Merge #1331

1331: Let bootloader partition be u32 r=rmja a=rmja

This is probably controversial but hear me out:)

The idea about changing from usize to u32 is to enable support for 16 bit mcu's with large flash, e.g. MSP430F5529. Its usize is only 16 bit, but its flash is larger than 64k. Hence, to address its entire flash, it needs the flash address space to be u32.

Missing from the PR is `update_len` in the verification methods. There is currently [a different PR](https://github.com/embassy-rs/embassy/pull/1323) that contains changes in those methods, and I will align depending on the merge order of the two.

The general distinction between u32 and usize is:
* If it is a size or address that only ever lives in flash, then it is u32.
* If the offset or size is ever representable in memory, then usize.

Co-authored-by: Rasmus Melchior Jacobsen <[email protected]>

8 files changed, 117 insertions, 137 deletions

diff --git a/embassy-boot/boot/src/boot_loader.rs b/embassy-boot/boot/src/boot_loader.rs
index 2412427c0..b959de2c4 100644
--- a/embassy-boot/boot/src/boot_loader.rs
+++ b/embassy-boot/boot/src/boot_loader.rs
@@ -50,13 +50,13 @@ pub trait FlashConfig {
 }
 
 trait FlashConfigEx {
-    fn page_size() -> usize;
+    fn page_size() -> u32;
 }
 
 impl<T: FlashConfig> FlashConfigEx for T {
     /// Get the page size which is the "unit of operation" within the bootloader.
-    fn page_size() -> usize {
-        core::cmp::max(T::ACTIVE::ERASE_SIZE, T::DFU::ERASE_SIZE)
+    fn page_size() -> u32 {
+        core::cmp::max(T::ACTIVE::ERASE_SIZE, T::DFU::ERASE_SIZE) as u32
     }
 }
 
@@ -86,7 +86,7 @@ impl BootLoader {
 
     /// Return the offset of the active partition into the active flash.
     pub fn boot_address(&self) -> usize {
-        self.active.from
+        self.active.from as usize
     }
 
     /// Perform necessary boot preparations like swapping images.
@@ -177,11 +177,11 @@ impl BootLoader {
     ///
     pub fn prepare_boot<P: FlashConfig>(&mut self, p: &mut P, aligned_buf: &mut [u8]) -> Result<State, BootError> {
         // Ensure we have enough progress pages to store copy progress
-        assert_eq!(0, P::page_size() % aligned_buf.len());
-        assert_eq!(0, P::page_size() % P::ACTIVE::WRITE_SIZE);
-        assert_eq!(0, P::page_size() % P::ACTIVE::ERASE_SIZE);
-        assert_eq!(0, P::page_size() % P::DFU::WRITE_SIZE);
-        assert_eq!(0, P::page_size() % P::DFU::ERASE_SIZE);
+        assert_eq!(0, P::page_size() % aligned_buf.len() as u32);
+        assert_eq!(0, P::page_size() % P::ACTIVE::WRITE_SIZE as u32);
+        assert_eq!(0, P::page_size() % P::ACTIVE::ERASE_SIZE as u32);
+        assert_eq!(0, P::page_size() % P::DFU::WRITE_SIZE as u32);
+        assert_eq!(0, P::page_size() % P::DFU::ERASE_SIZE as u32);
         assert!(aligned_buf.len() >= P::STATE::WRITE_SIZE);
         assert_eq!(0, aligned_buf.len() % P::ACTIVE::WRITE_SIZE);
         assert_eq!(0, aligned_buf.len() % P::DFU::WRITE_SIZE);
@@ -222,30 +222,27 @@ impl BootLoader {
     }
 
     fn is_swapped<P: FlashConfig>(&mut self, p: &mut P, aligned_buf: &mut [u8]) -> Result<bool, BootError> {
-        let page_count = self.active.len() / P::page_size();
+        let page_count = (self.active.size() / P::page_size()) as usize;
         let progress = self.current_progress(p, aligned_buf)?;
 
