refactor(core/embed): add initialized flag to display drivers

[no changelog]

core/embed/trezorhal/stm32f4/xdisplay/st-7789/display_driver.c

@@ -41,10 +41,17 @@
 #endif
 
 // Display driver instance
-display_driver_t g_display_driver;
+display_driver_t g_display_driver = {
+    .initialized = false,
+};
 
 void display_init(display_content_mode_t mode) {
   display_driver_t* drv = &g_display_driver;
+
+  if (drv->initialized) {
+    return;
+  }
+
   memset(drv, 0, sizeof(display_driver_t));
 
   if (mode == DISPLAY_RESET_CONTENT) {
@@ -67,9 +74,17 @@ void display_init(display_content_mode_t mode) {
 #ifdef XFRAMEBUFFER
   display_io_init_te_interrupt();
 #endif
+
+  drv->initialized = true;
 }
 
 void display_deinit(display_content_mode_t mode) {
+  display_driver_t* drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    return;
+  }
+
 #ifdef XFRAMEBUFFER
 #ifndef BOARDLOADER
   // Ensure that the ready frame buffer is transfered to
@@ -80,7 +95,8 @@ void display_deinit(display_content_mode_t mode) {
 #endif
 #endif
 
-  backlight_pwm_deinit(mode == DISPLAY_RESET_CONTENT ? BACKLIGHT_RESET : BACKLIGHT_RETAIN);
+  backlight_pwm_deinit(mode == DISPLAY_RESET_CONTENT ? BACKLIGHT_RESET
+                                                     : BACKLIGHT_RETAIN);
 
 #ifdef TREZOR_MODEL_T
   // This ensures backward compatibility with legacy bootloader/firmware
@@ -90,9 +106,17 @@ void display_deinit(display_content_mode_t mode) {
   }
   display_panel_set_big_endian();
 #endif
+
+  drv->initialized = false;
 }
 
 int display_set_backlight(int level) {
+  display_driver_t* drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    return 0;
+  }
+
 #ifdef XFRAMEBUFFER
 #ifndef BOARDLOADER
   // if turning on the backlight, wait until the panel is refreshed
@@ -110,6 +134,10 @@ int display_get_backlight(void) { return backlight_pwm_get(); }
 int display_set_orientation(int angle) {
   display_driver_t* drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   if (angle != drv->orientation_angle) {
     if (angle == 0 || angle == 90 || angle == 180 || angle == 270) {
       drv->orientation_angle = angle;
@@ -135,5 +163,9 @@ int display_set_orientation(int angle) {
 int display_get_orientation(void) {
   display_driver_t* drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->orientation_angle;
 }

core/embed/trezorhal/stm32f4/xdisplay/st-7789/display_fb.c

@@ -139,6 +139,14 @@ void DISPLAY_TE_INTERRUPT_HANDLER(void) {
 display_fb_info_t display_get_frame_buffer(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    display_fb_info_t fb = {
+        .ptr = NULL,
+        .stride = 0,
+    };
+    return fb;
+  }
+
   frame_buffer_state_t state;
 
   // We have to wait if the buffer was passed for copying
@@ -191,6 +199,10 @@ static void wait_for_te_signal(void) {
 void display_refresh(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   if (drv->queue.entry[drv->queue.wix] != FB_STATE_PREPARING) {
     // No refresh needed as the frame buffer is not in
     // the state to be copied to the display
@@ -234,6 +246,10 @@ void display_ensure_refreshed(void) {
 #ifndef BOARDLOADER
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   if (!is_mode_handler()) {
     bool copy_pending;
 
@@ -265,6 +281,10 @@ void display_ensure_refreshed(void) {
 void display_fill(const gfx_bitblt_t *bb) {
   display_fb_info_t fb = display_get_frame_buffer();
 
