Updated HackRF firmware

SoftwareDefined/HackRF/hackrf-2021.03.1/firmware/common/crc.c

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2019 Jared Boone <jared@sharebrained.com>
+ *
+ * This file is part of HackRF.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "crc.h"
+
+#include <stdbool.h>
+
+void crc32_init(crc32_t* const crc) {
+	crc->remainder = 0xffffffff;
+	crc->reversed_polynomial = 0xedb88320;
+	crc->final_xor = 0xffffffff;
+}
+
+void crc32_update(crc32_t* const crc, const uint8_t* const data, const size_t byte_count) {
+	uint32_t remainder = crc->remainder;
+	const size_t bit_count = byte_count * 8;
+	for(size_t bit_n=0; bit_n<bit_count; bit_n++) {
+		const bool bit_in = data[bit_n >> 3] & (1 << (bit_n & 7));
+		remainder ^= (bit_in ? 1 : 0);
+		const bool bit_out = (remainder & 1);
+		remainder >>= 1;
+		if( bit_out ) {
+			remainder ^= crc->reversed_polynomial;
+		}
+	}
+	crc->remainder = remainder;
+}
+
+uint32_t crc32_digest(const crc32_t* const crc) {
+	return crc->remainder ^ crc->final_xor;
+}