soc/stm32: add initial support for STM32F3X series

Supported SoCs:
- STM32F303XC
- STM32F334X8
- STM32F373XC

Change-Id: I74b9561272d54e270ae1a1f602fd389d4c86539a
Signed-off-by: Adam Podogrocki <adam.podogrocki@rndity.com>

arch/arm/soc/st_stm32/stm32f3/soc.c

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2016 RnDity Sp. z o.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @file
+ * @brief System/hardware module for STM32F3 processor
+ */
+
+#include <nanokernel.h>
+#include <device.h>
+#include <init.h>
+#include <soc.h>
+#include <arch/cpu.h>
+
+/**
+ * @brief Perform basic hardware initialization at boot.
+ *
+ * This needs to be run from the very beginning.
+ * So the init priority has to be 0 (zero).
+ *
+ * @return 0
+ */
+static int stm32f3_init(struct device *arg)
+{
+	uint32_t key;
+
+	ARG_UNUSED(arg);
+
+	key = irq_lock();
+
+	/* Clear all faults */
+	_ScbMemFaultAllFaultsReset();
+	_ScbBusFaultAllFaultsReset();
+	_ScbUsageFaultAllFaultsReset();
+
+	_ScbHardFaultAllFaultsReset();
+
+	/* Install default handler that simply resets the CPU
+	 * if configured in the kernel, NOP otherwise
+	 */
+	NMI_INIT();
+
+	irq_unlock(key);
+
+	return 0;
+}
+
+SYS_INIT(stm32f3_init, PRE_KERNEL_1, 0);