         Ok(progress >= page_count * 2)
     }
 
     fn current_progress<P: FlashConfig>(&mut self, config: &mut P, aligned_buf: &mut [u8]) -> Result<usize, BootError> {
-        let max_index = ((self.state.len() - P::STATE::WRITE_SIZE) / P::STATE::WRITE_SIZE) - 2;
+        let write_size = P::STATE::WRITE_SIZE as u32;
+        let max_index = (((self.state.size() - write_size) / write_size) - 2) as usize;
         let state_flash = config.state();
-        let state_word = &mut aligned_buf[..P::STATE::WRITE_SIZE];
+        let state_word = &mut aligned_buf[..write_size as usize];
 
-        self.state
-            .read_blocking(state_flash, P::STATE::WRITE_SIZE as u32, state_word)?;
+        self.state.read_blocking(state_flash, write_size, state_word)?;
         if state_word.iter().any(|&b| b != P::STATE_ERASE_VALUE) {
             // Progress is invalid
             return Ok(max_index);
         }
 
         for index in 0..max_index {
-            self.state.read_blocking(
-                state_flash,
-                (2 + index) as u32 * P::STATE::WRITE_SIZE as u32,
-                state_word,
-            )?;
+            self.state
+                .read_blocking(state_flash, (2 + index) as u32 * write_size, state_word)?;
 
             if state_word.iter().any(|&b| b == P::STATE_ERASE_VALUE) {
                 return Ok(index);
@@ -256,26 +253,29 @@ impl BootLoader {
 
     fn update_progress<P: FlashConfig>(
         &mut self,
-        index: usize,
+        progress_index: usize,
         p: &mut P,
         aligned_buf: &mut [u8],
     ) -> Result<(), BootError> {
         let state_word = &mut aligned_buf[..P::STATE::WRITE_SIZE];
         state_word.fill(!P::STATE_ERASE_VALUE);
-        self.state
-            .write_blocking(p.state(), (2 + index) as u32 * P::STATE::WRITE_SIZE as u32, state_word)?;
+        self.state.write_blocking(
+            p.state(),
+            (2 + progress_index) as u32 * P::STATE::WRITE_SIZE as u32,
+            state_word,
+        )?;
         Ok(())
     }
 
     fn copy_page_once_to_active<P: FlashConfig>(
         &mut self,
-        idx: usize,
+        progress_index: usize,
         from_offset: u32,
         to_offset: u32,
         p: &mut P,
         aligned_buf: &mut [u8],
     ) -> Result<(), BootError> {
-        if self.current_progress(p, aligned_buf)? <= idx {
+        if self.current_progress(p, aligned_buf)? <= progress_index {
             let page_size = P::page_size() as u32;
 
             self.active
@@ -288,20 +288,20 @@ impl BootLoader {
                     .write_blocking(p.active(), to_offset + offset_in_page as u32, aligned_buf)?;
             }
 
-            self.update_progress(idx, p, aligned_buf)?;
+            self.update_progress(progress_index, p, aligned_buf)?;
         }
         Ok(())
     }
 
     fn copy_page_once_to_dfu<P: FlashConfig>(
         &mut self,
-        idx: usize,
+        progress_index: usize,
         from_offset: u32,
         to_offset: u32,
         p: &mut P,
         aligned_buf: &mut [u8],
     ) -> Result<(), BootError> {
-        if self.current_progress(p, aligned_buf)? <= idx {
+        if self.current_progress(p, aligned_buf)? <= progress_index {
             let page_size = P::page_size() as u32;
 
             self.dfu
@@ -314,31 +314,28 @@ impl BootLoader {
                     .write_blocking(p.dfu(), to_offset + offset_in_page as u32, aligned_buf)?;
             }
 
-            self.update_progress(idx, p, aligned_buf)?;
+            self.update_progress(progress_index, p, aligned_buf)?;
         }
         Ok(())
     }
 
     fn swap<P: FlashConfig>(&mut self, p: &mut P, aligned_buf: &mut [u8]) -> Result<(), BootError> {
         let page_size = P::page_size();
-        let page_count = self.active.len() / page_size;
-        trace!("Page count: {}", page_count);
+        let page_count = self.active.size() / page_size;
         for page_num in 0..page_count {
-            trace!("COPY PAGE {}", page_num);
-
-            let idx = page_num * 2;
+            let progress_index = (page_num * 2) as usize;
 
