diff --git a/fsw/linux/libcan.c b/fsw/linux/libcan.c
index 31fcdfa..2c935b3 100644
--- a/fsw/linux/libcan.c
+++ b/fsw/linux/libcan.c
@@ -216,7 +216,6 @@ int32_t can_close_device(can_info_t* device)
 int32_t can_master_transaction(can_info_t* device) 
 {
   int32_t status;
-  uint8_t i;
 
   status = can_write(device);
   if (status != CAN_SUCCESS)
@@ -233,6 +232,7 @@ int32_t can_master_transaction(can_info_t* device)
   }
 
   #ifdef LIBCAN_VERBOSE
+    uint8_t i;
     OS_printf("can_master_transaction: \n");
     OS_printf("  can_id = 0x%08x \t tx: 0x", device->tx_frame.can_id);
     for (i = 0; i < device->tx_frame.can_dlc; i++)
diff --git a/fsw/linux/libgpio.c b/fsw/linux/libgpio.c
index b9c2797..2e92922 100644
--- a/fsw/linux/libgpio.c
+++ b/fsw/linux/libgpio.c
@@ -72,7 +72,7 @@ int32_t gpio_read(gpio_info_t* device, uint8_t* value)
 {
     int32_t status = GPIO_SUCCESS;
     char buffer[128];
-    char readValue;
+    char readValue[3];
     int fd;
 
     if(device->isOpen != GPIO_OPEN) 
@@ -95,8 +95,8 @@ int32_t gpio_read(gpio_info_t* device, uint8_t* value)
     }
 
     //convert from ASCII to decimal
-    if(readValue == '0') *value = 0;
-    else if(readValue == '1') *value = 1;
+    if(readValue[0] == '0') *value = 0;
+    else if(readValue[0] == '1') *value = 1;
     else {
         *value = 0;
     }
diff --git a/fsw/linux/libi2c.c b/fsw/linux/libi2c.c
index 6687c39..4ce6dbe 100644
--- a/fsw/linux/libi2c.c
+++ b/fsw/linux/libi2c.c
@@ -33,27 +33,27 @@ int32_t i2c_master_init(i2c_bus_info_t* device)
     device->handle = open(devname, O_RDWR);
     if (device->handle < 0)
     {
-        OS_printf("i2c bus open failed for handle = %d, %s\n", device->handle, strerror(errno));
+        printf("i2c bus open failed for handle = %d, %s\n", device->handle, strerror(errno));
         status = I2C_ERROR;
         device->isOpen = I2C_CLOSED;
     }
     else
     {
         device->isOpen = I2C_OPEN;
-        OS_printf("i2c bus open passed for handle = %d\n", device->handle);
+        printf("i2c bus open passed for handle = %d\n", device->handle);
     }
     return status;
 }
 
-int32_t i2c_master_transaction(int32_t handle, uint8_t addr, void * txbuf, uint8_t txlen, void * rxbuf, uint8_t rxlen, uint16_t timeout)
+int32_t i2c_master_transaction(i2c_bus_info_t* device, uint8_t addr, void * txbuf, uint8_t txlen, void * rxbuf, uint8_t rxlen, uint16_t timeout)
 {
     int32_t status = I2C_SUCCESS;
     int32_t resp;
 
     /* Set I2C slave address */
-    if (ioctl(handle, I2C_SLAVE, addr) < 0)
+    if (ioctl(device->handle, I2C_SLAVE, addr) < 0)
     {
-        OS_printf("i2c-%d setting slave address = 0x%X FAILED, %s\n", handle, addr, strerror(errno));
+        printf("i2c-%d setting slave address = 0x%X FAILED, %s\n", device->handle, addr, strerror(errno));
         status = I2C_ERROR;
         return status;
     }
@@ -61,20 +61,20 @@ int32_t i2c_master_transaction(int32_t handle, uint8_t addr, void * txbuf, uint8
     /* Perform write if needed */
     if (txlen > 0 )
     {
-        resp = write(handle, txbuf, txlen);
+        resp = write(device->handle, txbuf, txlen);
         if (resp != txlen)
         {
-            OS_printf("i2c-%d write to address 0x%X FAILED, [%u] %s\n", handle, addr, errno, strerror(errno));
+            printf("i2c-%d write to address 0x%X FAILED, [%u] %s\n", device->handle, addr, errno, strerror(errno));
             status = I2C_ERROR;
         }
     }
     /* Perform read if needed */
     if (rxlen > 0 )
     {
-        resp = read(handle, rxbuf, rxlen);
+        resp = read(device->handle, rxbuf, rxlen);
         if (resp != rxlen)
         {
-            OS_printf("i2c-%d read from address 0x%X FAILED, %s\n", handle, addr, strerror(errno));
+            printf("i2c-%d read from address 0x%X FAILED, %s\n", device->handle, addr, strerror(errno));
             status = I2C_ERROR;
         }
     }
@@ -82,69 +82,69 @@ int32_t i2c_master_transaction(int32_t handle, uint8_t addr, void * txbuf, uint8
     return status;
 }
 
-int32_t i2c_read_transaction(int32_t handle, uint8_t addr, void * rxbuf, uint8_t rxlen, uint8_t timeout)
+int32_t i2c_read_transaction(i2c_bus_info_t* device, uint8_t addr, void * rxbuf, uint8_t rxlen, uint8_t timeout)
 {
     int32_t resp;
     int32_t status = I2C_SUCCESS;
 
