refactor(core): do not use framebuffer dma copy in boardloader to safe flash space

[no changelog]

core/embed/trezorhal/stm32f4/displays/st7789v.c

@@ -65,7 +65,9 @@ __IO DISP_MEM_TYPE *const DISPLAY_DATA_ADDRESS =
 #error Framebuffer only supported on STM32U5 for now
 #endif
 
+#ifndef BOARDLOADER
 #include "bg_copy.h"
+#endif
 
 #define DATA_TRANSFER(X) \
   DATA((X)&0xFF);        \
@@ -79,6 +81,10 @@ ALIGN_32BYTES(static uint16_t PhysFrameBuffer1[DISPLAY_RESX * DISPLAY_RESY]);
 __attribute__((
     section(".framebuffer_select"))) static uint32_t act_frame_buffer = 0;
 
+#ifndef BOARDLOADER
+static bool pending_fb_switch = false;
+#endif
+
 static uint16_t window_x0 = 0;
 static uint16_t window_y0 = 0;
 static uint16_t window_x1 = 0;
@@ -247,11 +253,13 @@ int display_get_orientation(void) { return DISPLAY_ORIENTATION; }
 
 int display_backlight(int val) {
 #ifdef FRAMEBUFFER
+#ifndef BOARDLOADER
   // wait for DMA transfer to finish before changing backlight
   // so that we know that panel has current data
   if (backlight_pwm_get() != val && !is_mode_handler()) {
     bg_copy_wait();
   }
+#endif
 #endif
 
   return backlight_pwm_set(val);
@@ -515,6 +523,7 @@ void display_pixeldata(uint16_t c) {
 
 void display_sync(void) {}
 
+#ifndef BOARDLOADER
 void DISPLAY_TE_INTERRUPT_HANDLER(void) {
   HAL_NVIC_DisableIRQ(DISPLAY_TE_INTERRUPT_NUM);
 
@@ -529,53 +538,78 @@ void DISPLAY_TE_INTERRUPT_HANDLER(void) {
                               DISPLAY_RESX * DISPLAY_RESY * 2);
   }
 
+  pending_fb_switch = false;
   __HAL_GPIO_EXTI_CLEAR_FLAG(DISPLAY_TE_PIN);
 }
 
-void display_refresh(void) {
+static void wait_for_fb_switch(void) {
+  while (pending_fb_switch) {
+    __WFI();
+  }
   bg_copy_wait();
+}
+#endif
 
-  if (is_mode_handler()) {
-    // sync with the panel refresh
-    while (GPIO_PIN_SET == HAL_GPIO_ReadPin(DISPLAY_TE_PORT, DISPLAY_TE_PIN)) {
-    }
-    while (GPIO_PIN_RESET ==
-           HAL_GPIO_ReadPin(DISPLAY_TE_PORT, DISPLAY_TE_PIN)) {
-    }
+static void copy_fb_to_display(uint16_t *fb) {
+  for (int i = 0; i < DISPLAY_RESX * DISPLAY_RESY; i++) {
+    // 2 bytes per pixel because we're using RGB 5-6-5 format
+    DATA_TRANSFER(fb[i]);
+  }
+}
 
-    if (act_frame_buffer == 0) {
-      act_frame_buffer = 1;
-      for (int i = 0; i < DISPLAY_RESX * DISPLAY_RESY; i++) {
-        // 2 bytes per pixel because we're using RGB 5-6-5 format
-        DATA_TRANSFER(PhysFrameBuffer1[i]);
-      }
-      memcpy(PhysFrameBuffer0, PhysFrameBuffer1, sizeof(PhysFrameBuffer1));
+static void switch_fb_manually(void) {
+  // sync with the panel refresh
+  while (GPIO_PIN_SET == HAL_GPIO_ReadPin(DISPLAY_TE_PORT, DISPLAY_TE_PIN)) {
+  }
+  while (GPIO_PIN_RESET == HAL_GPIO_ReadPin(DISPLAY_TE_PORT, DISPLAY_TE_PIN)) {
+  }
+
+  if (act_frame_buffer == 0) {
+    act_frame_buffer = 1;
+    copy_fb_to_display(PhysFrameBuffer1);
+    memcpy(PhysFrameBuffer0, PhysFrameBuffer1, sizeof(PhysFrameBuffer1));
 
