port communication_mode to Rust

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 8eade8e..ab2af1c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -124,7 +124,6 @@ set(QTOUCH-SOURCES ${QTOUCH-SOURCES} PARENT_SCOPE)
 
 # The additional files required for the plus platform
 set(PLATFORM-BITBOX02-PLUS-SOURCES
-  ${CMAKE_SOURCE_DIR}/src/communication_mode.c
   ${CMAKE_SOURCE_DIR}/src/da14531/crc.c
   ${CMAKE_SOURCE_DIR}/src/da14531/da14531.c
   ${CMAKE_SOURCE_DIR}/src/da14531/da14531_protocol.c
diff --git a/src/bootloader/bootloader.c b/src/bootloader/bootloader.c
index ff4cc40..23b18ba 100644
--- a/src/bootloader/bootloader.c
+++ b/src/bootloader/bootloader.c
@@ -11,6 +11,7 @@
 #include <memory/memory_shared.h>
 #include <memory/nvmctrl.h>
 #include <pukcc/curve_p256.h>
+#include <rust/rust.h>
 #include <screen.h>
 #include <stdint.h>
 #include <string.h>
@@ -30,7 +31,6 @@
 #endif
 
 #if PLATFORM_BITBOX02PLUS == 1
-    #include <communication_mode.h>
     #include <da14531/da14531.h>
     #include <da14531/da14531_protocol.h>
     #include <uart.h>
@@ -328,7 +328,7 @@ void bootloader_render_default_screen(void)
     _load_logo();
 #if PLATFORM_BITBOX02PLUS == 1
     UG_PutString(0, SCREEN_HEIGHT - 9 * 2 - 5, "See the BitBoxApp", false);
-    if (communication_mode_ble_enabled() &&
+    if (rust_communication_mode_ble_enabled() &&
         da14531_connected_state < DA14531_CONNECTED_CONNECTED_SECURED) {
         char buf[MEMORY_DEVICE_NAME_MAX_LEN] = {0};
         memory_random_name(buf);
diff --git a/src/bootloader/startup.c b/src/bootloader/startup.c
index c9673fb..fb39534 100644
--- a/src/bootloader/startup.c
+++ b/src/bootloader/startup.c
@@ -19,7 +19,6 @@
 #endif
 
 #if PLATFORM_BITBOX02PLUS == 1
-    #include <communication_mode.h>
     #include <da14531/da14531.h>
     #include <da14531/da14531_handler.h>
     #include <da14531/da14531_protocol.h>
@@ -87,7 +86,7 @@ int main(void)
 
     ringbuffer_init(&uart_write_queue, &uart_write_buf, UART_OUT_BUF_LEN);
     if (!memory_ble_enabled()) {
-        communication_mode_ble_disable();
+        rust_communication_mode_ble_disable();
     }
 
     // Set product to bootloader string, this is necessary if we have rebooted from firmware. Must
@@ -114,7 +113,7 @@ int main(void)
     while (1) {
         // Do UART I/O
 #if PLATFORM_BITBOX02PLUS == 1
-        if (communication_mode_ble_enabled()) {
+        if (rust_communication_mode_ble_enabled()) {
             if (uart_read_buf_len < sizeof(uart_read_buf) ||
                 ringbuffer_num(&uart_write_queue) > 0) {
                 // screen_sprintf_debug(1000, "uart poll");
@@ -132,20 +131,20 @@ int main(void)
         if (!hww_data && hid_hww_read(&hww_frame[0])) {
             usb_packet_process((const USB_FRAME*)hww_frame);
 #if PLATFORM_BITBOX02PLUS == 1
-            if (communication_mode_ble_enabled()) {
+            if (rust_communication_mode_ble_enabled()) {
                 // Enqueue a power down command to the da14531
                 da14531_power_down(&uart_write_queue);
                 // Flush out the power down command. This will be the last UART communication we do.
                 while (ringbuffer_num(&uart_write_queue) > 0) {
                     uart_poll(NULL, 0, NULL, &uart_write_queue);
                 }
-                communication_mode_ble_disable();
+                rust_communication_mode_ble_disable();
                 bootloader_render_default_screen();
             }
 #endif
         }
 #if PLATFORM_BITBOX02PLUS == 1
-        if (communication_mode_ble_enabled()) {
+        if (rust_communication_mode_ble_enabled()) {
             struct da14531_protocol_frame* frame = da14531_protocol_poll(
                 &uart_read_buf[0], &uart_read_buf_len, &hww_data, &uart_write_queue);
 
