Implement embedded-storage traits #429
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
LGTM. Could you add example? Or link on example in other repository to docs of flash.rs mod |
|
Adding an example is problematic, because that requires modifying linker script to add an exclusive memory region for flash writing/reading and it has to not interfere with firmware binary size as well as total flash size. It would not be possible to have a single linker script that also supports 64K devices. What if instead I added an inline example in the docs? |
burrbull
approved these changes
Feb 3, 2022
|
bors r+ |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR implements embedded-storage traits for flash.
One major headache with F4 series is dual-bank flash and non-uniform sector sizes, which required quite a bit of code to abstract away. I went through all of the F4 reference manuals and believe that
flash_sectors(...)function should be correct for all variants. AFAIK, there is no single source about flash layout for all the chips. Moreover, ST lists F429 and F469 with 512 KB of flash as dual-bank, but there is no information about it in the reference manual. I believe this could be an error in the website and only 1 MB chips have dual-bank capabilities.The PAC crate is also missing
DB1Mfield for some of the dual-bank capable chips, so for now I hardcoded the bit position inOPTCRregister.The writable
NorFlashtrait was implemented for the largest sector size of 128 KB, becauseembedded-storagedoes not intend to supprot non-uniform sectors (see comment). Smaller sectors are erased together in the larger 128 KB group. There was a suggestion to add different types for the smaller sector ranges, but I'm not sure if that is useful?