orientation-screen: Migrate to rust

create an async friendly hardware supported delayin C and wrap it in
rust using Future.

Author: NickeZ

src/CMakeLists.txt

@@ -16,6 +16,7 @@
 
 set(DBB-FIRMWARE-SOURCES
   ${CMAKE_SOURCE_DIR}/src/firmware_main_loop.c
+  ${CMAKE_SOURCE_DIR}/src/delay.c
   ${CMAKE_SOURCE_DIR}/src/keystore.c
   ${CMAKE_SOURCE_DIR}/src/random.c
   ${CMAKE_SOURCE_DIR}/src/hardfault.c
@@ -36,7 +37,6 @@ set(DBB-FIRMWARE-SOURCES
   ${CMAKE_SOURCE_DIR}/src/touch/gestures.c
   ${CMAKE_SOURCE_DIR}/src/reset.c
   ${CMAKE_SOURCE_DIR}/src/cipher/cipher.c
-  ${CMAKE_SOURCE_DIR}/src/workflow/orientation_screen.c
   ${CMAKE_SOURCE_DIR}/src/queue.c
   ${CMAKE_SOURCE_DIR}/src/usb/usb_processing.c
 )

src/delay.c

@@ -0,0 +1,79 @@
+// Copyright 2025 Shift Crypto AG
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <delay.h>
+#include <hal_timer.h>
+#include <platform/driver_init.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+#include <util.h>
+#include <utils_assert.h>
+
+struct task {
+    struct timer_task timer;
+    volatile bool done;
+};
+
+static struct task _tasks[10] = {0};
+static struct task _empty = {0};
+
+static void _hal_timer_cb(const struct timer_task* const timer)
+{
+    for (size_t i = 0; i < COUNT_OF(_tasks); i++) {
+        if (&_tasks[i].timer == timer) {
+            _tasks[i].done = true;
+        }
+    }
+}
+
+bool delay_init_ms(delay_t* self, uint32_t ms)
+{
+    // find an unused slot in tasks
+    size_t i;
+    CRITICAL_SECTION_ENTER();
+    for (i = 0; i < COUNT_OF(_tasks); i++) {
+        if (memcmp(&_tasks[i], &_empty, sizeof(struct task)) == 0) {
+            break;
+        }
+    }
+    CRITICAL_SECTION_LEAVE();
+    if (i == COUNT_OF(_tasks)) {
+        return false;
+    }
+    _tasks[i].done = false;
+    memset(&_tasks[i], 0, sizeof(struct task));
+    _tasks[i].timer.interval = ms;
+    _tasks[i].timer.cb = _hal_timer_cb;
+    _tasks[i].timer.mode = TIMER_TASK_ONE_SHOT;
+    self->id = i;
+    return true;
+}
+
+void delay_start(const delay_t* self)
+{
+    ASSERT(self->id < COUNT_OF(_tasks));
+    ASSERT(!_tasks[self->id].done);
+    timer_add_task(&TIMER_0, &_tasks[self->id].timer);
+}
+
+bool delay_poll(const delay_t* self)
+{
+    ASSERT(self->id < COUNT_OF(_tasks));
+    if (_tasks[self->id].done) {
+        memset(&_tasks[self->id], 0, sizeof(struct task));
+        return true;
+    }
+    return false;
+}

test/hardware-fakes/src/fake_delay.c renamed to src/delay.h

@@ -1,4 +1,4 @@
-// Copyright 2019 Shift Cryptosecurity AG
+// Copyright 2025 Shift Crypto AG
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,15 +12,23 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#ifndef DELAY_H
+#define DELAY_H
+#include <stdbool.h>
+#include <stddef.h>
 #include <stdint.h>
-#include <unistd.h>
 
-void delay_ms(const uint16_t ms)
-{
-    usleep(1000 * ms);
-}
+typedef struct {
+    size_t id;
+} delay_t;
 
-void delay_us(const uint16_t us)
-{
-    usleep(us);
-}
+// Create a non-blocking delay instance. Poll with delay_poll to completion
+// Limited to 10 concurrent delays, will return false if it fails to allocate one
+bool delay_init_ms(delay_t* self, uint32_t ms);
+
+// Start the delay
+void delay_start(const delay_t* self);
+
+// returns true if time has passed. After it has returned true once it must not be called again
+bool delay_poll(const delay_t* self);
+#endif

src/firmware_main_loop.c

@@ -32,10 +32,10 @@
 #include "usb/usb.h"
 #include "usb/usb_frame.h"
 #include "usb/usb_processing.h"
-#include "workflow/orientation_screen.h"
 #include <rust/rust.h>
 #include <ui/fonts/monogram_5X9.h>
 #include <utils_ringbuffer.h>
+#include <version.h>
 #if APP_U2F == 1
 #include "u2f.h"
 #include "u2f/u2f_packet.h"
@@ -45,6 +45,36 @@
 // Must be power of 2
 #define UART_OUT_BUF_LEN 2048
 
