Makefile: remove unused variables and targets

Makefile

@@ -9,10 +9,10 @@ html:
 
 ## 1. Basic Setup and Checks
 
-### Default to create a bare-metal kernel image
+### Default to create all static libraries
 ifeq ($(MAKECMDGOALS),)
-  MAKECMDGOALS  = image
-  .DEFAULT_GOAL = image
+  MAKECMDGOALS  = libs
+  .DEFAULT_GOAL = libs
 endif
 
 ### Override checks when `make clean/clean-all/html`
@@ -37,7 +37,7 @@ PLATFORM   = $(word 2,$(ARCH_SPLIT))
 ### Checks end here
 endif
 
-## 2. General Compilation Targets
+## 2. Setup variables pointing to build and install directory
 
 ### Create the destination directory (`build/$ARCH`)
 WORK_DIR  ?= $(shell pwd)
@@ -47,7 +47,7 @@ INSTALLDIR ?= $(WORK_DIR)/build/install/$(ARCH)
 LIB_INSTALLDIR ?= $(INSTALLDIR)/lib
 INC_INSTALLDIR ?= $(INSTALLDIR)/include
 
-## 3. General Compilation Flags
+## 3. Toolchain setup
 
 ### (Cross) compilers, e.g., mips-linux-gnu-g++
 CC        ?= $(CROSS_COMPILE)gcc
@@ -59,37 +59,38 @@ OBJDUMP   ?= $(CROSS_COMPILE)objdump
 OBJCOPY   ?= $(CROSS_COMPILE)objcopy
 READELF   ?= $(CROSS_COMPILE)readelf
 
-CXXFLAGS +=  $(CFLAGS) -ffreestanding -fno-rtti -fno-exceptions
-LDFLAGS  += -z noexecstack
-INTERFACE_LDFLAGS  += -z noexecstack
-
 ## 4. Arch-Specific Configurations
 
-### Fall back to native gcc/binutils if there is no cross compiler
-ifeq ($(wildcard $(shell which $(CC))),)
-  $(info #  $(CC) not found; fall back to default gcc and binutils)
-  CROSS_COMPILE := riscv64-unknown-linux-gnu-
-endif
+# TODO: Removed CROSS_COMPILE toolchain setup as it's too complicated
+# 		  for Makefile to do right. Force the user to provide a CROSS_COMPILE
+# 		  prefix for now. They can also specify CFLAGS and LDFLAGS through
+# 		  environment variable.
+include $(AM_HOME)/scripts/$(ARCH).mk
 
 ## 5. Compilation Rules
 
 BUILDDIR := $(DST_DIR)
+COMMON_CFLAGS := $(CFLAGS) -g -O3 -MMD -Wall \
+                 -fno-asynchronous-unwind-tables -fno-builtin -fno-stack-protector \
+                 -Wno-main -U_FORTIFY_SOURCE -fvisibility=hidden
+INTERFACE_LDFLAGS += -z noexecstack
+INTERFACE_CFLAGS += -fno-asynchronous-unwind-tables \
+                    -fno-builtin -fno-stack-protector \
+                    -Wno-main -U_FORTIFY_SOURCE -fvisibility=hidden
 ### Build libam
-
 #### Include archetecture specific build flags
-include $(AM_HOME)/scripts/$(ARCH).mk
+COMMON_CFLAGS += -D__ARCH_$(shell echo $(ARCH) | tr a-z A-Z | tr - _) \
+                 -D__ISA_$(shell echo $(ISA) | tr a-z A-Z)__ \
+                 -DARCH_H=\"$(ARCH_H)\"
+INTERFACE_CFLAGS += -DARCH_H=\"$(ARCH_H)\"
 