+  if (fb.ptr == NULL) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = (uint16_t *)((uintptr_t)fb.ptr + fb.stride * bb_new.dst_y);
   bb_new.dst_stride = fb.stride;
@@ -275,6 +295,10 @@ void display_fill(const gfx_bitblt_t *bb) {
 void display_copy_rgb565(const gfx_bitblt_t *bb) {
   display_fb_info_t fb = display_get_frame_buffer();
 
+  if (fb.ptr == NULL) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = (uint16_t *)((uintptr_t)fb.ptr + fb.stride * bb_new.dst_y);
   bb_new.dst_stride = fb.stride;
@@ -285,6 +309,10 @@ void display_copy_rgb565(const gfx_bitblt_t *bb) {
 void display_copy_mono1p(const gfx_bitblt_t *bb) {
   display_fb_info_t fb = display_get_frame_buffer();
 
+  if (fb.ptr == NULL) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = (uint16_t *)((uintptr_t)fb.ptr + fb.stride * bb_new.dst_y);
   bb_new.dst_stride = fb.stride;
@@ -295,6 +323,10 @@ void display_copy_mono1p(const gfx_bitblt_t *bb) {
 void display_copy_mono4(const gfx_bitblt_t *bb) {
   display_fb_info_t fb = display_get_frame_buffer();
 
+  if (fb.ptr == NULL) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = (uint16_t *)((uintptr_t)fb.ptr + fb.stride * bb_new.dst_y);
   bb_new.dst_stride = fb.stride;

core/embed/trezorhal/stm32f4/xdisplay/st-7789/display_internal.h

@@ -41,6 +41,9 @@ typedef struct {
 
 // Display driver state
 typedef struct {
+  // Set if the driver is initialized
+  bool initialized;
+
 #ifdef XFRAMEBUFFER
   // Framebuffer queue
   // (accessed & updated in the context of the main thread

core/embed/trezorhal/stm32f4/xdisplay/stm32f429i-disc1/display_driver.c

@@ -33,6 +33,8 @@
 
 // Display driver context.
 typedef struct {
+  // Set if the driver is initialized
+  bool initialized;
   // Pointer to the frame buffer
   uint16_t *framebuf;
   // Current display orientation (0, 90, 180, 270)
@@ -42,10 +44,17 @@ typedef struct {
 } display_driver_t;
 
 // Display driver instance
-static display_driver_t g_display_driver;
+static display_driver_t g_display_driver = {
+    .initialized = false,
+};
 
 void display_init(display_content_mode_t mode) {
   display_driver_t *drv = &g_display_driver;
+
+  if (drv->initialized) {
+    return;
+  }
+
   memset(drv, 0, sizeof(display_driver_t));
   drv->framebuf = (uint16_t *)FRAME_BUFFER_ADDR;
 
@@ -55,15 +64,23 @@ void display_init(display_content_mode_t mode) {
     // Initialize external display controller
     ili9341_init();
   }
+
+  drv->initialized = true;
 }
 
 void display_deinit(display_content_mode_t mode) {
-  // Not used and intentionally left empty
+  display_driver_t *drv = &g_display_driver;
+
+  drv->initialized = false;
 }
 
 int display_set_backlight(int level) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   // Just emulation, not doing anything
   drv->backlight_level = level;
   return level;
@@ -72,12 +89,20 @@ int display_set_backlight(int level) {
 int display_get_backlight(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->backlight_level;
 }
 
 int display_set_orientation(int angle) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   if (angle == 0 || angle == 90 || angle == 180 || angle == 270) {
     // Just emulation, not doing anything
     drv->orientation_angle = angle;
@@ -89,18 +114,29 @@ int display_set_orientation(int angle) {
 int display_get_orientation(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->orientation_angle;
 }
 
 display_fb_info_t display_get_frame_buffer(void) {
   display_driver_t *drv = &g_display_driver;
 
