# Kernel Sources/Objects
C_SOURCEK = $(wildcard kernel/*.c kernel/**/*.c)
C_OBJECTk = ${C_SOURCEK:.c=.co}
C_OBJECTK = ${subst kernel/,obj/kernel/,${C_OBJECTk}}
A_SOURCEK = $(wildcard kernel/*.S kernel/**/*.S)
A_OBJECTk = ${A_SOURCEK:.S=.ao}
A_OBJECTK = ${subst kernel/,obj/kernel/,${A_OBJECTk}}
# User Sources/Objects
C_SOURCEU = $(wildcard usr/*.c usr/**/*.c)
C_OBJECTu = ${C_SOURCEU:.c=.co}
C_OBJECTU = ${subst usr/,obj/usr/,${C_OBJECTu}}
CXX_SOURCEU = $(wildcard usr/*.cpp usr/**/*.cpp)
CXX_OBJECTu = ${CXX_SOURCEU:.cpp=.cppo}
CXX_OBJECTU = ${subst usr/,obj/usr/,${CXX_OBJECTu}}
A_SOURCEU = $(wildcard usr/*.S usr/**/*.S)
A_OBJECTu = ${A_SOURCEU:.S=.ao}
A_OBJECTU = ${subst usr/,obj/usr/,${A_OBJECTu}}
# Combined Objects
C_OBJECTD = $(C_OBJECTK) $(C_OBJECTU)
CXX_OBJECTD = $(CXX_OBJECTU)
A_OBJECTD = $(A_OBJECTK) $(A_OBJECTU)

ATTACH_USB ?= 0
AUTO ?= 0
BSP ?= 2
GDEBUG ?= 0
DEBUG ?= 0
SILENT ?= 0

CROSS = arm-none-eabi
CC = ${CROSS}-gcc
CCPP = ${CROSS}-g++
AS = ${CROSS}-as
OBJCOPY = ${CROSS}-objcopy
OBJDUMP = ${CROSS}-objdump
QEMU = qemu-system-arm
GDB = gdb-multiarch
CFLAGS = -mcpu=cortex-a7 -fpic -ffreestanding -std=gnu99 -O3 -Wall -Wextra -nostdlib -Iinclude -g
CXXFLAGS = -mcpu=cortex-a7 -fpic -ffreestanding -fno-exceptions -O3 -Wall -Wextra -nostdlib -Iinclude -g
CFLAGS += -DVERSION="\"0.9z\""
AFLAGS = -mcpu=cortex-a7 -Iinclude -g
QFLAGS = -M raspi2b -cpu cortex-a7 -m 1G

# Attach USB if requested
ifneq ("$(ATTACH_USB)","0")
	QFLAGS += -device usb-kbd
	QFLAGS += -trace events=events
endif

# Use Automation Pipe if requested
ifneq ("$(AUTO)","0")
	QFLAGS += -chardev pipe,id=char0,mux=on,logfile=serial.log,path=guest -serial chardev:char0 -mon chardev=char0
else
	QFLAGS += -chardev stdio,id=char0,mux=on,logfile=serial.log,signal=off -serial chardev:char0 -mon chardev=char0
endif

# Use Correct MMIO Address
ifeq ($(BSP),2)
	BSP23 = 1
	CFLAGS += -DBSP23
endif

# Pause and wait for GDB if requested
ifneq ($(GDEBUG),0)
	QFLAGS += -s -S
endif

# Debugging Flag
ifneq ($(DEBUG),0)
	CFLAGS += -DDEBUG
endif

# Don't use screen if requested
ifneq ("$(SILENT)","0")
	QFLAGS += -nographic
endif

# Attach sd if exists
ifneq ("$(wildcard ./sd.hda)","")
	QFLAGS += -drive file=sd.hda,if=sd,format=raw
endif

.PHONY: clean debug disk dump run test tree

default: clean build/kernel7.img

build/kernel7.img: CFLAGS += -DRPI_BUILD
build/kernel7.img: CFLAGS := $(filter-out -g,$(CFLAGS))
build/kernel7.img: AFLAGS := $(filter-out -g,$(AFLAGS))
build/kernel7.img: build/kernel.elf
	@mkdir -p $(@D)
	${OBJCOPY} $< -O binary $@

build/kernel.list: build/kernel.elf
	@mkdir -p $(@D)
	${OBJDUMP} -D $< > $@

dump: build/kernel.list

build/kernel.elf: ${A_OBJECTD} ${CXX_OBJECTD} ${C_OBJECTD}
	@tput setaf 6 2> /dev/null || true; echo Linking Kernel; tput sgr0 2> /dev/null || true
	@mkdir -p $(@D)
	@echo ${C_SOURCEK}
	${CC} -T linker.ld -o $@ -ffreestanding -O3 -nostdlib $^

obj/kernel/%.co: kernel/%.c
	@mkdir -p $(@D)
	${CC} ${CFLAGS} -c $< -o $@

obj/kernel/%.ao: kernel/%.S
	@mkdir -p $(@D)
	${AS} ${AFLAGS} -c $< -o $@

obj/usr/%.co: usr/%.c
	@mkdir -p $(@D)
	${CC} ${CFLAGS} -c $< -o $@

obj/usr/%.cppo: usr/%.cpp
	@mkdir -p $(@D)
	${CCPP} ${CXXFLAGS} -c $< -o $@

obj/usr/%.ao: usr/%.S
	@mkdir -p $(@D)
	${AS} ${AFLAGS} -c $< -o $@

run: build/kernel.elf
	@tput setaf 6 2> /dev/null || true; echo Starting QEMU; tput sgr0 2> /dev/null || true
	@${QEMU} -kernel $< ${QFLAGS}

debug: build/kernel.list
	@tput setaf 6 2> /dev/null || true; echo Starting GDB; tput sgr0 2> /dev/null || true
	@${GDB} $< -command=gdbinit

sd.hda:
	@cp README.md sd.hda
	@dd if=/dev/zero of=sd.hda count=1 bs=1 seek=16383

disk: sd.hda

clean:
	@tput setaf 6 2> /dev/null || true; echo Clearing Build; tput sgr0 2> /dev/null || true
	rm -rf obj/* build/*

tree:
	@tree -a -I obj\|build\|.git\|.gitignore

test: clean build/kernel.elf
	@tput setaf 6 2> /dev/null || true; echo Running Tests; tput sgr0 2> /dev/null || true
	@./tests/run.sh

ifndef DISK
copy:
	@tput setaf 1 2> /dev/null || true; echo ERROR: No disk specified!; tput sgr0 2> /dev/null || true
else
copy: clean build/kernel7.img
	sudo mount $(DISK) /mnt/sd0
	sudo cp build/kernel7.img /mnt/sd0
	sudo umount /mnt/sd0
endif