max/embassy
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Avoid write to not-erased magic

Browse Source 
This introduces an additional marker to the state partition right after the magic which indicates whether the current progress is valid or not. Validation in tests that we never write without an erase is added.

There is currently a FIXME in the FirmwareUpdater. Let me know if we should take the erase value as a parameter. I opened a feature request in embedded-storage to get this value in the trait. Before this, the assumption about ERASE_VALUE=0xFF was the same.
This commit is contained in:
Rasmus Melchior Jacobsen
2023-04-04 07:18:29 +02:00
parent 7c11d85e1e
commit df3a1e1b9d
4 changed files with 63 additions and 81 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
embassy-boot/boot/src/firmware_updater.rs
View File

@ -220,11 +220,24 @@ impl FirmwareUpdater {
self.state.read(state_flash, 0, aligned).await?;
if aligned.iter().any(|&b| b != magic) {
aligned.fill(0);
// Read progress validity
self.state.read(state_flash, F::WRITE_SIZE as u32, aligned).await?;
self.state.write(state_flash, 0, aligned).await?;
// FIXME: Do not make this assumption.
const STATE_ERASE_VALUE: u8 = 0xFF;
if aligned.iter().any(|&b| b != STATE_ERASE_VALUE) {
// The current progress validity marker is invalid
} else {
// Invalidate progress
aligned.fill(!STATE_ERASE_VALUE);
self.state.write(state_flash, F::WRITE_SIZE as u32, aligned).await?;
}
// Clear magic and progress
self.state.wipe(state_flash).await?;
// Set magic
aligned.fill(magic);
self.state.write(state_flash, 0, aligned).await?;
}
@ -420,11 +433,24 @@ impl FirmwareUpdater {
self.state.read_blocking(state_flash, 0, aligned)?;
if aligned.iter().any(|&b| b != magic) {
aligned.fill(0);
// Read progress validity
self.state.read_blocking(state_flash, F::WRITE_SIZE as u32, aligned)?;
self.state.write_blocking(state_flash, 0, aligned)?;
// FIXME: Do not make this assumption.
const STATE_ERASE_VALUE: u8 = 0xFF;
if aligned.iter().any(|&b| b != STATE_ERASE_VALUE) {
// The current progress validity marker is invalid
} else {
// Invalidate progress
aligned.fill(!STATE_ERASE_VALUE);
self.state.write_blocking(state_flash, F::WRITE_SIZE as u32, aligned)?;
}
// Clear magic and progress
self.state.wipe_blocking(state_flash)?;
// Set magic
aligned.fill(magic);
self.state.write_blocking(state_flash, 0, aligned)?;
}