diff options
| -rw-r--r-- | src/flash/nor/core.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/flash/nor/core.c b/src/flash/nor/core.c index fc020a8a..767006d2 100644 --- a/src/flash/nor/core.c +++ b/src/flash/nor/core.c @@ -54,6 +54,63 @@ int flash_driver_erase(struct flash_bank *bank, int first, int last) int flash_driver_protect(struct flash_bank *bank, int set, int first, int last) { int retval; + bool updated = false; + + /* NOTE: "first == last" means protect just that sector */ + + /* callers may not supply illegal parameters ... */ + if (first < 0 || first > last || last >= bank->num_sectors) + return ERROR_FAIL; + + /* force "set" to 0/1 */ + set = !!set; + + /* + * Filter out what trivial nonsense we can, so drivers don't have to. + * + * Don't tell drivers to change to the current state... it's needless, + * and reducing the amount of work to be done (potentially to nothing) + * speeds at least some things up. + */ +scan: + for (int i = first; i < last; i++) { + struct flash_sector *sector = bank->sectors + i; + + /* Only filter requests to protect the already-protected, or + * to unprotect the already-unprotected. Changing from the + * unknown state (-1) to a known one is unwise but allowed; + * protection status is best checked first. + */ + if (sector->is_protected != set) + continue; + + /* Shrink this range of sectors from the start; don't overrun + * the end. Also shrink from the end; don't overun the start. + * + * REVISIT we could handle discontiguous regions by issuing + * more than one driver request. How much would that matter? + */ + if (i == first) { + updated = true; + first++; + } else if (i == last) { + updated = true; + last--; + } + } + + /* updating the range affects the tests in the scan loop above; so + * re-scan, to make sure we didn't miss anything. + */ + if (updated) { + updated = false; + goto scan; + } + + /* Single sector, already protected? Nothing to do! */ + if (first == last) + return ERROR_OK; + retval = bank->driver->protect(bank, set, first, last); if (retval != ERROR_OK) |