Added error correction limits to config documentation

littlefs-project · Oct 30, 2024 · fb666a0 · fb666a0
1 parent 6e661e3
commit fb666a0
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Showing 2 changed files with 8 additions and 0 deletions.
diff --git a/ramrsbd.c b/ramrsbd.c
@@ -37,6 +37,10 @@ int ramrsbd_create(const struct lfs_config *cfg,
                     * bd->cfg->ecc_size))
             == 0);
 
+    // There's only 255 non-zero elements in GF(256), so ramrsbd is limited
+    // to at most 255 byte codewords
+    LFS_ASSERT(bd->cfg->code_size <= 255);
+
     // Make sure the requested error correction is possible
     LFS_ASSERT(bd->cfg->error_correction <= 0
             || (lfs_size_t)bd->cfg->error_correction <= bd->cfg->ecc_size/2);

diff --git a/ramrsbd.h b/ramrsbd.h
@@ -29,11 +29,15 @@ extern "C"
 struct ramrsbd_config {
     // Size of a codeword in bytes.
     //
+    // Limited to at most 255 bytes (non-zero elements in GF(256)).
+    //
     // Note code_size = read_size and prog_size + ecc_size.
     lfs_size_t code_size;
 
     // Size of the error-correcting code in bytes.
     //
+    // ramrsbd can reliably correct up to floor(ecc_size/2) byte errors.
+    //
     // Note code_size = read_size and prog_size + ecc_size.
     lfs_size_t ecc_size;