+// Currently we have one firmware for both BB02 and BB02_PLUS, and only the
+// PRODUCT_BITBOX_MULTI/BTCONLY definitions apply. The PRODUCT_BITBOX_PLUS_MULTI/BTCONLY defs
+// currently only apply in the bootloader, which we don't need here.
+#if PRODUCT_BITBOX_MULTI == 1
+#define PRODUCT_STRING_SUFFIX "multi"
+#elif PRODUCT_BITBOX_BTCONLY == 1
+#define PRODUCT_STRING_SUFFIX "btconly"
+#elif PRODUCT_BITBOX02_FACTORYSETUP == 1
+// Dummy, not actually needed, but this file is currently needlessly compiled for factorysetup.
+#define PRODUCT_STRING_SUFFIX "factory"
+#else
+#error "unknown edition"
+#endif
+
+#define DEVICE_MODE \
+    "{\"p\":\"bb02p-" PRODUCT_STRING_SUFFIX "\",\"v\":\"" DIGITAL_BITBOX_VERSION "\"}"
+
+static void _orientation_done_cb(void* user_data)
+{
+    struct ringbuffer* uart_out_queue = (struct ringbuffer*)user_data;
+    // hww handler in usb_process must be setup before we can allow ble connections
+    if (memory_get_platform() == MEMORY_PLATFORM_BITBOX02_PLUS) {
+        da14531_handler_current_product = (const uint8_t*)DEVICE_MODE;
+        da14531_handler_current_product_len = sizeof(DEVICE_MODE) - 1;
+        da14531_set_product(
+            da14531_handler_current_product, da14531_handler_current_product_len, uart_out_queue);
+    }
+    usb_start();
+}
+
 void firmware_main_loop(void)
 {
     // Set the size of uart_read_buf to the size of the ringbuffer in the UART driver so we can read
@@ -63,7 +93,8 @@ void firmware_main_loop(void)
     da14531_set_name(buf, strlen(buf), &uart_write_queue);
 
     // This starts the async orientation screen workflow, which is processed by the loop below.
-    orientation_screen(&uart_write_queue);
+
+    rust_workflow_spawn_orientation_screen(_orientation_done_cb, &uart_write_queue);
 
     const uint8_t* hww_data = NULL;
     uint8_t hww_frame[USB_REPORT_SIZE] = {0};

src/rust/bitbox02-rust-c/src/lib.rs

@@ -39,7 +39,7 @@ extern crate util;
 // handler will print the available information on the screen and over RTT. If we compile with
 // `panic=abort` this code will never get executed.
 #[cfg_attr(feature = "bootloader", allow(unused_variables))]
-#[cfg(not(any(test, feature = "testing", feature = "c-unit-testing")))]
+#[cfg(not(any(feature = "testing", feature = "c-unit-testing")))]
 #[panic_handler]
 fn panic(info: &core::panic::PanicInfo) -> ! {
     #[cfg(feature = "firmware")]

src/rust/bitbox02-rust-c/src/workflow.rs

@@ -24,7 +24,7 @@ extern crate alloc;
 
 use alloc::boxed::Box;
 use alloc::string::String;
-use bitbox02_rust::workflow::confirm;
+use bitbox02_rust::workflow::{confirm, orientation_screen};
 use core::task::Poll;
 use util::bb02_async::{Task, spin};
 
@@ -42,6 +42,8 @@ static mut CONFIRM_PARAMS: Option<confirm::Params> = None;
 static mut CONFIRM_STATE: TaskState<'static, Result<(), confirm::UserAbort>> = TaskState::Nothing;
 static mut BITBOX02_HAL: bitbox02_rust::hal::BitBox02Hal = bitbox02_rust::hal::BitBox02Hal::new();
 
+static mut ORIENTATION_SCREEN_STATE: TaskState<'static, ()> = TaskState::Nothing;
+
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn rust_workflow_spawn_unlock() {
     unsafe {
@@ -71,6 +73,22 @@ pub unsafe extern "C" fn rust_workflow_spawn_confirm(
     }
 }
 
