Merge #1312

1312: Let bootloader partition have read/write/erase operations r=Dirbaio a=rmja

This change should not have any breaking changes.

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

5 files changed, 243 insertions, 224 deletions

diff --git a/embassy-boot/boot/src/boot_loader.rs b/embassy-boot/boot/src/boot_loader.rs
index ad6735112..e2e361e3c 100644
--- a/embassy-boot/boot/src/boot_loader.rs
+++ b/embassy-boot/boot/src/boot_loader.rs
@@ -79,7 +79,7 @@ impl BootLoader {
         Self { active, dfu, state }
     }
 
-    /// Return the boot address for the active partition.
+    /// Return the offset of the active partition into the active flash.
     pub fn boot_address(&self) -> usize {
         self.active.from
     }
@@ -193,13 +193,13 @@ impl BootLoader {
                 self.revert(p, magic, page)?;
 
                 // Overwrite magic and reset progress
-                let fstate = p.state();
+                let state_flash = p.state();
                 magic.fill(!P::STATE::ERASE_VALUE);
-                fstate.write(self.state.from as u32, magic)?;
-                fstate.erase(self.state.from as u32, self.state.to as u32)?;
+                self.state.write_blocking(state_flash, 0, magic)?;
+                self.state.wipe_blocking(state_flash)?;
 
                 magic.fill(BOOT_MAGIC);
-                fstate.write(self.state.from as u32, magic)?;
+                self.state.write_blocking(state_flash, 0, magic)?;
             }
         }
         Ok(state)
@@ -218,9 +218,10 @@ impl BootLoader {
         let max_index = ((self.state.len() - write_size) / write_size) - 1;
         aligned.fill(!P::STATE::ERASE_VALUE);
 
-        let flash = config.state();
+        let state_flash = config.state();
         for i in 0..max_index {
-            flash.read((self.state.from + write_size + i * write_size) as u32, aligned)?;
+            self.state
+                .read_blocking(state_flash, (write_size + i * write_size) as u32, aligned)?;
 
             if aligned.iter().any(|&b| b == P::STATE::ERASE_VALUE) {
                 return Ok(i);
@@ -230,47 +231,39 @@ impl BootLoader {
     }
 
     fn update_progress<P: FlashConfig>(&mut self, idx: usize, p: &mut P, magic: &mut [u8]) -> Result<(), BootError> {
-        let flash = p.state();
         let write_size = magic.len();
-        let w = self.state.from + write_size + idx * write_size;
 
         let aligned = magic;
         aligned.fill(!P::STATE::ERASE_VALUE);
-        flash.write(w as u32, aligned)?;
+        self.state
+            .write_blocking(p.state(), (write_size + idx * write_size) as u32, aligned)?;
         Ok(())
     }
 
-    fn active_addr(&self, n: usize, page_size: usize) -> usize {
-        self.active.from + n * page_size
-    }
-
-    fn dfu_addr(&self, n: usize, page_size: usize) -> usize {
-        self.dfu.from + n * page_size
-    }
-
     fn copy_page_once_to_active<P: FlashConfig>(
         &mut self,
         idx: usize,
-        from_page: usize,
-        to_page: usize,
+        from_offset: u32,
+        to_offset: u32,
         p: &mut P,
         magic: &mut [u8],
         page: &mut [u8],
     ) -> Result<(), BootError> {
         let buf = page;
         if self.current_progress(p, magic)? <= idx {
-            let mut offset = from_page;
+            let mut offset = from_offset;
             for chunk in buf.chunks_mut(P::DFU::BLOCK_SIZE) {
-                p.dfu().read(offset as u32, chunk)?;
-                offset += chunk.len();
+                self.dfu.read_blocking(p.dfu(), offset, chunk)?;
+                offset += chunk.len() as u32;
             }
 
-            p.active().erase(to_page as u32, (to_page + buf.len()) as u32)?;
+            self.active
+                .erase_blocking(p.active(), to_offset, to_offset + buf.len() as u32)?;
 