@@ -157,7 +156,7 @@ int main(void)
 #endif
 
 #if PLATFORM_BITBOX02PLUS == 1
-        if (!communication_mode_ble_enabled()) {
+        if (!rust_communication_mode_ble_enabled()) {
 #endif
             if (hww_data) {
                 if (hid_hww_write_poll(hww_data)) {
diff --git a/src/communication_mode.c b/src/communication_mode.c
deleted file mode 100644
index ee7b527..0000000
--- a/src/communication_mode.c
+++ /dev/null
@@ -1,28 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-
-#include "communication_mode.h"
-
-#include "memory/memory_shared.h"
-
-static bool _usb_hww_request_seen = false;
-
-void communication_mode_ble_disable(void)
-{
-    _usb_hww_request_seen = true;
-}
-
-static bool _has_ble(void)
-{
-    static bool has_ble;
-    static bool has_ble_initialized = false;
-    if (!has_ble_initialized) {
-        has_ble = memory_get_platform() == MEMORY_PLATFORM_BITBOX02_PLUS;
-        has_ble_initialized = true;
-    }
-    return has_ble;
-}
-
-bool communication_mode_ble_enabled(void)
-{
-    return !_usb_hww_request_seen && _has_ble();
-}
diff --git a/src/communication_mode.h b/src/communication_mode.h
deleted file mode 100644
index dc71f69..0000000
--- a/src/communication_mode.h
+++ /dev/null
@@ -1,19 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-
-#ifndef _FIRMWARE_COMMUNICATION_MODE_H_
-#define _FIRMWARE_COMMUNICATION_MODE_H_
-
-#include <stdbool.h>
-
-/**
- * Call this when the first USB request is seen. After this, `communication_mode_ble_enabled()` will
- * be false even on Bluetooth enabled devices (USB takes priority).
- */
-void communication_mode_ble_disable(void);
-
-/**
- * Returns true if this device is Bluetooth-enabled and we have not seen a USB request yet, which
- * means we are communicating via Bluetooth.
- */
-bool communication_mode_ble_enabled(void);
-#endif
diff --git a/src/da14531/da14531_protocol.c b/src/da14531/da14531_protocol.c
index c2b2540..1edc920 100644
--- a/src/da14531/da14531_protocol.c
+++ b/src/da14531/da14531_protocol.c
@@ -6,7 +6,7 @@
 #include "platform_config.h"
 #include "uart.h"
 #include "util.h"
-#include <communication_mode.h>
+#include <rust/rust.h>
 #include <stdlib.h>
 #include <utils_assert.h>
 #ifndef TESTING
@@ -119,7 +119,7 @@ static void _firmware_loader_poll(
     case FIRMWARE_LOADER_STATE_IDLE:
         if (ble_fw == NULL) {
             if (!memory_spi_get_active_ble_firmware(&ble_fw, &ble_fw_size, &ble_fw_checksum)) {
-                communication_mode_ble_disable();
+                rust_communication_mode_ble_disable();
                 util_log("da14531: no valid firmware");
             }
             *buf_in_len = 0;
diff --git a/src/firmware_main_loop.c b/src/firmware_main_loop.c
index 9ca5fde..bc57cfe 100644
--- a/src/firmware_main_loop.c
+++ b/src/firmware_main_loop.c
@@ -2,7 +2,6 @@
 
 #include "firmware_main_loop.h"
 
-#include "communication_mode.h"
 #include "da14531/da14531.h"
 #include "da14531/da14531_handler.h"
 #include "da14531/da14531_protocol.h"
@@ -84,12 +83,12 @@ void firmware_main_loop(void)
 #endif
 
     if (!memory_ble_enabled()) {
-        communication_mode_ble_disable();
+        rust_communication_mode_ble_disable();
     }
 
     while (1) {
         // Do UART I/O
-        if (communication_mode_ble_enabled()) {
+        if (rust_communication_mode_ble_enabled()) {
             if (uart_read_buf_len < sizeof(uart_read_buf) ||
                 ringbuffer_num(&uart_write_queue) > 0) {
                 uart_poll(
@@ -122,7 +121,7 @@ void firmware_main_loop(void)
         // Do USB Input
         if (!hww_data && hid_hww_read(&hww_frame[0])) {
             if (usb_packet_process((const USB_FRAME*)hww_frame)) {
-                if (communication_mode_ble_enabled()) {
+                if (rust_communication_mode_ble_enabled()) {
                     // Enqueue a power down command to the da14531
                     da14531_power_down(&uart_write_queue);
                     // Flush out the power down command. This will be the last UART communication we
@@ -130,7 +129,7 @@ void firmware_main_loop(void)
                     while (ringbuffer_num(&uart_write_queue) > 0) {
                         uart_poll(NULL, 0, NULL, &uart_write_queue);
                     }
-                    communication_mode_ble_disable();
+                    rust_communication_mode_ble_disable();
                 }
             } else {
                 util_log("usb_packet_process: invalid");
@@ -144,7 +143,7 @@ void firmware_main_loop(void)
 #endif
 
