Splitting out UEFI bootloader code from kernel

Now the bootloader should be responsible for all initial setup, loading the kernel, and then handing off to the kernel with proper data in place.
2025-12-09 16:04:32 -08:00 · 2017-07-26 01:41:46 -07:00
parent 9ae583b1ec
commit d02e1d97d9
14 changed files with 242 additions and 53 deletions
--- a/97
+++ b/97
@@ -20,7 +20,9 @@ DEPENDFLAGS    := -MMD

 INCLUDES       := -I $(ARCH_D)
 INCLUDES       += -I src/modules
-INCLUDES       += -isystem $(EFI_INCLUDES) -isystem $(EFI_INCLUDES)/$(ARCH) -isystem $(EFI_INCLUDES)/protocol
+INCLUDES       += -isystem $(EFI_INCLUDES)
+INCLUDES       += -isystem $(EFI_INCLUDES)/$(ARCH)
+INCLUDES       += -isystem $(EFI_INCLUDES)/protocol

 BASEFLAGS      := -O2 -fpic -nostdlib
 BASEFLAGS      += -ffreestanding -nodefaultlibs
@@ -30,35 +32,39 @@ ifdef CPU
 BASEFLAGS      += -mcpu=$(CPU)
 endif

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

 ASFLAGS        ?= 

-CFLAGS         ?= 
-CFLAGS         += $(INCLUDES) $(DEPENDFLAGS) $(BASEFLAGS) $(WARNFLAGS)
+CFLAGS         := $(INCLUDES) $(DEPENDFLAGS) $(BASEFLAGS) $(WARNFLAGS)
+CFLAGS         += -std=c11 -fpic -fshort-wchar
+CFLAGS         += -mno-red-zone -fno-stack-protector 
 CFLAGS         += -DGIT_VERSION="L\"$(VERSION)\""
-CFLAGS         += -std=c11 -fno-stack-protector -fpic -fshort-wchar -mno-red-zone
-CFLAGS         += -DEFI_DEBUG=0 -DEFI_DEBUG_CLEAR_MEMORY=0 -DGNU_EFI_USE_MS_ABI -DHAVE_USE_MS_ABI #-DEFI_FUNCTION_WRAPPER 
+CFLAGS         += -DEFI_DEBUG=0 -DEFI_DEBUG_CLEAR_MEMORY=0
+CFLAGS         += -DGNU_EFI_USE_MS_ABI -DHAVE_USE_MS_ABI
+#CFLAGS        += -DEFI_FUNCTION_WRAPPER 

+BOOT_CFLAGS	   := -I src/boot $(CFLAGS)
 ifdef MAX_HRES
-CFLAGS         += -DMAX_HRES=$(MAX_HRES)
+BOOT_CFLAGS    += -DMAX_HRES=$(MAX_HRES)
 endif

-LDFLAGS        ?= 
-LDFLAGS        += -L $(BUILD_D) -ggdb
-LDFLAGS        += -nostdlib -znocombreloc -shared -Bsymbolic -fPIC -nostartfiles 
-LDFLAGS        += -L $(EFI_ARCH_DIR)/lib -L $(EFI_ARCH_DIR)/gnuefi
+LDFLAGS        := -L $(BUILD_D) -ggdb -fPIC -shared
+LDFLAGS        += -nostdlib -znocombreloc -Bsymbolic -nostartfiles 
+
+BOOT_LDFLAGS   := $(LDFLAGS)
+BOOT_LDFLAGS   += -L $(EFI_ARCH_DIR)/lib -L $(EFI_ARCH_DIR)/gnuefi

 AS             ?= $(CROSS)as
 AR             ?= $(CROSS)ar
@@ -69,6 +75,11 @@ OBJC           := $(CROSS)objcopy
 OBJD           := $(CROSS)objdump

 INIT_DEP       := $(BUILD_D)/.builddir
+
+BOOT_SRCS      := $(wildcard src/boot/*.c)
+BOBJS          += $(patsubst src/boot/%,$(BUILD_D)/boot/%,$(patsubst %,%.o,$(BOOT_SRCS)))
+BDEPS          := $(patsubst src/boot/%,$(BUILD_D)/boot/%,$(patsubst %,%.d,$(BOOT_SRCS)))
+
 ARCH_SRCS      := $(wildcard $(ARCH_D)/*.s)
 ARCH_SRCS      += $(wildcard $(ARCH_D)/*.c)
 KOBJS          += $(patsubst $(ARCH_D)/%,$(BUILD_D)/arch/%,$(patsubst %,%.o,$(ARCH_SRCS)))
@@ -80,7 +91,13 @@ QEMU           ?= qemu-system-x86_64
 GDBPORT        ?= 27006
 CPUS           ?= 2
 OVMF           ?= assets/ovmf/x64/OVMF.fd 
-QEMUOPTS       := -bios $(OVMF) -hda $(BUILD_D)/fs.img -smp $(CPUS) -m 512 $(QEMUEXTRA) -d guest_errors
+
+QEMUOPTS       := -pflash $(OVMF)
+QEMUOPTS       += -drive file=$(BUILD_D)/fs.img,format=raw
+QEMUOPTS       += -smp $(CPUS)
+QEMUOPTS       += -m 512
+QEMUOPTS       += -d guest_errors
+QEMUOPTS       += $(QEMUEXTRA)


 all: $(BUILD_D)/fs.img
@@ -88,6 +105,7 @@ init: $(INIT_DEP)

