diff options
Diffstat (limited to 'src/barebox-state/backend_storage.c')
| -rw-r--r-- | src/barebox-state/backend_storage.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/barebox-state/backend_storage.c b/src/barebox-state/backend_storage.c index 9e80791..acc2623 100644 --- a/src/barebox-state/backend_storage.c +++ b/src/barebox-state/backend_storage.c @@ -26,6 +26,28 @@ #include "state.h" +/* + * The state framework stores data in so called buckets. A bucket is + * exactly one copy of the state we want to store. On flash type media + * a bucket corresponds to a single eraseblock. On media which do not + * need an erase operation a bucket corresponds to a storage area of + * @stridesize bytes. + * + * For redundancy and to make sure that we have valid data on the storage + * device at any time the state framework stores multiple buckets. The strategy + * is as follows: + * + * When loading the state from the storage we iterate over the buckets. We + * take the first one we find which has valid crcs. The next step is to + * restore consistency between the different buckets. This means rewriting + * a bucket when it signalled it needs refresh (i.e. returned -EUCLEAN) + * or when contains data different from the bucket we use. + * + * When the state backend initialized successfully we already restored + * consistency which means all buckets contain the same data. This means + * when storing a new state we can just write all buckets in order. + */ + const unsigned int min_copies_written = 1; /** |