         // Do UART Output
-        if (communication_mode_ble_enabled()) {
+        if (rust_communication_mode_ble_enabled()) {
             struct da14531_protocol_frame* frame = da14531_protocol_poll(
                 &uart_read_buf[0], &uart_read_buf_len, &hww_data, &uart_write_queue);
 
@@ -154,7 +153,7 @@ void firmware_main_loop(void)
         }
 
         // Do USB Output
-        if (!communication_mode_ble_enabled() && hww_data) {
+        if (!rust_communication_mode_ble_enabled() && hww_data) {
             if (hid_hww_write_poll(hww_data)) {
                 hww_data = NULL;
             }
diff --git a/src/rust/bitbox02-rust-c/src/lib.rs b/src/rust/bitbox02-rust-c/src/lib.rs
index 050e9df..a7b643e 100644
--- a/src/rust/bitbox02-rust-c/src/lib.rs
+++ b/src/rust/bitbox02-rust-c/src/lib.rs
@@ -20,6 +20,14 @@ pub mod workflow;
 #[cfg(feature = "firmware")]
 extern crate bitbox_aes;
 
+// Expose C interface defined in bitbox02_rust
+// Enable for firmware and for Nova bootloader (BitBox02 bootloader currently does not need it).
+#[cfg(any(
+    feature = "firmware",
+    all(feature = "bootloader", feature = "platform-bitbox02plus")
+))]
+extern crate bitbox02_rust;
+
 // Expose C interface defined in util
 extern crate util;
 
