split makefile into two parts

+ First part generates deps.mk, second part reads it.
  Allows us to use both bmake and gmake with the same makefiles.
  Only drawback seems to be that the first makefile considers all
  individual files as 'finished' targets, meaning that it's more
  difficult to do something like

  make kernel.elf

  though I haven't found this to be an issue.

2 files changed, 154 insertions, 51 deletions

diff --git a/scripts/gen-deps b/scripts/gen-deps
index 9a9ad6e..f45707c 100755
--- a/scripts/gen-deps
+++ b/scripts/gen-deps
@@ -1,60 +1,37 @@
 #!/bin/sh
 
-gencommon () {
-	lint="build/${path}/${s%.*}${1}.l"
-	dep="build/${path}/${s%.*}${1}.d"
-	obj="build/${path}/${s%.*}${1}"
+PREFIX=
+COMPILE=COMPILE
+LINT=LINT
+BUILD=build/
 
-	echo "${dep}:"		>> deps.mk
-	echo "-include ${dep}"	>> deps.mk
-	echo "${obj}: ${s}"		>> deps.mk
-}
-
-genlink () {
-	gencommon ".ld"
-	if [ ${kern} ]; then
-		echo "	\$(GENLINK) ${s} | \$(STRIPLINK) > ${obj}" >> deps.mk
-	else
-		echo "	\$(GENLINK) ${s} | \$(STRIPLINK) | \$(KERN_INFO) > ${obj}" >> deps.mk;
-	fi
-}
-
-genrule () {
-	gencommon "${1}"
-	echo "	\$(COMPILE) ${flags} -c ${s} -o ${obj}"	>> deps.mk
-
-	echo "${lint}: ${s}"			>> deps.mk
-	echo "	\$(LINT) ${flags} -c ${s} -o /dev/null"	>> deps.mk
-}
-
-case "${1}" in
-	--kernel)
-		kern=1
-		path=kernel
-		flags='$(KERN_FLAGS)'
-		;;
-	--init)
-		path=init
-		flags='$(INIT_FLAGS)'
-		;;
-esac
+while getopts "p:c:b:l:" opt; do
+	case "$opt" in
+		p) PREFIX="$OPTARG"_;;
+		c) COMPILE="$OPTARG";;
+		l) LINT="$OPTARG";;
+		b) BUILD=build/"$OPTARG";;
+		*) echo "unrecognised option -$OPTARG" >&2; exit 1;;
+	esac
+done
 
-case "${2}" in
-	--compile)
-		suffix=.o
-		func=genrule
-		;;
-	--link)
-		suffix=.ld
-		func=genlink
-esac
+shift $((OPTIND - 1))
 
 # create all subdirectories
-mkdir -p $(echo "${3}" | xargs -n 1 dirname | uniq | sed 's|^|build/init/|g')
-mkdir -p $(echo "${3}" | xargs -n 1 dirname | uniq | sed 's|^|build/kernel/|g')
+mkdir -p $(echo "${@}" | tr ' ' '\n' | sed "s|[^/]*$||;s|^|${BUILD}/|" | uniq)
 
