[add] laos using xv6-riscv thought

laos/Makefile

@@ -7,23 +7,54 @@ OD	:= $(LA_BIN_PATH)/$(LA_PREFIX)objdump
 OC	:= $(LA_BIN_PATH)/$(LA_PREFIX)objcopy
 RE	:= $(LA_BIN_PATH)/$(LA_PREFIX)readelf
 
+NPROC	:= $(shell nproc)
+
 CMAKE	:= cmake
 
-BUILD_DIR := build
+BUILD_DIR 	:= build
+ABS_BUILD	:= $(CURDIR)/$(BUILD_DIR)
 $(shell mkdir -p $(BUILD_DIR))
 
-BIN		:= neula-os
-COMMON_DIR	:= COMMON
+BIN			:= neula-os
+BINARY		:= $(BUILD_DIR)/$(BIN)
 
-FILES	:= $(shell find src -name *.c)
+TOP_SRC_DIR	:= src
+SOURCE_DIRS	:= $(shell ls $(TOP_SRC_DIR)/* -d)
+MK_DIRS		:= $(addprefix MAKE/,$(SOURCE_DIRS))
+ALL_SRCS	:= $(shell find . -name '*.c')
+LD_CSRIPT	:= kernel.ld
 
-.PHONY: build clean
+EXTRA_MACRO	:= # NDEBUG
 
-build:
-	$(CC) $(FILES) -static --no-pic -march=loongarch32r -o $(BUILD_DIR)/$(BIN)
-	$(OD) -D $(BUILD_DIR)/$(BIN) > $(BUILD_DIR)/$(BIN).dump
-	$(RE) -a $(BUILD_DIR)/$(BIN) > $(BUILD_DIR)/$(BIN).info
-	$(OC) $(BUILD_DIR)/$(BIN) -O binary $(BUILD_DIR)/$(BIN).bin
+EXTRA_FLAGS =  -Wall -Werror -O -fno-omit-frame-pointer -ggdb -gdwarf-2
+EXTRA_FLAGS += -MD
+EXTRA_FLAGS += -ffreestanding -fno-common -nostdlib
+EXTRA_FLAGS += -I.
+EXTRA_FLAGS += -fno-pie -no-pie
+EXTRA_FLAGS += $(shell $(CC) -fno-stack-protector -E -x c /dev/null >/dev/null 2>&1 && echo -fno-stack-protector)
+
+COMMONFLAGS	:= $(EXTRA_FLAGS) -march=loongarch32r
+CPPFLAGS	+= $(addprefix -D,$(EXTRA_MACRO)) -I$(CURDIR)/include
+CFLAGS		+= $(COMMONFLAGS) -O
+LDFLAGS		+= $(COMMONFLAGS) -z max-page-size=4096 -T$(LD_CSRIPT)
+
+.PHONY: all build clean
+
+all: build
+
+$(MK_DIRS): MAKE/%:% $(shell find $(%) -name '*.c')
+	@TOP_BUILD_DIR=$(ABS_BUILD) \
+	CC=$(CC)					\
+	CPPFLAGS="$(CPPFLAGS)"		\
+	CFLAGS="$(CFLAGS)"			\
+	LDFLAGS="$(LDFLAGS)"		\
+	$(MAKE) -C $< -j$(NPROC)
+
+build: $(MK_DIRS)
+	@$(CC) -o $(BINARY) $(shell find $(BUILD_DIR) -name '*.o') $(CPPFLAGS) $(CFLAGS) $(LDFLAGS)
+	@$(OD) -D $(BINARY) > $(BINARY).dump
+	@$(RE) -a $(BINARY) > $(BINARY).info
+	@$(OC) $(BINARY) -O binary $(BINARY).bin
 
 clean:
 	rm -rf $(BUILD_DIR)

laos/include/asm.h

@@ -0,0 +1,8 @@
+#include "defs.h"
+
+#ifndef ASM_H__
+#define ASM_H__
+
+#define CPUID   0x020
+
+#endif

laos/include/common.h

@@ -1,5 +1,10 @@
+#include "defs.h"
+
 #ifndef COMMON_H__
 #define COMMON_H__
 
+void main();
+void start();
+void _entry() __attribute__ ((section (".entry")));
 