             // Copy active page to the 'next' DFU page.
-            let active_from_offset = ((page_count - 1 - page_num) * page_size) as u32;
-            let dfu_to_offset = ((page_count - page_num) * page_size) as u32;
+            let active_from_offset = (page_count - 1 - page_num) * page_size;
+            let dfu_to_offset = (page_count - page_num) * page_size;
             //trace!("Copy active {} to dfu {}", active_from_offset, dfu_to_offset);
-            self.copy_page_once_to_dfu(idx, active_from_offset, dfu_to_offset, p, aligned_buf)?;
+            self.copy_page_once_to_dfu(progress_index, active_from_offset, dfu_to_offset, p, aligned_buf)?;
 
             // Copy DFU page to the active page
-            let active_to_offset = ((page_count - 1 - page_num) * page_size) as u32;
-            let dfu_from_offset = ((page_count - 1 - page_num) * page_size) as u32;
+            let active_to_offset = (page_count - 1 - page_num) * page_size;
+            let dfu_from_offset = (page_count - 1 - page_num) * page_size;
             //trace!("Copy dfy {} to active {}", dfu_from_offset, active_to_offset);
-            self.copy_page_once_to_active(idx + 1, dfu_from_offset, active_to_offset, p, aligned_buf)?;
+            self.copy_page_once_to_active(progress_index + 1, dfu_from_offset, active_to_offset, p, aligned_buf)?;
         }
 
         Ok(())
@@ -346,19 +343,19 @@ impl BootLoader {
 
     fn revert<P: FlashConfig>(&mut self, p: &mut P, aligned_buf: &mut [u8]) -> Result<(), BootError> {
         let page_size = P::page_size();
-        let page_count = self.active.len() / page_size;
+        let page_count = self.active.size() / page_size;
         for page_num in 0..page_count {
-            let idx = page_count * 2 + page_num * 2;
+            let progress_index = (page_count * 2 + page_num * 2) as usize;
 
             // Copy the bad active page to the DFU page
-            let active_from_offset = (page_num * page_size) as u32;
-            let dfu_to_offset = (page_num * page_size) as u32;
-            self.copy_page_once_to_dfu(idx, active_from_offset, dfu_to_offset, p, aligned_buf)?;
+            let active_from_offset = page_num * page_size;
+            let dfu_to_offset = page_num * page_size;
+            self.copy_page_once_to_dfu(progress_index, active_from_offset, dfu_to_offset, p, aligned_buf)?;
 
             // Copy the DFU page back to the active page
-            let active_to_offset = (page_num * page_size) as u32;
-            let dfu_from_offset = ((page_num + 1) * page_size) as u32;
-            self.copy_page_once_to_active(idx + 1, dfu_from_offset, active_to_offset, p, aligned_buf)?;
+            let active_to_offset = page_num * page_size;
+            let dfu_from_offset = (page_num + 1) * page_size;
+            self.copy_page_once_to_active(progress_index + 1, dfu_from_offset, active_to_offset, p, aligned_buf)?;
         }
 
         Ok(())
@@ -376,11 +373,11 @@ impl BootLoader {
     }
 }
 
-fn assert_partitions(active: Partition, dfu: Partition, state: Partition, page_size: usize, write_size: usize) {
-    assert_eq!(active.len() % page_size, 0);
-    assert_eq!(dfu.len() % page_size, 0);
-    assert!(dfu.len() - active.len() >= page_size);
-    assert!(2 + 2 * (active.len() / page_size) <= state.len() / write_size);
+fn assert_partitions(active: Partition, dfu: Partition, state: Partition, page_size: u32, state_write_size: usize) {
+    assert_eq!(active.size() % page_size, 0);
+    assert_eq!(dfu.size() % page_size, 0);
+    assert!(dfu.size() - active.size() >= page_size);
+    assert!(2 + 2 * (active.size() / page_size) <= state.size() / state_write_size as u32);
 }
 