diff --git a/src/rust/bitbox02-rust/src/communication_mode.rs b/src/rust/bitbox02-rust/src/communication_mode.rs
new file mode 100644
index 0000000..ea789d0
--- /dev/null
+++ b/src/rust/bitbox02-rust/src/communication_mode.rs
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: Apache-2.0
+
+//! The BitBox02 Nova has two communication modes: USB and Bluetooth.
+//! Bluetooth is active until the first USB request is seen, at which point USB takes priority.
+
+use crate::hal::Memory;
+use util::cell::SyncCell;
+
+static USB_HWW_REQUEST_SEEN: SyncCell<bool> = SyncCell::new(false);
+static HAS_BLE: SyncCell<Option<bool>> = SyncCell::new(None);
+
+/// Call this when the first USB request is seen. After this, `ble_enabled()` returns false even on
+/// Bluetooth-enabled devices (USB takes priority).
+pub fn ble_disable() {
+    USB_HWW_REQUEST_SEEN.write(true);
+}
+
+/// Returns true if this device is Bluetooth-enabled and we have not seen a USB request yet, which
+/// means we are communicating via Bluetooth.
+pub fn ble_enabled(hal: &mut impl crate::hal::Hal) -> bool {
+    !USB_HWW_REQUEST_SEEN.read() && has_ble(hal)
+}
+
+fn has_ble(hal: &mut impl crate::hal::Hal) -> bool {
+    if let Some(has_ble) = HAS_BLE.read() {
+        return has_ble;
+    }
+
+    let has_ble = matches!(
+        hal.memory().get_platform(),
+        Ok(bitbox02::memory::Platform::BitBox02Plus),
+    );
+    HAS_BLE.write(Some(has_ble));
+    has_ble
+}
+
+/// C interface.
+#[unsafe(no_mangle)]
+pub extern "C" fn rust_communication_mode_ble_disable() {
+    ble_disable();
+}
+
+/// C interface.
+#[unsafe(no_mangle)]
+pub extern "C" fn rust_communication_mode_ble_enabled() -> bool {
+    ble_enabled(&mut crate::hal::BitBox02Hal::new())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use crate::hal::testing::TestingHal;
+
+    fn reset_for_testing() {
+        USB_HWW_REQUEST_SEEN.write(false);
+        HAS_BLE.write(None);
+    }
+
+    #[test]
+    fn test_ble_disabled_on_non_plus() {
+        reset_for_testing();
+        let mut hal = TestingHal::new();
+        hal.memory
+            .set_platform(bitbox02::memory::Platform::BitBox02);
+
+        assert!(!ble_enabled(&mut hal));
+
+        ble_disable();
+        assert!(!ble_enabled(&mut hal));
+    }
+
+    #[test]
+    fn test_ble_enabled_until_usb_request_seen() {
+        reset_for_testing();
+        let mut hal = TestingHal::new();
+        hal.memory
+            .set_platform(bitbox02::memory::Platform::BitBox02Plus);
+
+        assert!(ble_enabled(&mut hal));
+
+        ble_disable();
+        assert!(!ble_enabled(&mut hal));
+    }
+}
diff --git a/src/rust/bitbox02-rust/src/hww/api/bluetooth.rs b/src/rust/bitbox02-rust/src/hww/api/bluetooth.rs
index b9bf31f..917e08e 100644
--- a/src/rust/bitbox02-rust/src/hww/api/bluetooth.rs
+++ b/src/rust/bitbox02-rust/src/hww/api/bluetooth.rs
@@ -156,7 +156,7 @@ async fn process_upgrade(
     if response.is_ok() {
         hal.ui().status("Upgrade\nsuccessful", true).await;
         bitbox02::reset_ble();
-        if bitbox02::communication_mode_ble_enabled() {
+        if crate::communication_mode::ble_enabled(hal) {
             // Since the Bluetooth host will not be there anymore to read this response, this task
             // will not be cleared by the executor. We do it manually to make space for the next
             // task upon reconnection.
diff --git a/src/rust/bitbox02-rust/src/hww/noise.rs b/src/rust/bitbox02-rust/src/hww/noise.rs
index 3b0967a..b0d48a1 100644
--- a/src/rust/bitbox02-rust/src/hww/noise.rs
+++ b/src/rust/bitbox02-rust/src/hww/noise.rs
@@ -94,7 +94,7 @@ pub(crate) async fn process(
                         memory::check_noise_remote_static_pubkey(&state.remote_static_pubkey()?);
                     // When communicating over BLE, we don't require noise pairing code
                     // confirmation, as BLE already requires pairing with a pairing code.
-                    if bitbox02::communication_mode_ble_enabled() || already_verified {
+                    if crate::communication_mode::ble_enabled(hal) || already_verified {
                         state.set_pairing_verified()?;
                         usb_out.push(0); // let app know we don't require verification
                     } else {
diff --git a/src/rust/bitbox02-rust/src/lib.rs b/src/rust/bitbox02-rust/src/lib.rs
index caf4941..872bc3f 100644
--- a/src/rust/bitbox02-rust/src/lib.rs
+++ b/src/rust/bitbox02-rust/src/lib.rs
@@ -20,6 +20,7 @@ pub mod backup;
 pub mod bb02_async;
 mod bip32;
 pub mod bip39;
+pub mod communication_mode;
 pub mod hal;
 pub mod hash;
 pub mod hww;
diff --git a/src/rust/bitbox02-sys/build.rs b/src/rust/bitbox02-sys/build.rs
index e33a9b2..ba0c776 100644
--- a/src/rust/bitbox02-sys/build.rs
+++ b/src/rust/bitbox02-sys/build.rs
@@ -60,7 +60,6 @@ const ALLOWLIST_FNS: &[&str] = &[
     "bitbox_secp256k1_dleq_prove",
     "bitbox_secp256k1_dleq_verify",
     "bitbox02_smarteeprom_init",
-    "communication_mode_ble_enabled",
     "confirm_create",
     "confirm_transaction_address_create",
     "confirm_transaction_fee_create",
@@ -205,7 +204,6 @@ const RUSTIFIED_ENUMS: &[&str] = &[
 
 // BITBOX02_SOURCES are only used for native builds (simulator). Avoid cross-target specific files.
 const BITBOX02_SOURCES: &[&str] = &[
-    "src/communication_mode.c",
     "src/da14531/crc.c",
     "src/da14531/da14531_handler.c",
     "src/da14531/da14531_protocol.c",
diff --git a/src/rust/bitbox02-sys/wrapper.h b/src/rust/bitbox02-sys/wrapper.h
index 6cc52c3..98e2ca2 100644
--- a/src/rust/bitbox02-sys/wrapper.h
+++ b/src/rust/bitbox02-sys/wrapper.h
@@ -1,6 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
 
-#include <communication_mode.h>
 #include <delay.h>
 #include <memory/bitbox02_smarteeprom.h>
 #include <memory/memory.h>
diff --git a/src/rust/bitbox02/src/lib.rs b/src/rust/bitbox02/src/lib.rs
index b21e134..01cfdb3 100644
--- a/src/rust/bitbox02/src/lib.rs
+++ b/src/rust/bitbox02/src/lib.rs
@@ -251,16 +251,6 @@ pub fn println_stdout(msg: &str) {
     }
 }
 
-#[cfg(not(feature = "testing"))]
-pub fn communication_mode_ble_enabled() -> bool {
-    unsafe { bitbox02_sys::communication_mode_ble_enabled() }
-}
-
-#[cfg(feature = "testing")]
-pub fn communication_mode_ble_enabled() -> bool {
-    false
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;