Makefile

###############################################################################
# Build script for Raspberry PI C code.
#
###############################################################################

####################
### Instructions ###
####################
#
# Replace PREFIX with the path to your yagarto or linaro install
# Replace ARMGNU with the root name of the compiler binaries
#   For yagarto it's usually $(PREFIX)/bin/arm-none-eabi
#   For linaro it's usually $(PREFIX)/bin/arm-eabi
# Replace SUFFIX with .exe if you're on Windows or just leave it blank for other OSs.
#
#
# Your SOURCE files go in a directory named "source".
# This includes *.c, *.h, *.s files.
# Your files will be compiled in build/ and your kernel will be output into bin/
#
# Example Directory Structure:
#
# lab_1
# | Makefile
# | kernel_c.ld
# | source/
#    | main.c
#    | gpio.c
#    | gpio.h
#    | boot.s
# | build/       <- generated for you
#    | ...
# | bin/         <- generated for you
#    | kernel7.img
#    | kernel7.list
#    | kernel7.map
#

###
# build environment
###

# Replace with the path to your yagarto install directory.
# Note: Any paths with spaces in it must have quotes around them, like below:
PREFIX ?= "/Users/danielcox/yagarto/yagarto-4.7.2"

ARMGNU ?= $(PREFIX)/bin/arm-none-eabi
#ARMGNU ?= $(PREFIX)/bin/arm-eabi

# Suffix on windows is .exe, other platforms it's nothing
#SUFFIX ?= .exe
#SUFFIX ?=

###########################
# DON'T CHANGE THIS STUFF #
###########################

# Uncomment to create a C assembler listing
CASM_LIST = -Wa,-adhln  > $(BUILD)$*.lst

# The intermediate directory for compiled object files.
BUILD = build/

OUTPUT = bin/

# The directory in which source files are stored.
SOURCE = source/

###
# Targets
###

# The name of the output file to generate.
TARGET = $(OUTPUT)kernel7.img

# The name of the assembler listing file to generate.
LIST = $(OUTPUT)kernel7.list

# The name of the map file to generate.
MAP = $(OUTPUT)kernel7.map

###
# Sources
###

# The name of the linker script to use.
LINKER = kernel_c.ld

# The names of all object files that must be generated. Deduced from the
# assembly code files in source.
OBJECTS := $(patsubst $(SOURCE)%.s,$(BUILD)%.o,$(wildcard $(SOURCE)*.s))
OBJECTS += $(patsubst $(SOURCE)%.c,$(BUILD)%.o,$(wildcard $(SOURCE)*.c))
OBJECTS += $(patsubst $(SOURCE)%.cpp,$(BUILD)%.o,$(wildcard $(SOURCE)*.cpp))

###
# Build flags
###

DEPENDFLAGS := -MD -MP
INCLUDES    := -I source

BASEFLAGS   := -pedantic -pedantic-errors -nostdlib
BASEFLAGS   += -nostartfiles -ffreestanding -nodefaultlibs

# Pi 1 compile flags
#BASEFLAGS   += -O2 -mfpu=vfp -mfloat-abi=hard -march=armv6zk -mtune=arm1176jzf-s

# A+ compile flags
# BASEFLAGS   += -O2 -mfpu=vfp -mfloat-abi=hard -march=armv6zk -mtune=arm1176jzf-s -DPI2

# Pi 2 compile flags
BASEFLAGS += -O2 -mfpu=neon-vfpv4 -mfloat-abi=hard -march=armv7-a -mtune=cortex-a7  -DPI2

# Pi 3 compile flags
#BASEFLAGS   += -O2 -march=armv8-a -mtune=cortex-a53 -DPI2

### Warnings ###

# -Wall turns on the following flags ( from https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html ):
# -Waddress
# -Warray-bounds=1 (only with -O2)
# -Wbool-compare
# -Wc++11-compat  -Wc++14-compat
# -Wchar-subscripts
# -Wcomment
# -Wduplicate-decl-specifier (C and Objective-C only)
# -Wenum-compare (in C/ObjC; this is on by default in C++)
# -Wformat
# -Wimplicit (C and Objective-C only)
# -Wimplicit-int (C and Objective-C only)
# -Wimplicit-function-declaration (C and Objective-C only)
# -Winit-self (only for C++)
# -Wlogical-not-parentheses
# -Wmain (only for C/ObjC and unless -ffreestanding)
# -Wmaybe-uninitialized
# -Wmemset-elt-size
# -Wmemset-transposed-args
# -Wmisleading-indentation (only for C/C++)
# -Wmissing-braces (only for C/ObjC)
# -Wnarrowing (only for C++)
# -Wnonnull
# -Wnonnull-compare
# -Wopenmp-simd
# -Wparentheses
# -Wpointer-sign
# -Wreorder
# -Wreturn-type
# -Wsequence-point
# -Wsign-compare (only in C++)
# -Wsizeof-pointer-memaccess
# -Wstrict-aliasing
# -Wstrict-overflow=1
# -Wswitch
# -Wtautological-compare
# -Wtrigraphs
# -Wuninitialized
# -Wunknown-pragmas
# -Wunused-function
# -Wunused-label
# -Wunused-value
# -Wunused-variable
# -Wvolatile-register-var