 #endif // COMMON_H__

laos/include/defs.h

@@ -0,0 +1,6 @@
+#ifndef DEFS_H__
+#define DEFS_H__
+
+#define NCPU    1
+
+#endif

laos/kernel.ld

@@ -0,0 +1,41 @@
+OUTPUT_ARCH( "loongarch32r" )
+ENTRY( _entry )
+
+SECTIONS
+{
+  /*
+   * ensure that entry.S / _entry is at 0x1C000000,
+   */
+  . = 0x1C000000;
+
+  .text : {
+    *(.entry)
+    . = ALIGN(0x1000);
+    *(.text .text.*)
+    . = ALIGN(0x1000);
+    PROVIDE(etext = .);
+  }
+
+  .rodata : {
+    . = ALIGN(16);
+    *(.srodata .srodata.*) /* do not need to distinguish this from .rodata */
+    . = ALIGN(16);
+    *(.rodata .rodata.*)
+  }
+
+  .data : {
+    . = ALIGN(16);
+    *(.sdata .sdata.*) /* do not need to distinguish this from .data */
+    . = ALIGN(16);
+    *(.data .data.*)
+  }
+
+  .bss : {
+    . = ALIGN(16);
+    *(.sbss .sbss.*) /* do not need to distinguish this from .bss */
+    . = ALIGN(16);
+    *(.bss .bss.*)
+  }
+
+  PROVIDE(end = .);
+}

laos/src/kernel/Makefile

@@ -0,0 +1,28 @@
+CURNAME		:= kernel
+BUILD_DIR	:= $(TOP_BUILD_DIR)/$(CURNAME)
+
+CSRC		:= $(wildcard *.c)
+OBJS		:= $(patsubst %.c,%.o,$(CSRC))
+BUILD_OBJS	:= $(addprefix $(BUILD_DIR)/,$(OBJS))
+
+ASSRC		:= $(wildcard *.S)
+ASOBJ		:= $(patsubst %.S,%.o,$(ASSRC))
+BUILD_ASOBJ	:= $(addprefix $(BUILD_DIR)/,$(ASOBJ))
+
+.PHONY: build all message
+
+all: message build
+
+$(BUILD_DIR):
+	@mkdir -p $(BUILD_DIR)
+
+$(BUILD_OBJS): $(BUILD_DIR)/%.o:%.c $(BUILD_DIR)
+	@$(CC) -c -o $@ $< $(CPPFLAGS) $(CFLAGS)
+
+$(BUILD_ASOBJ): $(BUILD_DIR)/%.o:%.S $(BUILD_DIR)
+	@$(CC) -c -o $@ $< $(CPPFLAGS) $(CFLAGS)
+
+build: $(BUILD_OBJS) $(BUILD_ASOBJ)
+
+message:
+	@echo "building $(CURNAME)"

laos/src/kernel/entry.S

@@ -0,0 +1,20 @@
+#include "asm.h"
+
+.section .entry
+.global _entry
+_entry:
+        # set up a stack for C.
+        # stack0 is declared in start.c,
+        # with a 4096-byte stack per CPU.
+        # sp = stack0 + (hartid * 4096)
+        la.global $sp, stack0
+        lu12i.w $a0, (1024*4 >> 12) & 0xfffff
+        addi.w $a0, $a0, 1024*4 & 0xfff
+        csrrd $a1, CPUID
+        addi.w $a1, $a1, 1
+        mul.w $a0, $a0, $a1
+        add.w $sp, $sp, $a0
+        # jump to start() in start.c
+        bl start
+spin:
+        b spin

laos/src/kernel/kalloc.c

@@ -0,0 +1 @@
+extern char end[];

laos/src/kernel/main.c

@@ -0,0 +1,3 @@
+void main() {
+
+}

laos/src/kernel/start.c

@@ -0,0 +1,7 @@
+#include "common.h"
+
+__attribute__ ((aligned (16))) char stack0[4096 * NCPU];
+
+void start() {
+
+}

laos/src/kernel/vm.c

@@ -0,0 +1 @@
+extern char etext[];

laos/src/main.c

@@ -1,6 +0,0 @@
-#include <stdio.h>
-
-int main() {
-    printf("%d", 123);
-    return 0;
-}

laos/src/util/Makefile

@@ -0,0 +1,21 @@
+CURNAME		:= util
+BUILD_DIR	:= $(TOP_BUILD_DIR)/$(CURNAME)
+
+CSRC		:= $(wildcard *.c)
+OBJS		:= $(patsubst %.c,%.o,$(CSRC))
+BUILD_OBJS	:= $(addprefix $(BUILD_DIR)/,$(OBJS))
+
+.PHONY: build all message
+
+all: message build
+
+$(BUILD_DIR):
+	@mkdir -p $(BUILD_DIR)
+
+$(BUILD_OBJS): $(BUILD_DIR)/%.o:%.c $(BUILD_DIR)
+	@$(CC) -c -o $@ $< $(CPPFLAGS) $(CFLAGS)
+
+build: $(BUILD_OBJS)
+
+message:
+	@echo "building $(CURNAME)"

laos/src/util/memops.c

@@ -0,0 +1 @@
+#include <assert.h>