-            let mut offset = to_page;
+            let mut offset = to_offset;
             for chunk in buf.chunks(P::ACTIVE::BLOCK_SIZE) {
-                p.active().write(offset as u32, chunk)?;
-                offset += chunk.len();
+                self.active.write_blocking(p.active(), offset, chunk)?;
+                offset += chunk.len() as u32;
             }
             self.update_progress(idx, p, magic)?;
         }
@@ -280,26 +273,27 @@ impl BootLoader {
     fn copy_page_once_to_dfu<P: FlashConfig>(
         &mut self,
         idx: usize,
-        from_page: usize,
-        to_page: usize,
+        from_offset: u32,
+        to_offset: u32,
         p: &mut P,
         magic: &mut [u8],
         page: &mut [u8],
     ) -> Result<(), BootError> {
         let buf = page;
         if self.current_progress(p, magic)? <= idx {
-            let mut offset = from_page;
+            let mut offset = from_offset;
             for chunk in buf.chunks_mut(P::ACTIVE::BLOCK_SIZE) {
-                p.active().read(offset as u32, chunk)?;
-                offset += chunk.len();
+                self.active.read_blocking(p.active(), offset, chunk)?;
+                offset += chunk.len() as u32;
             }
 
-            p.dfu().erase(to_page as u32, (to_page + buf.len()) as u32)?;
+            self.dfu
+                .erase_blocking(p.dfu(), to_offset as u32, to_offset + buf.len() as u32)?;
 
-            let mut offset = to_page;
+            let mut offset = to_offset;
             for chunk in buf.chunks(P::DFU::BLOCK_SIZE) {
-                p.dfu().write(offset as u32, chunk)?;
-                offset += chunk.len();
+                self.dfu.write_blocking(p.dfu(), offset, chunk)?;
+                offset += chunk.len() as u32;
             }
             self.update_progress(idx, p, magic)?;
         }
@@ -312,17 +306,20 @@ impl BootLoader {
         trace!("Page count: {}", page_count);
         for page_num in 0..page_count {
             trace!("COPY PAGE {}", page_num);
+
+            let idx = page_num * 2;
+
             // Copy active page to the 'next' DFU page.
-            let active_page = self.active_addr(page_count - 1 - page_num, page_size);
-            let dfu_page = self.dfu_addr(page_count - page_num, page_size);
-            //trace!("Copy active {} to dfu {}", active_page, dfu_page);
-            self.copy_page_once_to_dfu(page_num * 2, active_page, dfu_page, p, magic, 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;
+            //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, magic, page)?;
 
             // Copy DFU page to the active page
-            let active_page = self.active_addr(page_count - 1 - page_num, page_size);
-            let dfu_page = self.dfu_addr(page_count - 1 - page_num, page_size);
-            //trace!("Copy dfy {} to active {}", dfu_page, active_page);
-            self.copy_page_once_to_active(page_num * 2 + 1, dfu_page, active_page, p, magic, 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;
+            //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, magic, page)?;
         }
 
         Ok(())
@@ -332,23 +329,24 @@ impl BootLoader {
         let page_size = page.len();
         let page_count = self.active.len() / page_size;
         for page_num in 0..page_count {
+            let idx = page_count * 2 + page_num * 2;
+
             // Copy the bad active page to the DFU page
-            let active_page = self.active_addr(page_num, page_size);
-            let dfu_page = self.dfu_addr(page_num, page_size);
-            self.copy_page_once_to_dfu(page_count * 2 + page_num * 2, active_page, dfu_page, p, magic, 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, magic, page)?;
 
             // Copy the DFU page back to the active page
-            let active_page = self.active_addr(page_num, page_size);
-            let dfu_page = self.dfu_addr(page_num + 1, page_size);
-            self.copy_page_once_to_active(page_count * 2 + page_num * 2 + 1, dfu_page, active_page, p, magic, 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, magic, page)?;
         }
 
