added LLVM support to MakeFile

Makefile

@@ -1,47 +1,63 @@
 BUILD_DIR=build
 SRC_DIR=src
+
 FAT=mkfs.fat
 ASM=nasm
-CC=/home/novice/opt/cross/bin/i686-elf-gcc
-LD=/home/novice/opt/cross/bin/i686-elf-ld
-LIBGCC_PATH= /home/novice/opt/cross/lib/gcc/i686-elf/13.3.0
+
+# LLVM toolchain
+CC=clang
+LD=ld.lld
+
+# Target architecture
+TARGET=i686-elf
+
+# Compiler flags
+CFLAGS=--target=$(TARGET) -ffreestanding -nostdlib -fno-stack-protector -m32
+LDFLAGS=-m elf_i386
+
 LIB_DIR=$(abspath $(SRC_DIR)/lib/)
 
 export FAT
 export ASM
 export CC
 export LD
-export LIBGCC_PATH
+export TARGET
+export CFLAGS
+export LDFLAGS
 export LIB_DIR
 
-#
+
+# ----------------------
 # disk image
-#
+# ----------------------
 
 disk_image: $(BUILD_DIR)/main.img
 
 $(BUILD_DIR)/main.img: lib bootloader kernel
 	chmod +x make_disk.sh
 	./make_disk.sh $@ 52428800 $(BUILD_DIR)
 
-#
+
+# ----------------------
 # bootable usb
-#
+# ----------------------
 
 bootable_usb: lib bootloader kernel
 	chmod +x make_bootable_usb.sh
 	./make_bootable_usb.sh $(BUILD_DIR)
 
-#
+
+# ----------------------
 # lib
-#
+# ----------------------
 
 lib:
 	$(MAKE) -C $(LIB_DIR) BUILD_DIR=$(abspath $(BUILD_DIR))
 
-#
+
+# ----------------------
 # Bootloader
-#
+# ----------------------
 
 bootloader: stage1 stage2
 
@@ -51,12 +67,27 @@ stage1:
 stage2:
 	$(MAKE) -C $(SRC_DIR)/bootloader/stage2/ BUILD_DIR=$(abspath $(BUILD_DIR))
 
+
+# ----------------------
+# Kernel
+# ----------------------
+
 kernel:
 	$(MAKE) -C $(SRC_DIR)/kernel/ BUILD_DIR=$(abspath $(BUILD_DIR))
 
+
+# ----------------------
+# Run in emulator
+# ----------------------
+
 run: disk_image
 	chmod +x run.sh
 	./run.sh
 
+
+# ----------------------
+# Clean
+# ----------------------
+
 clean:
 	rm -rf build/*

run.sh

@@ -1 +1 @@
-qemu-system-i386 -debugcon stdio -m 64M -hda build/main.img
+qemu-system-i386 -debugcon stdio -m 64M -hda build/main.img 

src/bootloader/stage1/Makefile

@@ -1,17 +1,17 @@
-BUILD_DIR?=build
+BUILD_DIR ?= build
 
-ASM?=nasm
-ASMFLAGS= -f elf
+ASM ?= nasm
+ASMFLAGS ?= -f bin      # flat binary for stage1
 
-LIBGCC_PATH?=/home/novice/cross/i686-elf/lib/gcc/i686-elf/14.2.0
-CC?=/home/novice/cross/i686-elf/bin/i686-elf-gcc
-CFLAG=-ffreestanding -nostdlib -std=c99 -g -I $(abspath $(LIBGCC_PATH))
-
-LD?=/home/novice/cross/i686-elf/bin/i686-elf-ld
-LDFLAG=-T linker.ld -nostdlib -L $(LIBGCC_PATH)
+# LLVM toolchain (for later C stages)
+CC ?= clang
+LD ?= ld.lld
+TARGET ?= i686-elf
 
+# Stage1 target
 stage1: $(BUILD_DIR)/bootloader.bin
 
 $(BUILD_DIR)/bootloader.bin: boot.asm
-	@$(ASM) boot.asm -f bin -o $(BUILD_DIR)/bootloader.bin
-	@echo "--> Created:  bootloader.bin"
+	@mkdir -p $(@D)
+	@$(ASM) $(ASMFLAGS) boot.asm -o $(BUILD_DIR)/bootloader.bin
+	@echo "--> Created: bootloader.bin"

src/bootloader/stage2/Makefile

@@ -4,37 +4,45 @@ LIB_DIR?=lib
 ASM?=nasm
 ASMFLAGS= -f elf
 
-LIBGCC_PATH?=/home/novice/cross/i686-elf/lib/gcc/i686-elf/14.2.0
-CC?=/home/novice/cross/i686-elf/bin/i686-elf-gcc
-CFLAG=-ffreestanding -nostdlib -std=c99 -g -I $(LIB_DIR)
+# LLVM toolchain
+CC?=clang
+LD?=ld.lld
+TARGET=i686-elf
 
