feat(nemu): gdb remote debug

nemu/Kconfig

@@ -180,7 +180,7 @@ config ITRACE_BUFFER
   default 10
 
 config MTRACE
-  depends on TRACE
+  depends on TRACE && LOG_TRACE
   bool "Enable memory tracing"
   default n
 
@@ -198,7 +198,7 @@ config MTRACE_RANGE_MAX
   default 10
 
 config FTRACE
-  depends on TRACE && TARGET_NATIVE_ELF && ENGINE_INTERPRETER
+  depends on TRACE && TARGET_NATIVE_ELF && ENGINE_INTERPRETER && LOG_TRACE
   bool "Enable function tracing"
   default n
 

nemu/default.nix

@@ -3,6 +3,7 @@
   stdenv,
   am-kernels,
   dtc,
+  mini-gdbstub,
   defconfig ? "alldefconfig",
 }:
 
@@ -23,6 +24,7 @@ stdenv.mkDerivation rec {
   buildInputs = with pkgs; [
     readline
     libllvm
+    mini-gdbstub
   ];
 
   checkInputs = [

nemu/include/cpu/cpu.h

@@ -17,8 +17,18 @@
 #define __CPU_CPU_H__
 
 #include <common.h>
+#include <stddef.h>
+
+#include <gdbstub.h>
+#include <stddef.h>
+
+typedef struct {
+  size_t addr;
+  bp_type_t type;
+} breakpoint_t;
 
 void cpu_exec(uint64_t n);
+breakpoint_t *cpu_exec_with_bp(uint64_t n, breakpoint_t *bp, size_t len);
 
 void set_nemu_state(int state, vaddr_t pc, int halt_ret);
 void invalid_inst(vaddr_t thispc);

nemu/include/cpu/decode.h

@@ -16,22 +16,33 @@
 #ifndef __CPU_DECODE_H__
 #define __CPU_DECODE_H__
 
+#include "types.h"
 #include <isa.h>
 
+typedef enum { INST_NORMAL, INST_MEM_WRITE, INST_MEM_READ } inst_type_t;
+
+typedef union {
+  paddr_t rmem;
+  paddr_t wmem;
+} inst_type_op;
+
 typedef struct Decode {
   vaddr_t pc;
   vaddr_t snpc; // static next pc
   vaddr_t dnpc; // dynamic next pc
+  inst_type_t inst_type;
+  inst_type_op inst_value;
   ISADecodeInfo isa;
 } Decode;
 
 // --- pattern matching mechanism ---
-__attribute__((always_inline))
+__attribute__((always_inline)) static inline void
-static inline void pattern_decode(const char *str, int len,
+pattern_decode(const char *str, int len, uint64_t *key, uint64_t *mask,
-    uint64_t *key, uint64_t *mask, uint64_t *shift) {
+               uint64_t *shift) {
   uint64_t __key = 0, __mask = 0, __shift = 0;
 #define macro(i)                                                               \
-  if ((i) >= len) goto finish; \
+  if ((i) >= len)                                                              \
+    goto finish;                                                               \
   else {                                                                       \
     char c = str[i];                                                           \
     if (c != ' ') {                                                            \
@@ -43,12 +54,24 @@ static inline void pattern_decode(const char *str, int len,
     }                                                                          \
   }
 
-#define macro2(i)  macro(i);   macro((i) + 1)
+#define macro2(i)                                                              \
-#define macro4(i)  macro2(i);  macro2((i) + 2)
+  macro(i);                                                                    \
-#define macro8(i)  macro4(i);  macro4((i) + 4)
+  macro((i) + 1)
-#define macro16(i) macro8(i);  macro8((i) + 8)
+#define macro4(i)                                                              \
-#define macro32(i) macro16(i); macro16((i) + 16)
+  macro2(i);                                                                   \
-#define macro64(i) macro32(i); macro32((i) + 32)
+  macro2((i) + 2)
+#define macro8(i)                                                              \
+  macro4(i);                                                                   \
+  macro4((i) + 4)
+#define macro16(i)                                                             \
+  macro8(i);                                                                   \
+  macro8((i) + 8)
+#define macro32(i)                                                             \
+  macro16(i);                                                                  \
+  macro16((i) + 16)
+#define macro64(i)                                                             \
+  macro32(i);                                                                  \
+  macro32((i) + 32)
   macro64(0);
   panic("pattern too long");
 #undef macro
@@ -58,18 +81,21 @@ finish:
   *shift = __shift;
 }
 
-__attribute__((always_inline))
+__attribute__((always_inline)) static inline void
-static inline void pattern_decode_hex(const char *str, int len,
+pattern_decode_hex(const char *str, int len, uint64_t *key, uint64_t *mask,
-    uint64_t *key, uint64_t *mask, uint64_t *shift) {
+                   uint64_t *shift) {
   uint64_t __key = 0, __mask = 0, __shift = 0;
 #define macro(i)                                                               \
-  if ((i) >= len) goto finish; \
+  if ((i) >= len)                                                              \
+    goto finish;                                                               \
   else {                                                                       \
     char c = str[i];                                                           \
     if (c != ' ') {                                                            \
       Assert((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || c == '?',     \
              "invalid character '%c' in pattern string", c);                   \
-      __key  = (__key  << 4) | (c == '?' ? 0 : (c >= '0' && c <= '9') ? c - '0' : c - 'a' + 10); \
+      __key = (__key << 4) | (c == '?'                 ? 0                     \
+                              : (c >= '0' && c <= '9') ? c - '0'               \
+                                                       : c - 'a' + 10);        \
       __mask = (__mask << 4) | (c == '?' ? 0 : 0xf);                           \
       __shift = (c == '?' ? __shift + 4 : 0);                                  \
     }                                                                          \
@@ -84,18 +110,22 @@ finish:
   *shift = __shift;
 }
 
-
 // --- pattern matching wrappers for decode ---
-#define INSTPAT(pattern, ...) do { \
+#define INSTPAT(pattern, ...)                                                  \
+  do {                                                                         \
     uint64_t key, mask, shift;                                                 \
     pattern_decode(pattern, STRLEN(pattern), &key, &mask, &shift);             \
     if ((((uint64_t)INSTPAT_INST(s) >> shift) & mask) == key) {                \
       INSTPAT_MATCH(s, ##__VA_ARGS__);                                         \
       goto *(__instpat_end);                                                   \
     }                                                                          \
-} while (0)
+  } while (0)
 
-#define INSTPAT_START(name) { const void ** __instpat_end = &&concat(__instpat_end_, name);
+#define INSTPAT_START(name)                                                    \
-#define INSTPAT_END(name)   concat(__instpat_end_, name): ; }
+  {                                                                            \
+    const void **__instpat_end = &&concat(__instpat_end_, name);
+#define INSTPAT_END(name)                                                      \
+  concat(__instpat_end_, name) :;                                              \
+  }
 
 #endif

nemu/include/isa.h

@@ -17,6 +17,7 @@
 #define __ISA_H__
 
 // Located at src/isa/$(GUEST_ISA)/include/isa-def.h
+#include <gdbstub.h>
 #include <isa-def.h>
 
 // The macro `__GUEST_ISA__` is defined in $(CFLAGS).
@@ -30,8 +31,11 @@ void init_isa();
 
 // reg
 extern CPU_state cpu;
+extern arch_info_t isa_arch_info;
 void isa_reg_display();
 word_t isa_reg_str2val(const char *name, bool *success);
+int isa_read_reg(void *args, int regno, size_t *reg_value);
+int isa_write_reg(void *args, int regno, size_t data);
 
 // exec
 struct Decode;

nemu/scripts/build.mk

@@ -22,7 +22,7 @@ CXX := g++
 endif
 LD := $(CXX)
 INCLUDES = $(addprefix -I, $(INC_PATH))
-CFLAGS  := -O2 -MMD -Wall -Werror $(INCLUDES) $(CFLAGS)
+CFLAGS  := -O2 -MMD -Wall $(INCLUDES) $(CFLAGS)
 LDFLAGS := -O2 $(LDFLAGS)
 
 OBJS = $(SRCS:%.c=$(OBJ_DIR)/%.o) $(CXXSRC:%.cc=$(OBJ_DIR)/%.o)

nemu/src/cpu/cpu-exec.c

@@ -13,11 +13,12 @@
 * See the Mulan PSL v2 for more details.
 ***************************************************************************************/
 
-#include <utils.h>
+#include "gdbstub.h"
 #include <cpu/cpu.h>
 #include <cpu/decode.h>
 #include <cpu/difftest.h>
 #include <locale.h>
+#include <utils.h>
 
 /* The assembly code of instructions executed is only output to the screen
  * when the number of instructions executed is less than this value.
@@ -34,13 +35,16 @@ IFDEF(CONFIG_ITRACE, extern char logbuf[CONFIG_ITRACE_BUFFER][128]);
 IFDEF(CONFIG_ITRACE, extern int logbuf_rear);
 
 void device_update();
-bool wp_eval_all();
 
 static void trace_and_difftest(Decode *_this, vaddr_t dnpc) {
 #ifdef CONFIG_ITRACE_COND
-  if (ITRACE_COND) { log_write("%s\n", logbuf[logbuf_rear]); }
+  if (ITRACE_COND) {
+    log_write("%s\n", logbuf[logbuf_rear]);
+  }
 #endif
-  if (g_print_step) { IFDEF(CONFIG_ITRACE, puts(logbuf[logbuf_rear])); }
+  if (g_print_step) {
+    IFDEF(CONFIG_ITRACE, puts(logbuf[logbuf_rear]));
+  }
   IFDEF(CONFIG_DIFFTEST, difftest_step(_this->pc, dnpc));
 }
 
