Work in progress

src/CMakeLists.txt

@@ -22,11 +22,11 @@ add_executable(cpu_test ${CPU_SOURCES} cpu_test.c)
 add_executable(cpu_bench ${CPU_SOURCES} cpu_bench.c)
 
 add_executable(ewm ${CPU_SOURCES} ${BOO_SOURCES} ${ONE_SOURCES} ${TWO_SOURCES} ${SDL_SOURCES} ewm.c)
-target_link_libraries(ewm SDL2)
+target_link_libraries(ewm SDL2 readline)
 
 add_executable(tty_test ${CPU_SOURCES} ${ONE_SOURCES} ${SDL_SOURCES} tty_test.c)
-target_link_libraries(tty_test SDL2)
+target_link_libraries(tty_test SDL2 readline)
 
 add_executable(scr_test ${CPU_SOURCES} ${TWO_SOURCES} ${SDL_SOURCES} scr_test.c)
-target_link_libraries(scr_test SDL2)
+target_link_libraries(scr_test SDL2 readline)
 

src/Makefile

@@ -1,5 +1,5 @@
 # CMAKE generated file: DO NOT EDIT!
-# Generated by "Unix Makefiles" Generator, CMake Version 3.9
+# Generated by "Unix Makefiles" Generator, CMake Version 3.8
 
 # Default target executed when no arguments are given to make.
 default_target: all
@@ -39,10 +39,10 @@ cmake_force:
 SHELL = /bin/sh
 
 # The CMake executable.
-CMAKE_COMMAND = /usr/local/Cellar/cmake/3.9.4/bin/cmake
+CMAKE_COMMAND = /Applications/CLion.app/Contents/bin/cmake/bin/cmake
 
 # The command to remove a file.
-RM = /usr/local/Cellar/cmake/3.9.4/bin/cmake -E remove -f
+RM = /Applications/CLion.app/Contents/bin/cmake/bin/cmake -E remove -f
 
 # Escaping for special characters.
 EQUALS = =
@@ -59,7 +59,7 @@ CMAKE_BINARY_DIR = /Users/stefan/Projects/ewm/src
 # Special rule for the target rebuild_cache
 rebuild_cache:
 	@$(CMAKE_COMMAND) -E cmake_echo_color --switch=$(COLOR) --cyan "Running CMake to regenerate build system..."
-	/usr/local/Cellar/cmake/3.9.4/bin/cmake -H$(CMAKE_SOURCE_DIR) -B$(CMAKE_BINARY_DIR)
+	/Applications/CLion.app/Contents/bin/cmake/bin/cmake -H$(CMAKE_SOURCE_DIR) -B$(CMAKE_BINARY_DIR)
 .PHONY : rebuild_cache
 
 # Special rule for the target rebuild_cache
@@ -69,8 +69,8 @@ rebuild_cache/fast: rebuild_cache
 
 # Special rule for the target edit_cache
 edit_cache:
-	@$(CMAKE_COMMAND) -E cmake_echo_color --switch=$(COLOR) --cyan "Running CMake cache editor..."
-	/usr/local/Cellar/cmake/3.9.3_1/bin/ccmake -H$(CMAKE_SOURCE_DIR) -B$(CMAKE_BINARY_DIR)
+	@$(CMAKE_COMMAND) -E cmake_echo_color --switch=$(COLOR) --cyan "No interactive CMake dialog available..."
+	/Applications/CLion.app/Contents/bin/cmake/bin/cmake -E echo No\ interactive\ CMake\ dialog\ available.
 .PHONY : edit_cache
 
 # Special rule for the target edit_cache

src/cpu.h

@@ -38,6 +38,9 @@
 #define EWM_VECTOR_RES 0xfffc
 #define EWM_VECTOR_IRQ 0xfffe
 
+#define EWM_CPU_STATUS_RUNNING (0)
+#define EWM_CPU_STATUS_PAUSED  (1)
+
 struct cpu_instruction_t;
 struct ewm_lua_t;
 
@@ -62,6 +65,8 @@ struct cpu_t {
 #if defined(EWM_LUA)
    struct ewm_lua_t *lua;
 #endif
+
+   int status;
 };
 
 typedef void (*cpu_instruction_handler_t)(struct cpu_t *cpu);

src/dbg.c

@@ -20,5 +20,73 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <readline/readline.h>
+#include <readline/history.h>
+
+#include <SDL2/SDL.h>
+
+#include "cpu.h"
 #include "dbg.h"
 