-  display_fb_info_t fb = {
-      .ptr = (void *)drv->framebuf,
-      .stride = DISPLAY_RESX * sizeof(uint16_t),
-  };
-
-  return fb;
+  if (!drv->initialized) {
+    display_fb_info_t fb = {
+        .ptr = NULL,
+        .stride = 0,
+    };
+    return fb;
+  } else {
+    display_fb_info_t fb = {
+        .ptr = (void *)drv->framebuf,
+        .stride = DISPLAY_RESX * sizeof(uint16_t),
+    };
+    return fb;
+  }
 }
 
 void display_refresh(void) {
@@ -110,6 +146,10 @@ void display_refresh(void) {
 void display_fill(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = drv->framebuf + (DISPLAY_RESX * bb_new.dst_y);
   bb_new.dst_stride = DISPLAY_RESX * sizeof(uint16_t);
@@ -120,6 +160,10 @@ void display_fill(const gfx_bitblt_t *bb) {
 void display_copy_rgb565(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = drv->framebuf + (DISPLAY_RESX * bb_new.dst_y);
   bb_new.dst_stride = DISPLAY_RESX * sizeof(uint16_t);
@@ -130,6 +174,10 @@ void display_copy_rgb565(const gfx_bitblt_t *bb) {
 void display_copy_mono1p(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = drv->framebuf + (DISPLAY_RESX * bb_new.dst_y);
   bb_new.dst_stride = DISPLAY_RESX * sizeof(uint16_t);
@@ -140,6 +188,10 @@ void display_copy_mono1p(const gfx_bitblt_t *bb) {
 void display_copy_mono4(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = drv->framebuf + (DISPLAY_RESX * bb_new.dst_y);
   bb_new.dst_stride = DISPLAY_RESX * sizeof(uint16_t);

core/embed/trezorhal/stm32f4/xdisplay/ug-2828/display_driver.c

@@ -37,6 +37,8 @@
 
 // Display driver context.
 typedef struct {
+  // Set if the driver is initialized
+  bool initialized;
   // Frame buffer (8-bit Mono)
   uint8_t framebuf[DISPLAY_RESX * DISPLAY_RESY];
   // Current display orientation (0 or 180)
@@ -46,7 +48,9 @@ typedef struct {
 } display_driver_t;
 
 // Display driver instance
-static display_driver_t g_display_driver;
+static display_driver_t g_display_driver = {
+    .initialized = false,
+};
 
 // Macros to access display parallel interface
 
@@ -179,6 +183,10 @@ static void display_set_page_and_col(uint8_t page, uint8_t col) {
 static void display_sync_with_fb(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return NULL;
+  }
+
   for (int y = 0; y < DISPLAY_RESY / 8; y++) {
     display_set_page_and_col(y, 0);
     uint8_t *src = &drv->framebuf[y * DISPLAY_RESX * 8];
@@ -293,6 +301,11 @@ static void display_init_interface(void) {
 
 void display_init(display_content_mode_t mode) {
   display_driver_t *drv = &g_display_driver;
+
+  if (drv->initialized) {
+    return;
+  }
+
   memset(drv, 0, sizeof(display_driver_t));
 
   if (mode == DISPLAY_RESET_CONTENT) {
@@ -301,15 +314,23 @@ void display_init(display_content_mode_t mode) {
     // Initialize display controller
     display_init_controller();
   }
+
+  drv->initialized = true;
 }
 
 void display_deinit(display_content_mode_t mode) {
-  // Not used and intentionally left empty
+  display_driver_t *drv = &g_display_driver;
+
+  drv->initialized = false;
 }
 
 int display_set_backlight(int level) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   if (level != drv->backlight_level) {
     if (level >= 0 && level <= 255) {
       drv->backlight_level = level;
@@ -325,12 +346,20 @@ int display_set_backlight(int level) {
 int display_get_backlight(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->backlight_level;
 }
 
 int display_set_orientation(int angle) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   if (angle != drv->orientation_angle) {
     if (angle == 0 || angle == 180) {
       drv->orientation_angle = angle;
@@ -354,25 +383,48 @@ int display_set_orientation(int angle) {
 int display_get_orientation(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->orientation_angle;
 }
 
 display_fb_info_t display_get_frame_buffer(void) {
   display_driver_t *drv = &g_display_driver;
 