         Ok(())
     }
 
     fn read_state<P: FlashConfig>(&mut self, config: &mut P, magic: &mut [u8]) -> Result<State, BootError> {
-        let flash = config.state();
-        flash.read(self.state.from as u32, magic)?;
+        self.state.read_blocking(config.state(), 0, magic)?;
 
         if !magic.iter().any(|&b| b != SWAP_MAGIC) {
             Ok(State::Swap)
diff --git a/embassy-boot/boot/src/firmware_updater.rs b/embassy-boot/boot/src/firmware_updater.rs
index 2d8712277..af1ba114a 100644
--- a/embassy-boot/boot/src/firmware_updater.rs
+++ b/embassy-boot/boot/src/firmware_updater.rs
@@ -84,10 +84,10 @@ impl FirmwareUpdater {
     /// `mark_booted`.
     pub async fn get_state<F: AsyncNorFlash>(
         &mut self,
-        flash: &mut F,
+        state_flash: &mut F,
         aligned: &mut [u8],
     ) -> Result<State, FirmwareUpdaterError> {
-        flash.read(self.state.from as u32, aligned).await?;
+        self.state.read(state_flash, 0, aligned).await?;
 
         if !aligned.iter().any(|&b| b != SWAP_MAGIC) {
             Ok(State::Swap)
@@ -115,17 +115,16 @@ impl FirmwareUpdater {
     #[cfg(feature = "_verify")]
     pub async fn verify_and_mark_updated<F: AsyncNorFlash>(
         &mut self,
-        _flash: &mut F,
+        _state_and_dfu_flash: &mut F,
         _public_key: &[u8],
         _signature: &[u8],
         _update_len: usize,
         _aligned: &mut [u8],
     ) -> Result<(), FirmwareUpdaterError> {
-        let _end = self.dfu.from + _update_len;
         let _read_size = _aligned.len();
 
         assert_eq!(_aligned.len(), F::WRITE_SIZE);
-        assert!(_end <= self.dfu.to);
+        assert!(_update_len <= self.dfu.len());
 
         #[cfg(feature = "ed25519-dalek")]
         {
@@ -137,21 +136,10 @@ impl FirmwareUpdater {
             let signature = Signature::from_bytes(_signature).map_err(into_signature_error)?;
 
             let mut digest = Sha512::new();
-
-            let mut offset = self.dfu.from;
-            let last_offset = _end / _read_size * _read_size;
-
-            while offset < last_offset {
-                _flash.read(offset as u32, _aligned).await?;
-                digest.update(&_aligned);
-                offset += _read_size;
-            }
-
-            let remaining = _end % _read_size;
-
-            if remaining > 0 {
-                _flash.read(last_offset as u32, _aligned).await?;
-                digest.update(&_aligned[0..remaining]);
+            for offset in (0.._update_len).step_by(_aligned.len()) {
+                self.dfu.read(_state_and_dfu_flash, offset as u32, _aligned).await?;
+                let len = core::cmp::min(_update_len - offset, _aligned.len());
+                digest.update(&_aligned[..len]);
             }
 
             public_key
@@ -173,21 +161,10 @@ impl FirmwareUpdater {
             let signature = Signature::try_from(&signature).map_err(into_signature_error)?;
 
             let mut digest = Sha512::new();
-
-            let mut offset = self.dfu.from;
-            let last_offset = _end / _read_size * _read_size;
-
-            while offset < last_offset {
-                _flash.read(offset as u32, _aligned).await?;
-                digest.update(&_aligned);
-                offset += _read_size;
-            }
-
-            let remaining = _end % _read_size;
-
-            if remaining > 0 {
-                _flash.read(last_offset as u32, _aligned).await?;
-                digest.update(&_aligned[0..remaining]);
+            for offset in (0.._update_len).step_by(_aligned.len()) {
+                self.dfu.read(_state_and_dfu_flash, offset as u32, _aligned).await?;
+                let len = core::cmp::min(_update_len - offset, _aligned.len());
+                digest.update(&_aligned[..len]);
             }
 
             let message = digest.finalize();
@@ -202,7 +179,7 @@ impl FirmwareUpdater {
             r.map_err(into_signature_error)?
         }
 
-        self.set_magic(_aligned, SWAP_MAGIC, _flash).await
+        self.set_magic(_aligned, SWAP_MAGIC, _state_and_dfu_flash).await
     }
 