+static int ewm_dbg_thread(void *object) {
+   struct ewm_dbg_t *dbg = (struct ewm_dbg_t*) object;
+   printf("Welcome to the EWM debugger\n");
+   while (1) {
+      // Wait for the CPU to pause
+      while (dbg->cpu->status == EWM_CPU_STATUS_RUNNING) {
+         // TODO Replace this with a condition variable
+      }
+
+      printf("%.4x: A=%.2x X=%.2x Y=%.2x SP=%.2x\n", dbg->cpu->state.pc, dbg->cpu->state.a,
+         dbg->cpu->state.x, dbg->cpu->state.y, dbg->cpu->state.sp);
+
+      char *line = readline("(ewm) ");
+
+      if (strcmp(line, "quit") == 0) {
+         exit(0);
+      }
+
+      if (strcmp(line, "run") == 0) {
+         ewm_dbg_continue(dbg);
+         continue;
+      }
+
+      if (strcmp(line, "br $ffef") == 0) {
+         dbg_breakpoint_set(dbg, 0xffef);
+      }
+
+      printf("Sorry I don't understand that\n");
+   }
+   return 0;
+}
+
+int ewm_dbg_start(struct ewm_dbg_t *dbg) {
+   SDL_Thread *thread = SDL_CreateThread(ewm_dbg_thread, "ewm: debugger", dbg);
+   if (thread == NULL) {
+      return -1;
+   }
+   return 0;
+}
+
+void ewm_dbg_pause(struct ewm_dbg_t *dbg) {
+   dbg->cpu->status = EWM_CPU_STATUS_PAUSED;
+}
+
+void ewm_dbg_continue(struct ewm_dbg_t *dbg) {
+   dbg->cpu->status = EWM_CPU_STATUS_RUNNING;
+}
+
+void ewm_dbg_breakpoint_set(struct ewm_dbg_t *dbg, uint16_t addr) {
+   printf("Setting breakpoint at %.4x\n", addr);
+}
+
+struct ewm_dbg_t *ewm_dbg_create(struct cpu_t *cpu) {
+   struct ewm_dbg_t *dbg = (struct ewm_dbg_t*) malloc(sizeof(struct ewm_dbg_t));
+   if (dbg != NULL) {
+      dbg->cpu = cpu;
+   }
+   return dbg;
+}

src/dbg.h

@@ -23,4 +23,18 @@
 #ifndef EWM_DBG_H
 #define EWM_DBG_H
 
+struct cpu_t;
+
+struct ewm_dbg_t {
+   struct cpu_t *cpu;
+};
+
+struct ewm_dbg_t *ewm_dbg_create(struct cpu_t *cpu);
+int ewm_dbg_start(struct ewm_dbg_t *dbg);
+
+void ewm_dbg_pause(struct ewm_dbg_t *dbg);
+void ewm_dbg_continue(struct ewm_dbg_t *dbg);
+
+void ewm_dbg_breakpoint_set(struct ewm_dbg_t *dbg, uint16_t addr);
+
 #endif // EWM_DBG_H

src/one.c

@@ -145,6 +145,10 @@ static bool ewm_one_poll_event(struct ewm_one_t *one, SDL_Window *window) {
 }
 
 static bool ewm_one_step_cpu(struct ewm_one_t *one, int cycles) {
+   if (one->cpu->status == EWM_CPU_STATUS_PAUSED) {
+      return true;
+   }
+
    while (true) {
       int ret = cpu_step(one->cpu);
       if (ret < 0) {
@@ -305,9 +309,17 @@ int ewm_one_main(int argc, char **argv) {
 
    cpu_strict(one->cpu, strict);
    cpu_trace(one->cpu, trace_path);
-
    cpu_reset(one->cpu);
 
+   if (debug_port != 0) {
+      struct ewm_dbg_t *dbg = ewm_dbg_create(one->cpu);
+      ewm_dbg_pause(dbg);
+      if (ewm_dbg_start(dbg) != 0) {
+         printf("ewm: one: failed to start debugger\n");
+         exit(1);
+      }
+   }
+
    // Main loop
 
    SDL_StartTextInput();