     /* Set I2C slave address */
-    if (ioctl(handle, I2C_SLAVE, addr) < 0)
+    if (ioctl(device->handle, I2C_SLAVE, addr) < 0)
     {
-        OS_printf("i2c-%d setting slave address = 0x%X FAILED, %s\n", handle, addr, strerror(errno));
+        printf("i2c-%d setting slave address = 0x%X FAILED, %s\n", device->handle, addr, strerror(errno));
         status = I2C_ERROR;
         return status;
     }
 
-    resp = read(handle, rxbuf, rxlen); //<-- ACK would need to go in here
+    resp = read(device->handle, rxbuf, rxlen); //<-- ACK would need to go in here
     if (resp != rxlen)
     {
-        OS_printf("i2c-%d read from address 0x%X FAILED, %s\n", handle, addr, strerror(errno));
+        printf("i2c-%d read from address 0x%X FAILED, %s\n", device->handle, addr, strerror(errno));
         status = I2C_ERROR;
     }
 
     return status;
 }
 
-int32_t i2c_write_transaction(int32_t handle, uint8_t addr, void * txbuf, uint8_t txlen, uint8_t timeout)
+int32_t i2c_write_transaction(i2c_bus_info_t* device, uint8_t addr, void * txbuf, uint8_t txlen, uint8_t timeout)
 {
     int32_t resp;
     int32_t status = I2C_SUCCESS;
 
     /* Set I2C slave address */
-    if (ioctl(handle, I2C_SLAVE, addr) < 0)
+    if (ioctl(device->handle, I2C_SLAVE, addr) < 0)
     {
-        OS_printf("i2c-%d setting slave address = 0x%X FAILED, %s\n", handle, addr, strerror(errno));
+        printf("i2c-%d setting slave address = 0x%X FAILED, %s\n", device->handle, addr, strerror(errno));
         status = I2C_ERROR;
         return status;
     }
 
-    resp = write(handle, txbuf, txlen);
+    resp = write(device->handle, txbuf, txlen);
     if (resp != txlen)
     {
-        OS_printf("i2c-%d write from address 0x%X FAILED, %s\n", handle, addr, strerror(errno));
+        printf("i2c-%d write from address 0x%X FAILED, %s\n", device->handle, addr, strerror(errno));
         status = I2C_ERROR;
     }
 
     return status;
 }
 
-int32_t i2c_multiple_transaction(int32_t handle, uint8_t addr, struct i2c_rdwr_ioctl_data* rdwr_data, uint16_t timeout)
+int32_t i2c_multiple_transaction(i2c_bus_info_t* device, uint8_t addr, struct i2c_rdwr_ioctl_data* rdwr_data, uint16_t timeout)
 {
     /* Do combined read/write transaction without stop (simply restarts) in between. */
     int32_t status = I2C_SUCCESS;
 
     /* Set I2C slave address */
-    if (ioctl(handle, I2C_SLAVE, addr) < 0)
+    if (ioctl(device->handle, I2C_SLAVE, addr) < 0)
     {
-        OS_printf("i2c-%d setting slave address = 0x%X FAILED, %s\n", handle, addr, strerror(errno));
+        printf("i2c-%d setting slave address = 0x%X FAILED, %s\n", device->handle, addr, strerror(errno));
         status = I2C_ERROR;
         return status;
     }
 
     /* Make the ICOTL call */
-    if (ioctl(handle, I2C_RDWR, rdwr_data) < 0)
+    if (ioctl(device->handle, I2C_RDWR, rdwr_data) < 0)
     {
-        OS_printf("i2c-%d multple transaction error = 0x%X FAILED, %s\n", handle, addr, strerror(errno));
+        printf("i2c-%d multple transaction error = 0x%X FAILED, %s\n", device->handle, addr, strerror(errno));
         status = I2C_ERROR;
         return status;
     }
diff --git a/fsw/linux/libsocket.c b/fsw/linux/libsocket.c
index 2966970..64f0474 100644
--- a/fsw/linux/libsocket.c
+++ b/fsw/linux/libsocket.c
@@ -172,7 +172,6 @@ int32_t socket_accept(socket_info_t* socket_info)
     int ret;
     struct sockaddr_in client;
     int32_t status;
-    int ip_str_len;
 
     status = SOCKET_SUCCESS;
 
@@ -290,9 +289,7 @@ int32_t socket_send(socket_info_t* socket_info, uint8_t* buffer, size_t buflen,
 {
     int ret;
     int32_t status;
-    int address_family;
     struct sockaddr_in remote_sockaddr;
-    unsigned int i;
     status = SOCKET_SUCCESS;
 
    switch(socket_info->type)
@@ -354,7 +351,6 @@ int32_t socket_recv(socket_info_t* socket_info, uint8_t* buffer, size_t buflen,
 {
     int c;
     int ret;
-    int ip_str_len;
     int32_t status;
     struct sockaddr_in remote_sockaddr;
 
diff --git a/fsw/linux/libspi.c b/fsw/linux/libspi.c
index d8f6d3e..340e9b5 100644
--- a/fsw/linux/libspi.c
+++ b/fsw/linux/libspi.c
@@ -15,7 +15,6 @@ NASA IV&V
 ivv-itc@lists.nasa.gov
 */
 