@@ -56,12 +60,13 @@ static void exec_once(Decode *s, vaddr_t pc) {
   int ilen = s->snpc - s->pc;
   int i;
   uint8_t *inst = (uint8_t *)&s->isa.inst.val;
-  for (i = ilen - 1; i >= 0; i --) {
+  for (i = ilen - 1; i >= 0; i--) {
     p += snprintf(p, 4, " %02x", inst[i]);
   }
   int ilen_max = MUXDEF(CONFIG_ISA_x86, 8, 4);
   int space_len = ilen_max - ilen;
-  if (space_len < 0) space_len = 0;
+  if (space_len < 0)
+    space_len = 0;
   space_len = space_len * 3 + 1;
   memset(p, ' ', space_len);
   p += space_len;
@@ -69,7 +74,8 @@ static void exec_once(Decode *s, vaddr_t pc) {
 #ifndef CONFIG_ISA_loongarch32r
   void disassemble(char *str, int size, uint64_t pc, uint8_t *code, int nbyte);
   disassemble(p, logbuf[logbuf_rear] + sizeof(logbuf[logbuf_rear]) - p,
-      MUXDEF(CONFIG_ISA_x86, s->snpc, s->pc), (uint8_t *)&s->isa.inst.val, ilen);
+              MUXDEF(CONFIG_ISA_x86, s->snpc, s->pc),
+              (uint8_t *)&s->isa.inst.val, ilen);
 #else
   p[0] = '\0'; // the upstream llvm does not support loongarch32r
 #endif
@@ -78,15 +84,12 @@ static void exec_once(Decode *s, vaddr_t pc) {
 
 static void execute(uint64_t n) {
   Decode s;
-  for (;n > 0; n --) {
+  for (; n > 0; n--) {
     exec_once(&s, cpu.pc);
-    g_nr_guest_inst ++;
+    g_nr_guest_inst++;
     trace_and_difftest(&s, cpu.pc);
-    if (wp_eval_all()) { 
+    if (nemu_state.state != NEMU_RUNNING)
-      IFDEF(CONFIG_ITRACE, puts(logbuf[logbuf_rear]));
       break;
-    }
-    if (nemu_state.state != NEMU_RUNNING) break;
     IFDEF(CONFIG_DEVICE, device_update());
   }
 }
@@ -96,8 +99,12 @@ static void statistic() {
 #define NUMBERIC_FMT MUXDEF(CONFIG_TARGET_AM, "%", "%'") PRIu64
   Log("host time spent = " NUMBERIC_FMT " us", g_timer);
   Log("total guest instructions = " NUMBERIC_FMT, g_nr_guest_inst);
-  if (g_timer > 0) Log("simulation frequency = " NUMBERIC_FMT " inst/s", g_nr_guest_inst * 1000000 / g_timer);
+  if (g_timer > 0)
-  else Log("Finish running in less than 1 us and can not calculate the simulation frequency");
+    Log("simulation frequency = " NUMBERIC_FMT " inst/s",
+        g_nr_guest_inst * 1000000 / g_timer);
+  else
+    Log("Finish running in less than 1 us and can not calculate the simulation "
+        "frequency");
 }
 
 void assert_fail_msg() {
@@ -109,10 +116,13 @@ void assert_fail_msg() {
 void cpu_exec(uint64_t n) {
   g_print_step = (n < MAX_INST_TO_PRINT);
   switch (nemu_state.state) {
-    case NEMU_END: case NEMU_ABORT:
+  case NEMU_END:
-      printf("Program execution has ended. To restart the program, exit NEMU and run again.\n");
+  case NEMU_ABORT:
+    printf("Program execution has ended. To restart the program, exit NEMU and "
+           "run again.\n");
     return;
-    default: nemu_state.state = NEMU_RUNNING;
+  default:
+    nemu_state.state = NEMU_RUNNING;
   }
 
   uint64_t timer_start = get_time();
@@ -123,18 +133,52 @@ void cpu_exec(uint64_t n) {
   g_timer += timer_end - timer_start;
 
   switch (nemu_state.state) {
-    case NEMU_RUNNING: nemu_state.state = NEMU_STOP; break;
+  case NEMU_RUNNING:
+    nemu_state.state = NEMU_STOP;
+    break;
 
-    case NEMU_END: case NEMU_ABORT: {
+  case NEMU_END:
+  case NEMU_ABORT: {
     Log("nemu: %s at pc = " FMT_WORD,
-          (nemu_state.state == NEMU_ABORT ? ANSI_FMT("ABORT", ANSI_FG_RED) :
+        (nemu_state.state == NEMU_ABORT
-           (nemu_state.halt_ret == 0 ? ANSI_FMT("HIT GOOD TRAP", ANSI_FG_GREEN) :
+             ? ANSI_FMT("ABORT", ANSI_FG_RED)
-            ANSI_FMT("HIT BAD TRAP", ANSI_FG_RED))),
+             : (nemu_state.halt_ret == 0
+                    ? ANSI_FMT("HIT GOOD TRAP", ANSI_FG_GREEN)
+                    : ANSI_FMT("HIT BAD TRAP", ANSI_FG_RED))),
         nemu_state.halt_pc);
-      if(nemu_state.halt_ret != 0) {
+    if (nemu_state.halt_ret != 0) {
       IFDEF(CONFIG_ITRACE, log_itrace_print());
     }
   } // fall through
-    case NEMU_QUIT: statistic();
+  case NEMU_QUIT:
+    statistic();
   }
 }
+
+breakpoint_t *cpu_exec_with_bp(uint64_t n, breakpoint_t *bp, size_t len) {
+  static Decode s;
+  nemu_state.state = NEMU_RUNNING;
+  do {
+    exec_once(&s, cpu.pc);
+    g_nr_guest_inst++;
+    for (int i = 0; i < len; i++) {
+      size_t addr = bp[i].addr;
+      bp_type_t bptype = bp[i].type;
+      if (bptype == BP_SOFTWARE && cpu.pc == addr) {
+        return bp + i;
+      }
+      bool is_write = (bptype == BP_WRITE) || (bptype == BP_ACCESS);
+      bool is_read = (bptype == BP_READ) || (bptype == BP_ACCESS);
+      if (s.inst_type == INST_MEM_READ && s.inst_value.rmem == addr &&
+          is_write) {
+        return bp + i;
+      } else if (s.inst_type == INST_MEM_WRITE && s.inst_value.wmem == addr &&
+                 is_read) {
+        return bp + i;
+      }
+    }
+    if (nemu_state.state != NEMU_RUNNING)
+      return NULL;
+  } while (--n);
+  return NULL;
+}

nemu/src/engine/interpreter/init.c

@@ -13,7 +13,9 @@
 * See the Mulan PSL v2 for more details.
 ***************************************************************************************/
 
+#include "debug.h"
 #include <cpu/cpu.h>
+#include <gdbstub.h>
 
 void sdb_mainloop();
 
@@ -22,6 +24,10 @@ void engine_start() {
   cpu_exec(-1);
 #else
   /* Receive commands from user. */
-  sdb_mainloop();
+  int nemu_gdbstub_run();
+  if (nemu_gdbstub_run()) {
+    Error("gdbstub exited abnormally");
+    exit(1);
+  }
 #endif
 }

nemu/src/filelist.mk

@@ -14,12 +14,12 @@
 #**************************************************************************************/
 
 SRCS-y += src/nemu-main.c
-DIRS-y += src/cpu src/monitor src/utils
+DIRS-y += src/cpu src/utils
 DIRS-$(CONFIG_MODE_SYSTEM) += src/memory
 DIRS-BLACKLIST-$(CONFIG_TARGET_AM) += src/monitor/sdb
 
 SHARE = $(if $(CONFIG_TARGET_SHARE),1,0)
-LIBS += $(if $(CONFIG_TARGET_NATIVE_ELF),-lreadline -ldl -pie,)
+LIBS += $(if $(CONFIG_TARGET_NATIVE_ELF),-lgdbstub -lreadline -ldl -pie,)
 
 ifdef mainargs
 ASFLAGS += -DBIN_PATH=\"$(mainargs)\"

nemu/src/isa/riscv32/include/isa-def.h

@@ -20,6 +20,7 @@
 
 typedef struct {
   word_t gpr[MUXDEF(CONFIG_RVE, 16, 32)];
+  // word_t csr[MUXDEF(CONFIG_RVE, )]
   vaddr_t pc;
 } MUXDEF(CONFIG_RV64, riscv64_CPU_state, riscv32_CPU_state);
 

nemu/src/isa/riscv32/inst.c

@@ -13,31 +13,59 @@
  * See the Mulan PSL v2 for more details.
  ***************************************************************************************/
 
-#include <common.h>
 #include "local-include/reg.h"
 #include "macro.h"
+#include "types.h"
+#include <common.h>
 #include <cpu/cpu.h>
-#include <cpu/ifetch.h>
 #include <cpu/decode.h>
+#include <cpu/ifetch.h>
 #include <ftrace.h>
 #include <utils.h>
 
