATmega328p\n"
 atmega328: TARGET = atmega328
 atmega328: MCU_TARGET = atmega328p
 atmega328: CFLAGS += $(COMMON_OPTIONS)
@@ -356,6 +396,7 @@ atmega328_isp: EFUSE ?= FD
 atmega328_isp: isp
 
 #Atmega1280
+HELPTEXT += "target atmega1280    - ATmega1280 (100pin, 128k)\n"
 atmega1280: MCU_TARGET = atmega1280
 atmega1280: CFLAGS += $(COMMON_OPTIONS) -DBIGBOOT $(UART_CMD)
 atmega1280: AVR_FREQ ?= 16000000L
@@ -364,34 +405,6 @@ atmega1280: $(PROGRAM)_atmega1280.hex
 atmega1280: $(PROGRAM)_atmega1280.lst
 
 
-# ATmega8
-#
-atmega8: TARGET = atmega8
-atmega8: MCU_TARGET = atmega8
-atmega8: CFLAGS += $(COMMON_OPTIONS)
-atmega8: AVR_FREQ ?= 16000000L 
-ifndef BIGBOOT
-atmega8: LDSECTIONS  = -Wl,--section-start=.text=0x1e00 -Wl,--section-start=.version=0x1ffe -Wl,--gc-sections -Wl,--undefined=optiboot_version
-else
-atmega8: LDSECTIONS  = -Wl,--section-start=.text=0x1c00 -Wl,--section-start=.version=0x1ffe -Wl,--gc-sections -Wl,--undefined=optiboot_version
-endif
-atmega8: $(PROGRAM)_atmega8.hex
-atmega8: $(PROGRAM)_atmega8.lst
-
-atmega8_isp: atmega8
-atmega8_isp: TARGET = atmega8
-atmega8_isp: MCU_TARGET = atmega8
-ifndef BIGBOOT
-# SPIEN, CKOPT (for full swing xtal), Bootsize=512B
-atmega8_isp: HFUSE ?= CC
-else
-# SPIEN, CKOPT (for full swing xtal), Bootsize=1024B
-atmega8_isp: HFUSE ?= CA
-endif
-# 2.7V brownout, 16MHz Xtal, 16KCK/14CK+65ms
-atmega8_isp: LFUSE ?= BF
-atmega8_isp: isp
-
 
 #---------------------------------------------------------------------------
 # "Board-level Platform" targets.
@@ -598,3 +611,6 @@ clean:
 
 %.bin: %.elf
 	$(OBJCOPY) -j .text -j .data -j .version --set-section-flags .version=alloc,load -O binary $< $@
+
+help:
+	@echo $(HELPTEXT)

optiboot/bootloaders/optiboot/Makefile.1284

@@ -7,6 +7,7 @@
 
 # Chip level targets
 #
+HELPTEXT += "target atmega644p    - ATmega644p\n"
 atmega644p: TARGET = atmega644p
 atmega644p: MCU_TARGET = atmega644p
 atmega644p: CFLAGS += $(COMMON_OPTIONS) -DBIGBOOT
@@ -16,6 +17,7 @@ atmega644p: CFLAGS += $(UART_CMD)
 atmega644p: $(PROGRAM)_atmega644p.hex
 atmega644p: $(PROGRAM)_atmega644p.lst
 
+HELPTEXT += "target atmega1284    - ATmega1284p (40 pin, 128k)\n"
 atmega1284: TARGET = atmega1284p
 atmega1284: MCU_TARGET = atmega1284p
 atmega1284: CFLAGS += $(COMMON_OPTIONS) -DBIGBOOT
@@ -44,6 +46,7 @@ atmega1284_isp: isp
 
 # Sanguino has a minimum boot size of 1024 bytes, so enable extra functions
 #
+HELPTEXT += "target sanguino      - ATmega644p board\n"
 sanguino: TARGET = $@
 sanguino: CHIP = atmega644p
 sanguino:
@@ -62,6 +65,7 @@ sanguino_isp: LFUSE ?= F7
 sanguino_isp: EFUSE ?= FD
 sanguino_isp: isp
 
+HELPTEXT += "target mighty1284    - ManiacBug Mighty1284 board\n"
 mighty1284: TARGET = $@
 mighty1284: CHIP = atmega1284p
 mighty1284:
@@ -80,6 +84,7 @@ mighty1284_isp: LFUSE ?= F7
 mighty1284_isp: EFUSE ?= FD
 mighty1284_isp: isp
 
+HELPTEXT += "target bobuino       - Crossroads 1284 board\n"
 bobuino: TARGET = $@
 bobuino: CHIP = atmega1284p
 bobuino:
@@ -102,6 +107,7 @@ bobuino_isp: isp
 # Wicked Devices "Wildfire" boards (1284 with wireless!)
 #
 