-for s in ${3}
+for s in ${@}
 do
-	${func} ${suffix}
-	echo ${obj}
+	obj="${BUILD}/${s%.*}.o"
+	lint="${obj}.l"
+	dep="${obj}.d"
+
+	echo "${PREFIX}OBJS += ${obj}"			>> deps.mk
+	echo "${PREFIX}LINTS += ${lint}"		>> deps.mk
+	echo "${dep}:"					>> deps.mk
+	echo "-include ${dep}"				>> deps.mk
+	echo "${obj}: ${s}"				>> deps.mk
+	echo "	\$(${COMPILE}) -c ${s} -o ${obj}"	>> deps.mk
+	echo "${lint}: ${s}"				>> deps.mk
+	echo "	\$(${LINT}) -c ${s} -o /dev/null"	>> deps.mk
 done
diff --git a/scripts/makefile b/scripts/makefile
new file mode 100644
index 0000000..762c5c9
--- /dev/null
+++ b/scripts/makefile
@@ -0,0 +1,126 @@
+# this could be done better
+RELEASE		?= 0
+OPTFLAGS	!= [ "$(RELEASE)" != "0" ] \
+			&& echo "-O3 -flto" \
+			|| echo "-O0"
+
+DEBUG		?= 1
+DEBUGFLAGS	!= [ "$(DEBUG)" != "0" ] \
+			&& echo "-DDEBUG=1" \
+			|| echo "-DNDEBUG=1"
+
+GENERIC_UBOOT	?= 0
+UBOOTFLAGS	!= [ "$(GENERIC_UBOOT)" != "0" ] \
+			&& echo "-DGENERIC_UBOOT=1" \
+			|| echo
+
+ASSERT		?= 1
+ASSERTFLAGS	!= [ "$(ASSERT)" != "0" ] \
+			&& echo "-DASSERT=1" \
+			|| echo
+
+DEPFLAGS	= -MT $@ -MMD -MP -MF $@.d
+LINTFLAGS	= -fsyntax-only
+PREPROCESS	= -E
+
+LLVM		?= 0
+LDFLAGS		!= [ "$(LLVM)" = "0" ] \
+			&& echo -static-libgcc -lgcc \
+			|| echo
+
+BUILD		= build
+ARCH_KERN_BUILD	= $(BUILD)/kernel/arch/$(ARCH)
+ARCH_INIT_BUILD = $(BUILD)/init/arch/$(ARCH)
+ARCH_SOURCE	= arch/$(ARCH)
+
+all: kmi.bin
+
+# default values, overwrite if/when needed
+ARCH		?= riscv64
+CROSS_COMPILE	?= $(ARCH)-unknown-elf-
+
+OBJCOPY		!= [ "$(LLVM)" != "0" ] \
+			&& echo llvm-objcopy \
+			|| echo $(CROSS_COMPILE)objcopy
+
+COMPILER	!= [ "$(LLVM)" != "0" ] \
+			&& echo clang --target="$(CROSS_COMPILE)" \
+			|| echo $(CROSS_COMPILE)gcc
+
+
+OBFLAGS		= -ffreestanding -nostdlib -static -fno-pie -std=c17 -g
+WARNFLAGS	= -Wall -Wextra -Wvla
+ARCH_CFLAGS	= -D$(ARCH)
+
+include arch/$(ARCH)/source.mk
+
+COMPILE_FLAGS	= $(CFLAGS) $(WARNFLAGS) $(OPTFLAGS) $(OBFLAGS) $(ASSERTFLAGS) \
+		   $(DEBUGFLAGS) $(UBOOTFLAGS) $(ARCH_CFLAGS)
+
+LINK_FLAGS	= $(LDFLAGS) $(ARCH_LDFLAGS)
+
+INCLUDE_FLAGS	= -I include -include config.h -include arch/$(ARCH)/config.h
+
+# This makes sure .bss is loaded into the binary
+OBJCOPY_FLAGS	?= -Obinary -R .garbage \
+		   --set-section-flags .bss=alloc,load,contents
+
+COMPILE		= $(COMPILER) \
+		  $(COMPILE_FLAGS) $(DEPFLAGS) $(INCLUDE_FLAGS)
+
+LINT		= $(COMPILER) \
+		  $(COMPILE_FLAGS) $(LINTFLAGS) $(INCLUDE_FLAGS)
+
+GENELF		= $(COMPILER) \
+		  $(COMPILE_FLAGS) $(INCLUDE_FLAGS)
+
+GENLINK		= $(COMPILER) $(COMPILE_FLAGS) $(PREPROCESS) $(DEPFLAGS) $(INCLUDE_FLAGS)
+STRIPLINK	= sed -n '/^[^\#]/p'
+KERN_SIZE	= wc -c kernel.bin | awk '{print $$1}'
+KERN_INFO	= sed "s/<KERNEL_SIZE>/$$($(KERN_SIZE))/"
+
+KERNEL_LINK	= arch/$(ARCH)/conf/kernel-link.S
+INIT_LINK	= arch/$(ARCH)/conf/init-link.S
+
+KERNEL_LD	= build/kernel-link.ld
+INIT_LD		= build/init-link.ld
+
+UBSAN		?= 0
+KERN_FLAGS	!= [ "$(UBSAN)" != "0" ] \
+			&& echo -fsanitize=undefined \
+			|| echo
+
+INIT_FLAGS	:= -fpic
+
+COMPILE_KERNEL	= $(COMPILE) $(KERN_FLAGS)
+COMPILE_INIT	= $(COMPILE) $(INIT_FLAGS)
+
+-include deps.mk
+
+-include $(KERNEL_LD).d
+$(INIT_LD): kernel.bin
+$(INIT_LD): $(INIT_LINK)
+	$(GENLINK) $(INIT_LINK) | $(STRIPLINK) | $(KERN_INFO) > $(INIT_LD)
+
+-include $(KERNEL_LD).d
+$(KERNEL_LD): $(KERNEL_LINK)
+	$(GENLINK) $(KERNEL_LINK) | $(STRIPLINK) > $(KERNEL_LD)
+
+init.elf: $(INIT_OBJS) $(INIT_LD)
+	$(GENELF) $(INIT_FLAGS) -T $(INIT_LD) $(INIT_OBJS) -o init.elf $(LINK_FLAGS)
+
+kernel.elf: $(KERNEL_OBJS) $(KERNEL_LD)
+	$(GENELF) $(KERNEL_FLAGS) -T $(KERNEL_LD) $(KERNEL_OBJS) -o kernel.elf $(LINK_FLAGS)
+
+init.bin: init.elf
+	$(OBJCOPY) $(OBJCOPY_FLAGS) init.elf init.bin
+
+kernel.bin: kernel.elf
+	$(OBJCOPY) $(OBJCOPY_FLAGS) kernel.elf kernel.bin
+
+kmi.bin: init.bin kernel.bin
+	cat init.bin kernel.bin > kmi.bin
+
+# might lint some common things twice
+.PHONY:
+lint: $(INIT_LINTS) $(KERNEL_LINTS)