nand-image-builder: Fix the copyright header

Add NextThing Co. and Free Electrons copyrights and add myself as the
author of the randomizer and image builder implementation.

Remove the lengthy description explaining how the BCH implementation works,
since this is the purpose of this tool is not to expose a BCH library
(which was the case of the original source code I copied from the kernel).
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Bernhard Nortmann <bernhard.nortmann@web.de>
---
Changes since v1:
- Add a link to the original bch.c source file

nand-image-builder.c

@@ -14,55 +14,22 @@
  * this program; if not, write to the Free Software Foundation, Inc., 51
  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
+ * For the BCH implementation:
+ *
  * Copyright © 2011 Parrot S.A.
  *
  * Author: Ivan Djelic <ivan.djelic@parrot.com>
  *
- * Description:
- *
- * This library provides runtime configurable encoding/decoding of binary
- * Bose-Chaudhuri-Hocquenghem (BCH) codes.
- *
- * Call init_bch to get a pointer to a newly allocated bch_control structure for
- * the given m (Galois field order), t (error correction capability) and
- * (optional) primitive polynomial parameters.
- *
- * Call encode_bch to compute and store ecc parity bytes to a given buffer.
- * Call decode_bch to detect and locate errors in received data.
- *
- * On systems supporting hw BCH features, intermediate results may be provided
- * to decode_bch in order to skip certain steps. See decode_bch() documentation
- * for details.
- *
- * Option CONFIG_BCH_CONST_PARAMS can be used to force fixed values of
- * parameters m and t; thus allowing extra compiler optimizations and providing
- * better (up to 2x) encoding performance. Using this option makes sense when
- * (m,t) are fixed and known in advance, e.g. when using BCH error correction
- * on a particular NAND flash device.
- *
- * Algorithmic details:
+ * See also:
+ * http://lxr.free-electrons.com/source/lib/bch.c
  *
- * Encoding is performed by processing 32 input bits in parallel, using 4
- * remainder lookup tables.
+ * For the randomizer and image builder implementation:
  *
- * The final stage of decoding involves the following internal steps:
- * a. Syndrome computation
- * b. Error locator polynomial computation using Berlekamp-Massey algorithm
- * c. Error locator root finding (by far the most expensive step)
+ * Copyright © 2016 NextThing Co.
+ * Copyright © 2016 Free Electrons
  *
- * In this implementation, step c is not performed using the usual Chien search.
- * Instead, an alternative approach described in [1] is used. It consists in
- * factoring the error locator polynomial using the Berlekamp Trace algorithm
- * (BTA) down to a certain degree (4), after which ad hoc low-degree polynomial
- * solving techniques [2] are used. The resulting algorithm, called BTZ, yields
- * much better performance than Chien search for usual (m,t) values (typically
- * m >= 13, t < 32, see [1]).
+ * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
  *
- * [1] B. Biswas, V. Herbert. Efficient root finding of polynomials over fields
- * of characteristic 2, in: Western European Workshop on Research in Cryptology
- * - WEWoRC 2009, Graz, Austria, LNCS, Springer, July 2009, to appear.
- * [2] [Zin96] V.A. Zinoviev. On the solution of equations of degree 10 over
- * finite fields GF(2^q). In Rapport de recherche INRIA no 2829, 1996.
  */
 
 #include <stdint.h>