+HELPTEXT += "target wildfirev2    - Wicked Devices board\n"
 wildfirev2: TARGET = $@
 wildfirev2: CHIP = atmega1284p
 wildfirev2:
@@ -120,6 +126,7 @@ wildfirev2_isp: LFUSE ?= F7
 wildfirev2_isp: EFUSE ?= FD
 wildfirev2_isp: isp
 
+HELPTEXT += "target wildfirev3    - Wicked Devices board\n"
 wildfirev3: TARGET = $@
 wildfirev3: CHIP = atmega1284p
 wildfirev3:

optiboot/bootloaders/optiboot/Makefile.2560

@@ -7,6 +7,7 @@
 
 # Chip level targets
 #
+HELPTEXT += "target atmega2560    - ATmega2560p (100pin, 256k)\n"
 atmega2560: TARGET = atmega2560
 atmega2560: MCU_TARGET = atmega2560
 atmega2560: CFLAGS += $(COMMON_OPTIONS) -DBIGBOOT
@@ -34,6 +35,7 @@ atmega2560_isp: isp
 
 # Arduino/Geniuno MEGA 256 has a minimum boot size of 1024 bytes, so enable extra functions
 #
+HELPTEXT += "target mega2560      - Arduino MEGA2560 board, 2560ADK\n"
 mega2560: TARGET = $@
 mega2560: CHIP = atmega2560
 mega2560:

optiboot/bootloaders/optiboot/Makefile.atmel

@@ -12,6 +12,7 @@
 #  
 # 
 #
+HELPTEXT += "target xplained168pb - Atmel Xplained Mini 168pb Eval board\n"
 xplained168pb: TARGET = $@
 xplained168pb: CHIP = atmega168
 xplained168pb:
@@ -19,6 +20,7 @@ xplained168pb:
 	mv $(PROGRAM)_$(CHIP).hex $(PROGRAM)_$(TARGET).hex
 	mv $(PROGRAM)_$(CHIP).lst $(PROGRAM)_$(TARGET).lst
 
+HELPTEXT += "target xplained328pb - Atmel Xplained Mini 328pb Eval board\n"
 xplained328pb: TARGET = $@
 xplained328pb: CHIP = atmega328
 xplained328pb:
@@ -26,6 +28,7 @@ xplained328pb:
 	mv $(PROGRAM)_$(CHIP).hex $(PROGRAM)_$(TARGET).hex
 	mv $(PROGRAM)_$(CHIP).lst $(PROGRAM)_$(TARGET).lst
 
+HELPTEXT += "target xplained328p  - Atmel Xplained Mini 328p Eval board\n"
 xplained328p: TARGET = $@
 xplained328p: CHIP = atmega328
 xplained328p:

optiboot/bootloaders/optiboot/Makefile.custom

@@ -6,6 +6,7 @@
 # * See optiboot.c for details.
 
 
+HELPTEXT += "target wildfire      - Wicked Devices Wildfire v1 board\n"
 wildfire: TARGET = $@
 wildfire: CHIP = atmega1284p
 wildfire:

optiboot/bootloaders/optiboot/Makefile.extras

@@ -14,6 +14,7 @@
 #
 # ATmega88
 #
+HELPTEXT += "target atmega88      - ATmega88 or ATmega88p (28pin, 8k)\n"
 atmega88: TARGET = atmega88
 atmega88: MCU_TARGET = atmega88
 atmega88: CFLAGS += $(COMMON_OPTIONS)
@@ -47,6 +48,7 @@ atmega88p_isp: isp
 #
 # ATmega168p [QFN32]
 #
+HELPTEXT += "target atmega168p    - ATmega168p\n"
 atmega168p: TARGET = atmega168p
 atmega168p: MCU_TARGET = atmega168p
 atmega168p: CFLAGS += $(COMMON_OPTIONS)
@@ -64,9 +66,18 @@ atmega168p_isp: LFUSE ?= FF
 atmega168p_isp: EFUSE ?= 04
 atmega168p_isp: isp
 
+HELPTEXT += "target atmega16      - ATmega16 (40pin, 16k)\n"
+atmega16: TARGET = atmega16
+atmega16: MCU_TARGET = atmega16
+atmega16: CFLAGS += $(COMMON_OPTIONS)
+atmega16: AVR_FREQ ?= 16000000L 
+atmega16: $(PROGRAM)_atmega16.hex
+atmega16: $(PROGRAM)_atmega16.lst
+
 #
 # ATmega32
 #
+HELPTEXT += "target atmega32      - ATmega32 (40pin, 32k)\n"
 atmega32: TARGET = atmega32
 atmega32: MCU_TARGET = atmega32
 atmega32: CFLAGS += $(COMMON_OPTIONS)