 #define R(i) gpr(i)
-#define Mr vaddr_read
-#define Mw vaddr_write
 
 enum {
-  TYPE_R, TYPE_I, TYPE_I_SHIFT, TYPE_U, TYPE_S, TYPE_B, TYPE_J,
+  TYPE_R,
+  TYPE_I,
+  TYPE_I_SHIFT,
+  TYPE_U,
+  TYPE_S,
+  TYPE_B,
+  TYPE_J,
   TYPE_N, // none
 };
 
-#define src1R() do { *src1 = R(rs1); } while (0)
+#define src1R()                                                                \
-#define src2R() do { *src2 = R(rs2); } while (0)
+  do {                                                                         \
-#define immI() do { *imm = SEXT(BITS(i, 31, 20), 12); } while(0)
+    *src1 = R(rs1);                                                            \
-#define immU() do { *imm = SEXT(BITS(i, 31, 12), 20) << 12; } while(0)
+  } while (0)
-#define immS() do { *imm = SEXT(BITS(i, 31, 25), 7) << 5 | BITS(i, 11, 7); } while(0)
+#define src2R()                                                                \
-#define immB() do { *imm = SEXT(BITS(i, 31, 31), 1) << 12 | BITS(i, 30, 25) << 5 | BITS(i, 11, 8) << 1 | BITS(i, 7, 7) << 11; } while(0)
+  do {                                                                         \
-#define immJ() do { *imm = SEXT(BITS(i, 31, 31), 1) << 20 | BITS(i, 30, 21) << 1 | BITS(i, 20, 20) << 11 | BITS(i, 19, 12) << 12; } while(0)
+    *src2 = R(rs2);                                                            \
+  } while (0)
+#define immI()                                                                 \
+  do {                                                                         \
+    *imm = SEXT(BITS(i, 31, 20), 12);                                          \
+  } while (0)
+#define immU()                                                                 \
+  do {                                                                         \
+    *imm = SEXT(BITS(i, 31, 12), 20) << 12;                                    \
+  } while (0)
+#define immS()                                                                 \
+  do {                                                                         \
+    *imm = SEXT(BITS(i, 31, 25), 7) << 5 | BITS(i, 11, 7);                     \
+  } while (0)
+#define immB()                                                                 \
+  do {                                                                         \
+    *imm = SEXT(BITS(i, 31, 31), 1) << 12 | BITS(i, 30, 25) << 5 |             \
+           BITS(i, 11, 8) << 1 | BITS(i, 7, 7) << 11;                          \
+  } while (0)
+#define immJ()                                                                 \
+  do {                                                                         \
+    *imm = SEXT(BITS(i, 31, 31), 1) << 20 | BITS(i, 30, 21) << 1 |             \
+           BITS(i, 20, 20) << 11 | BITS(i, 19, 12) << 12;                      \
+  } while (0)
 
 static void decode_operand(Decode *s, int *rd, word_t *src1, word_t *src2,
                            word_t *imm, int type) {
@@ -46,12 +74,30 @@ static void decode_operand(Decode *s, int *rd, word_t *src1, word_t *src2,
   int rs2 = BITS(i, 24, 20);
   *rd = BITS(i, 11, 7);
   switch (type) {
-    case TYPE_R: src1R(); src2R();         break;
+  case TYPE_R:
-    case TYPE_I: src1R();          immI(); break;
+    src1R();
-    case TYPE_U:                   immU(); break;
+    src2R();
-    case TYPE_J:                   immJ(); break;
+    break;
-    case TYPE_S: src1R(); src2R(); immS(); break;
+  case TYPE_I:
-    case TYPE_B: src1R(); src2R(); immB(); break;
+    src1R();
+    immI();
+    break;
+  case TYPE_U:
+    immU();
+    break;
+  case TYPE_J:
+    immJ();
+    break;
+  case TYPE_S:
+    src1R();
+    src2R();
+    immS();
+    break;
+  case TYPE_B:
+    src1R();
+    src2R();
+    immB();
+    break;
   }
 }
 
@@ -62,11 +108,23 @@ static void do_branch(Decode *s, bool condition, word_t offset) {
   }
 }
 
+static inline word_t Mr(Decode *s, vaddr_t addr, int len) {
+  s->inst_type = INST_MEM_READ;
+  s->inst_value.rmem = addr & ~0x3;
+  return vaddr_read(addr, len);
+}
+
+static inline void Mw(Decode *s, vaddr_t addr, int len, word_t data) {
+  vaddr_write(addr, len, data);
+  s->inst_type = INST_MEM_WRITE;
+  s->inst_value.wmem = addr & ~0x3;
+}
+
 #ifdef CONFIG_FTRACE
 static void ftrace_jalr(Decode *s, int rd, vaddr_t dst) {
   uint32_t i = s->isa.inst.val;
   int rs1 = BITS(i, 19, 15);
-  if(rs1 == 1 && rd == 0) {
+  if (rs1 == 1 && rd == 0) {
     ftrace_return(s->pc, dst);
   } else {
     ftrace_call(s->pc, dst);
@@ -80,70 +138,118 @@ static int decode_exec(Decode *s) {
   s->dnpc = s->snpc;
 
 #define INSTPAT_INST(s) ((s)->isa.inst.val)
-#define INSTPAT_MATCH(s, name, type, ... /* execute body */ ) { \
+#define INSTPAT_MATCH(s, name, type, ... /* execute body */)                   \
+  {                                                                            \
     decode_operand(s, &rd, &src1, &src2, &imm, concat(TYPE_, type));           \
-  __VA_ARGS__ ; \
+    __VA_ARGS__;                                                               \
-}
+  }
 
   INSTPAT_START();
-  INSTPAT("??????? ????? ????? ??? ????? 01101 11", lui    , U, R(rd) = imm);
+  INSTPAT("??????? ????? ????? ??? ????? 01101 11", lui, U, R(rd) = imm);
-  INSTPAT("??????? ????? ????? ??? ????? 00101 11", auipc  , U, R(rd) = s->pc + imm);
+  INSTPAT("??????? ????? ????? ??? ????? 00101 11", auipc, U,
+          R(rd) = s->pc + imm);
 
-  INSTPAT("??????? ????? ????? ??? ????? 11011 11", jal    , J, do {
+  INSTPAT(
-    s->dnpc = s->pc + imm; R(rd) = s->pc + 4;
+      "??????? ????? ????? ??? ????? 11011 11", jal, J, do {
-    IFDEF(CONFIG_FTRACE, ftrace_call(s->pc, s->pc + imm)); } while(0));
+        s->dnpc = s->pc + imm;
-  INSTPAT("??????? ????? ????? ??? ????? 11001 11", jalr   , I, do {
+        R(rd) = s->pc + 4;
-    s->dnpc = src1 + imm; R(rd) = s->pc + 4; 
+        IFDEF(CONFIG_FTRACE, ftrace_call(s->pc, s->pc + imm));
-    IFDEF(CONFIG_FTRACE, ftrace_jalr(s, rd, src1 + imm)); } while(0));
+      } while (0));
-  INSTPAT("??????? ????? ????? 000 ????? 11000 11", beq    , B, do_branch(s, src1 == src2, imm));
+  INSTPAT(
-  INSTPAT("??????? ????? ????? 001 ????? 11000 11", bne    , B, do_branch(s, src1 != src2, imm));
+      "??????? ????? ????? ??? ????? 11001 11", jalr, I, do {
-  INSTPAT("??????? ????? ????? 100 ????? 11000 11", blt    , B, do_branch(s, (sword_t)src1 < (sword_t)src2, imm));
+        s->dnpc = src1 + imm;
-  INSTPAT("??????? ????? ????? 101 ????? 11000 11", bge    , B, do_branch(s, (sword_t)src1 >= (sword_t)src2, imm));
+        R(rd) = s->pc + 4;
-  INSTPAT("??????? ????? ????? 110 ????? 11000 11", bltu   , B, do_branch(s, src1 < src2, imm));
+        IFDEF(CONFIG_FTRACE, ftrace_jalr(s, rd, src1 + imm));
-  INSTPAT("??????? ????? ????? 111 ????? 11000 11", bgeu   , B, do_branch(s, src1 >= src2, imm));
+      } while (0));
+  INSTPAT("??????? ????? ????? 000 ????? 11000 11", beq, B,
+          do_branch(s, src1 == src2, imm));
+  INSTPAT("??????? ????? ????? 001 ????? 11000 11", bne, B,
+          do_branch(s, src1 != src2, imm));
+  INSTPAT("??????? ????? ????? 100 ????? 11000 11", blt, B,
+          do_branch(s, (sword_t)src1 < (sword_t)src2, imm));
+  INSTPAT("??????? ????? ????? 101 ????? 11000 11", bge, B,
+          do_branch(s, (sword_t)src1 >= (sword_t)src2, imm));
+  INSTPAT("??????? ????? ????? 110 ????? 11000 11", bltu, B,
+          do_branch(s, src1 < src2, imm));
+  INSTPAT("??????? ????? ????? 111 ????? 11000 11", bgeu, B,
+          do_branch(s, src1 >= src2, imm));
 
