Add GPS stub for linux

meson.build

@@ -163,6 +163,7 @@ linux_src = src + ['platform/targets/linux/emulator/emulator.c',
                    'platform/drivers/display/display_libSDL.c',
                    'platform/drivers/keyboard/keyboard_linux.c',
                    'platform/drivers/NVM/nvmem_linux.c',
+                   'platform/drivers/GPS/GPS_linux.c',
                    'platform/mcu/x86_64/drivers/gpio.c',
                    'platform/mcu/x86_64/drivers/delays.c',
                    'platform/mcu/x86_64/drivers/rtc.c',

platform/drivers/GPS/GPS_linux.c

@@ -0,0 +1,60 @@
+/***************************************************************************
+ *   Copyright (C) 2021 by Federico Amedeo Izzo IU2NUO,                    *
+ *                         Niccolò Izzo IU2KIN                             *
+ *                         Frederik Saraci IU2NRO                          *
+ *                         Silvano Seva IU2KWO                             *
+ *                                                                         *
+ *   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 3 of the License, 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; if not, see <http://www.gnu.org/licenses/>   *
+ ***************************************************************************/
+
+#include <interfaces/gps.h>
+#include <hwconfig.h>
+#include <string.h>
+#include <os.h>
+
+void gps_init(const uint16_t baud)
+{
+    ;
+}
+
+void gps_terminate()
+{
+    ;
+}
+
+void gps_enable()
+{
+    ;
+}
+
+void gps_disable()
+{
+    ;
+}
+
+bool gps_detect(uint16_t timeout)
+{
+    return true;
+}
+
+int gps_getNmeaSentence(char *buf, const size_t maxLength)
+{
+    OS_ERR os_err;
+
+    // Emulate GPS device by sending NMEA sentence every 1s
+    OSTimeDlyHMSM(0u, 0u, 1u, 0u, OS_OPT_TIME_HMSM_STRICT, &os_err);
+    char *nmea_sample = "$GPRMC,083703.000,A,4229.7596,N,00912.5377,E,0.15,92.15,040221,,,A*51";
+    strncpy(buf, nmea_sample, maxLength);
+}
+