 /// A flash wrapper implementing the Flash and embedded_storage traits.
diff --git a/embassy-boot/boot/src/firmware_updater.rs b/embassy-boot/boot/src/firmware_updater.rs
index 48e15024e..a2f822f4a 100644
--- a/embassy-boot/boot/src/firmware_updater.rs
+++ b/embassy-boot/boot/src/firmware_updater.rs
@@ -50,14 +50,14 @@ impl Default for FirmwareUpdater {
 
         let dfu = unsafe {
             Partition::new(
-                &__bootloader_dfu_start as *const u32 as usize,
-                &__bootloader_dfu_end as *const u32 as usize,
+                &__bootloader_dfu_start as *const u32 as u32,
+                &__bootloader_dfu_end as *const u32 as u32,
             )
         };
         let state = unsafe {
             Partition::new(
-                &__bootloader_state_start as *const u32 as usize,
-                &__bootloader_state_end as *const u32 as usize,
+                &__bootloader_state_start as *const u32 as u32,
+                &__bootloader_state_end as *const u32 as u32,
             )
         };
 
@@ -73,11 +73,6 @@ impl FirmwareUpdater {
         Self { dfu, state }
     }
 
-    /// Return the length of the DFU area
-    pub fn firmware_len(&self) -> usize {
-        self.dfu.len()
-    }
-
     /// Obtain the current state.
     ///
     /// This is useful to check if the bootloader has just done a swap, in order
@@ -119,11 +114,11 @@ impl FirmwareUpdater {
         _state_and_dfu_flash: &mut F,
         _public_key: &[u8],
         _signature: &[u8],
-        _update_len: usize,
+        _update_len: u32,
         _aligned: &mut [u8],
     ) -> Result<(), FirmwareUpdaterError> {
         assert_eq!(_aligned.len(), F::WRITE_SIZE);
-        assert!(_update_len <= self.dfu.len());
+        assert!(_update_len <= self.dfu.size());
 
         #[cfg(feature = "ed25519-dalek")]
         {
@@ -180,11 +175,10 @@ impl FirmwareUpdater {
     pub async fn hash<F: AsyncNorFlash, D: Digest>(
         &mut self,
         dfu_flash: &mut F,
-        update_len: usize,
+        update_len: u32,
         chunk_buf: &mut [u8],
         output: &mut [u8],
     ) -> Result<(), FirmwareUpdaterError> {
-        let update_len = update_len as u32;
         let mut digest = D::new();
         for offset in (0..update_len).step_by(chunk_buf.len()) {
             self.dfu.read(dfu_flash, offset, chunk_buf).await?;
@@ -340,11 +334,11 @@ impl FirmwareUpdater {
         _state_and_dfu_flash: &mut F,
         _public_key: &[u8],
         _signature: &[u8],
-        _update_len: usize,
+        _update_len: u32,
         _aligned: &mut [u8],
     ) -> Result<(), FirmwareUpdaterError> {
         assert_eq!(_aligned.len(), F::WRITE_SIZE);
-        assert!(_update_len <= self.dfu.len());
+        assert!(_update_len <= self.dfu.size());
 
         #[cfg(feature = "ed25519-dalek")]
         {
@@ -399,11 +393,10 @@ impl FirmwareUpdater {
     pub fn hash_blocking<F: NorFlash, D: Digest>(
         &mut self,
         dfu_flash: &mut F,
-        update_len: usize,
+        update_len: u32,
         chunk_buf: &mut [u8],
         output: &mut [u8],
     ) -> Result<(), FirmwareUpdaterError> {
-        let update_len = update_len as u32;
         let mut digest = D::new();
         for offset in (0..update_len).step_by(chunk_buf.len()) {
             self.dfu.read_blocking(dfu_flash, offset, chunk_buf)?;
@@ -534,7 +527,7 @@ mod tests {
         block_on(updater.write_firmware(0, to_write.as_slice(), &mut flash)).unwrap();
         let mut chunk_buf = [0; 2];
         let mut hash = [0; 20];
-        block_on(updater.hash::<_, Sha1>(&mut flash, update.len(), &mut chunk_buf, &mut hash)).unwrap();
+        block_on(updater.hash::<_, Sha1>(&mut flash, update.len() as u32, &mut chunk_buf, &mut hash)).unwrap();
 