-  INSTPAT("??????? ????? ????? 000 ????? 00000 11", lb     , I, R(rd) = SEXT(Mr(src1 + imm, 1), 8));
+  INSTPAT("??????? ????? ????? 000 ????? 00000 11", lb, I,
-  INSTPAT("??????? ????? ????? 001 ????? 00000 11", lh     , I, R(rd) = SEXT(Mr(src1 + imm, 2), 16));
+          R(rd) = SEXT(Mr(s, src1 + imm, 1), 8));
-  INSTPAT("??????? ????? ????? 010 ????? 00000 11", lw     , I, R(rd) = SEXT(Mr(src1 + imm, 4), 32));
+  INSTPAT("??????? ????? ????? 001 ????? 00000 11", lh, I,
-  INSTPAT("??????? ????? ????? 100 ????? 00000 11", lbu    , I, R(rd) = Mr(src1 + imm, 1));
+          R(rd) = SEXT(Mr(s, src1 + imm, 2), 16));
-  INSTPAT("??????? ????? ????? 101 ????? 00000 11", lhu    , I, R(rd) = Mr(src1 + imm, 2));
+  INSTPAT("??????? ????? ????? 010 ????? 00000 11", lw, I,
-  INSTPAT("??????? ????? ????? 000 ????? 01000 11", sb     , S, Mw(src1 + imm, 1, src2));
+          R(rd) = SEXT(Mr(s, src1 + imm, 4), 32));
-  INSTPAT("??????? ????? ????? 001 ????? 01000 11", sh     , S, Mw(src1 + imm, 2, src2));
+  INSTPAT("??????? ????? ????? 100 ????? 00000 11", lbu, I,
-  INSTPAT("??????? ????? ????? 010 ????? 01000 11", sw     , S, Mw(src1 + imm, 4, src2));
+          R(rd) = Mr(s, src1 + imm, 1));
+  INSTPAT("??????? ????? ????? 101 ????? 00000 11", lhu, I,
+          R(rd) = Mr(s, src1 + imm, 2));
+  INSTPAT("??????? ????? ????? 000 ????? 01000 11", sb, S,
+          Mw(s, src1 + imm, 1, src2));
+  INSTPAT("??????? ????? ????? 001 ????? 01000 11", sh, S,
+          Mw(s, src1 + imm, 2, src2));
+  INSTPAT("??????? ????? ????? 010 ????? 01000 11", sw, S,
+          Mw(s, src1 + imm, 4, src2));
 
-  INSTPAT("??????? ????? ????? 000 ????? 00100 11", addi   , I, R(rd) = src1 + imm);
+  INSTPAT("??????? ????? ????? 000 ????? 00100 11", addi, I,
-  INSTPAT("??????? ????? ????? 010 ????? 00100 11", slti   , I, R(rd) = (sword_t)src1 < (sword_t)imm ? 1 : 0);
+          R(rd) = src1 + imm);
-  INSTPAT("??????? ????? ????? 011 ????? 00100 11", sltiu  , I, R(rd) = src1 < imm ? 1 : 0);
+  INSTPAT("??????? ????? ????? 010 ????? 00100 11", slti, I,
-  INSTPAT("??????? ????? ????? 100 ????? 00100 11", xori   , I, R(rd) = src1 ^ imm);
+          R(rd) = (sword_t)src1 < (sword_t)imm ? 1 : 0);
-  INSTPAT("??????? ????? ????? 110 ????? 00100 11", ori    , I, R(rd) = src1 | imm);
+  INSTPAT("??????? ????? ????? 011 ????? 00100 11", sltiu, I,
-  INSTPAT("??????? ????? ????? 111 ????? 00100 11", andi   , I, R(rd) = src1 & imm);
+          R(rd) = src1 < imm ? 1 : 0);
-  INSTPAT("0000000 ????? ????? 001 ????? 00100 11", slli   , I, R(rd) = src1 << imm);
+  INSTPAT("??????? ????? ????? 100 ????? 00100 11", xori, I,
-  INSTPAT("0000000 ????? ????? 101 ????? 00100 11", srli   , I, R(rd) = src1 >> imm);
+          R(rd) = src1 ^ imm);
-  INSTPAT("0100000 ????? ????? 101 ????? 00100 11", srai   , I, R(rd) = (sword_t)src1 >> (imm & 0x01F));
+  INSTPAT("??????? ????? ????? 110 ????? 00100 11", ori, I, R(rd) = src1 | imm);
-  INSTPAT("0000000 ????? ????? 000 ????? 01100 11", add    , R, R(rd) = src1 + src2);
+  INSTPAT("??????? ????? ????? 111 ????? 00100 11", andi, I,
-  INSTPAT("0100000 ????? ????? 000 ????? 01100 11", sub    , R, R(rd) = src1 - src2);
+          R(rd) = src1 & imm);
-  INSTPAT("0000000 ????? ????? 001 ????? 01100 11", sll    , R, R(rd) = src1 << src2);
+  INSTPAT("0000000 ????? ????? 001 ????? 00100 11", slli, I,
-  INSTPAT("0000000 ????? ????? 010 ????? 01100 11", slt    , R, R(rd) = (sword_t)src1 < (sword_t)src2 ? 1 : 0);
+          R(rd) = src1 << imm);
-  INSTPAT("0000000 ????? ????? 011 ????? 01100 11", sltu   , R, R(rd) = src1 < src2 ? 1 : 0);
+  INSTPAT("0000000 ????? ????? 101 ????? 00100 11", srli, I,
-  INSTPAT("0000000 ????? ????? 100 ????? 01100 11", xor    , R, R(rd) = src1 ^ src2);
+          R(rd) = src1 >> imm);
-  INSTPAT("0000000 ????? ????? 101 ????? 01100 11", srl    , R, R(rd) = src1 >> src2);
+  INSTPAT("0100000 ????? ????? 101 ????? 00100 11", srai, I,
-  INSTPAT("0100000 ????? ????? 101 ????? 01100 11", sra    , R, R(rd) = (sword_t)src1 >> (src2 & 0x01F));
+          R(rd) = (sword_t)src1 >> (imm & 0x01F));
-  INSTPAT("0000000 ????? ????? 110 ????? 01100 11", or     , R, R(rd) = src1 | src2);
+  INSTPAT("0000000 ????? ????? 000 ????? 01100 11", add, R,
-  INSTPAT("0000000 ????? ????? 111 ????? 01100 11", and    , R, R(rd) = src1 & src2);
+          R(rd) = src1 + src2);
+  INSTPAT("0100000 ????? ????? 000 ????? 01100 11", sub, R,
+          R(rd) = src1 - src2);
+  INSTPAT("0000000 ????? ????? 001 ????? 01100 11", sll, R,
+          R(rd) = src1 << src2);
+  INSTPAT("0000000 ????? ????? 010 ????? 01100 11", slt, R,
+          R(rd) = (sword_t)src1 < (sword_t)src2 ? 1 : 0);
+  INSTPAT("0000000 ????? ????? 011 ????? 01100 11", sltu, R,
+          R(rd) = src1 < src2 ? 1 : 0);
+  INSTPAT("0000000 ????? ????? 100 ????? 01100 11", xor, R,
+          R(rd) = src1 ^ src2);
+  INSTPAT("0000000 ????? ????? 101 ????? 01100 11", srl, R,
+          R(rd) = src1 >> src2);
+  INSTPAT("0100000 ????? ????? 101 ????? 01100 11", sra, R,
+          R(rd) = (sword_t)src1 >> (src2 & 0x01F));
+  INSTPAT("0000000 ????? ????? 110 ????? 01100 11", or, R, R(rd) = src1 | src2);
+  INSTPAT("0000000 ????? ????? 111 ????? 01100 11", and, R,
+          R(rd) = src1 & src2);
 
-  INSTPAT("0000000 00001 00000 000 00000 11100 11", ebreak , N, NEMUTRAP(s->pc, R(10))); // R(10) is $a0
+  INSTPAT("0000000 00001 00000 000 00000 11100 11", ebreak, N,
+          NEMUTRAP(s->pc, R(10))); // R(10) is $a0
 
   // "M"
-  INSTPAT("0000001 ????? ????? 000 ????? 01100 11", mul    , R, R(rd) = src1 * src2);
+  INSTPAT("0000001 ????? ????? 000 ????? 01100 11", mul, R,
-  INSTPAT("0000001 ????? ????? 001 ????? 01100 11", mulh   , R, R(rd) = (int64_t)(sword_t)src1 * (sword_t)src2 >> 32);
+          R(rd) = src1 * src2);
-  INSTPAT("0000001 ????? ????? 010 ????? 01100 11", mulhsu , R, R(rd) = (int64_t)(sword_t)src1 * (uint64_t)src2 >> 32);
+  INSTPAT("0000001 ????? ????? 001 ????? 01100 11", mulh, R,
-  INSTPAT("0000001 ????? ????? 011 ????? 01100 11", mulhu  , R, R(rd) = (uint64_t)src1 * (uint64_t)src2 >> 32);
+          R(rd) = (int64_t)(sword_t)src1 * (sword_t)src2 >> 32);
-  INSTPAT("0000001 ????? ????? 100 ????? 01100 11", div    , R, R(rd) = (sword_t)src1 / (sword_t)src2);
+  INSTPAT("0000001 ????? ????? 010 ????? 01100 11", mulhsu, R,
-  INSTPAT("0000001 ????? ????? 101 ????? 01100 11", divu   , R, R(rd) = src1 / src2);
+          R(rd) = (int64_t)(sword_t)src1 * (uint64_t)src2 >> 32);
-  INSTPAT("0000001 ????? ????? 110 ????? 01100 11", rem    , R, R(rd) = (sword_t)src1 % (sword_t)src2);
+  INSTPAT("0000001 ????? ????? 011 ????? 01100 11", mulhu, R,
-  INSTPAT("0000001 ????? ????? 111 ????? 01100 11", remu   , R, R(rd) = src1 % src2);
+          R(rd) = (uint64_t)src1 * (uint64_t)src2 >> 32);
+  INSTPAT("0000001 ????? ????? 100 ????? 01100 11", div, R,
+          R(rd) = (sword_t)src1 / (sword_t)src2);
+  INSTPAT("0000001 ????? ????? 101 ????? 01100 11", divu, R,
+          R(rd) = src1 / src2);
+  INSTPAT("0000001 ????? ????? 110 ????? 01100 11", rem, R,
+          R(rd) = (sword_t)src1 % (sword_t)src2);
+  INSTPAT("0000001 ????? ????? 111 ????? 01100 11", remu, R,
+          R(rd) = src1 % src2);
 
