Generate DTB in runtime

Author: RinHizakura

.gitignore

@@ -20,6 +20,7 @@ build/linux-x86-softfp/
 build/riscv32/
 build/sail_cSim/
 build/sha1sum-*
+build/minimal.dtb
 *.a
 *.o
 *.o.d
@@ -29,3 +30,4 @@ tests/arch-test-target/sail_cSim/riscv_sim_RV32
 tests/scimark2/
 __pycache__/
 src/rv32_jit.c
+src/minimal_dtb.h

.gitmodules

@@ -31,3 +31,6 @@
 	path = tests/quake
 	url = https://github.com/sysprog21/quake-embedded
 	shallow = true
+[submodule "tools/bin_to_c"]
+	path = tools/bin_to_c
+	url = https://github.com/bitbank2/bin_to_c.git

Makefile

@@ -241,7 +241,7 @@ include mk/artifact.mk
 include mk/wasm.mk
 include mk/system.mk
 
-all: config $(BUILD_DTB) $(BIN)
+all: config $(BUILD_DTB) $(BUILD_DTB2C) $(BIN)
 
 OBJS := \
 	map.o \
@@ -369,7 +369,7 @@ endif
 endif
 
 clean:
-	$(RM) $(BIN) $(OBJS) $(DEV_OBJS) $(BUILD_DTB) $(HIST_BIN) $(HIST_OBJS) $(deps) $(WEB_FILES) $(CACHE_OUT) src/rv32_jit.c
+	$(RM) $(BIN) $(OBJS) $(DEV_OBJS) $(BUILD_DTB) $(BUILD_DTB2C) $(HIST_BIN) $(HIST_OBJS) $(deps) $(WEB_FILES) $(CACHE_OUT) src/rv32_jit.c
 distclean: clean
 	-$(RM) $(DOOM_DATA) $(QUAKE_DATA) $(BUILDROOT_DATA) $(LINUX_DATA)
 	$(RM) -r $(OUT)/linux-image

README.md

@@ -77,7 +77,7 @@ $ make ENABLE_SYSTEM=1 system
 Build using run using specified images:
 ```shell
 $ make ENABLE_SYSTEM=1
-$ build/rv32emu -k <kernel_img_path> -i <rootfs_img_path> -b <dtb_path>
+$ build/rv32emu -k <kernel_img_path> -i <rootfs_img_path>
 ```
 
 #### Build Linux image

mk/system.mk

@@ -4,10 +4,23 @@ ifeq ($(call has, SYSTEM), 1)
 DEV_SRC := src/devices
 
 DTC ?= dtc
-$(OUT)/minimal.dtb: $(DEV_SRC)/minimal.dts
+BUILD_DTB := $(OUT)/minimal.dtb
+$(BUILD_DTB): $(DEV_SRC)/minimal.dts
 	$(VECHO) " DTC\t$@\n"
 	$(Q)$(DTC) $^ -o $@
-BUILD_DTB := $(OUT)/minimal.dtb
+
+BIN_TO_C_DIR := tools/bin_to_c
+$(BIN_TO_C_DIR)/makefile:
+	git submodule update --init $(BIN_TO_C_DIR)
+
+BIN_TO_C := $(BIN_TO_C_DIR)/bin_to_c
+$(BIN_TO_C): $(BIN_TO_C_DIR)/makefile
+	$(MAKE) -C $(dir $<)
+
+BUILD_DTB2C := src/minimal_dtb.h
+$(BUILD_DTB2C): $(BIN_TO_C) $(BUILD_DTB)
+	$(BIN_TO_C) $(BUILD_DTB) > $(BUILD_DTB2C)
+	sed -i 's/PROGMEM//g' $(BUILD_DTB2C)
 
 $(DEV_OUT)/%.o: $(DEV_SRC)/%.c $(deps_emcc)
 	$(Q)mkdir -p $(DEV_OUT)
@@ -20,8 +33,8 @@ OBJS_EXT += system.o
 