     /// Mark to trigger firmware swap on next boot.
@@ -213,11 +190,11 @@ impl FirmwareUpdater {
     #[cfg(not(feature = "_verify"))]
     pub async fn mark_updated<F: AsyncNorFlash>(
         &mut self,
-        flash: &mut F,
+        state_flash: &mut F,
         aligned: &mut [u8],
     ) -> Result<(), FirmwareUpdaterError> {
         assert_eq!(aligned.len(), F::WRITE_SIZE);
-        self.set_magic(aligned, SWAP_MAGIC, flash).await
+        self.set_magic(aligned, SWAP_MAGIC, state_flash).await
     }
 
     /// Mark firmware boot successful and stop rollback on reset.
@@ -227,29 +204,29 @@ impl FirmwareUpdater {
     /// The `aligned` buffer must have a size of F::WRITE_SIZE, and follow the alignment rules for the flash being written to.
     pub async fn mark_booted<F: AsyncNorFlash>(
         &mut self,
-        flash: &mut F,
+        state_flash: &mut F,
         aligned: &mut [u8],
     ) -> Result<(), FirmwareUpdaterError> {
         assert_eq!(aligned.len(), F::WRITE_SIZE);
-        self.set_magic(aligned, BOOT_MAGIC, flash).await
+        self.set_magic(aligned, BOOT_MAGIC, state_flash).await
     }
 
     async fn set_magic<F: AsyncNorFlash>(
         &mut self,
         aligned: &mut [u8],
         magic: u8,
-        flash: &mut F,
+        state_flash: &mut F,
     ) -> Result<(), FirmwareUpdaterError> {
-        flash.read(self.state.from as u32, aligned).await?;
+        self.state.read(state_flash, 0, aligned).await?;
 
         if aligned.iter().any(|&b| b != magic) {
             aligned.fill(0);
 
-            flash.write(self.state.from as u32, aligned).await?;
-            flash.erase(self.state.from as u32, self.state.to as u32).await?;
+            self.state.write(state_flash, 0, aligned).await?;
+            self.state.wipe(state_flash).await?;
 
             aligned.fill(magic);
-            flash.write(self.state.from as u32, aligned).await?;
+            self.state.write(state_flash, 0, aligned).await?;
         }
         Ok(())
     }
@@ -265,26 +242,17 @@ impl FirmwareUpdater {
         &mut self,
         offset: usize,
         data: &[u8],
-        flash: &mut F,
+        dfu_flash: &mut F,
         block_size: usize,
     ) -> Result<(), FirmwareUpdaterError> {
         assert!(data.len() >= F::ERASE_SIZE);
 
-        flash
-            .erase(
-                (self.dfu.from + offset) as u32,
-                (self.dfu.from + offset + data.len()) as u32,
-            )
+        self.dfu
+            .erase(dfu_flash, offset as u32, (offset + data.len()) as u32)
             .await?;
 
-        trace!(
-            "Erased from {} to {}",
-            self.dfu.from + offset,
-            self.dfu.from + offset + data.len()
-        );
-
         FirmwareWriter(self.dfu)
-            .write_block(offset, data, flash, block_size)
+            .write_block(offset, data, dfu_flash, block_size)
             .await?;
 
         Ok(())
@@ -297,11 +265,9 @@ impl FirmwareUpdater {
     /// exchange for added complexity.
     pub async fn prepare_update<F: AsyncNorFlash>(
         &mut self,
-        flash: &mut F,
+        dfu_flash: &mut F,
     ) -> Result<FirmwareWriter, FirmwareUpdaterError> {
-        flash.erase((self.dfu.from) as u32, (self.dfu.to) as u32).await?;
-
-        trace!("Erased from {} to {}", self.dfu.from, self.dfu.to);
+        self.dfu.wipe(dfu_flash).await?;
 