-  INSTPAT("??????? ????? ????? ??? ????? ????? ??", inv    , N, INV(s->pc));
+  INSTPAT("??????? ????? ????? ??? ????? ????? ??", inv, N, INV(s->pc));
   INSTPAT_END();
 
   R(0) = 0; // reset $zero to 0

nemu/src/isa/riscv32/reg.c

@@ -13,20 +13,20 @@
 * See the Mulan PSL v2 for more details.
 ***************************************************************************************/
 
-#include <isa.h>
 #include "local-include/reg.h"
+#include "gdbstub.h"
 #include "macro.h"
+#include <errno.h>
+#include <isa.h>
 
-const char *regs[] = {
+const char *regs[] = {"$0", "ra", "sp",  "gp",  "tp", "t0", "t1", "t2",
-  "$0", "ra", "sp", "gp", "tp", "t0", "t1", "t2",
                       "s0", "s1", "a0",  "a1",  "a2", "a3", "a4", "a5",
                       "a6", "a7", "s2",  "s3",  "s4", "s5", "s6", "s7",
-  "s8", "s9", "s10", "s11", "t3", "t4", "t5", "t6"
+                      "s8", "s9", "s10", "s11", "t3", "t4", "t5", "t6"};
-};
 
 void isa_reg_display() {
   int colomn_per_row = 4;
-  for(int i = 0; i < ARRLEN(regs); i++) {
+  for (int i = 0; i < ARRLEN(regs); i++) {
     printf("\e[1;34m%3s\e[0m: " FMT_PADDR, reg_name(i), gpr(i));
     if (i % colomn_per_row == 3)
       putchar('\n');
@@ -49,3 +49,33 @@ word_t isa_reg_str2val(const char *s, bool *success) {
 
   return gpr(i);
 }
+
+int isa_read_reg(void *args, int regno, size_t *reg_value) {
+  if (regno > 32) {
+    return EFAULT;
+  }
+
+  if (regno == 32) {
+    *reg_value = cpu.pc;
+  } else {
+    *reg_value = cpu.gpr[regno];
+  }
+  return 0;
+}
+
+int isa_write_reg(void *args, int regno, size_t data) {
+  if (regno > 32) {
+    return EFAULT;
+  }
+
+  if (regno == 32) {
+    cpu.pc = data;
+  } else {
+    cpu.gpr[regno] = data;
+  }
+  return 0;
+}
+
+arch_info_t isa_arch_info = {.reg_num = 33,
+                             .reg_byte = MUXDEF(CONFIG_RV64, 8, 4),
+                             .target_desc = TARGET_RV32};

nemu/src/memory/paddr.c

@@ -15,10 +15,10 @@
 
 #include "common.h"
 #include "debug.h"
-#include <memory/host.h>
-#include <memory/paddr.h>
 #include <device/mmio.h>
 #include <isa.h>
+#include <memory/host.h>
+#include <memory/paddr.h>
 
 #if defined(CONFIG_PMEM_MALLOC)
 static uint8_t *pmem = NULL;
@@ -31,7 +31,7 @@ static word_t mtrace_end[CONFIG_MTRACE_RANGE_MAX] = {0};
 static int range_count = 0;
 #endif
 
-uint8_t* guest_to_host(paddr_t paddr) { return pmem + paddr - CONFIG_MBASE; }
+uint8_t *guest_to_host(paddr_t paddr) { return pmem + paddr - CONFIG_MBASE; }
 paddr_t host_to_guest(uint8_t *haddr) { return haddr - pmem + CONFIG_MBASE; }
 
 static word_t pmem_read(paddr_t addr, int len) {
@@ -44,15 +44,17 @@ static void pmem_write(paddr_t addr, int len, word_t data) {
 }
 
 static void out_of_bound(paddr_t addr) {
-  panic("address = " FMT_PADDR " is out of bound of pmem [" FMT_PADDR ", " FMT_PADDR "] at pc = " FMT_WORD,
+  panic("address = " FMT_PADDR " is out of bound of pmem [" FMT_PADDR
+        ", " FMT_PADDR "] at pc = " FMT_WORD,
         addr, PMEM_LEFT, PMEM_RIGHT, cpu.pc);
 }
 
 #ifdef CONFIG_MTRACE
 static void mtrace_print(char type, word_t addr, int len, word_t data) {
   for (int i = 0; i < range_count; i++)
-    if (addr <= mtrace_end[i] && addr >= mtrace_start[i] ) {
+    if (addr <= mtrace_end[i] && addr >= mtrace_start[i]) {
-      Trace("Mem %c " FMT_PADDR "%d D " FMT_PADDR, type, addr, len, data);
+      Trace("PC=" FMT_PADDR " Mem %c" FMT_PADDR " %d D " FMT_PADDR, cpu.pc,
+            type, addr, len, data);
       break;
     }
 }
@@ -67,15 +69,17 @@ void init_mem() {
   char range[sizeof(CONFIG_MTRACE_RANGE)] = CONFIG_MTRACE_RANGE;
   char *saveptr, *ptr;
   ptr = strtok_r(range, ",", &saveptr);
-  for (range_count = 0; range_count < CONFIG_MTRACE_RANGE_MAX; ) {
+  for (range_count = 0; range_count < CONFIG_MTRACE_RANGE_MAX;) {
     word_t start, end;
-    Assert(sscanf(ptr, FMT_PADDR "-" FMT_PADDR, &start, &end) == 2, "Config option MTRACE_RANGE has wrong format");
+    Assert(sscanf(ptr, FMT_PADDR "-" FMT_PADDR, &start, &end) == 2,
+           "Config option MTRACE_RANGE has wrong format");
     mtrace_start[range_count] = start;
     mtrace_end[range_count] = end;
 
     range_count++;
     ptr = strtok_r(NULL, ",", &saveptr);
-    if (!ptr) break;
+    if (!ptr)
+      break;
   }
   Trace("MTRACE ranges: ");
   for (int i = 0; i < range_count; i++) {
@@ -83,13 +87,17 @@ void init_mem() {
   }
 #endif
   IFDEF(CONFIG_MEM_RANDOM, memset(pmem, rand(), CONFIG_MSIZE));
-  Log("physical memory area [" FMT_PADDR ", " FMT_PADDR "]", PMEM_LEFT, PMEM_RIGHT);
+  Log("physical memory area [" FMT_PADDR ", " FMT_PADDR "]", PMEM_LEFT,
+      PMEM_RIGHT);
 }
 
 word_t paddr_read(paddr_t addr, int len) {
   word_t result = 0;
-  if (likely(in_pmem(addr))) { result = pmem_read(addr, len); goto mtrace;}
+  if (likely(in_pmem(addr))) {
-  IFDEF(CONFIG_DEVICE, result = mmio_read(addr, len); goto mtrace)
+    result = pmem_read(addr, len);
+    goto mtrace;
+  }
+  IFDEF(CONFIG_DEVICE, result = mmio_read(addr, len); goto mtrace;)
   out_of_bound(addr);
 
 mtrace:
@@ -100,7 +108,10 @@ mtrace:
 
 void paddr_write(paddr_t addr, int len, word_t data) {
   IFDEF(CONFIG_MTRACE, mtrace_print('W', addr, len, data));
-  if (likely(in_pmem(addr))) { pmem_write(addr, len, data); return; }
+  if (likely(in_pmem(addr))) {
+    pmem_write(addr, len, data);
+    return;
+  }
   IFDEF(CONFIG_DEVICE, mmio_write(addr, len, data); return);
   out_of_bound(addr);
 }

nemu/src/monitor/filelist.mk

@@ -0,0 +1,3 @@
+DIRS-y += src/monitor/monitor.c
+
+CXXSRC += src/monitor/gdbstub.cc

