diff --git a/src/bitboard.h-move-to-temp-migration-bitboard__bitboard.h b/src/bitboard.h-move-to-temp-migration-bitboard__bitboard.h
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+++ b/src/bitboard.h-move-to-temp-migration-bitboard__bitboard.h
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+/* bitboard.h - bitboard definitions.
+ *
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef BITBOARD_H
+#define BITBOARD_H
+
+#include "br.h"
+#include "chessdefs.h"
+#include "piece.h"
+#include "bitops.h"
+
+#define mask(s)  ( 1ULL << (s) )
+#define C64(const_u64) const_u64##ULL
+
+typedef enum square {
+    A1, B1, C1, D1, E1, F1, G1, H1,
+    A2, B2, C2, D2, E2, F2, G2, H2,
+    A3, B3, C3, D3, E3, F3, G3, H3,
+    A4, B4, C4, D4, E4, F4, G4, H4,
+    A5, B5, C5, D5, E5, F5, G5, H5,
+    A6, B6, C6, D6, E6, F6, G6, H6,
+    A7, B7, C7, D7, E7, F7, G7, H7,
+    A8, B8, C8, D8, E8, F8, G8, H8,
+    SQ_N,
+    SQ_0 = 0
+} square;
+
+typedef enum file {
+    FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H,
+    FILE_N,
+    FILE_0 = 0
+} file;
+
+typedef enum rank {
+    RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8,
+    RANK_N,
+    RANK_0 = 0
+} rank;
+
+typedef enum sq_bb {
+    //A1 = 0x01ULL, B1 = 0x02ULL, C1 = 1UL <<  2, D1 = 1UL <<  3,
+    //E1 = 1UL <<  4, F1 = 1UL <<  5, G1 = 1UL <<  6, H1 = 1UL <<
+    A1bb = mask(A1), A2bb = mask(A2), A3bb = mask(A3), A4bb = mask(A4),
+    A5bb = mask(A5), A6bb = mask(A6), A7bb = mask(A7), A8bb = mask(A8),
+    B1bb = mask(B1), B2bb = mask(B2), B3bb = mask(B3), B4bb = mask(B4),
+    B5bb = mask(B5), B6bb = mask(B6), B7bb = mask(B7), B8bb = mask(B8),
+    C1bb = mask(C1), C2bb = mask(C2), C3bb = mask(C3), C4bb = mask(C4),
+    C5bb = mask(C5), C6bb = mask(C6), C7bb = mask(C7), C8bb = mask(C8),
+    D1bb = mask(D1), D2bb = mask(D2), D3bb = mask(D3), D4bb = mask(D4),
+    D5bb = mask(D5), D6bb = mask(D6), D7bb = mask(D7), D8bb = mask(D8),
+    E1bb = mask(E1), E2bb = mask(E2), E3bb = mask(E3), E4bb = mask(E4),
+    E5bb = mask(E5), E6bb = mask(E6), E7bb = mask(E7), E8bb = mask(E8),
+    F1bb = mask(F1), F2bb = mask(F2), F3bb = mask(F3), F4bb = mask(F4),
+    F5bb = mask(F5), F6bb = mask(F6), F7bb = mask(F7), F8bb = mask(F8),
+    G1bb = mask(G1), G2bb = mask(G2), G3bb = mask(G3), G4bb = mask(G4),
+    G5bb = mask(G5), G6bb = mask(G6), G7bb = mask(G7), G8bb = mask(G8),
+    H1bb = mask(H1), H2bb = mask(H2), H3bb = mask(H3), H4bb = mask(H4),
+    H5bb = mask(H5), H6bb = mask(H6), H7bb = mask(H7), H8bb = mask(H8),
+} sq_bb;
+
+typedef enum file_bb {
+    FILE_Abb = 0x0101010101010101ULL,
+    FILE_Bbb = 0x0202020202020202ULL,
+    FILE_Cbb = 0x0404040404040404ULL,
+    FILE_Dbb = 0x0808080808080808ULL,
+    FILE_Ebb = 0x1010101010101010ULL,
+    FILE_Fbb = 0x2020202020202020ULL,
+    FILE_Gbb = 0x4040404040404040ULL,
+    FILE_Hbb = 0x8080808080808080ULL,
+} file_bb;
+
+typedef enum rank_bb {
+    RANK_1bb = 0x00000000000000ffULL,
+    RANK_2bb = 0x000000000000ff00ULL,
+    RANK_3bb = 0x0000000000ff0000ULL,
+    RANK_4bb = 0x00000000ff000000ULL,
+    RANK_5bb = 0x000000ff00000000ULL,
+    RANK_6bb = 0x0000ff0000000000ULL,
+    RANK_7bb = 0x00ff000000000000ULL,
+    RANK_8bb = 0xff00000000000000ULL
+} rank_bb;
+
+#define NORTH 8
+#define EAST  1
+#define SOUTH -NORTH
+#define WEST  -EAST
+
+#define NORTH_EAST (NORTH + EAST)
+#define SOUTH_EAST (SOUTH + EAST)
+#define SOUTH_WEST (SOUTH + WEST)
+#define NORTH_WEST (NORTH + WEST)
+
+void bitboard_init(void);
+
+#endif  /* BITBOARD_H */