         assert_eq!(Sha1::digest(update).as_slice(), hash);
     }
diff --git a/embassy-boot/boot/src/lib.rs b/embassy-boot/boot/src/lib.rs
index acd90996f..87457b173 100644
--- a/embassy-boot/boot/src/lib.rs
+++ b/embassy-boot/boot/src/lib.rs
@@ -90,13 +90,11 @@ mod tests {
         const DFU: Partition = Partition::new(61440, 122880);
         let mut flash = MemFlash::<131072, 4096, 4>::random();
 
-        let original: [u8; ACTIVE.len()] = [rand::random::<u8>(); ACTIVE.len()];
-        let update: [u8; DFU.len()] = [rand::random::<u8>(); DFU.len()];
+        let original = [rand::random::<u8>(); ACTIVE.size() as usize];
+        let update = [rand::random::<u8>(); ACTIVE.size() as usize];
         let mut aligned = [0; 4];
 
-        for i in ACTIVE.from..ACTIVE.to {
-            flash.mem[i] = original[i - ACTIVE.from];
-        }
+        flash.program(ACTIVE.from, &original).unwrap();
 
         let mut bootloader: BootLoader = BootLoader::new(ACTIVE, DFU, STATE);
         let mut updater = FirmwareUpdater::new(DFU, STATE);
@@ -111,14 +109,9 @@ mod tests {
                 .unwrap()
         );
 
-        for i in ACTIVE.from..ACTIVE.to {
-            assert_eq!(flash.mem[i], update[i - ACTIVE.from], "Index {}", i);
-        }
-
+        flash.assert_eq(ACTIVE.from, &update);
         // First DFU page is untouched
-        for i in DFU.from + 4096..DFU.to {
-            assert_eq!(flash.mem[i], original[i - DFU.from - 4096], "Index {}", i);
-        }
+        flash.assert_eq(DFU.from + 4096, &original);
 
         // Running again should cause a revert
         assert_eq!(
@@ -128,14 +121,9 @@ mod tests {
                 .unwrap()
         );
 
-        for i in ACTIVE.from..ACTIVE.to {
-            assert_eq!(flash.mem[i], original[i - ACTIVE.from], "Index {}", i);
-        }
-
+        flash.assert_eq(ACTIVE.from, &original);
         // Last page is untouched
-        for i in DFU.from..DFU.to - 4096 {
-            assert_eq!(flash.mem[i], update[i - DFU.from], "Index {}", i);
-        }
+        flash.assert_eq(DFU.from, &update);
 
         // Mark as booted
         block_on(updater.mark_booted(&mut flash, &mut aligned)).unwrap();
@@ -159,12 +147,10 @@ mod tests {
         let mut state = MemFlash::<4096, 128, 4>::random();
         let mut aligned = [0; 4];
 
-        let original: [u8; ACTIVE.len()] = [rand::random::<u8>(); ACTIVE.len()];
-        let update: [u8; DFU.len()] = [rand::random::<u8>(); DFU.len()];
+        let original = [rand::random::<u8>(); ACTIVE.size() as usize];
+        let update = [rand::random::<u8>(); ACTIVE.size() as usize];
 
-        for i in ACTIVE.from..ACTIVE.to {
-            active.mem[i] = original[i - ACTIVE.from];
-        }
+        active.program(ACTIVE.from, &original).unwrap();
 
         let mut updater = FirmwareUpdater::new(DFU, STATE);
 
@@ -181,14 +167,9 @@ mod tests {
                 .unwrap()
         );
 
-        for i in ACTIVE.from..ACTIVE.to {
-            assert_eq!(active.mem[i], update[i - ACTIVE.from], "Index {}", i);
-        }
-
+        active.assert_eq(ACTIVE.from, &update);
         // First DFU page is untouched
-        for i in DFU.from + 4096..DFU.to {
-            assert_eq!(dfu.mem[i], original[i - DFU.from - 4096], "Index {}", i);
-        }
+        dfu.assert_eq(DFU.from + 4096, &original);
     }
 