nemu/src/monitor/gdbstub.cc

@@ -0,0 +1,130 @@
+#include "utils.h"
+#include <vector>
+
+extern "C" {
+#include <cpu/cpu.h>
+#include <debug.h>
+#include <errno.h>
+#include <gdbstub.h>
+#include <isa.h>
+#include <memory/paddr.h>
+#include <stddef.h>
+#include <stdlib.h>
+}
+
+typedef struct {
+  std::vector<breakpoint_t> *bp;
+  bool halt;
+} DbgState;
+
+int nemu_read_mem(void *args, size_t addr, size_t len, void *val) {
+  if (!in_pmem(addr))
+    return EINVAL;
+  memcpy(val, guest_to_host(addr), len);
+  return 0;
+}
+
+int nemu_write_mem(void *args, size_t addr, size_t len, void *val) {
+  if (!in_pmem(addr))
+    return EINVAL;
+  memcpy(guest_to_host(addr), val, len);
+  return 0;
+}
+
+static void nemu_is_stopped(gdb_action_t *act, breakpoint_t *stopped_at) {
+  switch (nemu_state.state) {
+  case NEMU_RUNNING:
+    nemu_state.state = NEMU_STOP;
+    switch (stopped_at->type) {
+    case BP_SOFTWARE:
+      act->reason = gdb_action_t::ACT_BREAKPOINT;
+      break;
+    case BP_ACCESS:
+      act->reason = gdb_action_t::ACT_WATCH;
+      break;
+    case BP_WRITE:
+      act->reason = gdb_action_t::ACT_WWATCH;
+      break;
+    case BP_READ:
+      act->reason = gdb_action_t::ACT_RWATCH;
+      break;
+    }
+    act->data = stopped_at->addr;
+    break;
+
+  default:
+    act->reason = gdb_action_t::ACT_SHUTDOWN;
+    act->data = nemu_state.halt_ret;
+  }
+}
+
+void nemu_cont(void *args, gdb_action_t *res) {
+  DbgState *dbg_state = (DbgState *)args;
+  breakpoint_t *stopped_at =
+      cpu_exec_with_bp(-1, dbg_state->bp->data(), dbg_state->bp->size());
+  nemu_is_stopped(res, stopped_at);
+}
+
+void nemu_stepi(void *args, gdb_action_t *res) {
+  DbgState *dbg_state = (DbgState *)args;
+  breakpoint_t *stopped_at =
+      cpu_exec_with_bp(1, dbg_state->bp->data(), dbg_state->bp->size());
+  nemu_is_stopped(res, stopped_at);
+}
+
+bool nemu_set_bp(void *args, size_t addr, bp_type_t type) {
+  DbgState *dbg_state = (DbgState *)args;
+  for (const auto &bp : *dbg_state->bp) {
+    if (bp.addr == addr && bp.type == type) {
+      return true;
+    }
+  }
+  dbg_state->bp->push_back({.addr = addr, .type = type});
+  return true;
+}
+
+bool nemu_del_bp(void *args, size_t addr, bp_type_t type) {
+  DbgState *dbg_state = (DbgState *)args;
+  for (auto it = dbg_state->bp->begin(); it != dbg_state->bp->end(); it++) {
+    if (it->addr == addr && it->type == type) {
+      std::swap(*it, *dbg_state->bp->rbegin());
+      dbg_state->bp->pop_back();
+      return true;
+    }
+  }
+  return false;
+}
+
+void nemu_on_interrupt(void *args) {
+  // fputs("Not implemented", stderr);
+}
+
+static struct target_ops nemu_gdbstub_ops = {.cont = nemu_cont,
+                                             .stepi = nemu_stepi,
+                                             .read_reg = isa_read_reg,
+                                             .write_reg = isa_write_reg,
+                                             .read_mem = nemu_read_mem,
+                                             .write_mem = nemu_write_mem,
+                                             .set_bp = nemu_set_bp,
+                                             .del_bp = nemu_del_bp,
+                                             .on_interrupt = NULL};
+static DbgState dbg;
+extern "C" {
+static gdbstub_t gdbstub_priv;
+#define SOCKET_ADDR "127.0.0.1:1234"
+int nemu_gdbstub_init() {
+  dbg.bp = new std::vector<breakpoint_t>();
+  assert(dbg.bp);
+  if (!gdbstub_init(&gdbstub_priv, &nemu_gdbstub_ops,
+                    (arch_info_t)isa_arch_info, SOCKET_ADDR)) {
+    return EINVAL;
+  }
+  return 0;
+}
+int nemu_gdbstub_run() {
+  puts("Waiting for gdb connection at " SOCKET_ADDR);
+  bool success = gdbstub_run(&gdbstub_priv, &dbg);
+  gdbstub_close(&gdbstub_priv);
+  return !success;
+}
+}

nemu/src/monitor/monitor.c

@@ -22,24 +22,25 @@ void init_log(const char *log_file);
 void init_mem();
 void init_difftest(char *ref_so_file, long img_size, int port);
 void init_device();
-void init_sdb();
 void init_disasm(const char *triple);
+int nemu_gdbstub_init();
 
 static void welcome() {
-  Log("Trace: %s", MUXDEF(CONFIG_TRACE, ANSI_FMT("ON", ANSI_FG_GREEN), ANSI_FMT("OFF", ANSI_FG_RED)));
+  Log("Trace: %s", MUXDEF(CONFIG_TRACE, ANSI_FMT("ON", ANSI_FG_GREEN),
-  IFDEF(CONFIG_TRACE, Log("If trace is enabled, a log file will be generated "
+                          ANSI_FMT("OFF", ANSI_FG_RED)));
+  IFDEF(CONFIG_TRACE,
+        Log("If trace is enabled, a log file will be generated "
             "to record the trace. This may lead to a large log file. "
             "If it is not necessary, you can disable it in menuconfig"));
   Log("Build time: %s, %s", __TIME__, __DATE__);
-  printf("Welcome to %s-NEMU!\n", ANSI_FMT(str(__GUEST_ISA__), ANSI_FG_YELLOW ANSI_BG_RED));
+  printf("Welcome to %s-NEMU!\n",
+         ANSI_FMT(str(__GUEST_ISA__), ANSI_FG_YELLOW ANSI_BG_RED));
   printf("For help, type \"help\"\n");
 }
 
 #ifndef CONFIG_TARGET_AM
 #include <getopt.h>
 
-void sdb_set_batch_mode();
-
 static char *log_file = NULL;
 static char *elf_file = NULL;
 static char *diff_so_file = NULL;
@@ -70,23 +71,32 @@ static long load_img() {
 
 static int parse_args(int argc, char *argv[]) {
   const struct option table[] = {
-    {"batch"    , no_argument      , NULL, 'b'},
+      {"batch", no_argument, NULL, 'b'},
-    {"log"      , required_argument, NULL, 'l'},
+      {"log", required_argument, NULL, 'l'},
-    {"diff"     , required_argument, NULL, 'd'},
+      {"diff", required_argument, NULL, 'd'},
-    {"port"     , required_argument, NULL, 'p'},
+      {"port", required_argument, NULL, 'p'},
-    {"elf"      , required_argument, NULL, 'f'},
+      {"elf", required_argument, NULL, 'f'},
-    {"help"     , no_argument      , NULL, 'h'},
+      {"help", no_argument, NULL, 'h'},
-    {0          , 0                , NULL,  0 },
+      {0, 0, NULL, 0},
   };
   int o;
-  while ( (o = getopt_long(argc, argv, "-bhl:d:p:", table, NULL)) != -1) {
+  while ((o = getopt_long(argc, argv, "-bhl:d:p:", table, NULL)) != -1) {
     switch (o) {
-      case 'b': sdb_set_batch_mode(); break;
+    case 'p':
-      case 'p': sscanf(optarg, "%d", &difftest_port); break;
+      sscanf(optarg, "%d", &difftest_port);
-      case 'l': log_file = optarg; break;
+      break;
-      case 'd': diff_so_file = optarg; break;
+    case 'l':
-      case 'f': elf_file = optarg; break;
+      log_file = optarg;
-      case 1: img_file = optarg; return 0;
+      break;
+    case 'd':
+      diff_so_file = optarg;
+      break;
+    case 'f':
+      elf_file = optarg;
+      break;
+    case 1:
+      img_file = optarg;
+      return 0;
     default:
       printf("Usage: %s [OPTION...] IMAGE [args]\n\n", argv[0]);
       printf("\t-b,--batch              run with batch mode\n");
@@ -128,11 +138,14 @@ void init_monitor(int argc, char *argv[]) {
   /* Initialize differential testing. */
   init_difftest(diff_so_file, img_size, difftest_port);
 
-  /* Initialize the simple debugger. */
+  /* Initialize debugger */
-  init_sdb();
+  if (nemu_gdbstub_init()) {
+    Error("Failed to init");
+    exit(1);
+  }
 
   // printf("elf_file: %s\n", elf_file);
-  if(elf_file != NULL) {
+  if (elf_file != NULL) {
 #ifdef CONFIG_FTRACE
     void init_elf(const char *path);
     init_elf(elf_file);
@@ -142,14 +155,13 @@ void init_monitor(int argc, char *argv[]) {
   }
 
 #ifndef CONFIG_ISA_loongarch32r
-  IFDEF(CONFIG_ITRACE, init_disasm(
+  IFDEF(CONFIG_ITRACE,
+        init_disasm(
             MUXDEF(CONFIG_ISA_x86, "i686",
                    MUXDEF(CONFIG_ISA_mips32, "mipsel",
                           MUXDEF(CONFIG_ISA_riscv,
-      MUXDEF(CONFIG_RV64,      "riscv64",
+                                 MUXDEF(CONFIG_RV64, "riscv64", "riscv32"),
-                               "riscv32"),
+                                 "bad"))) "-pc-linux-gnu"));
-                               "bad"))) "-pc-linux-gnu"
-  ));
 #endif
 