 $(INIT_DEP):
 	mkdir -p $(BUILD_D) $(patsubst %,$(BUILD_D)/d.%,$(MODULES))
+	mkdir -p $(BUILD_D)/boot
 	mkdir -p $(BUILD_D)/arch
 	touch $(INIT_DEP)

@@ -108,32 +126,47 @@ $(BUILD_D)/.version:
 $(EFI_LIB):
 	make -C external/gnu-efi all

-$(BUILD_D)/kernel.elf: $(KOBJS) $(MOD_TARGETS) $(EFI_LIB)
-	$(LD) $(LDFLAGS) -T $(EFI_LDS) -o $@ \
-		$(EFI_CRT_OBJ) $(KOBJS) $(patsubst %,-l%,$(MODULES)) -lefi -lgnuefi
+$(BUILD_D)/kernel.elf: $(KOBJS) $(MOD_TARGETS) $(ARCH_D)/kernel.ld
+	$(LD) $(LDFLAGS) -T $(ARCH_D)/kernel.ld -o $@ $(KOBJS) $(patsubst %,-l%,$(MODULES))

-$(BUILD_D)/kernel.efi: $(BUILD_D)/kernel.elf
+$(BUILD_D)/boot.elf: $(BOBJS) $(EFI_LIB)
+	$(LD) $(BOOT_LDFLAGS) -T $(EFI_LDS) -o $@ \
+		$(EFI_CRT_OBJ) $(BOBJS) $(patsubst %,-l%,$(MODULES)) -lefi -lgnuefi
+
+$(BUILD_D)/boot.efi: $(BUILD_D)/boot.elf
 	objcopy -j .text -j .sdata -j .data -j .dynamic \
 	-j .dynsym  -j .rel -j .rela -j .reloc \
 	--target=efi-app-$(ARCH) $^ $@

-$(BUILD_D)/kernel.debug.efi: $(BUILD_D)/kernel.elf
+$(BUILD_D)/boot.debug.efi: $(BUILD_D)/boot.elf
 	objcopy -j .text -j .sdata -j .data -j .dynamic \
 	-j .dynsym  -j .rel -j .rela -j .reloc \
 	-j .debug_info -j .debug_abbrev -j .debug_loc -j .debug_str \
 	-j .debug_aranges -j .debug_line -j .debug_macinfo \
 	--target=efi-app-$(ARCH) $^ $@

-$(BUILD_D)/%.dump: $(BUILD_D)/%.efi
+$(BUILD_D)/%.elf.dump: $(BUILD_D)/%.elf
 	$(OBJD) -D -S $< > $@

+$(BUILD_D)/%.bin.dump: $(BUILD_D)/%.bin
+	$(OBJD) -D $< > $@
+
+$(BUILD_D)/%.bin: $(BUILD_D)/%.elf
+	$(OBJC) $< -O binary $@
+
+$(BUILD_D)/boot/%.s.o: src/boot/%.s $(INIT_DEP)
+	$(AS) $(ASFLAGS) -o $@ $<
+
+$(BUILD_D)/boot/%.c.o: src/boot/%.c $(INIT_DEP)
+	$(CC) $(BOOT_CFLAGS) -c -o $@ $<
+
 $(BUILD_D)/arch/%.s.o: $(ARCH_D)/%.s $(INIT_DEP)
 	$(AS) $(ASFLAGS) -o $@ $<

 $(BUILD_D)/arch/%.c.o: $(ARCH_D)/%.c $(INIT_DEP)
 	$(CC) $(CFLAGS) -c -o $@ $<

-$(BUILD_D)/fs.img: $(BUILD_D)/kernel.efi
+$(BUILD_D)/fs.img: $(BUILD_D)/boot.efi $(BUILD_D)/kernel.bin
 	$(eval TEMPFILE := $(shell mktemp --suffix=.img))
 	dd if=/dev/zero of=$@.tmp bs=512 count=93750
 	$(PARTED) $@.tmp -s -a minimal mklabel gpt
@@ -143,7 +176,9 @@ $(BUILD_D)/fs.img: $(BUILD_D)/kernel.efi
 	mformat -i $(TEMPFILE) -h 32 -t 32 -n 64 -c 1
 	mmd -i $(TEMPFILE) ::/EFI
 	mmd -i $(TEMPFILE) ::/EFI/BOOT
-	mcopy -i $(TEMPFILE) $^ ::/EFI/BOOT/BOOTX64.efi
+	mcopy -i $(TEMPFILE) $(BUILD_D)/boot.efi ::/EFI/BOOT/BOOTX64.efi
+	mcopy -i $(TEMPFILE) $(BUILD_D)/kernel.bin ::/kernel.bin
+	mlabel -i $(TEMPFILE) ::Popcorn_OS
 	dd if=$(TEMPFILE) of=$@.tmp bs=512 count=91669 seek=2048 conv=notrunc
 	rm $(TEMPFILE)
 	mv $@.tmp $@
@@ -159,7 +194,7 @@ qemu: $(BUILD_D)/fs.img
 qemu-window: $(BUILD_D)/fs.img
 	"$(QEMU)" $(QEMUOPTS)

-qemu-gdb: $(BUILD_D)/fs.img $(BUILD_D)/kernel.debug.efi
+qemu-gdb: $(BUILD_D)/fs.img $(BUILD_D)/boot.debug.efi
 	"$(QEMU)" $(QEMUOPTS) -S -D popcorn-qemu.log -s

 # vim: ft=make ts=4