-#include "osapi.h"
 #include "libspi.h"
 
 spi_mutex_t spi_bus_mutex[MAX_SPI_BUSES];
diff --git a/fsw/linux/libtrq.c b/fsw/linux/libtrq.c
index aeac317..8787132 100644
--- a/fsw/linux/libtrq.c
+++ b/fsw/linux/libtrq.c
@@ -37,21 +37,21 @@ int32_t trq_set_time_high(trq_info_t* device, uint32_t new_time)
 {
     if(!device->enabled)
     {
-        OS_printf("trq_set_time_high: Error setting trq %d timer period because it's disabled! \n", device->trq_num); 
+        printf("trq_set_time_high: Error setting trq %d timer period because it's disabled! \n", device->trq_num); 
         return TRQ_ERROR; 
     }
 
 	// Make sure the time high isn't greater than the period
 	if(new_time > device->timer_period_ns) 
     {
-		OS_printf("trq_set_time_high: Error setting trq %d time high, must not exceed the period! \n", device->trq_num);
+		printf("trq_set_time_high: Error setting trq %d time high, must not exceed the period! \n", device->trq_num);
 		return TRQ_TIME_HIGH_VAL_ERR;
 	}
 
     ioctl(device->timerfd, TMRCTR_PWM_DISABLE); 
     if(ioctl(device->timerfd, TMRCTR_PWM_SET_HIGH_TIME, new_time) < 0)
     {
-        OS_printf("trq_set_time_high: Error setting trq %d high time! \n", device->trq_num); 
+        printf("trq_set_time_high: Error setting trq %d high time! \n", device->trq_num); 
         return TRQ_ERROR; 
     }
 	device->timer_high_ns = new_time;
@@ -61,7 +61,7 @@ int32_t trq_set_time_high(trq_info_t* device, uint32_t new_time)
         ioctl(device->timerfd, TMRCTR_PWM_ENABLE);
     }
 
-    //OS_printf("trq_set_time_high: timer_period_ns = %d, timer_high_ns = %d\n", device->timer_period_ns, device->timer_high_ns); 
+    //printf("trq_set_time_high: timer_period_ns = %d, timer_high_ns = %d\n", device->timer_period_ns, device->timer_high_ns); 
     return TRQ_SUCCESS;
 }
 
@@ -79,7 +79,7 @@ int32_t trq_set_period(trq_info_t* device)
 {
     if(!device->enabled)
     {
-        OS_printf("trq_set_period: Error setting trq %d timer period because it's disabled! \n", device->trq_num); 
+        printf("trq_set_period: Error setting trq %d timer period because it's disabled! \n", device->trq_num); 
         return TRQ_ERROR; 
     }
 
@@ -88,7 +88,7 @@ int32_t trq_set_period(trq_info_t* device)
 
     if(ioctl(device->timerfd, TMRCTR_PWM_SET_PERIOD, device->timer_period_ns) < 0)
     {
-        OS_printf("trq_set_period: Error setting trq %d timer period! \n", device->trq_num); 
+        printf("trq_set_period: Error setting trq %d timer period! \n", device->trq_num); 
         return TRQ_ERROR; 
     }
 
@@ -125,7 +125,7 @@ int32_t trq_set_direction(trq_info_t* device, bool direction)
 
     if (write(device->direction_pin_fd, &charVal, 1) != 1) 
     {
-        OS_printf("trq_set_direction: Error setting trq %d direction! \n", device->trq_num);
+        printf("trq_set_direction: Error setting trq %d direction! \n", device->trq_num);
         return TRQ_ERROR;
     }
     device->positive_direction = direction;
@@ -148,7 +148,6 @@ int32_t trq_init(trq_info_t* device)
 {
     int32_t status = TRQ_SUCCESS;
     char devname[TRQ_FNAME_SIZE];
-    char pinname[TRQ_FNAME_SIZE]; 
 
     if(!device->enabled)
     {
@@ -156,7 +155,7 @@ int32_t trq_init(trq_info_t* device)
         snprintf(devname, TRQ_FNAME_SIZE, "/dev/tmrctr%d", device->trq_num); 
         if((device->timerfd = open(devname, O_RDWR, 0)) < 0)
         {
-            OS_printf("trq_init: Error opening axi timer device %s \n", devname); 
+            printf("trq_init: Error opening axi timer device %s \n", devname); 
             return TRQ_INIT_ERR; 
         } 
         //printf("trq_init: Initialized AXI Timer Device: %s for device->trq_num %d \n", devname, device->trq_num);
@@ -165,7 +164,7 @@ int32_t trq_init(trq_info_t* device)
         snprintf(devname, TRQ_FNAME_SIZE, "/dev/hb%d", device->trq_num); 
         if((device->direction_pin_fd = open(devname, O_RDWR, 0)) < 0)
         {
-            OS_printf("trq_init: Error opening axi timer device %s \n", devname); 
+            printf("trq_init: Error opening axi timer device %s \n", devname); 
             return TRQ_INIT_ERR; 
         }
 
