Check all modifikators of type declarations

All local variables and functions should be declared static.
All global variables/contexts/etc should be declared volatile.
Fun reading which mirrors our problems xD @Martin.dold @evileli

Maybe this struct in hal_uart.c is the problem. The pointers are declared volatile, but not the variables they are pointing to?

#define UART_RX_DATA_BUF_SIZE   8192
#define UART_TX_DATA_BUF_SIZE   8192


#define IS_BUF_EMPTY(x, y)   (x == y)

/*! Structure defining the context of an UART port. */
struct S_HAL_UART_CTX_T
{
  uint32_t ui32_baseAddr;

  volatile uint8_t ac_rxData[UART_RX_DATA_BUF_SIZE];
  volatile uint8_t *pc_rxDataWrite;
  volatile uint8_t *pc_rxDataRead;

  volatile uint8_t ac_txData[UART_TX_DATA_BUF_SIZE];
  volatile uint8_t *pc_txDataWrite;
  volatile uint8_t *pc_txDataRead;
};