Merge remote-tracking branch 'origin'

1 files changed, 16 insertions, 26 deletions

diff --git a/embassy-boot/boot/src/boot_loader.rs b/embassy-boot/boot/src/boot_loader.rs
index a8c19197b..e568001bc 100644
--- a/embassy-boot/boot/src/boot_loader.rs
+++ b/embassy-boot/boot/src/boot_loader.rs
@@ -5,7 +5,7 @@ use embassy_sync::blocking_mutex::raw::NoopRawMutex;
 use embassy_sync::blocking_mutex::Mutex;
 use embedded_storage::nor_flash::{NorFlash, NorFlashError, NorFlashErrorKind};
 
-use crate::{State, BOOT_MAGIC, STATE_ERASE_VALUE, SWAP_MAGIC};
+use crate::{State, BOOT_MAGIC, DFU_DETACH_MAGIC, STATE_ERASE_VALUE, SWAP_MAGIC};
 
 /// Errors returned by bootloader
 #[derive(PartialEq, Eq, Debug)]
@@ -135,51 +135,44 @@ impl<ACTIVE: NorFlash, DFU: NorFlash, STATE: NorFlash> BootLoader<ACTIVE, DFU, S
     /// The provided aligned_buf argument must satisfy any alignment requirements
     /// given by the partition flashes. All flash operations will use this buffer.
     ///
-    /// SWAPPING
+    /// ## SWAPPING
     ///
     /// Assume a flash size of 3 pages for the active partition, and 4 pages for the DFU partition.
     /// The swap index contains the copy progress, as to allow continuation of the copy process on
     /// power failure. The index counter is represented within 1 or more pages (depending on total
-    /// flash size), where a page X is considered swapped if index at location (X + WRITE_SIZE)
+    /// flash size), where a page X is considered swapped if index at location (`X + WRITE_SIZE`)
     /// contains a zero value. This ensures that index updates can be performed atomically and
     /// avoid a situation where the wrong index value is set (page write size is "atomic").
     ///
-    /// +-----------+------------+--------+--------+--------+--------+
+    ///
     /// | Partition | Swap Index | Page 0 | Page 1 | Page 3 | Page 4 |
-    /// +-----------+------------+--------+--------+--------+--------+
+    /// |-----------|------------|--------|--------|--------|--------|
     /// |    Active |          0 |      1 |      2 |      3 |      - |
     /// |       DFU |          0 |      3 |      2 |      1 |      X |
-    /// +-----------+------------+--------+--------+--------+--------+
     ///
     /// The algorithm starts by copying 'backwards', and after the first step, the layout is
     /// as follows:
     ///
-    /// +-----------+------------+--------+--------+--------+--------+
     /// | Partition | Swap Index | Page 0 | Page 1 | Page 3 | Page 4 |
-    /// +-----------+------------+--------+--------+--------+--------+
+    /// |-----------|------------|--------|--------|--------|--------|
     /// |    Active |          1 |      1 |      2 |      1 |      - |
     /// |       DFU |          1 |      3 |      2 |      1 |      3 |
-    /// +-----------+------------+--------+--------+--------+--------+
     ///
     /// The next iteration performs the same steps
     ///
-    /// +-----------+------------+--------+--------+--------+--------+
     /// | Partition | Swap Index | Page 0 | Page 1 | Page 3 | Page 4 |
-    /// +-----------+------------+--------+--------+--------+--------+
+    /// |-----------|------------|--------|--------|--------|--------|
     /// |    Active |          2 |      1 |      2 |      1 |      - |
     /// |       DFU |          2 |      3 |      2 |      2 |      3 |
-    /// +-----------+------------+--------+--------+--------+--------+
     ///
     /// And again until we're done
     ///
-    /// +-----------+------------+--------+--------+--------+--------+
     /// | Partition | Swap Index | Page 0 | Page 1 | Page 3 | Page 4 |
-    /// +-----------+------------+--------+--------+--------+--------+
+    /// |-----------|------------|--------|--------|--------|--------|
     /// |    Active |          3 |      3 |      2 |      1 |      - |
     /// |       DFU |          3 |      3 |      1 |      2 |      3 |
-    /// +-----------+------------+--------+--------+--------+--------+
     ///
-    /// REVERTING
+    /// ## REVERTING
     ///
     /// The reverting algorithm uses the swap index to discover that images were swapped, but that
     /// the application failed to mark the boot successful. In this case, the revert algorithm will
@@ -190,28 +183,21 @@ impl<ACTIVE: NorFlash, DFU: NorFlash, STATE: NorFlash> BootLoader<ACTIVE, DFU, S
     ///
     /// The revert algorithm works forwards, by starting copying into the 'unused' DFU page at the start.
     ///
-    /// +-----------+--------------+--------+--------+--------+--------+
     /// | Partition | Revert Index | Page 0 | Page 1 | Page 3 | Page 4 |
-    //*/
-    /// +-----------+--------------+--------+--------+--------+--------+
+    /// |-----------|--------------|--------|--------|--------|--------|
     /// |    Active |            3 |      1 |      2 |      1 |      - |
     /// |       DFU |            3 |      3 |      1 |      2 |      3 |
-    /// +-----------+--------------+--------+--------+--------+--------+
     ///
     ///
-    /// +-----------+--------------+--------+--------+--------+--------+
     /// | Partition | Revert Index | Page 0 | Page 1 | Page 3 | Page 4 |
-    /// +-----------+--------------+--------+--------+--------+--------+
+    /// |-----------|--------------|--------|--------|--------|--------|
     /// |    Active |            3 |      1 |      2 |      1 |      - |
     /// |       DFU |            3 |      3 |      2 |      2 |      3 |
-    /// +-----------+--------------+--------+--------+--------+--------+
     ///
-    /// +-----------+--------------+--------+--------+--------+--------+
     /// | Partition | Revert Index | Page 0 | Page 1 | Page 3 | Page 4 |
-    /// +-----------+--------------+--------+--------+--------+--------+
+    /// |-----------|--------------|--------|--------|--------|--------|
     /// |    Active |            3 |      1 |      2 |      3 |      - |
     /// |       DFU |            3 |      3 |      2 |      1 |      3 |
-    /// +-----------+--------------+--------+--------+--------+--------+
     ///
     pub fn prepare_boot(&mut self, aligned_buf: &mut [u8]) -> Result<State, BootError> {
         // Ensure we have enough progress pages to store copy progress
@@ -224,6 +210,7 @@ impl<ACTIVE: NorFlash, DFU: NorFlash, STATE: NorFlash> BootLoader<ACTIVE, DFU, S
         assert_eq!(0, aligned_buf.len() % ACTIVE::WRITE_SIZE);
         assert_eq!(0, aligned_buf.len() % DFU::WRITE_SIZE);
 