 #### Generating build rules with ADD_LIBRARY call. Target specific build flags can be tuned via changing prefixed variables (AM_ here)
 AM_INCPATH += $(AM_HOME)/am/include $(AM_HOME)/am/src $(AM_HOME)/klib/include
-AM_CFLAGS  += -lm -g -O3 -MMD -Wall $(addprefix -I, $(AM_INCPATH)) \
-              -D__ISA__=\"$(ISA)\" -D__ISA_$(shell echo $(ISA) | tr a-z A-Z)__ \
-              -D__ARCH__=$(ARCH) -D__ARCH_$(shell echo $(ARCH) | tr a-z A-Z | tr - _) \
-              -D__PLATFORM__=$(PLATFORM) -D__PLATFORM_$(shell echo $(PLATFORM) | tr a-z A-Z | tr - _) \
-              -DARCH_H=\"$(ARCH_H)\"
+AM_CFLAGS += $(COMMON_CFLAGS) $(addprefix -I, $(AM_INCPATH))
 AM_INTERFACE_INCPATH += $(AM_HOME)/am/include $(AM_HOME)/klib/include
-AM_INTERFACE_CFLAGS += $(addprefix -I, $(AM_INTERFACE_INCPATH:%=$(INC_INSTALLDIR))) \
-                       -lm -DARCH_H=\"$(ARCH_H)\" -fno-asynchronous-unwind-tables -fno-builtin -fno-stack-protector \
-                       -Wno-main -U_FORTIFY_SOURCE -fvisibility=hidden
+AM_INTERFACE_CFLAGS += 
+                       
+AM_INTERFACE_LDFLAGS += -lm -lam-$(ARCH)
 
 $(eval $(call ADD_LIBRARY,$(LIB_BUILDDIR)/libam-$(ARCH).a,AM_))
 
@@ -98,10 +99,10 @@ $(eval $(call ADD_LIBRARY,$(LIB_BUILDDIR)/libam-$(ARCH).a,AM_))
 KLIB_SRCS := $(shell find klib/src/ -name "*.c")
 
 KLIB_INCPATH += $(AM_HOME)/am/include $(AM_HOME)/klib/include
-KLIB_CFLAGS += -MMD -Wall $(addprefix -I, $(KLIB_INCPATH)) \
-               -DARCH_H=\"$(ARCH_H)\"
+KLIB_CFLAGS += $(COMMON_CFLAGS) $(addprefix -I, $(KLIB_INCPATH))
 KLIB_INTERFACE_INCPATH += $(AM_HOME)/am/include $(AM_HOME)/klib/include
-KLIB_INTERFACE_CFLAGS += -DARCH_H=\"$(ARCH_H)\" $(addprefix -I, $(KLIB_INTERFACE_INCPATH:%=$(INC_INSTALLDIR)))
+KLIB_INTERFACE_CFLAGS +=
+KLIB_INTERFACE_LDFLAGS += -lklib-$(ARCH)
 
 $(eval $(call ADD_LIBRARY,$(LIB_BUILDDIR)/libklib-$(ARCH).a,KLIB_))
 
@@ -109,35 +110,18 @@ LIBS := am klib
 libs: $(addsuffix -$(ARCH).a, $(addprefix $(LIB_BUILDDIR)/lib, $(ALL)))
 $(LIBS): %: $(addsuffix -$(ARCH).a, $(addprefix $(LIB_BUILDDIR)/lib, %))
 