 # system target execution by using default dependencies
 LINUX_IMAGE_DIR := linux-image
-system_action := ($(BIN) -k $(OUT)/$(LINUX_IMAGE_DIR)/Image -i $(OUT)/$(LINUX_IMAGE_DIR)/rootfs.cpio -b $(OUT)/minimal.dtb)
-system_deps += artifact $(BUILD_DTB) $(BIN)
+system_action := ($(BIN) -k $(OUT)/$(LINUX_IMAGE_DIR)/Image -i $(OUT)/$(LINUX_IMAGE_DIR)/rootfs.cpio)
+system_deps += artifact $(BUILD_DTB) $(BUILD_DTB2C) $(BIN)
 system: $(system_deps)
 	$(system_action)
 

src/dtc

@@ -0,0 +1 @@
+Subproject commit 039a99414e778332d8f9c04cbd3072e1dcc62798

src/main.c

@@ -42,7 +42,7 @@ static char *opt_prog_name;
 /* target argc and argv */
 static int prog_argc;
 static char **prog_args;
-static const char *optstr = "tgqmhpd:a:k:i:b:";
+static const char *optstr = "tgqmhpd:a:k:i:";
 
 /* enable misaligned memory access */
 static bool opt_misaligned = false;
@@ -55,7 +55,6 @@ static char *prof_out_file;
 /* Linux kernel data */
 static char *opt_kernel_img;
 static char *opt_rootfs_img;
-static char *opt_dtb;
 #endif
 
 static void print_usage(const char *filename)
@@ -73,7 +72,6 @@ static void print_usage(const char *filename)
 #if RV32_HAS(SYSTEM) && !RV32_HAS(ELF_LOADER)
             "  -k <image> : use <image> as kernel image\n"
             "  -i <image> : use <image> as rootfs\n"
-            "  -b <dtb> : use <dtb> as device tree blob\n"
 #endif
             "  -d [filename]: dump registers as JSON to the "
             "given file or `-` (STDOUT)\n"
@@ -114,10 +112,6 @@ static bool parse_args(int argc, char **args)
             opt_rootfs_img = optarg;
             emu_argc++;
             break;
-        case 'b':
-            opt_dtb = optarg;
-            emu_argc++;
-            break;
 #endif
         case 'q':
             opt_quiet_outputs = true;
@@ -263,7 +257,6 @@ int main(int argc, char **args)
 #if RV32_HAS(SYSTEM) && !RV32_HAS(ELF_LOADER)
     attr.data.system.kernel = opt_kernel_img;
     attr.data.system.initrd = opt_rootfs_img;
-    attr.data.system.dtb = opt_dtb;
 #else
     attr.data.user.elf_program = opt_prog_name;
 #endif

src/riscv.c

@@ -11,6 +11,8 @@
 #include <string.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 
 #if RV32_HAS(SYSTEM) && !RV32_HAS(ELF_LOADER)
 #include <termios.h>
@@ -259,6 +261,14 @@ static void map_file(char **ram_loc, const char *name)
     exit(EXIT_FAILURE);
 }
 
+static void load_dtb(char **ram_loc)
+{
+#include "minimal_dtb.h"
+    memcpy(*ram_loc, minimal, sizeof(minimal));
+    *ram_loc += sizeof(minimal);
+    return;
+}
+
 /*
  * The control mode flag for keyboard.
  *
@@ -294,6 +304,7 @@ static void capture_keyboard_input()
     term.c_lflag &= ~TERMIOS_C_CFLAG;
     tcsetattr(0, TCSANOW, &term);
 }
+
 #endif
 
 /*
@@ -409,7 +420,7 @@ riscv_t *rv_create(riscv_user_t rv_attr)
 
     uint32_t dtb_addr = attr->mem->mem_size - (1 * 1024 * 1024);
     ram_loc = ((char *) attr->mem->mem_base) + dtb_addr;
-    map_file(&ram_loc, attr->data.system.dtb);
+    load_dtb(&ram_loc);
     /*
      * Load optional initrd image at last 8 MiB before the dtb region to
      * prevent kernel from overwritting it
@@ -517,8 +528,7 @@ void rv_run(riscv_t *rv)
     vm_attr_t *attr = PRIV(rv);
     assert(attr &&
 #if RV32_HAS(SYSTEM) && !RV32_HAS(ELF_LOADER)
-           attr->data.system.kernel && attr->data.system.initrd &&
-           attr->data.system.dtb
+           attr->data.system.kernel && attr->data.system.initrd
 #else
            attr->data.user.elf_program
 #endif

src/riscv.h

@@ -551,7 +551,6 @@ typedef struct {
 typedef struct {
     char *kernel;
     char *initrd;
-    char *dtb;
 } vm_system_t;
 #endif /* RV32_HAS(SYSTEM) */