New: src/mcu-stm32f103.c.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

src/mcu-stm32f103.c

@@ -0,0 +1,50 @@
+/*
+ * mcu-stm32f103.c - STM32F103 specific routines
+ *
+ * Copyright (C) 2017
+ *               Free Software Initiative of Japan
+ * Author: NIIBE Yutaka <gniibe@fsij.org>
+ *
+ * This file is a part of Gnuk, a GnuPG USB Token implementation.
+ *
+ * Gnuk 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Gnuk 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.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdint.h>
+#include "mcu/stm32f103.h"
+
+static uint32_t
+rbit (uint32_t v)
+{
+  uint32_t r;
+
+  asm ("rbit	%0, %1" : "=r" (r) : "r" (v));
+  return r;
+}
+
+int
+check_crc32 (const uint32_t *start_p, const uint32_t *end_p)
+{
+  uint32_t crc32 = *end_p;
+  const uint32_t *p;
+
+  RCC->AHBENR |= RCC_AHBENR_CRCEN;
+  CRC->CR = CRC_CR_RESET;
+
+  for (p = start_p; p < end_p; p++)
+    CRC->DR = rbit (*p);
+
+  return (rbit (CRC->DR) ^ crc32) == 0xffffffff;
+}