-### Rule (link): objects (`*.o`) and libraries (`*.a`) -> `IMAGE.elf`, the final ELF binary to be packed into image (ld)
-$(IMAGE).elf: $(OBJS) $(LIBS)
-	@echo + LD "->" $(IMAGE_REL).elf
-	@$(LD) $(LDFLAGS) -o $(IMAGE).elf --start-group $(LINKAGE) --end-group
-
-## 6. Miscellaneous
-
-### Build order control
-image: image-dep
-archive: $(ARCHIVE)
-image-dep: $(OBJS) $(LIBS)
-	@echo \# Creating image [$(ARCH)]
-.PHONY: image image-dep archive run libs $(LIBS) install
-
-### Install rules
-
+## 6. Install rules
 INTERFACE_INCPATH += $(sort $(KLIB_INTERFACE_INCPATH) $(AM_INTERFACE_INCPATH))
-INTERFACE_CFLAGS += $(sort $(KLIB_INTERFACE_CFLAGS) $(AM_INTERFACE_CFLAGS))
-INTERFACE_LDFLAGS += $(sort $(KLIB_LDFLAGS) $(AM_LDFLAGS))
+# TODO: Use sort here will cause error on seperated flags, such as: -e _start
+# but without sort, duplicated flags will not be removed.
+INTERFACE_CFLAGS += $(addprefix -I, $(INTERFACE_INCPATH:%=$(INC_INSTALLDIR))) $(sort $(KLIB_INTERFACE_CFLAGS) $(AM_INTERFACE_CFLAGS))
+INTERFACE_LDFLAGS += -L$(LIB_INSTALLDIR) $(sort $(KLIB_INTERFACE_LDFLAGS) $(AM_INTERFACE_LDFLAGS))
 
 EXPORT_FLAGS_FILE := $(LIB_INSTALLDIR)/make/flags-$(ARCH).mk
 EXPORT_FLAGS_TEMPLATE := $(file < $(AM_HOME)/scripts/templates/flags.tmpl)
 HELPERS := $(wildcard find scripts/helpers/*.mk)
 EXPORT_HELPERS := $(HELPERS:scripts/helpers/%=$(LIB_INSTALLDIR)/make/%)
 
-test:
-	@echo $(EXPORT_HELPERS)
-	@echo $(LIB_INSTALLDIR)
-
 EXPORTS := $(EXPORT_FLAGS_FILE) $(EXPORT_HELPERS)
 
 $(EXPORT_HELPERS): $(LIB_INSTALLDIR)/make/%: scripts/helpers/%
@@ -150,6 +134,13 @@ $(EXPORT_FLAGS_FILE):
 	@echo + INSTALL $(patsubst $(INSTALLDIR)/%,%,$@)
 	@install -Dm644 <(printf $(EXPORT_FLAGS_TEMPLATE)) $(EXPORT_FLAGS_FILE)
 
+LDSCRIPTS := $(patsubst $(AM_HOME)/scripts/%, $(LIB_INSTALLDIR)/ldscripts/%, $(shell find $(AM_HOME)/scripts -name "*.ld"))
+
+$(LDSCRIPTS): $(LIB_INSTALLDIR)/ldscripts/%: $(AM_HOME)/scripts/%
+	@echo + INSTALL $(patsubst $(INSTALLDIR)/%,%,$@)
+	@mkdir -p $(LIB_INSTALLDIR)/ldscripts
+	@install -Dm644 $< $(dir $@)
+
 install-libs: $(LIBS)
 	@echo + INSTALL LIBS: $(LIBS) 
 	@install -dm755 $(LIB_INSTALLDIR)
@@ -161,7 +152,9 @@ install-headers: $(HEADERS)	# Headers needs to be reinstalled if they are change
 	@install -dm755 $(INC_INSTALLDIR)
 	@cp -r $(addsuffix /*, $(INTERFACE_INCPATH)) $(INC_INSTALLDIR)
 
-install: $(EXPORTS) install-libs install-headers
+install: $(EXPORTS) install-libs install-headers $(LDSCRIPTS)
+
+.PHONY: libs $(LIBS) install
 
 ### Clean a single project (remove `build/`)
 clean:

am/src/platform/nemu/ioe/ioe.c

@@ -59,3 +59,4 @@ bool ioe_init() {
 
 void ioe_read(int reg, void *buf) { ((handler_t)lut[reg])(buf); }
 void ioe_write(int reg, void *buf) { ((handler_t)lut[reg])(buf); }
+