-  display_fb_info_t fb = {
-      .ptr = &drv->framebuf[0],
-      .stride = DISPLAY_RESX,
-  };
-
-  return fb;
+  if (!drv->initialized) {
+    const static display_fb_info_t fb = {
+        .ptr = NULL,
+        .stride = 0,
+    };
+    return fb;
+  } else {
+    display_fb_info_t fb = {
+        .ptr = &drv->framebuf[0],
+        .stride = DISPLAY_RESX,
+    };
+    return fb;
+  }
 }
 
-void display_refresh(void) { display_sync_with_fb(); }
+void display_refresh(void) {
+  display_driver_t *drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    return NULL;
+  }
+
+  display_sync_with_fb();
+}
 
 void display_fill(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return NULL;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = &drv->framebuf[DISPLAY_RESX * bb_new.dst_y];
   bb_new.dst_stride = DISPLAY_RESX;
@@ -383,6 +435,10 @@ void display_fill(const gfx_bitblt_t *bb) {
 void display_copy_mono1p(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return NULL;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = &drv->framebuf[DISPLAY_RESX * bb_new.dst_y];
   bb_new.dst_stride = DISPLAY_RESX;

core/embed/trezorhal/stm32f4/xdisplay/vg-2864/display_driver.c

@@ -42,6 +42,8 @@
 
 // Display driver context.
 typedef struct {
+  // Set if the driver is initialized
+  bool initialized;
   // SPI driver instance
   SPI_HandleTypeDef spi;
   // Frame buffer (8-bit Mono)
@@ -53,7 +55,9 @@ typedef struct {
 } display_driver_t;
 
 // Display driver instance
-static display_driver_t g_display_driver;
+static display_driver_t g_display_driver = {
+    .initialized = false,
+};
 
 // Display controller registers
 #define OLED_SETCONTRAST 0x81
@@ -223,6 +227,10 @@ static void display_sync_with_fb(display_driver_t *drv) {
 void display_init(display_content_mode_t mode) {
   display_driver_t *drv = &g_display_driver;
 
+  if (drv->initialized) {
+    return;
+  }
+
   memset(drv, 0, sizeof(display_driver_t));
   drv->backlight_level = 255;
 
@@ -289,15 +297,23 @@ void display_init(display_content_mode_t mode) {
   } else {
     display_init_spi(drv);
   }
+
+  drv->initialized = true;
 }
 
 void display_deinit(display_content_mode_t mode) {
-  // Not used and intentionally left empty
+  display_driver_t *drv = &g_display_driver;
+
+  drv->initialized = false;
 }
 
 int display_set_backlight(int level) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   drv->backlight_level = 255;
   return drv->backlight_level;
 }
@@ -305,12 +321,20 @@ int display_set_backlight(int level) {
 int display_get_backlight(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->backlight_level;
 }
 
 int display_set_orientation(int angle) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   if (angle != drv->orientation_angle) {
     if (angle == 0 || angle == 180) {
       drv->orientation_angle = angle;
@@ -324,23 +348,38 @@ int display_set_orientation(int angle) {
 int display_get_orientation(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->orientation_angle;
 }
 
 display_fb_info_t display_get_frame_buffer(void) {
   display_driver_t *drv = &g_display_driver;
 
-  display_fb_info_t fb = {
-      .ptr = &drv->framebuf[0],
-      .stride = DISPLAY_RESX,
-  };
-
-  return fb;
+  if (!drv->initialized) {
+    static const display_fb_info_t fb = {
+        .ptr = NULL,
+        .stride = 0,
+    };
+    return fb;
+  } else {
+    display_fb_info_t fb = {
+        .ptr = &drv->framebuf[0],
+        .stride = DISPLAY_RESX,
+    };
+    return fb;
+  }
 }
 