@@ -175,7 +174,6 @@ int32_t trq_init(trq_info_t* device)
         {
             return TRQ_INIT_ERR;
         }
-        //OS_printf("trq_init: Initialized direction pin: %s for device->trq_num %d\n", pinname, device->trq_num);
 
         device->enabled = true;
     }
@@ -214,7 +212,6 @@ int32_t trq_command(trq_info_t *device, uint8_t percent_high, bool pos_dir)
 {
     int32_t status = TRQ_SUCCESS;
     uint32_t time_high_ns;
-    char charVal;
 
     if(!device->enabled)
     {
@@ -225,7 +222,7 @@ int32_t trq_command(trq_info_t *device, uint8_t percent_high, bool pos_dir)
     // Calculate time high
     if (percent_high > 100)
     {
-        OS_printf("trq_command: Error setting percent high greater than 100! \n");
+        printf("trq_command: Error setting percent high greater than 100! \n");
         return TRQ_ERROR;
     }
     time_high_ns = device->timer_period_ns * (percent_high / 100.00);
@@ -249,7 +246,7 @@ int32_t trq_command(trq_info_t *device, uint8_t percent_high, bool pos_dir)
         status = trq_set_direction(device, pos_dir);
         if(status != TRQ_SUCCESS)
         {
-            OS_printf("trq_command: Error setting trq %d direction! \n", device->trq_num);
+            printf("trq_command: Error setting trq %d direction! \n", device->trq_num);
             status = TRQ_INIT_ERR;
             return status;
         }
@@ -269,7 +266,7 @@ void trq_close(trq_info_t* device)
 {
     if(!device->enabled)
     {
-        OS_printf("trq_close: Error closing trq %d, already disabled! \n", device->trq_num); 
+        printf("trq_close: Error closing trq %d, already disabled! \n", device->trq_num); 
         return; 
     }
 
diff --git a/fsw/linux/libuart.c b/fsw/linux/libuart.c
index 46c2fd9..fbbb87f 100644
--- a/fsw/linux/libuart.c
+++ b/fsw/linux/libuart.c
@@ -130,7 +130,7 @@ int32_t uart_init_port(uart_info_t* device)
     // Set the port to blocking read with timeout of 0.1 sec
     device->options.c_cc[VMIN] = 0;       // min of bytes to read
     device->options.c_cc[VTIME] = 1;      // intra-byte time to wait - tenths of sec
-    fcntl(device->handle, F_SETFL, 0);    // Have serial port block
+    fcntl(device->handle, F_SETFL, O_NONBLOCK);    // Don't have serial port block
 
     // TODO - any other options needed like hw control?
     tcflush(device->handle, TCIOFLUSH);
@@ -144,7 +144,7 @@ int32_t uart_init_port(uart_info_t* device)
   }
   else
   {
-      OS_printf("Oh no!  Open \"%s\" failed and reported: %s \n", device->deviceString, strerror(device->handle));
+      printf("Oh no!  Open \"%s\" failed and reported: %s \n", device->deviceString, strerror(device->handle));
       device->isOpen = PORT_CLOSED;
       status = OS_ERR_FILE;
   }
@@ -152,23 +152,23 @@ int32_t uart_init_port(uart_info_t* device)
   return status;
 }
 
-int32_t uart_bytes_available(int32_t handle)
+int32_t uart_bytes_available(uart_info_t* device)
 {
   int32_t bytes_available = 0;
 
-  ioctl(handle, FIONREAD, &bytes_available);
+  ioctl(device->handle, FIONREAD, &bytes_available);
 
   return bytes_available;
 }
 
-int32_t uart_flush(int32_t handle)
+int32_t uart_flush(uart_info_t* device)
 {
-  tcflush(handle,TCIOFLUSH);
+  tcflush(device->handle,TCIOFLUSH);
 
   return UART_SUCCESS;
 }
 
-int32_t uart_read_port(int32_t handle, uint8_t data[], const uint32_t numBytes)
+int32_t uart_read_port(uart_info_t* device, uint8_t data[], const uint32_t numBytes)
 {
   int32_t status = UART_SUCCESS;
 
@@ -176,7 +176,7 @@ int32_t uart_read_port(int32_t handle, uint8_t data[], const uint32_t numBytes)
   {
     // TODO - this read blocks forever if no serial data on the port.
     //        it should be timing out - need to look into this ASAP
-    status = read(handle, data, numBytes);
+    status = read(device->handle, data, numBytes);
   }
   else
   {
@@ -186,22 +186,22 @@ int32_t uart_read_port(int32_t handle, uint8_t data[], const uint32_t numBytes)
   return status;
 }
 
-int32_t uart_write_port(int32_t handle, uint8_t data[], const uint32_t numBytes)
+int32_t uart_write_port(uart_info_t* device, uint8_t data[], const uint32_t numBytes)
 {
   int32_t status = UART_SUCCESS;
 
-  status = write(handle, data, numBytes);
+  status = write(device->handle, data, numBytes);
 
   return status;
 }
 
-int32_t uart_close_port(int32_t handle)
+int32_t uart_close_port(uart_info_t* device)
 {
   int32_t status = UART_SUCCESS;
 
-  if (handle >= 0)
+  if (device->handle >= 0)
   {
-    status = close(handle);
+    status = close(device->handle);
     if (0 == status) /* todo remove magic number */
     {
       status = UART_SUCCESS;
diff --git a/fsw/public_inc/hwlib.h b/fsw/public_inc/hwlib.h
index 702aed8..ca52643 100644
--- a/fsw/public_inc/hwlib.h
+++ b/fsw/public_inc/hwlib.h
@@ -38,6 +38,8 @@ ivv-itc@lists.nasa.gov
 ** Outside of cFS build
 *************************************************************************/
 #ifndef OS_SUCCESS
+    #pragma GCC diagnostic ignored "-Wall"
+    #pragma GCC diagnostic warning "-Wunused-value"
     #define OS_printf           printf
     #define OS_TaskDelay(n)     ( usleep((n) * 1000) )
     #if defined (__GNUC__)
diff --git a/fsw/src/hwlib.c b/fsw/src/hwlib.c
index e767df8..4bfce8a 100644
--- a/fsw/src/hwlib.c
+++ b/fsw/src/hwlib.c
@@ -53,10 +53,15 @@ ivv-itc@lists.nasa.gov
 int32 hwlib_Init(void)
 {
     /*
-     ** Register the events
-     */
+    ** Register the events
+    */
     CFE_EVS_Register(NULL, 0, CFE_EVS_NO_FILTER);
 