scripts/helpers/rules.mk

@@ -56,7 +56,7 @@ $(eval $(call COMPILE_RULES,$(2)))
 $(1).elf: $$($(2)OBJS) 
 	@mkdir -p $$(dir $$@)
 	@echo + LD "->" $$(patsubst $$(CURDIR)/%,%,$(1).elf)
-	@$$(LD) $$($(2)_LDFLAGS) -o $$@ --start-group $$($(2)OBJS) --end-group
+	@$$(LD) $$($(2)LDFLAGS) -o $$@ --start-group $$($(2)OBJS) --end-group
 $(1).bin: $(1).elf
 	@echo + OBJCOPY "->" $$(patsubst $$(CURDIR)/%,%,$(1))
 	@$$(OBJCOPY) -S --set-section-flags .bss=alloc,contents -O binary $(1).elf $(1).bin

scripts/isa/riscv.mk

@@ -1,4 +1,3 @@
-CROSS_COMPILE := riscv64-linux-gnu-
 AM_CFLAGS        += -static -fno-pic -march=rv64g -mcmodel=medany  -mstrict-align
 AM_ASFLAGS       += -static -fno-pic -march=rv32g_zicsr -mcmodel=medany -O0
 AM_LDFLAGS       += -melf64lriscv -O2

scripts/platform/nemu.mk

@@ -7,19 +7,16 @@ AM_SRCS := am/src/platform/nemu/trm.c \
            am/src/platform/nemu/ioe/disk.c \
            am/src/platform/nemu/mpe.c
 
-AM_CFLAGS    += -fdata-sections -ffunction-sections
-AM_LDFLAGS   += -T $(AM_HOME)/scripts/linker.ld \
-             --defsym=_pmem_start=0x80000000 --defsym=_entry_offset=0x0
-AM_LDFLAGS   += --gc-sections -e _start
-
-AM_CFLAGS += -DMAINARGS=\"$(mainargs)\"
+AM_PUBLIC_CFLAGS := -fdata-sections -ffunction-sections
+AM_PUBLIC_LDFLAGS := --defsym=_pmem_start=0x80000000 --defsym=_entry_offset=0x0 \
+                     --gc-sections --entry=_start
+AM_CFLAGS += $(AM_PUBLIC_CFLAGS) -DMAINARGS=\"$(mainargs)\"
+AM_LDFLAGS += -T$(AM_HOME)/scripts/linker.ld $(AM_PUBLIC_LDFLAGS)
 AM_INCPATH += $(AM_HOME)/am/src/platform/nemu/include
-.PHONY: $(AM_HOME)/am/src/platform/nemu/trm.c
 
-image: $(IMAGE).elf
-	@$(OBJDUMP) -d $(IMAGE).elf > $(IMAGE).txt
-	@echo + OBJCOPY "->" $(IMAGE_REL).bin
-	@$(OBJCOPY) -S --set-section-flags .bss=alloc,contents -O binary $(IMAGE).elf $(IMAGE).bin
+AM_INTERFACE_CFLAGS += $(AM_PUBLIC_CFLAGS)
+AM_INTERFACE_LDFLAGS += -T$(LIB_INSTALLDIR)/ldscripts/linker.ld $(AM_PUBLIC_LDFLAGS)
+.PHONY: $(AM_HOME)/am/src/platform/nemu/trm.c
 
 NEMUFLAGS += -b 
 #-l $(shell dirname $(IMAGE).elf)/nemu-log.txt 

scripts/riscv32-nemu.mk

@@ -1,7 +1,7 @@
 include $(AM_HOME)/scripts/isa/riscv.mk
 include $(AM_HOME)/scripts/platform/nemu.mk
-AM_CFLAGS  += -DISA_H=\"riscv/riscv.h\" -march=rv32im_zicsr -mabi=ilp32  # overwrite
-AM_LDFLAGS += -melf32lriscv                   # overwrite
+AM_CFLAGS  += -DISA_H=\"riscv/riscv.h\" -march=rv32im_zicsr -mabi=ilp32
+AM_LDFLAGS += -melf32lriscv
 
 AM_SRCS += am/src/riscv/nemu/start.S \
            am/src/riscv/nemu/cte.c \