 void display_refresh(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
 #if defined USE_CONSUMPTION_MASK && !defined BOARDLOADER
   // This is an intentional randomization of the consumption masking algorithm
   // after every change on the display
@@ -354,6 +393,10 @@ void display_refresh(void) {
 void display_fill(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = &drv->framebuf[DISPLAY_RESX * bb_new.dst_y];
   bb_new.dst_stride = DISPLAY_RESX;
@@ -364,6 +407,10 @@ void display_fill(const gfx_bitblt_t *bb) {
 void display_copy_mono1p(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = &drv->framebuf[DISPLAY_RESX * bb_new.dst_y];
   bb_new.dst_stride = DISPLAY_RESX;

core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_driver.c

@@ -30,18 +30,18 @@
 #error "Incompatible display resolution"
 #endif
 
-// Display driver context.
-typedef struct {
-  // Current display orientation (0, 90, 180, 270)
-  int orientation_angle;
-  // Current backlight level ranging from 0 to 255
-  int backlight_level;
-} display_driver_t;
-
 // Display driver instance
-static display_driver_t g_display_driver;
+display_driver_t g_display_driver = {
+    .initialized = false,
+};
 
 void display_init(display_content_mode_t mode) {
+  display_driver_t *drv = &g_display_driver;
+
+  if (drv->initialized) {
+    return;
+  }
+
   if (mode == DISPLAY_RESET_CONTENT) {
     RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
 
@@ -76,19 +76,33 @@ void display_init(display_content_mode_t mode) {
       BSP_LCD_SetFrameBuffer(0, GFXMMU_VIRTUAL_BUFFER0_BASE_S);
     }
   }
+
+  drv->initialized = true;
 }
 
 void display_deinit(display_content_mode_t mode) {
+  display_driver_t *drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    return;
+  }
+
   if (mode == DISPLAY_RESET_CONTENT) {
     BSP_LCD_DisplayOff(0);
     BSP_LCD_SetBrightness(0, 0);
     BSP_LCD_DeInit(0);
   }
+
+  drv->initialized = false;
 }
 
 int display_set_backlight(int level) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   // Just emulation, not doing anything
   drv->backlight_level = level;
   return level;
@@ -97,12 +111,20 @@ int display_set_backlight(int level) {
 int display_get_backlight(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->orientation_angle;
 }
 
 int display_set_orientation(int angle) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   if (angle == 0 || angle == 90 || angle == 180 || angle == 270) {
     // Just emulation, not doing anything
     drv->orientation_angle = angle;
@@ -114,12 +136,20 @@ int display_set_orientation(int angle) {
 int display_get_orientation(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->orientation_angle;
 }
 
 void display_fill(const gfx_bitblt_t *bb) {
   display_fb_info_t fb = display_get_frame_buffer();
 
+  if (fb.ptr == NULL) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = (uint8_t *)fb.ptr + (fb.stride * bb_new.dst_y);
   bb_new.dst_stride = fb.stride;
@@ -130,6 +160,10 @@ void display_fill(const gfx_bitblt_t *bb) {
 void display_copy_rgb565(const gfx_bitblt_t *bb) {
   display_fb_info_t fb = display_get_frame_buffer();
 
+  if (fb.ptr == NULL) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = (uint8_t *)fb.ptr + (fb.stride * bb_new.dst_y);
   bb_new.dst_stride = fb.stride;
@@ -140,6 +174,10 @@ void display_copy_rgb565(const gfx_bitblt_t *bb) {
 void display_copy_mono1p(const gfx_bitblt_t *bb) {
   display_fb_info_t fb = display_get_frame_buffer();
 
+  if (fb.ptr == NULL) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = (uint8_t *)fb.ptr + (fb.stride * bb_new.dst_y);
   bb_new.dst_stride = fb.stride;
@@ -150,6 +188,10 @@ void display_copy_mono1p(const gfx_bitblt_t *bb) {
 void display_copy_mono4(const gfx_bitblt_t *bb) {
   display_fb_info_t fb = display_get_frame_buffer();
 