         Ok(FirmwareWriter(self.dfu))
     }
@@ -317,10 +283,10 @@ impl FirmwareUpdater {
     /// `mark_booted`.
     pub fn get_state_blocking<F: NorFlash>(
         &mut self,
-        flash: &mut F,
+        state_flash: &mut F,
         aligned: &mut [u8],
     ) -> Result<State, FirmwareUpdaterError> {
-        flash.read(self.state.from as u32, aligned)?;
+        self.state.read_blocking(state_flash, 0, aligned)?;
 
         if !aligned.iter().any(|&b| b != SWAP_MAGIC) {
             Ok(State::Swap)
@@ -348,7 +314,7 @@ impl FirmwareUpdater {
     #[cfg(feature = "_verify")]
     pub fn verify_and_mark_updated_blocking<F: NorFlash>(
         &mut self,
-        _flash: &mut F,
+        _state_and_dfu_flash: &mut F,
         _public_key: &[u8],
         _signature: &[u8],
         _update_len: usize,
@@ -370,21 +336,10 @@ impl FirmwareUpdater {
             let signature = Signature::from_bytes(_signature).map_err(into_signature_error)?;
 
             let mut digest = Sha512::new();
-
-            let mut offset = self.dfu.from;
-            let last_offset = _end / _read_size * _read_size;
-
-            while offset < last_offset {
-                _flash.read(offset as u32, _aligned)?;
-                digest.update(&_aligned);
-                offset += _read_size;
-            }
-
-            let remaining = _end % _read_size;
-
-            if remaining > 0 {
-                _flash.read(last_offset as u32, _aligned)?;
-                digest.update(&_aligned[0..remaining]);
+            for offset in (0.._update_len).step_by(_aligned.len()) {
+                self.dfu.read_blocking(_state_and_dfu_flash, offset as u32, _aligned)?;
+                let len = core::cmp::min(_update_len - offset, _aligned.len());
+                digest.update(&_aligned[..len]);
             }
 
             public_key
@@ -406,21 +361,10 @@ impl FirmwareUpdater {
             let signature = Signature::try_from(&signature).map_err(into_signature_error)?;
 
             let mut digest = Sha512::new();
-
-            let mut offset = self.dfu.from;
-            let last_offset = _end / _read_size * _read_size;
-
-            while offset < last_offset {
-                _flash.read(offset as u32, _aligned)?;
-                digest.update(&_aligned);
-                offset += _read_size;
-            }
-
-            let remaining = _end % _read_size;
-
-            if remaining > 0 {
-                _flash.read(last_offset as u32, _aligned)?;
-                digest.update(&_aligned[0..remaining]);
+            for offset in (0.._update_len).step_by(_aligned.len()) {
+                self.dfu.read_blocking(_state_and_dfu_flash, offset as u32, _aligned)?;
+                let len = core::cmp::min(_update_len - offset, _aligned.len());
+                digest.update(&_aligned[..len]);
             }
 
             let message = digest.finalize();
@@ -435,7 +379,7 @@ impl FirmwareUpdater {
             r.map_err(into_signature_error)?
         }
 
-        self.set_magic_blocking(_aligned, SWAP_MAGIC, _flash)
+        self.set_magic_blocking(_aligned, SWAP_MAGIC, _state_and_dfu_flash)
     }
 
     /// Mark to trigger firmware swap on next boot.
@@ -446,11 +390,11 @@ impl FirmwareUpdater {
     #[cfg(not(feature = "_verify"))]
     pub fn mark_updated_blocking<F: NorFlash>(
         &mut self,
-        flash: &mut F,
+        state_flash: &mut F,
         aligned: &mut [u8],
     ) -> Result<(), FirmwareUpdaterError> {
         assert_eq!(aligned.len(), F::WRITE_SIZE);
-        self.set_magic_blocking(aligned, SWAP_MAGIC, flash)
+        self.set_magic_blocking(aligned, SWAP_MAGIC, state_flash)
     }
 