   /* Display welcome message. */

nemu/src/monitor/sdb/addrexp.l

@@ -1,24 +0,0 @@
-%{
-    #include <isa.h>
-    #include <addrexp.h>
-    static bool success = false;
-    void yyerror(word_t *result, const char *err); 
-%}
-%option noyywrap
-
-%%
-
-0[xX][0-9a-fA-F]+ { yylval = strtoul(yytext, NULL, 16); return HEX_NUMBER; }
-[0-9]+            { yylval = strtoul(yytext, NULL, 10); return NUMBER; }
-$[asgprt$][0-9pa][0-9]?    {
-    yylval = isa_reg_str2val(yytext + 1, &success);
-    if(!success) {
-        yyerror(NULL, "Failed to convert reg to value");
-        return YYerror;
-    }
-    return REGISTER;
-}
-[+\-*/<=()]         { return *yytext; }
-[ \t]             {  }
-.                 { printf("Unexpected character: %s\n", yytext); return YYerror; }
-%%

nemu/src/monitor/sdb/addrexp.y

@@ -1,60 +0,0 @@
-%code requires {
-    #include <common.h>
-    #include <memory/vaddr.h>
-    #include <stdio.h>
-    #include <stdlib.h>
-    extern int yylex(void);
-}
-%{
-    #include <common.h>
-    #include <utils.h>
-    #include <isa.h>
-    #include <stdio.h>
-    #include <stdlib.h>
-    void yyerror(word_t *result, const char *err) {
-      Error("%s", err);
-    }
-%}
-
-%token NUMBER HEX_NUMBER
-%token REGISTER
-%locations
-%start input
-%define api.value.type { word_t }
-%parse-param { uint32_t *result }
-%left '-' '+'
-%left '*' '/'
-
-%%
-input
-    : expression { *result = $1; }
-    ;
-
-expression
-    : number { $$ = $1; }
-    | expression '>' '=' expression { $$ = ($1 >= $4); }
-    | expression '<' '=' expression { $$ = ($1 <= $4); }
-    | expression '=' '=' expression { $$ = ($1 == $4); }
-    | expression '!' '=' expression { $$ = ($1 == $4); }
-    | expression '>' expression { $$ = ($1 > $3); }
-    | expression '<' expression { $$ = ($1 < $3); }
-    | expression '+' expression { $$ = $1 + $3; }
-    | expression '-' expression { $$ = $1 - $3; }
-    | expression '*' expression { $$ = $1 * $3; } 
-    | expression '/' expression {
-        if($3 == 0) {
-          fprintf(stderr, "Error: divide by zero at %u / %u\n", $1, $3);
-          YYABORT;
-        };
-        $$ = $1 / $3;
-      }
-    | '-' number { $$ = -$2; }
-    | '*' expression { $$ = vaddr_read($2, WORD_BYTES); }
-    | '(' expression ')' { $$ = $2; }
-
-number
-    : REGISTER
-    | NUMBER 
-    | HEX_NUMBER 
-
-%%

nemu/src/monitor/sdb/filelist.mk

@@ -1,2 +0,0 @@
-SRCS-y += src/monitor/sdb/addrexp.tag.c src/monitor/sdb/addrexp.yy.c
-LFLAGS += -DYY_NO_UNPUT -DYY_NO_INPUT

nemu/src/monitor/sdb/sdb.c

@@ -1,361 +0,0 @@
-/***************************************************************************************
- * Copyright (c) 2014-2022 Zihao Yu, Nanjing University
- *
- * NEMU is licensed under Mulan PSL v2.
- * You can use this software according to the terms and conditions of the Mulan
- *PSL v2. You may obtain a copy of Mulan PSL v2 at:
- *          http://license.coscl.org.cn/MulanPSL2
- *
- * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY
- *KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
- *NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
- *
- * See the Mulan PSL v2 for more details.
- ***************************************************************************************/
-
-#include "sdb.h"
-#include "common.h"
-#include "sys/types.h"
-#include <addrexp.h>
-#include <addrexp_lex.h>
-#include <cpu/cpu.h>
-#include <errno.h>
-#include <isa.h>
-#include <memory/vaddr.h>
-#include <readline/history.h>
-#include <readline/readline.h>
-#include <stdint.h>
-
-static int is_batch_mode = false;
-
-// command handlers
-static int cmd_help(char *args);
-static int cmd_c(char *args);
-static int cmd_p(char *args);
-static int cmd_q(char *args);
-static int cmd_w(char *args);
-static int cmd_x(char *args);
-static int cmd_si(char *args);
-static int cmd_info(char *args);
-static int cmd_info_r(char *args);
-static int cmd_info_w(char *args);
-
-static struct CommandTable {
-  const char *name;
-  const char *description;
-  int (*handler)(char *);
-  struct CommandTable *subcommand;
-  int nr_subcommand;
-} cmd_info_table[] =
-    {
-        {"r", "List all registers and their contents", cmd_info_r, NULL, 0},
-        {"w", "Status of specified watchpoints", cmd_info_w, NULL, 0},
-},
-  cmd_table[] = {
-      {"help", "Display information about all supported commands", cmd_help,
-       NULL, 0},
-      {"c", "Continue the execution of the program", cmd_c, NULL, 0},
-      {"p", "Print expression result", cmd_p, NULL, 0},
-      {"q", "Exit NEMU", cmd_q, NULL, 0},
-      {"x", "Examine content of physical memory address", cmd_x, NULL, 0},
-      {"w", "Break when expression is changed", cmd_w, NULL, 0},
-      {"si", "Execute next [n] program line", cmd_si, NULL, 0},
-      {"info", "Print information of registers or watchpoints", cmd_info,
-       cmd_info_table, ARRLEN(cmd_info_table)},
-};
-
-#define NR_CMD ARRLEN(cmd_table)
-
-void init_regex();
-void init_wp_pool();
-
-/* We use the `readline' library to provide more flexibility to read from stdin.
- */
-static char *rl_gets() {
-  static char *line_read = NULL;
-
-  if (line_read) {
-    free(line_read);
-    line_read = NULL;
-  }
-
-  line_read = readline("\e[1;34m(nemu)\e[0m ");
-
-  if (line_read && *line_read) {
-    add_history(line_read);
-  }
-
-  return line_read;
-}
-
-/* Extract Integer from a string. Can handle hex, binary and decimal numbers.
- * Print error if meet any error.
- * Return `UINTMAX_MAX` if the string is invalid or number exceed the limit of
- * uint.
- */
-static word_t parse_uint(const char *arg, bool *success) {
-  if (arg == NULL) {
-    puts("Invalid uint argument.");
-    *success = false;
-    return 0;
-  }
-  int base = 10;
-  int token_length = strnlen(arg, 34);
-  if (token_length > 2) {
-    if (arg[0] == '0' && (arg[1] == 'b' || arg[1] == 'B')) {
-      base = 2;
-      arg = arg + 2;
-    } else if (arg[0] == '0' && (arg[1] == 'x' || arg[1] == 'X')) {
-      base = 16;
-      arg = arg + 2;
-    }
-  }
-  char *endptr;
-  uintmax_t n = strtoumax(arg, &endptr, base);
-  if (errno == ERANGE || n > WORD_T_MAX) {
-    printf("%s exceed the limit of uint\n", arg);
-    *success = false;
-    return 0;
-  } else if (arg == endptr) {
-    puts("Invalid uint argument.");
-    *success = false;
-    return 0;
-  } else if (n > WORD_T_MAX) {
-    *success = false;
-    return WORD_T_MAX;
-  } else {
-    *success = true;
-    return n;
-  }
-}
-
-word_t parse_expr(const char *arg, bool *success) {
-  if (arg == NULL) {
-    puts("Invalid expr argument.");
-    *success = false;
-    return 0;
-  } else {
-    word_t res;
-    yy_scan_string(arg);
-    *success = !yyparse(&res);
-    yylex_destroy();
-    return res;
-  }
-}
-
-static int cmd_c(char *args) {
-  cpu_exec(-1);
-  return 0;
-}
-
-static int cmd_p(char *args) {
-  char *arg = strtok(NULL, "");
-  bool res = false;
-
-  word_t result = parse_expr(arg, &res);
-  if (!res)
-    goto wrong_usage;
-  printf("%s: %u\n", arg, result);
-  return 0;
-
-wrong_usage:
-  printf("Invalid argument for command p: %s\n", arg);
-  printf("Usage: p [EXPR: <expr>]\n");
-  return 0;
-}
-
-static int cmd_q(char *args) {
-  nemu_state.state = NEMU_QUIT;
-  return -1;
-}
-
-/* Single stepping
- * <step>: execute <step> step
- */
-static int cmd_si(char *args) {
-  char *arg = strtok(NULL, " ");
-  if (arg == NULL) {
-    cpu_exec(1);
-  } else {
-    bool res = false;
-    word_t n = parse_uint(arg, &res);
-    if (!res)
-      goto wrong_usage;
-    cpu_exec(n);
-  }
-  return 0;
-
-wrong_usage:
-  printf("Invalid argument for command si: %s\n", args);
-  printf("Usage: si [N: uint]\n");
-  return 0;
-}
-
-static int cmd_info_r(char *args) {
-  isa_reg_display();
-  return 0;
-}
-
-static int cmd_info_w(char *args) {
-  printf("Not implemented");
-  return 0;
-}
-
-static int cmd_w(char *args) {
-  char *expr = strtok(NULL, "");
-  wp_add(expr);
-  return 0;
-}
-
-static int cmd_x(char *args) {
-  char *arg = strtok(NULL, " ");
-  bool res = false;
-  word_t n = parse_uint(arg, &res);
-  if (!res)
-    goto wrong_usage;
-  // No deliminter here, just pass all the remain argument to `parse_expr()`
-  arg = strtok(NULL, "");
-  word_t start_addr = parse_expr(arg, &res);
-  if (!res)
-    goto wrong_usage;
-  start_addr = start_addr & ~(WORD_BYTES - 1);
-  for (vaddr_t vaddr = start_addr; vaddr < start_addr + n; vaddr += WORD_BYTES) {
-    word_t value = vaddr_read(vaddr, WORD_BYTES);
-    printf("\e[1;34m" FMT_PADDR "\e[0m"
-           "  " FMT_WORD "\n",
-           vaddr, value);
-  }
-  return 0;
-
-wrong_usage:
-  printf("Invalid argument for command x: %s\n", arg);
-  printf("Usage: x [N: uint] [EXPR: <expr>]\n");
-  return 0;
-}
-
-static int cmd_info(char *args) {
-  char *arg = strtok(NULL, " ");
-  int i;
-  if (arg == NULL) {
-    goto wrong_usage;
-    return 0;
-  }
-  for (i = 0; i < ARRLEN(cmd_info_table); i++) {
-    if (strcmp(arg, cmd_info_table[i].name) == 0) {
-      cmd_info_table[i].handler(args);
-      return 0;
-    }
-  }
-
-wrong_usage:
-  printf("Invalid argument for command info: %s\n", args);
-  printf("Usage: info [r | w]\n");
-  return 0;
-}
-
-static int cmd_help_print(char *args, struct CommandTable *cur_cmd_table,
-                          int cur_nr_cmd) {
-  int i;
-  char *arg = strtok(NULL, " ");
-  if (arg == NULL) {
-    return -1;
-  } else {
-    for (i = 0; i < cur_nr_cmd; i++) {
-      if (strcmp(arg, cur_cmd_table[i].name) == 0) {
-        printf("%s ", cur_cmd_table[i].name);
-        if (cmd_help_print(arg, cur_cmd_table[i].subcommand,
-                           cur_cmd_table[i].nr_subcommand) == -1) {
-          printf("-- %s\n", cur_cmd_table[i].description);
-        }
-        return 0;
-      }
-    }
-    return -1;
-  }
-}
-
-static int cmd_help(char *args) {
-  /* extract the first argument */
-  char *arg = strtok(NULL, " ");
-  int i;
-
-  if (arg == NULL) {
-    /* no argument given */
-    for (i = 0; i < NR_CMD; i++) {
-      printf("%s -- %s\n", cmd_table[i].name, cmd_table[i].description);
-    }
-  } else {
-    for (i = 0; i < NR_CMD; i++) {
-      if (strcmp(arg, cmd_table[i].name) == 0) {
-        printf("%s ", cmd_table[i].name);
-        if (cmd_help_print(args, cmd_table[i].subcommand,
-                           cmd_table[i].nr_subcommand) == -1) {
-          printf("-- %s\n", cmd_table[i].description);
-          // Print available subcommands
-          for (int j = 0; j < cmd_table[i].nr_subcommand; j++) {
-            struct CommandTable *sub_cmd_table = cmd_table[i].subcommand;
-            printf("  > %s -- %s\n", sub_cmd_table[j].name,
-                   sub_cmd_table[j].description);
-          }
-        }
-        return 0;
-      }
-    }
-    printf("Unknown command '%s'\n", arg);
-  }
-  return 0;
-}
-
-void sdb_set_batch_mode() { is_batch_mode = true; }
-
-void sdb_mainloop() {
-  if (is_batch_mode) {
-    cmd_c(NULL);
-    return;
-  }
-
-  for (char *str; (str = rl_gets()) != NULL;) {
-    char *str_end = str + strlen(str);
-
-    /* extract the first token as the command */
-    char *cmd = strtok(str, " ");
-    if (cmd == NULL) {
-      continue;
-    }
-
-    /* treat the remaining string as the arguments,
-     * which may need further parsing
-     */
-    char *args = cmd + strlen(cmd) + 1;
-    if (args >= str_end) {
-      args = NULL;
-    }
-
-#ifdef CONFIG_DEVICE
-    extern void sdl_clear_event_queue();
-    sdl_clear_event_queue();
-#endif
-
-    int i;
-    for (i = 0; i < NR_CMD; i++) {
-      if (strcmp(cmd, cmd_table[i].name) == 0) {
-        if (cmd_table[i].handler(args) < 0) {
-          return;
-        }
-        break;
-      }
-    }
-
-    if (i == NR_CMD) {
-      printf("Unknown command '%s'\n", cmd);
-    }
-  }
-}
-
-void init_sdb() {
-  // /* Compile the regular expressions. */
-  // init_regex();
-
-  /* Initialize the watchpoint pool. */
-  init_wp_pool();
-}