+    /*
+    ** Resolve statement with no effect
+    */
+    
+
     /*
     ** Init all hardware subsystems and interfaces
     ** order may be important.
diff --git a/fsw/stubs/libcan.c b/fsw/stubs/libcan.c
new file mode 100644
index 0000000..c65b690
--- /dev/null
+++ b/fsw/stubs/libcan.c
@@ -0,0 +1,58 @@
+/* Copyright (C) 2009 - 2019 National Aeronautics and Space Administration. All Foreign Rights are Reserved to the U.S. Government.
+
+This software is provided "as is" without any warranty of any, kind either express, implied, or statutory, including, but not
+limited to, any warranty that the software will conform to, specifications any implied warranties of merchantability, fitness
+for a particular purpose, and freedom from infringement, and any warranty that the documentation will conform to the program, or
+any warranty that the software will be error free.
+
+In no event shall NASA be liable for any damages, including, but not limited to direct, indirect, special or consequential damages,
+arising out of, resulting from, or in any way connected with the software or its documentation.  Whether or not based upon warranty,
+contract, tort or otherwise, and whether or not loss was sustained from, or arose out of the results of, or use of, the software,
+documentation or services provided hereunder
+
+ITC Team
+NASA IV&V
+ivv-itc@lists.nasa.gov
+*/
+
+#include "libcan.h"
+
+/* The `libsocketcan` library wraps many of the netlink operations to control a SocketCAN interface
+ * Documentation here: https://lalten.github.io/libsocketcan/Documentation/html/group__extern.html */
+
+// Bring CAN network interface
+int32_t can_init_dev(can_info_t* device) 
+{
+  return CAN_SUCCESS;
+}
+
+// Call the `libsocketcan` function to set each CAN mode on/off
+int32_t can_set_modes(can_info_t* device) 
+{
+  return CAN_SUCCESS;
+}
+
+// Write a can_frame  from `device->tx_Frame` to CAN bus from SocketCAN socket specified by `device`
+int32_t can_write(can_info_t* device) 
+{  
+  return CAN_SUCCESS;
+}
+
+// Read a can_frame from SocketCAN interface specified by `device` into `device->rx_frame`
+// Does a nonblocking read call
+int32_t can_read(can_info_t* device) 
+{		
+  return CAN_SUCCESS;
+}
+
+// Bring CAN network interface down
+int32_t can_close_device(can_info_t* device) 
+{
+  return CAN_SUCCESS;
+}
+
+// Perform non-blocking can transaction
+int32_t can_master_transaction(can_info_t* device) 
+{
+  return CAN_SUCCESS;
+}
diff --git a/fsw/stubs/libgpio.c b/fsw/stubs/libgpio.c
new file mode 100644
index 0000000..747d3aa
--- /dev/null
+++ b/fsw/stubs/libgpio.c
@@ -0,0 +1,38 @@
+/* Copyright (C) 2009 - 2019 National Aeronautics and Space Administration. All Foreign Rights are Reserved to the U.S. Government.
+
+This software is provided "as is" without any warranty of any, kind either express, implied, or statutory, including, but not
+limited to, any warranty that the software will conform to, specifications any implied warranties of merchantability, fitness
+for a particular purpose, and freedom from infringement, and any warranty that the documentation will conform to the program, or
+any warranty that the software will be error free.
+
+In no event shall NASA be liable for any damages, including, but not limited to direct, indirect, special or consequential damages,
+arising out of, resulting from, or in any way connected with the software or its documentation.  Whether or not based upon warranty,
+contract, tort or otherwise, and whether or not loss was sustained from, or arose out of the results of, or use of, the software,
+documentation or services provided hereunder
+
+ITC Team
+NASA IV&V
+ivv-itc@lists.nasa.gov
+*/
+
+#include "libgpio.h"
+
+int32_t gpio_init(gpio_info_t* device) 
+{    
+    return GPIO_SUCCESS;
+}
+
+int32_t gpio_read(gpio_info_t* device, uint8_t* value)
+{
+    return GPIO_SUCCESS;
+}
+
+int32_t gpio_write(gpio_info_t* device, uint8_t value)
+{
+    return GPIO_SUCCESS;
+}
+
+int32_t gpio_close(gpio_info_t* device)
+{
+    return GPIO_SUCCESS;
+}
diff --git a/fsw/stubs/libi2c.c b/fsw/stubs/libi2c.c
new file mode 100644
index 0000000..c0b99a2
--- /dev/null
+++ b/fsw/stubs/libi2c.c
@@ -0,0 +1,50 @@
+/* Copyright (C) 2009 - 2018 National Aeronautics and Space Administration. All Foreign Rights are Reserved to the U.S. Government.
+
+This software is provided "as is" without any warranty of any, kind either express, implied, or statutory, including, but not
+limited to, any warranty that the software will conform to, specifications any implied warranties of merchantability, fitness
+for a particular purpose, and freedom from infringement, and any warranty that the documentation will conform to the program, or
+any warranty that the software will be error free.
+
+In no event shall NASA be liable for any damages, including, but not limited to direct, indirect, special or consequential damages,
