csrc = $(wildcard src/*.c) $(wildcard src/libc/*.c)
ssrc = $(wildcard src/*.s) $(wildcard src/libc/*.s)

obj = $(csrc:.c=.o) $(ssrc:.s=.o)
dep = $(csrc:.c=.d)
elf = kern.elf

warn = -pedantic -Wall
dbg = -g
inc = -Isrc -Isrc/libc
gccflags = -fno-pic -ffreestanding -nostdinc -fno-builtin -fcommon

CFLAGS = $(ccarch) -march=i386 $(warn) $(opt) $(dbg) $(gccflags) $(inc) $(def) -MMD
ASFLAGS = $(asarch) -march=i386 $(dbg) -nostdinc -fno-builtin $(inc)
LDFLAGS = $(ldarch) -nostdlib -T kern.ld -print-gc-sections

ifneq ($(shell uname -m), i386)
	ccarch = -m32
	asarch = --32
	ldarch = -m elf_i386
endif

# uncomment to use a specific toolchain
#TOOLPREFIX = x86_64-elf-

CC = $(TOOLPREFIX)gcc
AS = $(TOOLPREFIX)as
LD = $(TOOLPREFIX)ld
OBJCOPY = $(TOOLPREFIX)objcopy
OBJDUMP = $(TOOLPREFIX)objdump


$(elf): $(obj)
	$(LD) -o $@ $(obj) -Map link.map $(LDFLAGS)

%.o: %.S
	$(CC) -o $@ $(CFLAGS) -c $<

-include $(dep)

.PHONY: clean
clean:
	rm -f $(obj) $(elf)


.PHONY: cleandep
cleandep:
	rm -f $(dep)


QEMUFLAGS = -serial file:serial.log

.PHONY: run
run: $(elf)
	qemu-system-i386 -kernel $(elf) $(QEMUFLAGS)

.PHONY: debug
debug: $(elf)
	qemu-system-i386 -kernel $(elf) $(QEMUFLAGS) -s -S