nemu/src/monitor/sdb/sdb.h

@@ -1,25 +0,0 @@
-/***************************************************************************************
-* Copyright (c) 2014-2022 Zihao Yu, Nanjing University
-*
-* NEMU is licensed under Mulan PSL v2.
-* You can use this software according to the terms and conditions of the Mulan PSL v2.
-* You may obtain a copy of Mulan PSL v2 at:
-*          http://license.coscl.org.cn/MulanPSL2
-*
-* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
-* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
-* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
-*
-* See the Mulan PSL v2 for more details.
-***************************************************************************************/
-
-#ifndef __SDB_H__
-#define __SDB_H__
-
-#include <common.h>
-
-word_t parse_expr(const char *arg, bool *success);
-int wp_add(char * expr);
-int wp_remove_by_number(int number);
-
-#endif

nemu/src/monitor/sdb/watchpoint.c

@@ -1,150 +0,0 @@
-/***************************************************************************************
- * Copyright (c) 2014-2022 Zihao Yu, Nanjing University
- *
- * NEMU is licensed under Mulan PSL v2.
- * You can use this software according to the terms and conditions of the Mulan
- *PSL v2. You may obtain a copy of Mulan PSL v2 at:
- *          http://license.coscl.org.cn/MulanPSL2
- *
- * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY
- *KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
- *NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
- *
- * See the Mulan PSL v2 for more details.
- ***************************************************************************************/
-
-#include "sdb.h"
-#include <common.h>
-#include <stdio.h>
-
-#define NR_WP 32
-
-typedef struct watchpoint {
-  int NO;
-  struct watchpoint *next;
-  word_t val;
-  char *expr;
-} WP;
-
-static WP wp_pool[NR_WP] = {};
-static WP *head = NULL, *tail = NULL, *free_ = NULL;
-static int wp_count = 0;
-
-void init_wp_pool() {
-  int i;
-  for (i = 0; i < NR_WP; i++) {
-    wp_pool[i].NO = i;
-    wp_pool[i].next = (i == NR_WP - 1 ? NULL : &wp_pool[i + 1]);
-  }
-
-  head = NULL;
-  free_ = wp_pool;
-}
-
-static WP *wp_new() {
-  if (free_ == NULL) {
-    Error("wp_pool: Watchpoint pool not initialized or is full.");
-    return NULL;
-  }
-  
-  WP *ret = free_;
-  free_ = free_->next;
-
-  ret->NO = 0;
-  ret->next = NULL;
-  return ret;
-}
-
-static void wp_delete(WP *wp) {
-  Assert(wp, "Failed to delete watchpoint from pool.");
-  wp->next = free_;
-  free_ = wp;
-}
-
-int wp_add(char * expr) {
-  WP *wp = wp_new();
-  if (wp == NULL) {
-    Error("watchpoint: Failed to add watchpoint, pool is full.");
-    goto failed_create;
-  }
-
-  wp->NO = wp_count++;
-  if (tail == NULL) {
-    head = wp;
-    tail = wp;
-  } else {
-    tail->next = wp;
-    tail = wp;
-  }
-
-  bool success = false;
-  wp->val = parse_expr(expr, &success);
-  if (!success) {
-    Error("Failed to parse given expression `%s`", expr);
-    goto failed_create;
-  }
-
-  int len = strlen(expr);
-  wp->expr = malloc((len + 1) * sizeof(char));
-  if (wp->expr == NULL) {
-    Error("Failed to allocate memory for expression");
-    goto failed_create;
-  }
-  strncpy(wp->expr, expr, len + 1);
-  wp->expr[len] = '\0';
-  return 0;
-
-failed_create:
-  wp_delete(wp);
-  return 1;
-}
-
-int wp_remove_by_number(int number) {
-  WP *target_prev;
-  // Find previous node of target number
-  for (target_prev = head; target_prev != NULL && target_prev->next->NO != number; target_prev = target_prev->next) ;
-  if (target_prev == NULL) {
-    Error("Watchpoint not found, you can check current watchpoints with `info w`");
-    return 1;
-  }
-  WP *target = target_prev->next;
-  target_prev->next = target->next;
-  if (target == head) {
-    head = target->next;
-  } else if (target == tail) {
-    tail = target_prev;
-  }
-  wp_delete(target);
-  return 0;
-}
-
-static bool wp_check_change(WP* wp) {
-  bool success = false;
-  word_t result;
-
-  result = parse_expr(wp->expr, &success);
-  if (!success) {
-    panic("Failed to evaluate expression `%s`", wp->expr);
-  } 
-  if (result != wp->val) {
-    wp->val = result;
-    return true;
-  }
-  return false;
-}
-
-/* 
-  Check if watchpoint value changed after execution
-*/
-bool wp_eval_all() {
-  WP *wp;
-  bool value_change = false;
-  for (wp = head; wp != NULL; wp = wp->next) {
-    int prev_val = wp->val;
-    if (wp_check_change(wp)) {
-      printf("Watchpoint %d: %s\n  %u -> %u\n", wp->NO, wp->expr, prev_val, wp->val);
-      value_change = true;
-    }
-  }
-  return value_change;
-}