     /// Mark firmware boot successful and stop rollback on reset.
@@ -460,29 +404,29 @@ impl FirmwareUpdater {
     /// The `aligned` buffer must have a size of F::WRITE_SIZE, and follow the alignment rules for the flash being written to.
     pub fn mark_booted_blocking<F: NorFlash>(
         &mut self,
-        flash: &mut F,
+        state_flash: &mut F,
         aligned: &mut [u8],
     ) -> Result<(), FirmwareUpdaterError> {
         assert_eq!(aligned.len(), F::WRITE_SIZE);
-        self.set_magic_blocking(aligned, BOOT_MAGIC, flash)
+        self.set_magic_blocking(aligned, BOOT_MAGIC, state_flash)
     }
 
     fn set_magic_blocking<F: NorFlash>(
         &mut self,
         aligned: &mut [u8],
         magic: u8,
-        flash: &mut F,
+        state_flash: &mut F,
     ) -> Result<(), FirmwareUpdaterError> {
-        flash.read(self.state.from as u32, aligned)?;
+        self.state.read_blocking(state_flash, 0, aligned)?;
 
         if aligned.iter().any(|&b| b != magic) {
             aligned.fill(0);
 
-            flash.write(self.state.from as u32, aligned)?;
-            flash.erase(self.state.from as u32, self.state.to as u32)?;
+            self.state.write_blocking(state_flash, 0, aligned)?;
+            self.state.wipe_blocking(state_flash)?;
 
             aligned.fill(magic);
-            flash.write(self.state.from as u32, aligned)?;
+            self.state.write_blocking(state_flash, 0, aligned)?;
         }
         Ok(())
     }
@@ -498,23 +442,15 @@ impl FirmwareUpdater {
         &mut self,
         offset: usize,
         data: &[u8],
-        flash: &mut F,
+        dfu_flash: &mut F,
         block_size: usize,
     ) -> Result<(), FirmwareUpdaterError> {
         assert!(data.len() >= F::ERASE_SIZE);
 
-        flash.erase(
-            (self.dfu.from + offset) as u32,
-            (self.dfu.from + offset + data.len()) as u32,
-        )?;
+        self.dfu
+            .erase_blocking(dfu_flash, offset as u32, (offset + data.len()) as u32)?;
 
-        trace!(
-            "Erased from {} to {}",
-            self.dfu.from + offset,
-            self.dfu.from + offset + data.len()
-        );
-
-        FirmwareWriter(self.dfu).write_block_blocking(offset, data, flash, block_size)?;
+        FirmwareWriter(self.dfu).write_block_blocking(offset, data, dfu_flash, block_size)?;
 
         Ok(())
     }
@@ -528,9 +464,7 @@ impl FirmwareUpdater {
         &mut self,
         flash: &mut F,
     ) -> Result<FirmwareWriter, FirmwareUpdaterError> {
-        flash.erase((self.dfu.from) as u32, (self.dfu.to) as u32)?;
-
-        trace!("Erased from {} to {}", self.dfu.from, self.dfu.to);
+        self.dfu.wipe_blocking(flash)?;
 
         Ok(FirmwareWriter(self.dfu))
     }
diff --git a/embassy-boot/boot/src/firmware_writer.rs b/embassy-boot/boot/src/firmware_writer.rs
index f992021bb..46079e731 100644
--- a/embassy-boot/boot/src/firmware_writer.rs
+++ b/embassy-boot/boot/src/firmware_writer.rs
@@ -21,32 +21,11 @@ impl FirmwareWriter {
         flash: &mut F,
         block_size: usize,
     ) -> Result<(), F::Error> {
-        trace!(
-            "Writing firmware at offset 0x{:x} len {}",
-            self.0.from + offset,
-            data.len()
-        );
-
-        let mut write_offset = self.0.from + offset;
+        let mut offset = offset as u32;
         for chunk in data.chunks(block_size) {
-            trace!("Wrote chunk at {}: {:?}", write_offset, chunk);
-            flash.write(write_offset as u32, chunk).await?;
-            write_offset += chunk.len();
-        }
-        /*
-        trace!("Wrote data, reading back for verification");
-
-        let mut buf: [u8; 4096] = [0; 4096];
-        let mut data_offset = 0;
-        let mut read_offset = self.dfu.from + offset;
-        for chunk in buf.chunks_mut(block_size) {
-            flash.read(read_offset as u32, chunk).await?;
-            trace!("Read chunk at {}: {:?}", read_offset, chunk);
-            assert_eq!(&data[data_offset..data_offset + block_size], chunk);
-            read_offset += chunk.len();
-            data_offset += chunk.len();
+            self.0.write(flash, offset, chunk).await?;
+            offset += chunk.len() as u32;
         }
-        */
 
