BSP.md

+The **Board Support Package** is a module that contains the hardware initialization and configuration of the microcontroller.   
+  
+The `bsp.cpp` and `bsp_impl.h` files can be found under: `/libs/miosix-kernel/arch/<your-arch>/<your-board>/interfaces_impl/`.  
+  
+The `bsp.cpp` contains the implementation of some functions that are called when the board is powered up and initialized.
+
+### IRQbspInit
+In this function the speed of the GPIO ports is configured. Here you can also configure the GPIO mode (e.g. configuring the correct alternate mode for the pins that belong to an SPI bus), the default serial port along with its speed and so on. 
+```cpp
+void IRQbspInit()
+{
+    // Enable all gpios
+    RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN | RCC_AHB1ENR_GPIOBEN |
+                    RCC_AHB1ENR_GPIOCEN | RCC_AHB1ENR_GPIODEN |
+                    RCC_AHB1ENR_GPIOEEN | RCC_AHB1ENR_GPIOHEN;
+    RCC_SYNC();
+
+    // Default to 50MHz speed for all GPIOS
+    GPIOA->OSPEEDR=0xaaaaaaaa; 
+    GPIOB->OSPEEDR=0xaaaaaaaa;
+    GPIOC->OSPEEDR=0xaaaaaaaa;
+    GPIOD->OSPEEDR=0xaaaaaaaa;
+    GPIOE->OSPEEDR=0xaaaaaaaa;
+    GPIOH->OSPEEDR=0xaaaaaaaa;
+
+    // Peripherals initialization
+    using namespace interfaces;
+    myspi::sck::mode(Mode::ALTERNATE);
+    myspi::sck::alternateFunction(5);
+    myspi::miso::mode(Mode::ALTERNATE);
+    myspi::miso::alternateFunction(5);
+    myspi::mosi::mode(Mode::ALTERNATE);
+    myspi::mosi::alternateFunction(5);
+
+    mysensor::cs::mode(Mode::OUTPUT);
+    mysensor::cs::high();
+    mysensor::int1::mode(Mode::INPUT);
+
+    // Setup default serial port on USART3 with a baud rate of 19200
+    DefaultConsole::instance().IRQset(intrusive_ref_ptr<Device>(
+        new STM32Serial(3, 19200,
+            defaultSerialFlowctrl ? STM32Serial::RTSCTS : STM32Serial::NOFLOWCTRL)));
+}
+```
+Note that `myspi` and `mysensor` along with their corresponding GPIOs are defined in the [hardware mapping](Hardware-Mapping) file (`hwmapping.h`).
+
+### bspInit2
+```cpp
+void bspInit2()
+{
+    #ifdef WITH_FILESYSTEM
+    // Open GPS serial on USART2 with a baud rate of 115200
+    intrusive_ref_ptr<DevFs> devFs = basicFilesystemSetup(SDIODriver::instance());
+    devFs->addDevice("gps", intrusive_ref_ptr<Device>(new STM32Serial(2, 115200)));
+    #endif //WITH_FILESYSTEM
+}
+```
+### Shutdown and Reboot
+Usually for safety reasons when designing a new board for a rocket, we never want the board to completely shotdown. So in that case the *shutdown()* function performs a *reboot()*.
+```cpp
+void shutdown()
+{
+    reboot();
+}
+
+void reboot()
+{
+    ioctl(STDOUT_FILENO,IOCTL_SYNC,0);
+    
+    #ifdef WITH_FILESYSTEM
+    FilesystemManager::instance().umountAll();
+    #endif //WITH_FILESYSTEM
+
+    disableInterrupts();
+    miosix_private::IRQsystemReboot();
+}
+```
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