+  if (fb.ptr == NULL) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = (uint8_t *)fb.ptr + (fb.stride * bb_new.dst_y);
   bb_new.dst_stride = fb.stride;

core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_fb.c

@@ -39,6 +39,16 @@ __attribute__((section(".framebuffer_select"))) uint32_t current_frame_buffer =
     0;
 
 display_fb_info_t display_get_frame_buffer(void) {
+  display_driver_t *drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    display_fb_info_t fb = {
+        .ptr = NULL,
+        .stride = 0,
+    };
+    return fb;
+  }
+
   uintptr_t addr;
 
   if (current_frame_buffer == 0) {
@@ -63,6 +73,12 @@ display_fb_info_t display_get_frame_buffer(void) {
 }
 
 void display_refresh(void) {
+  display_driver_t *drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    return;
+  }
+
   if (current_frame_buffer == 0) {
     current_frame_buffer = 1;
     BSP_LCD_SetFrameBuffer(0, GFXMMU_VIRTUAL_BUFFER1_BASE_S);

core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_internal.h

@@ -20,8 +20,22 @@
 #ifndef TREZOR_HAL_DISPLAY_INTERNAL_H
 #define TREZOR_HAL_DISPLAY_INTERNAL_H
 
+#include <stdbool.h>
 #include <stdint.h>
 
+// Display driver context.
+typedef struct {
+  // Set if the driver is initialized
+  bool initialized;
+  // Current display orientation (0, 90, 180, 270)
+  int orientation_angle;
+  // Current backlight level ranging from 0 to 255
+  int backlight_level;
+} display_driver_t;
+
+// Display driver instance
+extern display_driver_t g_display_driver;
+
 // Size of the physical frame buffer in bytes
 //
 // It's smaller than size of the virtual frame buffer

core/embed/trezorhal/unix/display_driver.c

@@ -32,6 +32,8 @@
 #define EMULATOR_BORDER 16
 
 typedef struct {
+  // Set if the driver is initialized
+  bool initialized;
   // Current display orientation (0 or 180)
   int orientation_angle;
   // Current backlight level ranging from 0 to 255
@@ -52,7 +54,9 @@ typedef struct {
 
 } display_driver_t;
 
-static display_driver_t g_display_driver;
+static display_driver_t g_display_driver = {
+    .initialized = false,
+};
 
 //!@# TODO get rid of this...
 int sdl_display_res_x = DISPLAY_RESX, sdl_display_res_y = DISPLAY_RESY;
@@ -65,6 +69,10 @@ static void display_exit_handler(void) {
 void display_init(display_content_mode_t mode) {
   display_driver_t *drv = &g_display_driver;
 
+  if (drv->initialized) {
+    return;
+  }
+
   if (SDL_Init(SDL_INIT_VIDEO) != 0) {
     printf("%s\n", SDL_GetError());
     error_shutdown("SDL_Init error");
@@ -144,11 +152,16 @@ void display_init(display_content_mode_t mode) {
 #else
   drv->orientation_angle = 0;
 #endif
+  drv->initialized = true;
 }
 
 void display_deinit(display_content_mode_t mode) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   SDL_FreeSurface(drv->prev_saved);
   SDL_FreeSurface(drv->buffer);
   if (drv->background != NULL) {
@@ -164,11 +177,17 @@ void display_deinit(display_content_mode_t mode) {
     SDL_DestroyWindow(drv->window);
   }
   SDL_Quit();
+
+  drv->initialized = false;
 }
 
 int display_set_backlight(int level) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return 0;
+  }
+
 #if !USE_BACKLIGHT
   level = 255;
 #endif
@@ -183,11 +202,21 @@ int display_set_backlight(int level) {
 
 int display_get_backlight(void) {
   display_driver_t *drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->backlight_level;
 }
 
 int display_set_orientation(int angle) {
   display_driver_t *drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    return 0;
+  }
+
   if (angle != drv->orientation_angle) {
 #if defined ORIENTATION_NSEW
     if (angle == 0 || angle == 90 || angle == 180 || angle == 270) {
@@ -205,6 +234,11 @@ int display_set_orientation(int angle) {
 
 int display_get_orientation(void) {
   display_driver_t *drv = &g_display_driver;
+
+  if (!drv->initialized) {
+    return 0;
+  }
+
   return drv->orientation_angle;
 }
 