+arising out of, resulting from, or in any way connected with the software or its documentation.  Whether or not based upon warranty,
+contract, tort or otherwise, and whether or not loss was sustained from, or arose out of the results of, or use of, the software,
+documentation or services provided hereunder
+
+ITC Team
+NASA IV&V
+ivv-itc@lists.nasa.gov
+*/
+
+#include <errno.h>
+#include <string.h>
+
+#include "libi2c.h"
+
+/* Call to configure a specific i2c device from /dev
+** i2c_bus- struct with bus configuration
+** speed  - currently unused
+*/
+int32_t i2c_master_init(i2c_bus_info_t* device)
+{
+    return I2C_SUCCESS;
+}
+
+int32_t i2c_master_transaction(i2c_bus_info_t* device, uint8_t addr, void * txbuf, uint8_t txlen, void * rxbuf, uint8_t rxlen, uint16_t timeout)
+{
+    return I2C_SUCCESS;
+}
+
+int32_t i2c_read_transaction(i2c_bus_info_t* device, uint8_t addr, void * rxbuf, uint8_t rxlen, uint8_t timeout)
+{
+    return I2C_SUCCESS;
+}
+
+int32_t i2c_write_transaction(i2c_bus_info_t* device, uint8_t addr, void * txbuf, uint8_t txlen, uint8_t timeout)
+{
+    return I2C_SUCCESS;
+}
+
+int32_t i2c_multiple_transaction(i2c_bus_info_t* device, uint8_t addr, struct i2c_rdwr_ioctl_data* rdwr_data, uint16_t timeout)
+{
+    return I2C_SUCCESS;
+}
diff --git a/fsw/stubs/libsocket.c b/fsw/stubs/libsocket.c
new file mode 100644
index 0000000..32298fb
--- /dev/null
+++ b/fsw/stubs/libsocket.c
@@ -0,0 +1,83 @@
+#include "libsocket.h"
+
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <fcntl.h>
+#include <errno.h>
+
+// Creates an endpoint for communication
+// Binds stream, server sockets to localhost and port number
+//
+// Inputs:
+//      socket_info->address_family
+//      socket_info->type
+//      socket_info->port_num (used for stream sockets)
+//      socket_info->block
+//
+// Outputs:
+//      socket_info->sockfd
+//      socket_info->created
+//      socket_info->bound  
+int32_t socket_create(socket_info_t* socket_info)
+{
+    return SOCKET_SUCCESS;
+}
+
+// Listens on a connection on a socket
+//
+// Inputs:
+//      socket_info->bound
+//      socket_info->sockfd
+//
+// Outputs:
+//      socket_info->listening
+int32_t socket_listen(socket_info_t* socket_info)
+{
+    return SOCKET_SUCCESS;
+}
+
+// Accepts a connection on a socket
+//
+// Inputs:
+//      socket_info->listening
+//      socket_info->sockfd
+//
+// Outputs:
+//      socket_info->connected
+//      socket_info->sockfd
+int32_t socket_accept(socket_info_t* socket_info)
+{
+    return SOCKET_SUCCESS;
+} 
+
+// Initiates a connection to a remote ip address and port number
+//
+// Inputs:
+//      socket_info->created
+//      socket_info->category
+//      socket_info->address_family
+//      socket_info->sockfd
+//      remote_ip_address (the remote ip address)
+//      remote_port_num (the remote port number)
+//
+// Outputs:
+//      socket_info->connected
+int32_t socket_connect(socket_info_t* socket_info, char* remote_ip_address, int remote_port_num)
+{
+    return SOCKET_SUCCESS;
+}
+
+int32_t socket_send(socket_info_t* socket_info, uint8_t* buffer, size_t buflen, size_t* bytes_sent, char* remote_ip_address, int remote_port_num)
+{
+    return SOCKET_SUCCESS;
+}
+
+int32_t socket_recv(socket_info_t* socket_info, uint8_t* buffer, size_t buflen, size_t* bytes_recvd)
+{
+    return SOCKET_SUCCESS;
+}
+
+int32_t socket_close(socket_info_t* socket_info)
+{
+    return SOCKET_SUCCESS;
+}
diff --git a/fsw/stubs/libspi.c b/fsw/stubs/libspi.c
new file mode 100644
index 0000000..e3d88cd
--- /dev/null
+++ b/fsw/stubs/libspi.c
@@ -0,0 +1,60 @@
+/* Copyright (C) 2009 - 2018 National Aeronautics and Space Administration. All Foreign Rights are Reserved to the U.S. Government.
+
+This software is provided "as is" without any warranty of any, kind either express, implied, or statutory, including, but not
+limited to, any warranty that the software will conform to, specifications any implied warranties of merchantability, fitness
+for a particular purpose, and freedom from infringement, and any warranty that the documentation will conform to the program, or
+any warranty that the software will be error free.
+
+In no event shall NASA be liable for any damages, including, but not limited to direct, indirect, special or consequential damages,
+arising out of, resulting from, or in any way connected with the software or its documentation.  Whether or not based upon warranty,
+contract, tort or otherwise, and whether or not loss was sustained from, or arose out of the results of, or use of, the software,
+documentation or services provided hereunder
+
+ITC Team
+NASA IV&V
+ivv-itc@lists.nasa.gov
+*/
+
+#include "libspi.h"
+
+spi_mutex_t spi_bus_mutex[MAX_SPI_BUSES];
+
+int32_t spi_init_dev(spi_info_t* device)
+{
+  return SPI_SUCCESS;
+}
+
+int32_t spi_set_mode(spi_info_t* device)
+{
+  return SPI_SUCCESS;
+}
+
+int32_t spi_get_mode(spi_info_t* device)
+{
+  return SPI_SUCCESS;
+}
+