-LD?=/home/novice/cross/i686-elf/bin/i686-elf-ld
-LDFLAG=-T linker.ld -nostdlib -L $(LIBGCC_PATH)
+CFLAG=--target=$(TARGET) -ffreestanding -nostdlib -std=c99 -g -m32 -fno-stack-protector -I $(LIB_DIR)
+
+LDFLAG=-T linker.ld -nostdlib -m elf_i386
 
 
 SOURCES_C=$(wildcard *.c)
 SOURCES_ASM=$(wildcard *.asm)
-OBJECTS_C=$(patsubst %.c, $(BUILD_DIR)/bootloader/c/%.obj, $(SOURCES_C))
-OBJECTS_ASM=$(patsubst %.asm, $(BUILD_DIR)/bootloader/asm/%.obj, $(SOURCES_ASM))
 
-LIB_OBJECT =	$(wildcard $(BUILD_DIR)/lib/*.obj) \
-			$(wildcard $(BUILD_DIR)/lib/*/*.obj) \
-			$(wildcard $(BUILD_DIR)/lib/*/*/*.obj) \
-			$(wildcard $(BUILD_DIR)/lib/*/*/*/*.obj) \
+OBJECTS_C=$(patsubst %.c,$(BUILD_DIR)/bootloader/c/%.obj,$(SOURCES_C))
+OBJECTS_ASM=$(patsubst %.asm,$(BUILD_DIR)/bootloader/asm/%.obj,$(SOURCES_ASM))
+
+LIB_OBJECT = \
+	$(wildcard $(BUILD_DIR)/lib/*.obj) \
+	$(wildcard $(BUILD_DIR)/lib/*/*.obj) \
+	$(wildcard $(BUILD_DIR)/lib/*/*/*.obj) \
+	$(wildcard $(BUILD_DIR)/lib/*/*/*/*.obj)
+
 
 stage2: $(BUILD_DIR)/boot0.bin
 
+
 $(BUILD_DIR)/boot0.bin: $(OBJECTS_ASM) $(OBJECTS_C)
 	@mkdir -p $(@D)
-	@$(LD) $(LDFLAG) -o $@ $^ $(LIB_OBJECT) -lgcc -Map $(BUILD_DIR)/boot0.map
+	@$(LD) $(LDFLAG) -o $@ $^ $(LIB_OBJECT) -Map $(BUILD_DIR)/boot0.map
 	@echo "--> Created:  boot0.bin"
 
+
 $(BUILD_DIR)/bootloader/c/%.obj: %.c
 	@mkdir -p $(@D)
 	@$(CC) $(CFLAG) -c $< -o $@
 	@echo "--> Compiled: " $<
 
+
 $(BUILD_DIR)/bootloader/asm/%.obj: %.asm
 	@mkdir -p $(@D)
 	@$(ASM) $(ASMFLAGS) -o $@ $<
-	@echo "--> Compiled: " $<
+	@echo "--> Compiled: " $<

src/kernel/Makefile

@@ -4,13 +4,15 @@ LIB_DIR?=lib
 ASM?=nasm
 ASMFLAGS= -f elf
 
-LIBGCC_PATH?=/home/novice/cross/i686-elf/lib/gcc/i686-elf/14.2.0
-CC?=/home/novice/cross/i686-elf/bin/i686-elf-gcc
-CFLAG=-ffreestanding -nostdlib -std=c99 -g -I include -I $(abspath $(LIB_DIR))
+# LLVM toolchain
+CC?=clang
+LD?=ld.lld
+TARGET=i686-elf
 
-LD?=/home/novice/cross/i686-elf/bin/i686-elf-ld
-LDFLAG=-T linker.ld -nostdlib -L $(LIBGCC_PATH)
-LDFLAG-ELF=-T linker-elf.ld -nostdlib -L $(LIBGCC_PATH)
+CFLAG=--target=$(TARGET) -ffreestanding -nostdlib -std=c99 -g -m32 -fno-stack-protector -I include -I $(abspath $(LIB_DIR))
+
+LDFLAG=-T linker.ld -nostdlib -m elf_i386
+LDFLAG-ELF=-T linker-elf.ld -nostdlib -m elf_i386
 
 
 HEADERS_C = $(wildcard *.h) \
@@ -33,38 +35,47 @@ HEADERS_ASM = $(wildcard *.inc) \
 SOURCES_ASM =  $(wildcard *.asm) \
 			  $(wildcard */*.asm) \
 			  $(wildcard */*/*.asm) \
-			  $(wildcard */*/*/*.asm) \
+			  $(wildcard */*/*/*.asm)
 
