refactor(core): remove cyclic depenendency - ensure display compatibility

diff --git a/core/embed/io/display/stm32f4/compatibility.c b/core/embed/io/display/stm32f4/compatibility.c
new file mode 100644
index 00000000..b4db7001
--- /dev/null
+++ b/core/embed/io/display/stm32f4/compatibility.c
@@ -0,0 +1,43 @@
+/*
+ * This file is part of the Trezor project, https://trezor.io/
+ *
+ * Copyright (c) SatoshiLabs
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef KERNEL_MODE
+
+#include <trezor_bsp.h>
+#include <trezor_model.h>
+
+#include <io/display.h>
+#include <sys/bootutils.h>
+
+void ensure_compatible_display_settings_for_bootloader(void) {
+  // We are going to jump directly to the bootloader, so we need to
+  // ensure that the device is in a compatible state. Following lines
+  // ensure the display is properly deinitialized, CPU frequency is
+  // properly set and we are running in privileged thread mode.
+  display_deinit(DISPLAY_RESET_CONTENT);
+}
+
+void ensure_compatible_display_settings(void) {
+  // Ensure the display is properly deinitialized, CPU frequency is
+  // properly set. It's needed for backward compatibility with the older
+  // firmware.
+  display_deinit(DISPLAY_JUMP_BEHAVIOR);
+}
+
+#endif  // KERNEL_MODE
diff --git a/core/embed/sys/startup/inc/sys/bootutils.h b/core/embed/sys/startup/inc/sys/bootutils.h
index 9d523026..752aac2b 100644
--- a/core/embed/sys/startup/inc/sys/bootutils.h
+++ b/core/embed/sys/startup/inc/sys/bootutils.h
@@ -93,3 +93,13 @@ void __attribute__((noreturn)) reboot_or_halt_after_rsod(void);
 // memory and registers that could contain sensitive information.
 void __attribute__((noreturn)) jump_to_next_stage(uint32_t vectbl_address,
                                                   const startup_args_t *args);
+
+// Ensures the device is in a compatible state before jumping to the next stage.
+// This function is used to ensure backward compatibility with older versions of
+// released bootloaders and firmware. Implementation is platform dependand.
+void ensure_compatible_display_settings_for_bootloader(void);
+
+// Ensures the device is in a compatible state before jumping to to kernel.
+// This function is used to ensure backward compatibility with older versions of
+// released bootloaders and firmware. Implementation is platform dependand.
+void ensure_compatible_display_settings(void);
diff --git a/core/embed/sys/startup/inc/sys/sysutils.h b/core/embed/sys/startup/inc/sys/sysutils.h
index d79f8bca..45b9c3fb 100644
--- a/core/embed/sys/startup/inc/sys/sysutils.h
+++ b/core/embed/sys/startup/inc/sys/sysutils.h
@@ -48,13 +48,13 @@ __attribute((noreturn)) void call_with_new_stack(uint32_t arg1, uint32_t arg2,
 //    error_handler callback that draws an RSOD screen.
 void ensure_thread_mode(void);
 
-// Ensure compatible hardware settings before jumping to
+// Ensure compatible core clock settings before jumping to
 // the different booting stage. This function is used to
 // ensure backward compatibility with older versions of
 // released bootloaders and firmware.
 //
 // Does nothing on almost all platforms.
-void ensure_compatible_settings(void);
+void ensure_compatible_core_clock(void);
 
 // Clears USB peripheral fifo memory
 //
diff --git a/core/embed/sys/startup/stm32/bootutils.c b/core/embed/sys/startup/stm32/bootutils.c
index c55aa8c9..a6cfc234 100644
--- a/core/embed/sys/startup/stm32/bootutils.c
+++ b/core/embed/sys/startup/stm32/bootutils.c
@@ -32,10 +32,6 @@
 #include <sys/systick.h>
 #include <sys/sysutils.h>
 
-#ifdef STM32F4
-#include <io/display.h>
-#endif
-
 // Battery powered devices (USE_POWER_MANAGER) should not stall
 // after showing RSOD, as it would drain the battery.
 #ifdef USE_POWER_MANAGER
@@ -190,11 +186,10 @@ __attribute__((noreturn)) static void reboot_with_args(boot_command_t command,
 
