# Building system script (for 'make')

#------------------------------------------------------------------------------
# Common configuration that affects both kernel and user programs
#------------------------------------------------------------------------------

OS_NAME = "OSEER"
NAME_MAJOR := $(shell basename "`cd ..; pwd -P`")
NAME_MINOR := $(shell basename "`pwd -P`")
PROJECT := $(NAME_MINOR)

PLATFORM = i386
VERSION = 1.0
AUTHOR = leonardo@zemris.fer.hr

# Intermediate and output files are placed into BUILDDIR
BUILDDIR = build

BINFILE = $(BUILDDIR)/$(PROJECT).elf
CDIMAGE = $(BUILDDIR)/$(PROJECT).iso

CMACROS = OS_NAME="\"$(OS_NAME)\"" PROJECT="\"$(PROJECT)\"" \
      NAME_MAJOR="\"$(NAME_MAJOR)\"" NAME_MINOR="\"$(NAME_MINOR)\"" \
      PLATFORM="\"$(PLATFORM)\"" AUTHOR="\"$(AUTHOR)\"" \
      VERSION="\"$(VERSION)\""

CC = gcc
CFLAGS = -O3 -m32 -Wall -ffreestanding -nostdlib -fno-stack-protector \
    -fdata-sections -ffunction-sections

LINK = ld
LDSCRIPT = arch/$(PLATFORM)/ldscript.ld
LDFLAGS = -O3 -melf_i386 -T $(LDSCRIPT) --gc-sections -s


#------------------------------------------------------------------------------
# Devices

DEVICES = VGA_TEXT

CMACROS += $(DEVICES)

#------------------------------------------------------------------------------
# Stack

CMACROS += STACK_SIZE=0x1000

#------------------------------------------------------------------------------
all: $(CDIMAGE)
#------------------------------------------------------------------------------

DIRS_K := arch/$(PLATFORM)/arch arch/$(PLATFORM)/arch/devices kernel
DIRS_P := programs/api programs/hello_world
LIBS = lib

DIRS := $(DIRS_K) $(DIRS_P) $(LIBS)

INCLUDES := . programs arch/$(PLATFORM)

FILES := $(foreach DIR,$(DIRS),$(wildcard $(DIR)/*.c $(DIR)/*.S))
OBJS := $(addprefix $(BUILDDIR)/,$(FILES:.c=.o))
OBJS := $(OBJS:.S=.asm.o)
DEPS := $(OBJS:.o=.d)

# dummy file that indicate directories for kernel objects are created
DIRS_CREATED = $(BUILDDIR)/.null

# create required directories in $(BUILDDIR) directory (including $(BUILDDIR))
$(DIRS_CREATED):
    @-if [ ! -e $(BUILDDIR) ]; then mkdir -p $(BUILDDIR); fi;
    @-$(foreach DIR,$(DIRS), if [ ! -e $(BUILDDIR)/$(DIR) ]; \
        then mkdir -p $(BUILDDIR)/$(DIR); fi; )
    @touch $(DIRS_CREATED)

# define how to compile .c files
$(BUILDDIR)/%.o: %.c $(DIRS_CREATED) Makefile
    @echo [compiling] $< ...
    @$(CC) -c $< -o $@ -MMD $(CFLAGS) \
        $(foreach INC,$(INCLUDES),-I $(INC)) \
        $(foreach MACRO,$(CMACROS),-D $(MACRO))

# define how to compile .S files (assembler)
$(BUILDDIR)/%.asm.o: %.S $(DIRS_CREATED) Makefile
    @echo [compiling] $< ...
    @$(CC) -c $< -o $@ -MMD $(CFLAGS) \
        $(foreach INC,$(INCLUDES),-I$(INC)) \
        $(foreach MACRO,$(CMACROS),-D $(MACRO))


# OS image
$(BINFILE): $(OBJS)
    @echo [linking $@]
    @$(LINK) $(LDFLAGS) $(OBJS) -o$@


BOOTCD := $(BUILDDIR)/cd
GRUBMENU := $(BOOTCD)/boot/grub/menu.lst
GRUBFILE := $(BOOTCD)/boot/grub/stage2_eltorito
GRUBFILE_ORIG := arch/$(PLATFORM)/grub_file

$(GRUBFILE):
    @-if [ ! -e $(BOOTCD) ]; then mkdir -p $(BOOTCD)/boot/grub ; fi;
    @cp -a $(GRUBFILE_ORIG) $(GRUBFILE)

$(GRUBMENU):
    @-if [ ! -e $(BOOTCD) ]; then mkdir -p $(BOOTCD)/boot/grub ; fi;
    @echo "default 0" > $(GRUBMENU)
    @echo "timeout=0" >> $(GRUBMENU)
    @echo "title $(PROJECT)" >> $(GRUBMENU)
    @echo "root (cd)" >> $(GRUBMENU)
    @echo "kernel /boot/$(PROJECT).elf" >> $(GRUBMENU)
    @echo "boot" >> $(GRUBMENU)

# ISO CD image for booting (with grub as boot loader and $(KERNEL) as OS image)
$(CDIMAGE): $(BINFILE) $(GRUBFILE) $(GRUBMENU)
    @cp $(BINFILE) $(BOOTCD)/boot/$(PROJECT).elf
    @mkisofs -m '.svn' -J -R -b boot/grub/stage2_eltorito       \
    -no-emul-boot -boot-load-size 4 -boot-info-table -V $(PROJECT)  \
    -A $(PROJECT) -o $(CDIMAGE) $(BOOTCD) 2> /dev/null
    @echo
    @echo ISO CD image: $(CDIMAGE)
    @echo

clean:
    @echo Cleaning.
    @-rm -f $(OBJECTS) $(DEPS) $(CDIMAGE) $(BINFILE)

clean_all cleanall:
    @echo Removing build directory!
    @-rm -rf $(BUILDDIR)

# starting compiled system in 'qemu' emulator
qemu: $(CDIMAGE)
    @echo Starting...
    @qemu -m 4 -no-kvm -cdrom $(CDIMAGE)

-include $(DEPS)