Mount EFS only once

With this patch, the EFS is only mounted once if it is mountable.  This
significantly reduces bootup time by approximately 0.5 s.

Fixes: #440

CHANGELOG.md

@@ -6,7 +6,9 @@
 
 - fido-authenticator: Implement the largeBlobKey extension and the largeBlobs command ([fido-authenticator#38][])
 - piv: Fix crash when changing PUK ([piv-authenticator#38][])
+- Improve external flash mounting to decrease startup time ([#440][])
 
+[#440]: https://github.com/Nitrokey/nitrokey-3-firmware/issues/440
 [fido-authenticator#38]: https://github.com/Nitrokey/fido-authenticator/issues/38
 [piv-authenticator#38]: https://github.com/Nitrokey/piv-authenticator/issues/38
 

Cargo.toml

@@ -28,7 +28,7 @@ trussed = { git = "https://github.com/Nitrokey/trussed.git", tag = "v0.1.0-nitro
 apdu-dispatch = { git = "https://github.com/Nitrokey/apdu-dispatch.git", tag = "v0.1.2-nitrokey.3" }
 ctap-types = { git = "https://github.com/trussed-dev/ctap-types.git", rev = "a9f8003a1d9f05f9eea39e615b9159bc0613fcb5" }
 ctaphid-dispatch = { git = "https://github.com/Nitrokey/ctaphid-dispatch.git", tag = "v0.1.1-nitrokey.3" }
-littlefs2 = { git = "https://github.com/trussed-dev/littlefs2.git", rev = "960e57d9fc0d209308c8e15dc26252bbe1ff6ba8" }
+littlefs2 = { git = "https://github.com/trussed-dev/littlefs2.git", rev = "2ad77859559c02c7a464ab4d3290a318cf81422d" }
 littlefs2-sys = { git = "https://github.com/trussed-dev/littlefs2-sys.git", rev = "39626c0dbc2f6c38b74889a5bf9d5a200614f121" }
 usbd-ctaphid = { git = "https://github.com/trussed-dev/usbd-ctaphid.git", rev = "1db2e014f28669bc484c81ab0406c54b16bba33c" }
 usbd-ccid = { git = "https://github.com/Nitrokey/usbd-ccid", tag = "v0.2.0-nitrokey.1" }

components/boards/src/store.rs

@@ -265,16 +265,17 @@ fn init_efs<B: Board>(
     simulated_efs: bool,
     status: &mut InitStatus,
 ) -> LfsResult<Filesystem<'static, B::ExternalStorage>> {
-    if !Filesystem::is_mountable(efs_storage) {
-        let fmt_ext = Filesystem::format(efs_storage);
+    Filesystem::mount_or_else(efs_alloc, efs_storage, |_err, storage| {
+        error_now!("EFS Mount Error {:?}", _err);
+        let fmt_ext = Filesystem::format(storage);
         if simulated_efs && fmt_ext == Err(littlefs2::io::Error::NoSpace) {
             info_now!("Formatting simulated EFS failed as expected");
         } else {
-            error_now!("EFS Mount Error, Reformat {:?}", fmt_ext);
+            error_now!("EFS Reformat {:?}", fmt_ext);
             status.insert(InitStatus::EXTERNAL_FLASH_ERROR);
         }
-    };
-    Filesystem::mount(efs_alloc, efs_storage)
+        Ok(())
+    })
 }
 
 #[inline(always)]