uint8_t data[128];
data[0] = ''; //null terminate so we don't print garbage

for( ; ; ) {
    //get a chunk of data off the FIFO buffer
    const int uart_num = UART_NUM_2;
    int length = 0;
    IotLogInfo( "preread" );
    length = uart_read_bytes(uart_num, data, 10, 1000 / portTICK_RATE_MS); //read 10 bytes or time out after a second.

    if(length == -1)
        IotLogInfo( "read reported error! -1" );

    //did we rx anything?
    if(length > 0){
        data[length] = ''; //null terminate the string
        IotLogInfo( "Rx: %n bytes", length );
        IotLogInfo( "Rx: %s ", data );
    }
    else{
        IotLogInfo( "rx no data" );
    }
}

110 11021 [_readSerialForM] [INFO ][DEMO][110210] preread

111 11121 [_readSerialForM] [INFO ][DEMO][111210] rx no data

112 11221 [_readSerialForM] [INFO ][DEMO][112210] preread

113 11321 [_readSerialForM] [INFO ][DEMO][113210] rx no data

114 11421 [_readSerialForM] [INFO ][DEMO][114210] preread

Guru Meditation Error: Core  0 panic'ed (StoreProhibited). Exception was unhandled.
Core 0 register dump:
PC      : 0x4011dd49  PS      : 0x00060130  A0      : 0x801abf6d  A1      : 0x3ffeaed0
A2      : 0x3ffeaee0  A3      : 0x00000000  A4      : 0x00000004  A5      : 0x00000001
A6      : 0x3ffeaee0  A7      : 0x00000018  A8      : 0x00000009  A9      : 0x00000004
A10     : 0x00000024  A11     : 0x0000002a  A12     : 0xffffffff  A13     : 0x3f40149c
A14     : 0x00ff0000  A15     : 0xff000000  SAR     : 0x00000004  EXCCAUSE: 0x0000001d
EXCVADDR: 0x00000004  LBEG    : 0x400014fd  LEND    : 0x4000150d  LCOUNT  : 0xffffffff

Backtrace: 0x4011dd49:0x3ffeaed0 0x401abf6a:0x3ffeb1e0 0x401abfa6:0x3ffeb270 0x401739f7:0x3ffeb2b0 0x400d469a:0x3ffeb330

Rebooting...
ets Jun  8 2016 00:22:57

rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee