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VERSION = 0.1.0-alpha
CC = clang
LD = ld.lld
NM = llvm-nm
OBJCOPY = llvm-objcopy
COMPILER = $(shell $(CC) --version | head -n 1)
LINKER = $(shell $(LD) --version | head -n 1)
ARCH_NAME := $(shell grep '^arch:' BuildConfig | sed 's/^arch://' | awk '{$$1=$$1; print}')
ARCH_FLAG := $(shell grep '^arch_flag:' BuildConfig | sed 's/^arch_flag://' | awk '{$$1=$$1; print}')
COMMON_FLAGS = \
-ffreestanding \
-fno-builtin \
-fno-stack-protector \
-fno-exceptions \
-fno-rtti \
-fno-unwind-tables \
-fno-asynchronous-unwind-tables \
-nostdlib \
-nostdinc \
-nodefaultlibs \
-DVERSION='"$(VERSION)"' \
-DCOMPILER_NAME='"$(COMPILER)"' \
-DLINKER_NAME='"$(LINKER)"' \
-DARCH_NAME='"$(ARCH_NAME)"'
KERNEL_FLAG = $(COMMON_FLAGS) -static
MODULE_FLAG = $(COMMON_FLAGS) -fPIC -fpie
SECTION_FLAG = \
-ffunction-sections \
-fdata-sections \
-fno-common
INCLUDE_FLAG = -Iinclude
OPT_FLAG = -O2 -g3
WARN_FLAG = -Wall -Wextra -Werror -Wundef
KERNEL_OBJCOPY_FLAG = -O binary \
--strip-all \
--remove-section=.comment \
--remove-section=.debug* \
--remove-section=.note* \
--remove-section=.eh_frame \
--remove-section=.eh_frame_ptr \
--remove-section=.eh_frame_hdr
MODULE_OBJCOPY_FLAG = \
--strip-debug \
--remove-section=.comment \
--remove-section=.note*
KERNEL_CFLAGS = $(ARCH_FLAG) $(KERNEL_FLAG) $(SECTION_FLAG) $(INCLUDE_FLAG) $(OPT_FLAG) $(WARN_FLAG)
MODULE_CFLAGS = $(ARCH_FLAG) $(MODULE_FLAG) $(SECTION_FLAG) $(INCLUDE_FLAG) $(OPT_FLAG) $(WARN_FLAG) -D__KERNEL_MODULE__
MODULES = $(wildcard $(shell grep '^modules:' BuildConfig | sed 's/^modules://' | awk '{$$1=$$1; print}'))
MODULE_OBJECTS = $(foreach m,$(MODULES),$m/$m.ko)
define module_template
$(1)_SRCS = $$(wildcard $$(shell grep '^$(1):' BuildConfig | sed 's/^$(1)://' | awk '{$$$$1=$$$$1; print}'))
$(1)_ELF = $(1)/$(1).elf
$(1)_BIN = $(1)/$(1).ko
$(1)_C_SRCS = $$(filter %.c,$$($(1)_SRCS))
$(1)_S_SRCS = $$(filter %.S,$$($(1)_SRCS))
$(1)_C_OBJS = $$($(1)_C_SRCS:.c=.o)
$(1)_S_OBJS = $$($(1)_S_SRCS:.S=.o)
$(1)_OBJS = $$($(1)_C_OBJS) $$($(1)_S_OBJS)
$$($(1)_C_OBJS): %.o: %.c
@echo " CC [MOD] $$<"
$$(CC) $$(MODULE_CFLAGS) -c $$< -o $$@
$$($(1)_S_OBJS): %.o: %.S
@echo " AS [MOD] $$<"
$$(CC) $$(MODULE_CFLAGS) -c $$< -o $$@
$$($(1)_ELF): $$($(1)_OBJS)
@echo " LD [MOD] $$@"
$$(LD) $$(MODULE_LD_FLAG) $$^ -o $$@