         Ok(())
     }
@@ -65,32 +44,11 @@ impl FirmwareWriter {
         flash: &mut F,
         block_size: usize,
     ) -> Result<(), F::Error> {
-        trace!(
-            "Writing firmware at offset 0x{:x} len {}",
-            self.0.from + offset,
-            data.len()
-        );
-
-        let mut write_offset = self.0.from + offset;
+        let mut offset = offset as u32;
         for chunk in data.chunks(block_size) {
-            trace!("Wrote chunk at {}: {:?}", write_offset, chunk);
-            flash.write(write_offset as u32, chunk)?;
-            write_offset += chunk.len();
-        }
-        /*
-        trace!("Wrote data, reading back for verification");
-
-        let mut buf: [u8; 4096] = [0; 4096];
-        let mut data_offset = 0;
-        let mut read_offset = self.dfu.from + offset;
-        for chunk in buf.chunks_mut(block_size) {
-            flash.read(read_offset as u32, chunk).await?;
-            trace!("Read chunk at {}: {:?}", read_offset, chunk);
-            assert_eq!(&data[data_offset..data_offset + block_size], chunk);
-            read_offset += chunk.len();
-            data_offset += chunk.len();
+            self.0.write_blocking(flash, offset, chunk)?;
+            offset += chunk.len() as u32;
         }
-        */
 
         Ok(())
     }
diff --git a/embassy-boot/boot/src/lib.rs b/embassy-boot/boot/src/lib.rs
index a2259411f..4c28d7aa4 100644
--- a/embassy-boot/boot/src/lib.rs
+++ b/embassy-boot/boot/src/lib.rs
@@ -313,7 +313,8 @@ mod tests {
         ))
         .is_ok());
     }
-    struct MemFlash<const SIZE: usize, const ERASE_SIZE: usize, const WRITE_SIZE: usize>([u8; SIZE]);
+
+    pub struct MemFlash<const SIZE: usize, const ERASE_SIZE: usize, const WRITE_SIZE: usize>(pub [u8; SIZE]);
 
     impl<const SIZE: usize, const ERASE_SIZE: usize, const WRITE_SIZE: usize> NorFlash
         for MemFlash<SIZE, ERASE_SIZE, WRITE_SIZE>
diff --git a/embassy-boot/boot/src/partition.rs b/embassy-boot/boot/src/partition.rs
index 46f80a23c..3ccd4dd76 100644
--- a/embassy-boot/boot/src/partition.rs
+++ b/embassy-boot/boot/src/partition.rs
@@ -1,10 +1,13 @@
+use embedded_storage::nor_flash::{NorFlash, ReadNorFlash};
+use embedded_storage_async::nor_flash::{NorFlash as AsyncNorFlash, ReadNorFlash as AsyncReadNorFlash};
+
 /// A region in flash used by the bootloader.
 #[derive(Copy, Clone, Debug)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct Partition {
-    /// Start of the flash region.
+    /// The offset into the flash where the partition starts.
     pub from: usize,
-    /// End of the flash region.
+    /// The offset into the flash where the partition ends.
     pub to: usize,
 }
 