 OBJECTS_C = $(patsubst %.c, $(BUILD_DIR)/kernel/c/%.obj, $(SOURCES_C))
-
 OBJECTS_ASM = $(patsubst %.asm, $(BUILD_DIR)/kernel/asm/%.obj, $(SOURCES_ASM))
 
 LIB_OBJECT =	$(wildcard $(BUILD_DIR)/lib/*.obj) \
 			$(wildcard $(BUILD_DIR)/lib/*/*.obj) \
 			$(wildcard $(BUILD_DIR)/lib/*/*/*.obj) \
-			$(wildcard $(BUILD_DIR)/lib/*/*/*/*.obj) \
+			$(wildcard $(BUILD_DIR)/lib/*/*/*/*.obj)
 
 kernel: isr_generator $(BUILD_DIR)/kernel.bin $(BUILD_DIR)/kernel.elf
 
+
 isr_generator:
 	@sed -i 's/\r//' hal/isr_generator.sh
 	@./hal/isr_generator.sh hal/isrs_gen.c hal/isrs_gen.inc
 	@echo "--> Generating: hal/isrs_gen.c hal/isrs_gen.inc"
 
+
 $(BUILD_DIR)/kernel/c/%.obj: %.c $(HEADERS_C)
 	@mkdir -p $(@D)
-	@$(CC) $(CFLAG) -c $< -o $@ 
+	@$(CC) $(CFLAG) -c $< -o $@
 	@echo "--> Compiled: " $<
 
+
 $(BUILD_DIR)/kernel/asm/%.obj: %.asm $(HEADERS_ASM)
 	@mkdir -p $(@D)
 	@$(ASM) $(ASMFLAGS) -o $@ $<
 	@echo "--> Compiled: " $<
 
-$(BUILD_DIR)/kernel.bin: $(OBJECTS_ASM) $(OBJECTS_C)
-	@$(LD) $(LDFLAG) -o $@ $^ $(LIB_OBJECT) -lgcc -Map $(BUILD_DIR)/kernel.map
-	@echo "--> Created:  kernel.bin"
+
+# Step 1: build ELF
+$(BUILD_DIR)/kernel.elf: $(OBJECTS_ASM) $(OBJECTS_C)
+	@$(LD) $(LDFLAG-ELF) -o $@ $^ $(LIB_OBJECT) -Map $(BUILD_DIR)/kernel.map
+	@echo "--> Created: kernel.elf"
+
+# Step 2: generate flat binary from ELF
+$(BUILD_DIR)/kernel.bin: $(BUILD_DIR)/kernel.elf
+	@llvm-objcopy -O binary $< $@
+	@echo "--> Created: kernel.bin"
 
 $(BUILD_DIR)/kernel.elf: $(OBJECTS_ASM) $(OBJECTS_C)
-	@$(LD) $(LDFLAG-ELF) -o $@ $^ $(LIB_OBJECT) -lgcc
-	@echo "--> Created:  kernel.elf (for debugging)"
+	@$(LD) $(LDFLAG-ELF) -o $@ $^ $(LIB_OBJECT)
+	@echo "--> Created:  kernel.elf (for debugging)"

src/lib/Makefile

@@ -1,17 +1,16 @@
 BUILD_DIR?=build
 
 ASM?=nasm
-ASMFLAGS= -f elf
+ASMFLAGS=-f elf32
 
-LIBGCC_PATH?=/home/novice/cross/i686-elf/lib/gcc/i686-elf/14.2.0
-CC?=/home/novice/cross/i686-elf/bin/i686-elf-gcc
-CFLAG=-ffreestanding -nostdlib -std=c99 -g -I $(abspath $(LIBGCC_PATH))
+# LLVM toolchain
+CC?=clang
+TARGET=i686-elf
 
-LD?=/home/novice/cross/i686-elf/bin/i686-elf-ld
-LDFLAG=-T linker.ld -nostdlib -L $(LIBGCC_PATH)
+CFLAG=--target=$(TARGET) -m32 -ffreestanding -nostdlib -fno-stack-protector -fno-pic -std=c99 -g
 
 SOURCES_C=$(wildcard *.c)
-OBJECTS_C=$(patsubst %.c, $(BUILD_DIR)/lib/c/%.obj, $(SOURCES_C))
+OBJECTS_C=$(patsubst %.c,$(BUILD_DIR)/lib/c/%.obj,$(SOURCES_C))
 
 lib: $(OBJECTS_C)
 

src/lib/compiler_rt.c

@@ -0,0 +1,17 @@
+#include <stdint.h>
+
+uint64_t __udivdi3(uint64_t n, uint64_t d) {
+    uint64_t q = 0;
+    while (n >= d) {
+        n -= d;
+        q++;
+    }
+    return q;
+}
+
+uint64_t __umoddi3(uint64_t n, uint64_t d) {
+    while (n >= d) {
+        n -= d;
+    }
+    return n;
+}