# SPDX-License-Identifier: BSD-3-Clause

#
# This file is meant to be included by in-tree payloads
# to provide default targets for incremental builds.
#
# Variables with file names and directory overrides have
# to be defined in advance for proper dependency tracking.
# Then, include this file. e.g
#
#     obj := output
#     OBJS := $(obj)/payload.o
#     TARGET := $(obj)/payload.elf
#     include ../path/to/libpayload/Makefile.payload
#

# Find relative path to libpayload (where this Makefile resides).
LIBPAYLOAD_SRC := $(dir $(lastword $(MAKEFILE_LIST)))
LIBPAYLOAD_SRC := $(patsubst %/,%,$(LIBPAYLOAD_SRC))

# Build dir and config for libpayload. Need absolute
# paths to pass to libpayload's sub-make.
LIBPAYLOAD_OBJ	?= $(CURDIR)/libpayload
LIBPAYLOAD	:= $(LIBPAYLOAD_OBJ)/libpayload.a
LIBPAYLOAD_CONFIG_H := $(LIBPAYLOAD_OBJ)/libpayload-config.h
LIBPAYLOAD_DOTCONFIG ?= $(CURDIR)/.lp.config
LIBPAYLOAD_DEFCONFIG ?= $(CURDIR)/$(LIBPAYLOAD_SRC)/configs/defconfig

# Some default dependencies for all targets:
DEFAULT_DEPS := Makefile $(lastword $(MAKEFILE_LIST))
DEFAULT_DEPS += $(PAYLOAD_DEPS)

obj ?= build

ARCH ?=
OBJS ?=
CCACHE ?=

CFLAGS  = $(GCC_CFLAGS_$(ARCH))
CFLAGS += -Os -ffreestanding
CFLAGS += -Wall -Wextra -Wmissing-prototypes -Wvla -Werror

STRIP ?= debug

$(TARGET):

# Make is silent per default, but `make V=1` will show all calls.
Q:=@
ifneq ($(V),1)
ifneq ($(Q),)
.SILENT:
MAKEFLAGS += -s
endif
endif
export V

ifeq ($(filter %clean,$(MAKECMDGOALS)),)

xcompile	:= $(obj)/xcompile
xcompile_script	:= $(LIBPAYLOAD_SRC)/../../util/xcompile/xcompile

# In addition to the dependency below, create the file if it doesn't exist
# to silence warnings about a file that would be generated anyway.
$(if $(wildcard $(xcompile)),,$(shell	\
	mkdir -p $(dir $(xcompile)) &&	\
	$(xcompile_script) $(XGCCPATH) > $(xcompile) ||	rm -f $(xcompile)))

$(xcompile): $(xcompile_script)
	$< $(XGCCPATH) > $@

include $(xcompile)

ifneq ($(XCOMPILE_COMPLETE),1)
$(shell rm -f $(XCOMPILE_COMPLETE))
$(error $(xcompile) deleted because it's invalid. \
        Restarting the build should fix that, or explain the problem.)
endif

# `lpgcc` in in-tree mode:
LPGCC  = CC="$(CCACHE) $(GCC_CC_$(ARCH))"
LPGCC += _OBJ="$(LIBPAYLOAD_OBJ)"
LPGCC += $(LIBPAYLOAD_SRC)/bin/lpgcc

LPAS  = AS="$(AS_$(ARCH))"
LPAS += $(LIBPAYLOAD_SRC)/bin/lpas

OBJCOPY = $(OBJCOPY_$(ARCH))

$(obj)/%.bin: $(OBJS) $(LIBPAYLOAD) $(DEFAULT_DEPS)
	@printf "    LPGCC      $(subst $(obj)/,,$@)\n"
	$(LPGCC) $(CFLAGS) -o $@ $(OBJS)

$(obj)/%.map: $(obj)/%.bin
	@printf "    SYMS       $(subst $(obj)/,,$@)\n"
	$(NM_$(ARCH)) -n $< > $@

$(obj)/%.debug: $(obj)/%.bin
	@printf "    DEBUG      $(subst $(obj)/,,$@)\n"
	$(OBJCOPY) --only-keep-debug $< $@

.PRECIOUS: $(obj)/%.debug

$(obj)/%.elf: $(obj)/%.bin $(obj)/%.debug
	@printf "    STRIP      $(subst $(obj)/,,$@)\n"
	$(OBJCOPY) --strip-$(STRIP) $< $@
	$(OBJCOPY) --add-gnu-debuglink=$(obj)/$*.debug $@

$(obj)/%.o: %.c $(LIBPAYLOAD_CONFIG_H) $(DEFAULT_DEPS)
	@printf "    LPGCC      $(subst $(obj)/,,$@)\n"
	$(LPGCC) -MMD $(CFLAGS) -c $< -o $@

$(obj)/%.S.o: %.S $(LIBPAYLOAD_CONFIG_H) $(DEFAULT_DEPS)
	@printf "    LPAS       $(subst $(obj)/,,$@)\n"
	$(LPAS) $< -o $@

-include $(OBJS:.o=.d)

.PRECIOUS: $(OBJS)

LIBPAYLOAD_OPTS := obj="$(LIBPAYLOAD_OBJ)"
LIBPAYLOAD_OPTS += DOTCONFIG="$(LIBPAYLOAD_DOTCONFIG)"
LIBPAYLOAD_OPTS += CONFIG_=CONFIG_LP_
LIBPAYLOAD_OPTS += $(if $(CCACHE),CONFIG_LP_CCACHE=y)

defconfig: lp-defconfig
lp-defconfig: $(LIBPAYLOAD_DOTCONFIG)
$(LIBPAYLOAD_DOTCONFIG): $(LIBPAYLOAD_DEFCONFIG) | $(PAYLOAD_DEPS)
	$(MAKE) -C $(LIBPAYLOAD_SRC) $(LIBPAYLOAD_OPTS) \
		KBUILD_DEFCONFIG=$(LIBPAYLOAD_DEFCONFIG) defconfig

$(LIBPAYLOAD_CONFIG_H): $(LIBPAYLOAD_DOTCONFIG)
	$(MAKE) -C $(LIBPAYLOAD_SRC) $(LIBPAYLOAD_OPTS) $(LIBPAYLOAD_CONFIG_H)

oldconfig: lp-oldconfig
lp-oldconfig:
	[ ! -f $(LIBPAYLOAD_DOTCONFIG) ] || \
	$(MAKE) -C $(LIBPAYLOAD_SRC) $(LIBPAYLOAD_OPTS) oldconfig

$(LIBPAYLOAD): lp-defconfig | $(LIBPAYLOAD_CONFIG_H)
	$(MAKE) -C $(LIBPAYLOAD_SRC) $(LIBPAYLOAD_OPTS)

$(shell mkdir -p $(sort $(dir $(OBJS))))

.PHONY: oldconfig lp-oldconfig defconfig lp-defconfig

else # %clean,$(MAKECMDGOALS)

default-payload-clean:
	rm -rf $(obj) $(LIBPAYLOAD_OBJ)
clean: default-payload-clean

default-payload-distclean: clean
	rm -f $(LIBPAYLOAD_DOTCONFIG) $(LIBPAYLOAD_DOTCONFIG).old
distclean: default-payload-distclean

.PHONY: default-payload-clean clean default-payload-distclean distclean

endif