@@ -14,9 +17,134 @@ impl Partition {
         Self { from, to }
     }
 
-    /// Return the length of the partition
+    /// Return the size of the partition
     #[allow(clippy::len_without_is_empty)]
     pub const fn len(&self) -> usize {
         self.to - self.from
     }
+
+    /// Read from the partition on the provided flash
+    pub(crate) async fn read<F: AsyncReadNorFlash>(
+        &self,
+        flash: &mut F,
+        offset: u32,
+        bytes: &mut [u8],
+    ) -> Result<(), F::Error> {
+        let offset = self.from as u32 + offset;
+        flash.read(offset, bytes).await
+    }
+
+    /// Write to the partition on the provided flash
+    pub(crate) async fn write<F: AsyncNorFlash>(
+        &self,
+        flash: &mut F,
+        offset: u32,
+        bytes: &[u8],
+    ) -> Result<(), F::Error> {
+        let offset = self.from as u32 + offset;
+        flash.write(offset, bytes).await?;
+        trace!("Wrote from 0x{:x} len {}", offset, bytes.len());
+        Ok(())
+    }
+
+    /// Erase part of the partition on the provided flash
+    pub(crate) async fn erase<F: AsyncNorFlash>(&self, flash: &mut F, from: u32, to: u32) -> Result<(), F::Error> {
+        let from = self.from as u32 + from;
+        let to = self.from as u32 + to;
+        flash.erase(from, to).await?;
+        trace!("Erased from 0x{:x} to 0x{:x}", from, to);
+        Ok(())
+    }
+
+    /// Erase the entire partition
+    pub(crate) async fn wipe<F: AsyncNorFlash>(&self, flash: &mut F) -> Result<(), F::Error> {
+        let from = self.from as u32;
+        let to = self.to as u32;
+        flash.erase(from, to).await?;
+        trace!("Wiped from 0x{:x} to 0x{:x}", from, to);
+        Ok(())
+    }
+
+    /// Read from the partition on the provided flash
+    pub(crate) fn read_blocking<F: ReadNorFlash>(
+        &self,
+        flash: &mut F,
+        offset: u32,
+        bytes: &mut [u8],
+    ) -> Result<(), F::Error> {
+        let offset = self.from as u32 + offset;
+        flash.read(offset, bytes)
+    }
+
+    /// Write to the partition on the provided flash
+    pub(crate) fn write_blocking<F: NorFlash>(&self, flash: &mut F, offset: u32, bytes: &[u8]) -> Result<(), F::Error> {
+        let offset = self.from as u32 + offset;
+        flash.write(offset, bytes)?;
+        trace!("Wrote from 0x{:x} len {}", offset, bytes.len());
+        Ok(())
+    }
+
+    /// Erase part of the partition on the provided flash
+    pub(crate) fn erase_blocking<F: NorFlash>(&self, flash: &mut F, from: u32, to: u32) -> Result<(), F::Error> {
+        let from = self.from as u32 + from;
+        let to = self.from as u32 + to;
+        flash.erase(from, to)?;
+        trace!("Erased from 0x{:x} to 0x{:x}", from, to);
+        Ok(())
+    }
+
+    /// Erase the entire partition
+    pub(crate) fn wipe_blocking<F: NorFlash>(&self, flash: &mut F) -> Result<(), F::Error> {
+        let from = self.from as u32;
+        let to = self.to as u32;
+        flash.erase(from, to)?;
+        trace!("Wiped from 0x{:x} to 0x{:x}", from, to);
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::MemFlash;
+    use crate::Partition;
+
+    #[test]
+    fn can_erase() {
+        let mut flash = MemFlash::<1024, 64, 4>([0x00; 1024]);
+        let partition = Partition::new(256, 512);
+
+        partition.erase_blocking(&mut flash, 64, 192).unwrap();
+
+        for (index, byte) in flash.0.iter().copied().enumerate().take(256 + 64) {
+            assert_eq!(0x00, byte, "Index {}", index);
+        }
+
+        for (index, byte) in flash.0.iter().copied().enumerate().skip(256 + 64).take(128) {
+            assert_eq!(0xFF, byte, "Index {}", index);
+        }
+
+        for (index, byte) in flash.0.iter().copied().enumerate().skip(256 + 64 + 128) {
+            assert_eq!(0x00, byte, "Index {}", index);
+        }
+    }
+
+    #[test]
+    fn can_wipe() {
+        let mut flash = MemFlash::<1024, 64, 4>([0x00; 1024]);
+        let partition = Partition::new(256, 512);
+
+        partition.wipe_blocking(&mut flash).unwrap();
+
+        for (index, byte) in flash.0.iter().copied().enumerate().take(256) {
+            assert_eq!(0x00, byte, "Index {}", index);
+        }
+
+        for (index, byte) in flash.0.iter().copied().enumerate().skip(256).take(256) {
+            assert_eq!(0xFF, byte, "Index {}", index);
+        }
+
+        for (index, byte) in flash.0.iter().copied().enumerate().skip(512) {
+            assert_eq!(0x00, byte, "Index {}", index);
+        }
+    }
 }