# -Wextra turns on the following errors:
# -Wclobbered
# -Wempty-body
# -Wignored-qualifiers
# -Wmissing-field-initializers
# -Wmissing-parameter-type (C only)
# -Wold-style-declaration (C only)
# -Woverride-init
# -Wsign-compare (C only)
# -Wtype-limits
# -Wuninitialized
# -Wshift-negative-value (in C++03 and in C99 and newer)
# -Wunused-parameter (only with -Wunused or -Wall).  Removed below with -Wno-unused-parameter
# -Wunused-but-set-parameter (only with -Wunused or -Wall).  Removed below with -Wno-unused-but-set-parameter

WARNFLAGS   := -Wall -Wextra -Wshadow -Wcast-align -Wwrite-strings
WARNFLAGS   += -Wredundant-decls -Winline
WARNFLAGS   += -Wno-attributes -Wno-deprecated-declarations
WARNFLAGS   += -Wno-div-by-zero -Wno-endif-labels -Wfloat-equal
WARNFLAGS   += -Wformat=2 -Wno-format-extra-args -Winit-self
WARNFLAGS   += -Winvalid-pch -Wmissing-format-attribute
WARNFLAGS   += -Wmissing-include-dirs -Wno-multichar
WARNFLAGS   += -Wredundant-decls -Wshadow
WARNFLAGS   += -Wno-sign-compare -Wsystem-headers -Wundef
WARNFLAGS   += -Wno-pragmas -Wno-unused-but-set-parameter
WARNFLAGS   += -Wno-unused-but-set-variable -Wno-unused-result -Wno-unused-parameter
WARNFLAGS   += -Wwrite-strings -Wdisabled-optimization -Wpointer-arith
WARNFLAGS   += -Wno-unused-function -Wno-unused-variable

#Warnings are errors.
WARNFLAGS   += -Werror

### Assembly Flags ###

ASFLAGS     := $(INCLUDES) $(DEPENDFLAGS) -D__ASSEMBLY__

### C Flags ###
CFLAGS      := $(INCLUDES) $(DEPENDFLAGS) $(BASEFLAGS) $(WARNFLAGS)
CFLAGS      += -std=c11

### C++ Flags ###
CXXFLAGS    := $(INCLUDES) $(DEPENDFLAGS) $(BASEFLAGS) $(WARNFLAGS)
CXXFLAGS    += -std=c++14

###
# Rules
###

# Rule to make everything.
all: $(TARGET) $(LIST)

# Rule to remake everything. Does not include clean.
rebuild: all


# Rule to make the listing file.
$(LIST) : $(BUILD)output.elf $(OUTPUT)
        $(ARMGNU)-objdump$(SUFFIX) -d $(BUILD)output.elf > $(LIST)

# Rule to make the image file.
$(TARGET) : $(BUILD)output.elf $(OUTPUT)
        $(ARMGNU)-objcopy$(SUFFIX) $(BUILD)output.elf -O binary $(TARGET)

# Rule to make the elf file.
$(BUILD)output.elf : $(OBJECTS) $(LINKER) $(BUILD) $(OUTPUT)
        $(ARMGNU)-ld$(SUFFIX) --no-undefined $(OBJECTS) -Map $(MAP) -o $(BUILD)output.elf -T $(LINKER)

# Rule to make the assembler object files.
$(BUILD)%.o: $(SOURCE)%.s $(BUILD)
        $(ARMGNU)-as$(SUFFIX) -I $(SOURCE) $< -o $@

# C.
$(BUILD)%.o: $(SOURCE)%.c $(BUILD)
        $(ARMGNU)-gcc$(SUFFIX) $(CFLAGS) -c $< -o $@  $(CASM_LIST)

# CPP.
$(BUILD)%.o: $(SOURCE)%.cpp $(BUILD)
        $(ARMGNU)-g++$(SUFFIX) $(CXXFLAGS) -c $< -o $@  $(CASM_LIST)

$(BUILD):
        mkdir -p $(BUILD)

$(OUTPUT):
        mkdir -p $(OUTPUT)

# Rule to clean files.
clean :
        -rm -f $(BUILD)*.o
        -rm -f $(BUILD)*.d
        -rm -f $(BUILD)*.lst
        -rm -f $(BUILD)output.elf
        -rm -f $(TARGET)
        -rm -f $(LIST)
        -rm -f $(MAP)
        -rmdir $(BUILD)
        -rmdir $(OUTPUT)