     #[test]
@@ -203,12 +184,10 @@ mod tests {
         let mut dfu = MemFlash::<16384, 4096, 8>::random();
         let mut state = MemFlash::<4096, 128, 4>::random();
 
-        let original: [u8; ACTIVE.len()] = [rand::random::<u8>(); ACTIVE.len()];
-        let update: [u8; DFU.len()] = [rand::random::<u8>(); DFU.len()];
+        let original = [rand::random::<u8>(); ACTIVE.size() as usize];
+        let update = [rand::random::<u8>(); ACTIVE.size() as usize];
 
-        for i in ACTIVE.from..ACTIVE.to {
-            active.mem[i] = original[i - ACTIVE.from];
-        }
+        active.program(ACTIVE.from, &original).unwrap();
 
         let mut updater = FirmwareUpdater::new(DFU, STATE);
 
@@ -227,14 +206,9 @@ mod tests {
                 .unwrap()
         );
 
-        for i in ACTIVE.from..ACTIVE.to {
-            assert_eq!(active.mem[i], update[i - ACTIVE.from], "Index {}", i);
-        }
-
+        active.assert_eq(ACTIVE.from, &update);
         // First DFU page is untouched
-        for i in DFU.from + 4096..DFU.to {
-            assert_eq!(dfu.mem[i], original[i - DFU.from - 4096], "Index {}", i);
-        }
+        dfu.assert_eq(DFU.from + 4096, &original);
     }
 
     #[test]
@@ -281,7 +255,7 @@ mod tests {
             &mut flash,
             &public_key.to_bytes(),
             &signature.to_bytes(),
-            firmware_len,
+            firmware_len as u32,
             &mut aligned,
         ))
         .is_ok());
diff --git a/embassy-boot/boot/src/mem_flash.rs b/embassy-boot/boot/src/mem_flash.rs
index dd85405c8..c62379b24 100644
--- a/embassy-boot/boot/src/mem_flash.rs
+++ b/embassy-boot/boot/src/mem_flash.rs
@@ -32,6 +32,23 @@ impl<const SIZE: usize, const ERASE_SIZE: usize, const WRITE_SIZE: usize> MemFla
             pending_write_successes: None,
         }
     }
+
+    pub fn program(&mut self, offset: u32, bytes: &[u8]) -> Result<(), MemFlashError> {
+        let offset = offset as usize;
+        assert!(bytes.len() % WRITE_SIZE == 0);
+        assert!(offset % WRITE_SIZE == 0);
+        assert!(offset + bytes.len() <= SIZE);
+
+        self.mem[offset..offset + bytes.len()].copy_from_slice(bytes);
+
+        Ok(())
+    }
+
+    pub fn assert_eq(&self, offset: u32, expectation: &[u8]) {
+        for i in 0..expectation.len() {
+            assert_eq!(self.mem[offset as usize + i], expectation[i], "Index {}", i);
+        }
+    }
 }
 
 impl<const SIZE: usize, const ERASE_SIZE: usize, const WRITE_SIZE: usize> Default
diff --git a/embassy-boot/boot/src/partition.rs b/embassy-boot/boot/src/partition.rs
index ac6b0ed0f..7529059b6 100644
--- a/embassy-boot/boot/src/partition.rs
+++ b/embassy-boot/boot/src/partition.rs
@@ -6,20 +6,19 @@ use embedded_storage_async::nor_flash::{NorFlash as AsyncNorFlash, ReadNorFlash
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct Partition {
     /// The offset into the flash where the partition starts.
-    pub from: usize,
+    pub from: u32,
     /// The offset into the flash where the partition ends.
-    pub to: usize,
+    pub to: u32,
 }
 
 impl Partition {
     /// Create a new partition with the provided range
-    pub const fn new(from: usize, to: usize) -> Self {
+    pub const fn new(from: u32, to: u32) -> Self {
         Self { from, to }
     }
 
