From c1652c34b0acd551850936b82ff42f3ab2db5367 Mon Sep 17 00:00:00 2001
From: jn <jn@ccc.ac>
Date: Thu, 26 Jan 2023 22:21:35 +0100
Subject: [PATCH 1/2] Initialize VM state and scan arguments before
 initializing SDL

---
 src/main.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/main.c b/src/main.c
index 68878e2..ad74fe9 100644
--- a/src/main.c
+++ b/src/main.c
@@ -40,13 +40,6 @@ void main_loop(void);
 void load_rom(const char *filename);
 
 int main(int argc, char *argv[]) {
-    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
-        fprintf(stderr, "unable to initialize SDL: %s", SDL_GetError());
-        return 1;
-    }
-
-    SDL_ShowCursor(SDL_DISABLE);
-
     fox32_init(&vm);
     vm.io_read = bus_io_read;
     vm.io_write = bus_io_write;
@@ -90,6 +83,12 @@ int main(int argc, char *argv[]) {
             return 1;
         }
     }
+    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
+        fprintf(stderr, "unable to initialize SDL: %s", SDL_GetError());
+        return 1;
+    }
+
+    SDL_ShowCursor(SDL_DISABLE);
 
     ScreenCreate(
         FRAMEBUFFER_WIDTH, FRAMEBUFFER_HEIGHT,

From 17f452bacf8092e98e1f08bd352822bac62c87a6 Mon Sep 17 00:00:00 2001
From: jn <jn@ccc.ac>
Date: Fri, 20 Jan 2023 20:07:34 +0100
Subject: [PATCH 2/2] Add headless mode

---
 src/cpu.h  |  1 +
 src/main.c | 47 +++++++++++++++++++++++++++--------------------
 2 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/src/cpu.h b/src/cpu.h
index ce9874d..edb3c2c 100644
--- a/src/cpu.h
+++ b/src/cpu.h
@@ -58,6 +58,7 @@ typedef struct {
     bool halted;
 
     bool debug;
+    bool headless;
 
     bool mmu_enabled;
 
diff --git a/src/main.c b/src/main.c
index ad74fe9..d08e84a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -58,6 +58,7 @@ int main(int argc, char *argv[]) {
                     "  --disk DISK    Specify a disk image to use\n"
                     "  --rom ROM      Specify a ROM image to use\n"
                     "  --debug        Enable debug output\n"
+                    "  --headless     Headless mode: don't open a window\n"
                    , argv[0]);
             return 0;
         } else if (strcmp(argv[i], "--disk") == 0) {
@@ -78,32 +79,37 @@ int main(int argc, char *argv[]) {
             }
         } else if (strcmp(argv[i], "--debug") == 0) {
             vm.debug = true;
+        } else if (strcmp(argv[i], "--headless") == 0) {
+            vm.headless = true;
         } else {
             fprintf(stderr, "unrecognized option %s\n", argv[i]);
             return 1;
         }
     }
-    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
-        fprintf(stderr, "unable to initialize SDL: %s", SDL_GetError());
-        return 1;
+
+    if (!vm.headless) {
+        if (SDL_Init(SDL_INIT_VIDEO) != 0) {
+            fprintf(stderr, "unable to initialize SDL: %s", SDL_GetError());
+            return 1;
+        }
+
+        SDL_ShowCursor(SDL_DISABLE);
+
+        ScreenCreate(
+            FRAMEBUFFER_WIDTH, FRAMEBUFFER_HEIGHT,
+            draw_framebuffer,
+            key_pressed,
+            key_released,
+            mouse_pressed,
+            mouse_released,
+            mouse_moved,
+            drop_file
+        );
+
+        ScreenInit();
+        ScreenDraw();
     }
 
-    SDL_ShowCursor(SDL_DISABLE);
-
-    ScreenCreate(
-        FRAMEBUFFER_WIDTH, FRAMEBUFFER_HEIGHT,
-        draw_framebuffer,
-        key_pressed,
-        key_released,
-        mouse_pressed,
-        mouse_released,
-        mouse_moved,
-        drop_file
-    );
-
-    ScreenInit();
-    ScreenDraw();
-
     tick_start = SDL_GetTicks();
     tick_end = SDL_GetTicks();
 
@@ -158,7 +164,8 @@ void main_loop(void) {
     }
 
     if ((ticks % TPF) == 0) {
-        ScreenDraw();
+        if (!vm.headless)
+            ScreenDraw();
         fox32_raise(&vm, VSYNC_INTERRUPT_VECTOR);
         vm.halted = false;
     }