+int32_t spi_write(spi_info_t* device, uint8_t data[], const uint32_t numBytes)
+{
+  return SPI_SUCCESS;  
+}
+
+int32_t spi_read(spi_info_t* device, uint8_t data[], const uint32_t numBytes)
+{
+  return SPI_SUCCESS; 
+}
+
+int32_t spi_transaction(spi_info_t* device, uint8_t *txBuff, uint8_t * rxBuffer, uint32_t length, uint16_t delay, uint8_t bits, uint8_t deselect)
+{
+  return SPI_SUCCESS;
+}
+
+int32_t spi_select_chip(spi_info_t* device)
+{
+  return SPI_SUCCESS;
+}
+
+int32_t spi_close_device(spi_info_t* device)
+{
+  return SPI_SUCCESS;
+}
diff --git a/fsw/stubs/libtrq.c b/fsw/stubs/libtrq.c
new file mode 100644
index 0000000..215fcd1
--- /dev/null
+++ b/fsw/stubs/libtrq.c
@@ -0,0 +1,116 @@
+/* Copyright (C) 2009 - 2019 National Aeronautics and Space Administration. All Foreign Rights are Reserved to the U.S. Government.
+
+This software is provided "as is" without any warranty of any, kind either express, implied, or statutory, including, but not
+limited to, any warranty that the software will conform to, specifications any implied warranties of merchantability, fitness
+for a particular purpose, and freedom from infringement, and any warranty that the documentation will conform to the program, or
+any warranty that the software will be error free.
+
+In no event shall NASA be liable for any damages, including, but not limited to direct, indirect, special or consequential damages,
+arising out of, resulting from, or in any way connected with the software or its documentation.  Whether or not based upon warranty,
+contract, tort or otherwise, and whether or not loss was sustained from, or arose out of the results of, or use of, the software,
+documentation or services provided hereunder
+
+ITC Team
+NASA IV&V
+ivv-itc@lists.nasa.gov
+*/
+
+#include <fcntl.h>
+#include "libtrq.h"
+#include "libtrq_ioctl.h"
+
+#define TRQ_FNAME_SIZE 50
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *
+ * trq_set_time_high(): Configure the time high per period in nanoseconds for a TRQ device. Time high lengths
+ *                      may not exceed a device's period length. 
+ *
+ * Inputs:              trq_info_t *device      -   TRQ device info structure 
+ *                      uint32_t    new_time    -   New time high length for the device period in nanoseconds
+ *
+ * Outputs:             trq_info_t *device      -   High time set to new_time if successful
+ *                      returns int32_t         -   TRQ_ERROR_* type on failure, TRQ_SUCCESS on success
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+int32_t trq_set_time_high(trq_info_t* device, uint32_t new_time) 
+{
+    return TRQ_SUCCESS;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *
+ * trq_set_period():    Configure the period length for a TRQ device in nanoseconds. Note that timer time high 
+ *                      is set to zero before this function is called. 
+ *
+ * Inputs:              trq_info_t *device      -   TRQ device info structure 
+ *
+ * Outputs:             returns int32_t         -   TRQ_ERROR on failure, TRQ_SUCCESS on success
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+int32_t trq_set_period(trq_info_t* device) 
+{
+    return TRQ_SUCCESS;
+}
+
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *
+ * trq_set_direction():    Configure the direction of the TRQ device. 
+ *
+ * Inputs:              trq_info_t *device      -   TRQ device info structure 
+ *                      bool        direction   -   New direction desired for device
+ *
+ * Outputs:             trq_info_t *device      -   positive_direction set to direction if successful
+ *                      returns int32_t         -   TRQ_ERROR on failure, TRQ_SUCCESS on success
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+int32_t trq_set_direction(trq_info_t* device, bool direction) 
+{
+    return TRQ_SUCCESS;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *
+ * trq_init():          Opens a TRQ device and initializes it. This function can also be
+ *                      used on an already opened TRQ number to reset it. 
+ *
+ * Inputs:              trq_info_t *device  -   TRQ Device info structure to initialize   
+ * 
+ * Outputs:             trq_info_t *device  -   Info structure contains AXI timer device file descriptor. 
+ *                      returns int32_t     -   <0 on failure, TRQ_SUCCESS on success
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+int32_t trq_init(trq_info_t* device) 
+{
+    return TRQ_SUCCESS;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ *
+ * trq_command():   Change TQR period, time high, or direction.
+ *
+ * Inputs:              trq_info_t* device      -   TQR device info structure to modify
+ *                      uint8_t percent_high    -   Percent of the period to be high (0-100)
+ *                      bool pos_dir            -   Direction - True for positive, False for negative
+ *