     /// Return the size of the partition
-    #[allow(clippy::len_without_is_empty)]
-    pub const fn len(&self) -> usize {
+    pub const fn size(&self) -> u32 {
         self.to - self.from
     }
 
diff --git a/embassy-boot/nrf/src/lib.rs b/embassy-boot/nrf/src/lib.rs
index a2176f609..d46ed9f36 100644
--- a/embassy-boot/nrf/src/lib.rs
+++ b/embassy-boot/nrf/src/lib.rs
@@ -30,20 +30,20 @@ impl Default for BootLoader<PAGE_SIZE> {
 
         let active = unsafe {
             Partition::new(
-                &__bootloader_active_start as *const u32 as usize,
-                &__bootloader_active_end as *const u32 as usize,
+                &__bootloader_active_start as *const u32 as u32,
+                &__bootloader_active_end as *const u32 as u32,
             )
         };
         let dfu = unsafe {
             Partition::new(
-                &__bootloader_dfu_start as *const u32 as usize,
-                &__bootloader_dfu_end as *const u32 as usize,
+                &__bootloader_dfu_start as *const u32 as u32,
+                &__bootloader_dfu_end as *const u32 as u32,
             )
         };
         let state = unsafe {
             Partition::new(
-                &__bootloader_state_start as *const u32 as usize,
-                &__bootloader_state_end as *const u32 as usize,
+                &__bootloader_state_start as *const u32 as u32,
+                &__bootloader_state_end as *const u32 as u32,
             )
         };
 
diff --git a/embassy-boot/rp/src/lib.rs b/embassy-boot/rp/src/lib.rs
index 0031efa63..c3cb22299 100644
--- a/embassy-boot/rp/src/lib.rs
+++ b/embassy-boot/rp/src/lib.rs
@@ -66,20 +66,20 @@ impl Default for BootLoader<ERASE_SIZE> {
 
         let active = unsafe {
             Partition::new(
-                &__bootloader_active_start as *const u32 as usize,
-                &__bootloader_active_end as *const u32 as usize,
+                &__bootloader_active_start as *const u32 as u32,
+                &__bootloader_active_end as *const u32 as u32,
             )
         };
         let dfu = unsafe {
             Partition::new(
-                &__bootloader_dfu_start as *const u32 as usize,
-                &__bootloader_dfu_end as *const u32 as usize,
+                &__bootloader_dfu_start as *const u32 as u32,
+                &__bootloader_dfu_end as *const u32 as u32,
             )
         };
         let state = unsafe {
             Partition::new(
-                &__bootloader_state_start as *const u32 as usize,
-                &__bootloader_state_end as *const u32 as usize,
+                &__bootloader_state_start as *const u32 as u32,
+                &__bootloader_state_end as *const u32 as u32,
             )
         };
 
diff --git a/embassy-boot/stm32/src/lib.rs b/embassy-boot/stm32/src/lib.rs
index 1f63fcd63..94404697f 100644
--- a/embassy-boot/stm32/src/lib.rs
+++ b/embassy-boot/stm32/src/lib.rs
@@ -61,20 +61,20 @@ impl<const BUFFER_SIZE: usize> Default for BootLoader<BUFFER_SIZE> {
 
         let active = unsafe {
             Partition::new(
-                &__bootloader_active_start as *const u32 as usize,
-                &__bootloader_active_end as *const u32 as usize,
+                &__bootloader_active_start as *const u32 as u32,
+                &__bootloader_active_end as *const u32 as u32,
             )
         };
         let dfu = unsafe {
             Partition::new(
-                &__bootloader_dfu_start as *const u32 as usize,
-                &__bootloader_dfu_end as *const u32 as usize,
+                &__bootloader_dfu_start as *const u32 as u32,
+                &__bootloader_dfu_end as *const u32 as u32,
             )
         };
         let state = unsafe {
             Partition::new(
-                &__bootloader_state_start as *const u32 as usize,
-                &__bootloader_state_end as *const u32 as usize,
+                &__bootloader_state_start as *const u32 as u32,
+                &__bootloader_state_end as *const u32 as u32,
             )
         };