Makefile: start moving to macro based Makefile target generation

- libam-riscv32-nemu is working.
- libam on platforms other than riscv32-nemu has not been worked on yet.
- klib has not been worked on yet.

scripts/helpers/rules.mk

@@ -0,0 +1,47 @@
+
+# Usage:
+# $(1): Target prefix
+#
+# Generate build rules for files in variable <PREFIX>_SRCS. Use <PREFIX>_CFLAGS,
+# <PREFIX>_CXXFLAGS, <PREFIX>_ASFLAGS to control build flags.
+# E.g: 
+# $(eval $(call COMPILE_RULES,AM_))
+define COMPILE_RULES
+AM_OBJS := $(addprefix $(DST_DIR)/, $(addsuffix .o, $(AM_SRCS)))
+### Rule (compile): a single `.c` -> `.c.o` (gcc)
+$$(filter %.c.o, $$($(1)OBJS)): $$(DST_DIR)/%.c.o: %.c
+	@mkdir -p $$(dir $$@) && echo + CC $$<
+	@$$(CC) $$($(1)CFLAGS) -c -o $$@ $$(realpath $$<)
+
+### Rule (compile): a single `.cc` -> `.cc.o` (g++)
+$$(filter %.cc.o, $$($(1)OBJS)): $$(DST_DIR)/%.cc.o: %.cc
+	@mkdir -p $$(dir $$@) && echo + CXX $$<
+	@$$(CXX) $$($(1)CXXFLAGS) -c -o $$@ $$(realpath $$<)
+
+### Rule (compile): a single `.cpp` -> `.cpp.o` (g++)
+$$(filter %.cpp.o, $$($(1)OBJS)): $$(DST_DIR)/%.cpp.o: %.cpp
+	@mkdir -p $$(dir $$@) && echo + CXX $$<
+	@$$(CXX) $$($(1)CXXFLAGS) -c -o $$@ $$(realpath $$<)
+
+### Rule (compile): a single `.S` -> `.S.o` (gcc, which preprocesses and calls as)
+$$(filter %.S.o, $$($(1)OBJS)): $$(DST_DIR)/%.S.o: %.S
+	@mkdir -p $$(dir $$@) && echo + AS $$<
+	@$$(AS) $$($(1)ASFLAGS) -c -o $$@ $$(realpath $$<)
+
+### Rule (`#include` dependencies): paste in `.d` files generated by gcc on `-MMD`
+-include $$(addprefix $$(DST_DIR)/, $$(addsuffix .d, $$(filter %.c %.cc, $$(AM_SRCS))))
+endef
+
+# Usage:
+# $(1): Library name
+# $(2): Library variable prefix
+# E.g: 
+# $(eval $(call ADD_LIBRARY,am-riscv,AM_))
+define ADD_LIBRARY
+$(eval $(call COMPILE_RULES,$(2)))
+$(1): $$($(2)OBJS) 
+	@mkdir -p $$(dir $$@)
+	@echo + AR "->" $$(patsubst $$(CURDIR)/%,%,$(1))
+	@$$(AR) rcs $$@ $$($(2)OBJS)
+endef
+

scripts/isa/riscv.mk

@@ -1,8 +1,7 @@
 CROSS_COMPILE := riscv64-linux-gnu-
-COMMON_CFLAGS := -fno-pic -march=rv64g -mcmodel=medany  -mstrict-align
-CFLAGS        += $(COMMON_CFLAGS) -static
-ASFLAGS       += $(COMMON_CFLAGS) -O0
-LDFLAGS       += -melf64lriscv -O2
+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
 
 # overwrite ARCH_H defined in $(AM_HOME)/Makefile
 ARCH_H := arch/riscv.h

scripts/platform/nemu.mk

@@ -1,21 +1,19 @@
-AM_SRCS := platform/nemu/trm.c \
-           platform/nemu/ioe/ioe.c \
-           platform/nemu/ioe/timer.c \
-           platform/nemu/ioe/input.c \
-           platform/nemu/ioe/gpu.c \
-           platform/nemu/ioe/audio.c \
-           platform/nemu/ioe/disk.c \
-           platform/nemu/mpe.c
+AM_SRCS := am/src/platform/nemu/trm.c \
+           am/src/platform/nemu/ioe/ioe.c \
+           am/src/platform/nemu/ioe/timer.c \
+           am/src/platform/nemu/ioe/input.c \
+           am/src/platform/nemu/ioe/gpu.c \
+           am/src/platform/nemu/ioe/audio.c \
+           am/src/platform/nemu/ioe/disk.c \
+           am/src/platform/nemu/mpe.c
 
-CFLAGS    += -fdata-sections -ffunction-sections
-LDFLAGS   += -T $(AM_HOME)/scripts/linker.ld \
+AM_CFLAGS    += -fdata-sections -ffunction-sections
+AM_LDFLAGS   += -T $(AM_HOME)/scripts/linker.ld \
              --defsym=_pmem_start=0x80000000 --defsym=_entry_offset=0x0
-LDFLAGS   += --gc-sections -e _start
-NEMUFLAGS += -b 
-#-l $(shell dirname $(IMAGE).elf)/nemu-log.txt 
+AM_LDFLAGS   += --gc-sections -e _start
 
-CFLAGS += -DMAINARGS=\"$(mainargs)\"
-CFLAGS += -I$(AM_HOME)/am/src/platform/nemu/include
+AM_CFLAGS += -DMAINARGS=\"$(mainargs)\"
+AM_INCPATH += $(AM_HOME)/am/src/platform/nemu/include
 .PHONY: $(AM_HOME)/am/src/platform/nemu/trm.c
 
 image: $(IMAGE).elf
@@ -23,6 +21,9 @@ image: $(IMAGE).elf
 	@echo + OBJCOPY "->" $(IMAGE_REL).bin
 	@$(OBJCOPY) -S --set-section-flags .bss=alloc,contents -O binary $(IMAGE).elf $(IMAGE).bin
 
+NEMUFLAGS += -b 
+#-l $(shell dirname $(IMAGE).elf)/nemu-log.txt 
+
 run: image
 	$(MAKE) -C $(NEMU_HOME) ISA=$(ISA) run ARGS="$(NEMUFLAGS)" IMG=$(IMAGE).bin
 

scripts/riscv32-nemu.mk

@@ -1,10 +1,9 @@
 include $(AM_HOME)/scripts/isa/riscv.mk
 include $(AM_HOME)/scripts/platform/nemu.mk
-CFLAGS  += -DISA_H=\"riscv/riscv.h\"
-COMMON_CFLAGS += -march=rv32im_zicsr -mabi=ilp32  # overwrite
-LDFLAGS       +=  -melf32lriscv                   # overwrite
+AM_CFLAGS  += -DISA_H=\"riscv/riscv.h\" -march=rv32im_zicsr -mabi=ilp32  # overwrite
+AM_LDFLAGS += -melf32lriscv                   # overwrite
 
-AM_SRCS += riscv/nemu/start.S \
-           riscv/nemu/cte.c \
-           riscv/nemu/trap.S \
-           riscv/nemu/vme.c
+AM_SRCS += am/src/riscv/nemu/start.S \
+           am/src/riscv/nemu/cte.c \
+           am/src/riscv/nemu/trap.S \
+           am/src/riscv/nemu/vme.c