@@ -212,25 +246,32 @@ int display_get_orientation(void) {
 display_fb_info_t display_get_frame_buffer(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    display_fb_info_t fb = {
+        .ptr = NULL,
+        .stride = 0,
+    };
+    return fb;
+  } else {
 #ifdef DISPLAY_MONO
-  display_fb_info_t fb = {
-      .ptr = drv->mono_framebuf,
-      .stride = DISPLAY_RESX,
-  };
+    display_fb_info_t fb = {
+        .ptr = drv->mono_framebuf,
+        .stride = DISPLAY_RESX,
+    };
 #else
-  display_fb_info_t fb = {
-      .ptr = drv->buffer->pixels,
-      .stride = DISPLAY_RESX * sizeof(uint16_t),
-  };
+    display_fb_info_t fb = {
+        .ptr = drv->buffer->pixels,
+        .stride = DISPLAY_RESX * sizeof(uint16_t),
+    };
 #endif
-
-  return fb;
+    return fb;
+  }
 }
 
 #else  // XFRAMEBUFFER
 
 void display_wait_for_sync(void) {
-  // not used
+  // not implemented in the emulator
 }
 #endif
 
@@ -253,7 +294,7 @@ static void copy_mono_framebuf(display_driver_t *drv) {
 void display_refresh(void) {
   display_driver_t *drv = &g_display_driver;
 
-  if (!drv->renderer) {
+  if (!drv->initialized) {
     return;
   }
 
@@ -292,6 +333,10 @@ void display_refresh(void) {
 void display_fill(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row =
       (uint8_t *)drv->buffer->pixels + (drv->buffer->pitch * bb_new.dst_y);
@@ -303,6 +348,10 @@ void display_fill(const gfx_bitblt_t *bb) {
 void display_copy_rgb565(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row =
       (uint8_t *)drv->buffer->pixels + (drv->buffer->pitch * bb_new.dst_y);
@@ -314,6 +363,10 @@ void display_copy_rgb565(const gfx_bitblt_t *bb) {
 void display_copy_mono1p(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row =
       (uint8_t *)drv->buffer->pixels + (drv->buffer->pitch * bb_new.dst_y);
@@ -325,6 +378,10 @@ void display_copy_mono1p(const gfx_bitblt_t *bb) {
 void display_copy_mono4(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row =
       (uint8_t *)drv->buffer->pixels + (drv->buffer->pitch * bb_new.dst_y);
@@ -338,6 +395,10 @@ void display_copy_mono4(const gfx_bitblt_t *bb) {
 void display_fill(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = drv->mono_framebuf + (DISPLAY_RESX * bb_new.dst_y);
   bb_new.dst_stride = DISPLAY_RESX;
@@ -348,6 +409,10 @@ void display_fill(const gfx_bitblt_t *bb) {
 void display_copy_mono1p(const gfx_bitblt_t *bb) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   gfx_bitblt_t bb_new = *bb;
   bb_new.dst_row = drv->mono_framebuf + (DISPLAY_RESX * bb_new.dst_y);
   bb_new.dst_stride = DISPLAY_RESX;
@@ -360,7 +425,7 @@ void display_copy_mono1p(const gfx_bitblt_t *bb) {
 const char *display_save(const char *prefix) {
   display_driver_t *drv = &g_display_driver;
 
-  if (!drv->renderer) {
+  if (!drv->initialized) {
     return NULL;
   }
 
@@ -396,6 +461,10 @@ const char *display_save(const char *prefix) {
 void display_clear_save(void) {
   display_driver_t *drv = &g_display_driver;
 
+  if (!drv->initialized) {
+    return;
+  }
+
   SDL_FreeSurface(drv->prev_saved);
   drv->prev_saved = NULL;
 }