$$($(1)_BIN): $$($(1)_ELF)
@echo " OBJCOPY [MOD] $$@"
$$(OBJCOPY) $$(MODULE_OBJCOPY_FLAG) $$^ $$@
endef
$(foreach module,$(MODULES),$(eval $(call module_template,$(module))))
KERNEL_SRCS = $(wildcard $(shell grep '^kernel:' BuildConfig | sed 's/^kernel://' | awk '{$$1=$$1; print}'))
KERNEL_LD := $(shell grep '^linker_script:' BuildConfig | sed 's/^linker_script://' | awk '{$$1=$$1; print}')
KERNEL_LD_FLAG = $(shell grep '^link_flag:' BuildConfig | sed 's/^link_flag://' | awk '{$$1=$$1; print}')
MODULE_LD_FLAG = -nostdlib -shared -m $(shell grep '^module_link_arch:' BuildConfig | sed 's/^module_link_arch://' | awk '{$$1=$$1; print}') --gc-sections
KERNEL_TARGET := $(shell grep '^kernel_target:' BuildConfig | sed 's/^kernel_target://' | awk '{$$1=$$1; print}')
KERNEL_OBJS = $(KERNEL_SRCS:.c=.o)
KERNEL_OBJS := $(KERNEL_OBJS:.S=.o)
KERNEL_BIN := $(KERNEL_TARGET)/kernel.bin
KERNEL_ELF := $(KERNEL_TARGET)/kernel.elf
KERNEL_IMAGE := $(KERNEL_TARGET)/Image
KASSEMBLE_BIN := misc/kassemble
KASSEMBLE_SRC := misc/kassemble.c
GENERATED = \
$(KERNEL_OBJS) \
$(KERNEL_ELF) \
$(KERNEL_BIN) \
$(KERNEL_IMAGE) \
$(foreach m,$(MODULES),$(m)/$(m).elf) \
$(foreach m,$(MODULES),$(m)/$(m).ko) \
$(foreach m,$(MODULES),$($(m)_OBJS)) \
$(KASSEMBLE_BIN)
.PHONY: all kernel kassemble clean modules $(MODULES)
$(V).SILENT:
ifeq ($(shell grep '^needs_kassemble:' BuildConfig | sed 's/^needs_kassemble://' | awk '{$$1=$$1; print}'), yes)
all: kassemble kernel modules
kernel: $(KERNEL_IMAGE)
else
all: kernel modules
kernel: $(KERNEL_ELF)
endif
modules: $(MODULES)
kassemble: $(KASSEMBLE_BIN)
$(MODULES): $(MODULE_OBJECTS)
%.o: %.c
@echo " CC $<"
$(CC) $(KERNEL_CFLAGS) -c $< -o $@
%.o: %.S
@echo " AS $<"
$(CC) $(KERNEL_CFLAGS) -c $< -o $@
$(KASSEMBLE_BIN): $(KASSEMBLE_SRC)
@echo " HOSTCC $<"
$(CC) -O2 $< -o $@
$(KERNEL_ELF): $(KERNEL_OBJS) $(KERNEL_LD) | $(KERNEL_OUTDIR)/
@echo " LD $@"
$(LD) $(KERNEL_LD_FLAG) $(KERNEL_OBJS)
$(KERNEL_BIN): $(KERNEL_ELF) | $(KERNEL_OUTDIR)/
@echo " OBJCOPY $@"
$(OBJCOPY) $(KERNEL_OBJCOPY_FLAG) $(KERNEL_ELF) $(KERNEL_BIN)
$(KERNEL_IMAGE): $(KERNEL_BIN) | $(KERNEL_OUTDIR)/
@echo " KASSEMBLE $@"
$(KASSEMBLE_BIN) $< $@ $$($(NM) $(KERNEL_ELF) | awk '/__image_size/{print $$1}')
clean:
@echo " CLEAN $(GENERATED)"
$(RM) $(GENERATED)
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