-    } else {
-      act_frame_buffer = 0;
-      for (int i = 0; i < DISPLAY_RESX * DISPLAY_RESY; i++) {
-        // 2 bytes per pixel because we're using RGB 5-6-5 format
-        DATA_TRANSFER(PhysFrameBuffer0[i]);
-      }
-      memcpy(PhysFrameBuffer1, PhysFrameBuffer0, sizeof(PhysFrameBuffer1));
-    }
   } else {
-    if (act_frame_buffer == 0) {
-      act_frame_buffer = 1;
+    act_frame_buffer = 0;
+    copy_fb_to_display(PhysFrameBuffer0);
+    memcpy(PhysFrameBuffer1, PhysFrameBuffer0, sizeof(PhysFrameBuffer1));
+  }
+}
 
-      memcpy(PhysFrameBuffer0, PhysFrameBuffer1, sizeof(PhysFrameBuffer1));
+#ifndef BOARDLOADER
+static void switch_fb_in_backround(void) {
+  if (act_frame_buffer == 0) {
+    act_frame_buffer = 1;
 
-      __HAL_GPIO_EXTI_CLEAR_FLAG(DISPLAY_TE_PIN);
-      svc_enableIRQ(DISPLAY_TE_INTERRUPT_NUM);
-    } else {
-      act_frame_buffer = 0;
-      memcpy(PhysFrameBuffer1, PhysFrameBuffer0, sizeof(PhysFrameBuffer1));
+    memcpy(PhysFrameBuffer0, PhysFrameBuffer1, sizeof(PhysFrameBuffer1));
 
-      __HAL_GPIO_EXTI_CLEAR_FLAG(DISPLAY_TE_PIN);
-      svc_enableIRQ(DISPLAY_TE_INTERRUPT_NUM);
-    }
+    pending_fb_switch = true;
+    __HAL_GPIO_EXTI_CLEAR_FLAG(DISPLAY_TE_PIN);
+    svc_enableIRQ(DISPLAY_TE_INTERRUPT_NUM);
+  } else {
+    act_frame_buffer = 0;
+    memcpy(PhysFrameBuffer1, PhysFrameBuffer0, sizeof(PhysFrameBuffer1));
+
+    pending_fb_switch = true;
+    __HAL_GPIO_EXTI_CLEAR_FLAG(DISPLAY_TE_PIN);
+    svc_enableIRQ(DISPLAY_TE_INTERRUPT_NUM);
   }
 }
+#endif
+
+void display_refresh(void) {
+#ifndef BOARDLOADER
+  wait_for_fb_switch();
+
+  if (is_mode_handler()) {
+    switch_fb_manually();
+  } else {
+    switch_fb_in_backround();
+  }
+#else
+  switch_fb_manually();
+#endif
+}
 
 void display_set_window(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1) {
   window_x0 = x0;
@@ -646,7 +680,11 @@ void display_efficient_clear(void) {
   memzero(PhysFrameBuffer0, sizeof(PhysFrameBuffer0));
 }
 
-void display_finish_actions(void) { bg_copy_wait(); }
+void display_finish_actions(void) {
+#ifndef BOARDLOADER
+  bg_copy_wait();
+#endif
+}
 #else
 //  NOT FRAMEBUFFER
 

core/site_scons/boards/trezor_t3t1_v4.py

@@ -41,12 +41,15 @@ def configure(
         "embed/models/model_T3T1_layout.c",
     ]
     sources += [f"embed/trezorhal/stm32u5/displays/{display}"]
-    sources += [f"embed/trezorhal/stm32u5/bg_copy.c"]
     sources += ["embed/trezorhal/stm32u5/backlight_pwm.c"]
     sources += [
         "embed/trezorhal/stm32u5/displays/panels/lx154a2422.c",
     ]
 
+    env_constraints = env.get("CONSTRAINTS")
+    if not (env_constraints and "limited_util_s" in env_constraints):
+        sources += ["embed/trezorhal/stm32u5/bg_copy.c"]
+
     features_available.append("backlight")
 
     if "input" in features_wanted: