Move to src/obj directory structure

kernel/.gitignore

@@ -1,4 +1,4 @@
-/limine.h
+/src/limine.h
+/obj
 *.elf
 *.o
-*.d

kernel/GNUmakefile

@@ -61,7 +61,7 @@ override CFLAGS += \
 
 # Internal C preprocessor flags that should not be changed by the user.
 override CPPFLAGS := \
-    -I. \
+    -I src \
     $(CPPFLAGS) \
     -MMD \
     -MP
@@ -84,17 +84,17 @@ override NASMFLAGS += \
 
 # Use "find" to glob all *.c, *.S, and *.asm files in the tree and obtain the
 # object and header dependency file names.
-override CFILES := $(shell find -L . -type f -name '*.c')
-override ASFILES := $(shell find -L . -type f -name '*.S')
-override NASMFILES := $(shell find -L . -type f -name '*.asm')
-override OBJ := $(CFILES:.c=.c.o) $(ASFILES:.S=.S.o) $(NASMFILES:.asm=.asm.o)
-override HEADER_DEPS := $(CFILES:.c=.c.d) $(ASFILES:.S=.S.d)
+override CFILES := $(shell cd src && find -L . -type f -name '*.c')
+override ASFILES := $(shell cd src && find -L . -type f -name '*.S')
+override NASMFILES := $(shell cd src && find -L . -type f -name '*.asm')
+override OBJ := $(addprefix obj/,$(CFILES:.c=.c.o) $(ASFILES:.S=.S.o) $(NASMFILES:.asm=.asm.o))
+override HEADER_DEPS := $(addprefix obj/,$(CFILES:.c=.c.d) $(ASFILES:.S=.S.d))
 
 # Default target.
 .PHONY: all
 all: $(KERNEL)
 
-limine.h:
+src/limine.h:
 	curl -Lo $@ https://github.com/limine-bootloader/limine/raw/trunk/limine.h
 
 # Link rules for the final kernel executable.
@@ -105,22 +105,25 @@ $(KERNEL): GNUmakefile linker.ld $(OBJ)
 -include $(HEADER_DEPS)
 
 # Compilation rules for *.c files.
-%.c.o: %.c GNUmakefile limine.h
+obj/%.c.o: src/%.c GNUmakefile src/limine.h
+	mkdir -p obj
 	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@
 
 # Compilation rules for *.S files.
-%.S.o: %.S GNUmakefile limine.h
+obj/%.S.o: src/%.S GNUmakefile src/limine.h
+	mkdir -p obj
 	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@
 
 # Compilation rules for *.asm (nasm) files.
-%.asm.o: %.asm GNUmakefile
+obj/%.asm.o: src/%.asm GNUmakefile
+	mkdir -p obj
 	nasm $(NASMFLAGS) $< -o $@
 
 # Remove object files and the final executable.
 .PHONY: clean
 clean:
-	rm -rf $(KERNEL) $(OBJ) $(HEADER_DEPS)
+	rm -rf $(KERNEL) obj
 
 .PHONY: distclean
 distclean: clean
-	rm -f limine.h
+	rm -f src/limine.h