 #ifdef STM32F4
   // We are going to jump directly to the bootloader, so we need to
-  // ensure that the device is in a compatible state. Following lines
-  // ensure the display is properly deinitialized, CPU frequency is
-  // properly set and we are running in privileged thread mode.
-  display_deinit(DISPLAY_RESET_CONTENT);
-  ensure_compatible_settings();
+  // ensure that the device is in a compatible state.
+  ensure_compatible_display_settings_for_bootloader();
+  ensure_compatible_core_clock();
+  // Ensure the device is running in privileged thread mode.
   ensure_thread_mode();
 #endif
 
@@ -274,10 +269,10 @@ void __attribute__((noreturn)) jump_to_next_stage(uint32_t vectbl_address,
                                                   const startup_args_t* args) {
 #ifdef STM32F4
   // Ensure the display is properly deinitialized, CPU frequency is
-  // properly set. It's needed for backward compatibility with the older
+  // properly set. This is needed for backward compatibility with the older
   // firmware.
-  display_deinit(DISPLAY_JUMP_BEHAVIOR);
-  ensure_compatible_settings();
+  ensure_compatible_display_settings();
+  ensure_compatible_core_clock();
 #endif
 
   // Disable interrupts, MPU, clear all registers and set up a new stack
diff --git a/core/embed/sys/startup/stm32/sysutils.c b/core/embed/sys/startup/stm32/sysutils.c
index 9c732ee4..324f2a79 100644
--- a/core/embed/sys/startup/stm32/sysutils.c
+++ b/core/embed/sys/startup/stm32/sysutils.c
@@ -219,7 +219,7 @@ __attribute((used)) void clear_otg_hs_memory(void) {
 #endif
 }
 
-void ensure_compatible_settings(void) {
+void ensure_compatible_core_clock(void) {
 #ifdef TREZOR_MODEL_T2T1
   // Early version of bootloader on T2T1 expects 168 MHz core clock.
   // So we need to set it here before handover to the bootloader.
diff --git a/core/site_scons/models/D001/discovery.py b/core/site_scons/models/D001/discovery.py
index 813948dd..3e19cf51 100644
--- a/core/site_scons/models/D001/discovery.py
+++ b/core/site_scons/models/D001/discovery.py
@@ -47,6 +47,7 @@ def configure(
 
     if "display" in features_wanted:
         sources += [
+            "embed/io/display/stm32f4/compatibility.c",
             "embed/io/display/stm32f429i-disc1/display_driver.c",
             "embed/io/display/stm32f429i-disc1/display_ltdc.c",
             "embed/io/display/stm32f429i-disc1/ili9341_spi.c",
diff --git a/core/site_scons/models/T2B1/trezor_r_v10.py b/core/site_scons/models/T2B1/trezor_r_v10.py
index 945b4f1e..ddad65a6 100644
--- a/core/site_scons/models/T2B1/trezor_r_v10.py
+++ b/core/site_scons/models/T2B1/trezor_r_v10.py
@@ -59,7 +59,10 @@ def configure(
     defines += [("USE_SECRET_KEYS", "1")]
 
     if "display" in features_wanted:
-        sources += ["embed/io/display/vg-2864/display_driver.c"]
+        sources += [
+            "embed/io/display/stm32f4/compatibility.c",
+            "embed/io/display/vg-2864/display_driver.c",
+        ]
         paths += ["embed/io/display/inc"]
         defines += [("USE_DISPLAY", "1")]
 
diff --git a/core/site_scons/models/T2T1/trezor_t.py b/core/site_scons/models/T2T1/trezor_t.py
index c56b2b70..eb64ded9 100644
--- a/core/site_scons/models/T2T1/trezor_t.py
+++ b/core/site_scons/models/T2T1/trezor_t.py
@@ -54,6 +54,7 @@ def configure(
     defines += [("USE_SECRET_KEYS", "1")]
 
     if "display" in features_wanted:
+        sources += ["embed/io/display/stm32f4/compatibility.c"]
         sources += ["embed/io/display/st-7789/display_nofb.c"]
         sources += ["embed/io/display/st-7789/display_driver.c"]
         sources += ["embed/io/display/st-7789/display_io.c"]