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn rust_workflow_spawn_orientation_screen(
+    orientation_selected_cb: Option<extern "C" fn(*mut core::ffi::c_void)>,
+    user_data: *mut core::ffi::c_void,
+) {
+    let callback = move || {
+        if let Some(cb) = orientation_selected_cb {
+            cb(user_data)
+        }
+    };
+    unsafe {
+        ORIENTATION_SCREEN_STATE =
+            TaskState::Running(Box::pin(orientation_screen::create(callback)));
+    }
+}
+
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn rust_workflow_spin() {
     unsafe {
@@ -92,6 +110,15 @@ pub unsafe extern "C" fn rust_workflow_spin() {
             }
             _ => (),
         }
+        match ORIENTATION_SCREEN_STATE {
+            TaskState::Running(ref mut task) => {
+                let result = spin(task);
+                if let Poll::Ready(result) = result {
+                    ORIENTATION_SCREEN_STATE = TaskState::ResultAvailable(result);
+                }
+            }
+            _ => (),
+        }
     }
 }
 
@@ -131,6 +158,20 @@ pub unsafe extern "C" fn rust_workflow_confirm_poll(result_out: &mut bool) -> bo
     }
 }
 
+/// Returns true if there was a result.
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn rust_workflow_orientation_screen_poll() -> bool {
+    unsafe {
+        match ORIENTATION_SCREEN_STATE {
+            TaskState::ResultAvailable(_) => {
+                ORIENTATION_SCREEN_STATE = TaskState::Nothing;
+                true
+            }
+            _ => false,
+        }
+    }
+}
+
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn rust_workflow_abort_current() {
     unsafe {
@@ -140,5 +181,7 @@ pub unsafe extern "C" fn rust_workflow_abort_current() {
         CONFIRM_BODY = None;
         CONFIRM_PARAMS = None;
         CONFIRM_STATE = TaskState::Nothing;
+
+        ORIENTATION_SCREEN_STATE = TaskState::Nothing;
     }
 }

src/rust/bitbox02-rust/src/workflow.rs

@@ -17,6 +17,7 @@ pub mod confirm;
 pub mod menu;
 #[cfg_attr(feature = "c-unit-testing", path = "workflow/mnemonic_c_unit_tests.rs")]
 pub mod mnemonic;
+pub mod orientation_screen;
 pub mod pairing;
 pub mod password;
 pub mod sdcard;

src/rust/bitbox02-rust/src/workflow/orientation_screen.rs

@@ -0,0 +1,43 @@
+// Copyright 2025 Shift Crypto AG
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use util::bb02_async::option;
+
+pub async fn create<CB>(orientation_selected_cb: CB)
+where
+    CB: FnOnce(),
+{
+    let result = core::cell::RefCell::new(None as Option<()>);
+    let mut orientation_arrows = bitbox02::ui::orientation_arrows(|upside_down| {
+        if upside_down {
+            bitbox02::screen_rotate()
+        }
+        *result.borrow_mut() = Some(());
+    });
+    orientation_arrows.screen_stack_push();
+
+    // Wait until orientation has been chosen
+    option(&result).await;
+    drop(orientation_arrows);
+
+    // During this delay the bb02 logotype is shown
+    if let Ok(delay) = bitbox02::delay::Delay::from_ms(1300) {
+        delay.await;
+    }
+
+    // Switch to lockscreen that shows "See the bitbox app" and device name
+    bitbox02::ui::screen_process_waiting_switch_to_lockscreen();
+
+    orientation_selected_cb();
+}

src/rust/bitbox02-sys/build.rs

@@ -68,12 +68,15 @@ const ALLOWLIST_FNS: &[&str] = &[
     "confirm_create",
     "confirm_transaction_address_create",
     "confirm_transaction_fee_create",
+    "delay_init_ms",
     "delay_ms",
+    "delay_poll",
+    "delay_start",
     "delay_us",
     "empty_create",
-    "unlock_animation_create",
     "keystore_bip39_mnemonic_to_seed",
     "keystore_copy_seed",
+    "unlock_animation_create",
     "keystore_copy_bip39_seed",
     "keystore_encrypt_and_store_seed",
     "keystore_get_bip39_word",
@@ -121,6 +124,7 @@ const ALLOWLIST_FNS: &[&str] = &[
     "menu_create",
     "fake_memory_factoryreset",
     "spi_mem_full_erase",
+    "orientation_arrows_create",
     "printf",
     "progress_create",
     "progress_set",
@@ -133,8 +137,10 @@ const ALLOWLIST_FNS: &[&str] = &[
     "screen_print_debug",
     "screen_process",
     "screen_process_waiting_switch_to_logo",
+    "screen_process_waiting_switch_to_lockscreen",
     "screen_saver_disable",
     "screen_saver_enable",
+    "screen_rotate",
     "sd_card_inserted",
     "sd_erase_file_in_subdir",
     "sd_format",
@@ -256,7 +262,6 @@ const BITBOX02_SOURCES: &[&str] = &[
     "src/usb/usb_processing.c",
     "src/usb/usb.c",
     "src/util.c",
-    "src/workflow/orientation_screen.c",
     "external/asf4-drivers/hal/utils/src/utils_ringbuffer.c",
 ];