+ * Outputs:             trq_info_t *device      -   Parameters set to new values if successful
+ *                      returns int32_t         -   TRQ_ERROR_* type on failure, TRQ_SUCCESS on success
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+int32_t trq_command(trq_info_t *device, uint8_t percent_high, bool pos_dir)
+{
+    return TRQ_SUCCESS;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 
+ *
+ * trq_close():         Disables and closes an active TRQ device. 
+ * 
+ * Inputs:              trq_info_t *device - TRQ device info structure for TRQ device to disable
+ *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+void trq_close(trq_info_t* device)
+{
+    return TRQ_SUCCESS;
+}
diff --git a/fsw/stubs/libtrq_ioctl.h b/fsw/stubs/libtrq_ioctl.h
new file mode 100644
index 0000000..e3ba0ea
--- /dev/null
+++ b/fsw/stubs/libtrq_ioctl.h
@@ -0,0 +1,42 @@
+/* Copyright (C) 2009 - 2019 National Aeronautics and Space Administration. All Foreign Rights are Reserved to the U.S. Government.
+
+This software is provided "as is" without any warranty of any, kind either express, implied, or statutory, including, but not
+limited to, any warranty that the software will conform to, specifications any implied warranties of merchantability, fitness
+for a particular purpose, and freedom from infringement, and any warranty that the documentation will conform to the program, or
+any warranty that the software will be error free.
+
+In no event shall NASA be liable for any damages, including, but not limited to direct, indirect, special or consequential damages,
+arising out of, resulting from, or in any way connected with the software or its documentation.  Whether or not based upon warranty,
+contract, tort or otherwise, and whether or not loss was sustained from, or arose out of the results of, or use of, the software,
+documentation or services provided hereunder
+
+ITC Team
+NASA IV&V
+ivv-itc@lists.nasa.gov
+*/
+
+
+/* IOCTL commands */
+#include <sys/ioctl.h>
+
+#define TMRCTR_MAGIC                            15
+
+#define TMRCTR_START                _IO(    TMRCTR_MAGIC, 0         )
+#define TMRCTR_STOP                 _IO(    TMRCTR_MAGIC, 1         )
+#define TMRCTR_PWM_ENABLE           _IO(    TMRCTR_MAGIC, 2         )
+#define TMRCTR_PWM_SET_PERIOD       _IOW(   TMRCTR_MAGIC, 3,    long)
+#define TMRCTR_PWM_SET_HIGH_TIME    _IOW(   TMRCTR_MAGIC, 4,    long)
+#define TMRCTR_PWM_DISABLE          _IO(    TMRCTR_MAGIC, 5         )
+#define TMRCTR_SELFTEST             _IO(    TMRCTR_MAGIC, 6         )
+#define TMRCTR_SETOPTION            _IOW(   TMRCTR_MAGIC, 7,    long)
+#define TMRCTR_GETOPTION            _IOR(   TMRCTR_MAGIC, 8,    long)
+#define TMRCTR_RESET                _IO(    TMRCTR_MAGIC, 9         )
+#define TMRCTR_SET_RESET_VALUE      _IOW(   TMRCTR_MAGIC, 10,   long)
+#define TMRCTR_GET_VALUE            _IOR(   TMRCTR_MAGIC, 11,   long)
+#define TMRCTR_GET_CAPTURE_VALUE    _IOR(   TMRCTR_MAGIC, 12,   long)
+#define TMRCTR_CHECK_UPDATE         _IOR(   TMRCTR_MAGIC, 13,   long)
+#define TMRCTR_TMR_SELECT           _IOW(   TMRCTR_MAGIC, 14,   long)
+
+/* IOCTL Errors */
+#define TMRCTR_BAD_CMD            (-1)
+
diff --git a/fsw/stubs/libuart.c b/fsw/stubs/libuart.c
new file mode 100644
index 0000000..e9bfc17
--- /dev/null
+++ b/fsw/stubs/libuart.c
@@ -0,0 +1,48 @@
+/* Copyright (C) 2009 - 2018 National Aeronautics and Space Administration. All Foreign Rights are Reserved to the U.S. Government.
+
+This software is provided "as is" without any warranty of any, kind either express, implied, or statutory, including, but not
+limited to, any warranty that the software will conform to, specifications any implied warranties of merchantability, fitness
+for a particular purpose, and freedom from infringement, and any warranty that the documentation will conform to the program, or
+any warranty that the software will be error free.
+
+In no event shall NASA be liable for any damages, including, but not limited to direct, indirect, special or consequential damages,
+arising out of, resulting from, or in any way connected with the software or its documentation.  Whether or not based upon warranty,
+contract, tort or otherwise, and whether or not loss was sustained from, or arose out of the results of, or use of, the software,
+documentation or services provided hereunder
+
+ITC Team
+NASA IV&V
+ivv-itc@lists.nasa.gov
+*/
+
+#include "libuart.h"
+
+int32_t uart_init_port(uart_info_t* device)
+{
+  return UART_SUCCESS;
+}
+
+int32_t uart_bytes_available(uart_info_t* device)
+{
+  return 1;
+}
+
+int32_t uart_flush(uart_info_t* device)
+{
+  return UART_SUCCESS;
+}
+
+int32_t uart_read_port(uart_info_t* device, uint8_t data[], const uint32_t numBytes)
+{
+  return numBytes;
+}
+
+int32_t uart_write_port(uart_info_t* device, uint8_t data[], const uint32_t numBytes)
+{
+  return numBytes;
+}
+
+int32_t uart_close_port(uart_info_t* device)
+{
+  return UART_SUCCESS;
+}