+        // Ensure our partitions are able to handle boot operations
         assert_partitions(&self.active, &self.dfu, &self.state, Self::PAGE_SIZE);
 
         // Copy contents from partition N to active
@@ -384,6 +371,8 @@ impl<ACTIVE: NorFlash, DFU: NorFlash, STATE: NorFlash> BootLoader<ACTIVE, DFU, S
 
         if !state_word.iter().any(|&b| b != SWAP_MAGIC) {
             Ok(State::Swap)
+        } else if !state_word.iter().any(|&b| b != DFU_DETACH_MAGIC) {
+            Ok(State::DfuDetach)
         } else {
             Ok(State::Boot)
         }
@@ -398,6 +387,7 @@ fn assert_partitions<ACTIVE: NorFlash, DFU: NorFlash, STATE: NorFlash>(
 ) {
     assert_eq!(active.capacity() as u32 % page_size, 0);
     assert_eq!(dfu.capacity() as u32 % page_size, 0);
+    // DFU partition has to be bigger than ACTIVE partition to handle swap algorithm
     assert!(dfu.capacity() as u32 - active.capacity() as u32 >= page_size);
     assert!(2 + 2 * (active.capacity() as u32 / page_size) <= state.capacity() as u32 / STATE::WRITE_SIZE as u32);
 }