# UART2 Linux application mode is not working **URL:** \ **Category:** Uncategorized\ **Created:** [October 27, 2020, 6:32pm UTC](https://forum.legato.io/t/uart2-linux-application-mode-is-not-working/5479 "2020-10-27T18:32:22Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![arun](https://avatars.discourse-cdn.com/v4/letter/a/ee7513/32.png) [@arun](https://forum.legato.io/u/arun)\ **Post date:** [October 27, 2020, 6:32pm UTC](https://forum.legato.io/t/uart2-linux-application-mode-is-not-working/5479/1 "2020-10-27T18:32:22Z")
Hi all, i am facing an issue with UART2 in application mode , Once i enable uart 2 for application mode, ttyHSL1 is coming as disabled (checked by dmesg | grep tty). While running the app it reporting the below mentioned error Jan 6 05:49:27 swi-mdm9x28-wp user.err Legato: =ERR= | supervisor[859]/supervisor T=main | app.c GetDevID() 670 | Could not get file info for ‘/dev/ttyHSL1’. No such file or directory. Jan 6 05:49:27 swi-mdm9x28-wp user.err Legato: =ERR= | supervisor[859]/supervisor T=main | app.c SetCfgDevicePermissions() 775 | Failed to set permissions (rw) for app ‘rs232app\_test’ on device ‘/dev/ttyHSL1’. Jan 6 05:49:27 swi-mdm9x28-wp user.err Legato: =ERR= | supervisor[859]/supervisor T=main | app.c app\_Start() 3452 | Failed to set Smack rules or set up app area. Please suggest a solution to overcome this issue, Thanks in advance Regards, Arun ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [October 27, 2020, 11:03pm UTC](https://forum.legato.io/t/uart2-linux-application-mode-is-not-working/5479/2 "2020-10-27T23:03:57Z")
Can you attach your app here? What module and fw ate you using? Have yoh tried unsandbox the app? BTW, have you set the AT!MAPUART=17,2 so that UART2 can be used in linux app? once you set this, after reset, you should not see /dev/ttyHSL1 ---
**Author:** ![arun](https://avatars.discourse-cdn.com/v4/letter/a/ee7513/32.png) [@arun](https://forum.legato.io/u/arun)\ **Post date:** [October 28, 2020, 5:04am UTC](https://forum.legato.io/t/uart2-linux-application-mode-is-not-working/5479/3 "2020-10-28T05:04:31Z")
Hi, Please find the code snipped below void\* Modbus\_Reading\_Thread(void\* object) { int res = 0; ``` LE_INFO("MODBUS Thread Started"); while(1) { res = read(Serial_Port_fd,&Rx_Buffer[Rx_count],RX_RS485_SIZE-2); if(res) { Rx_count += res; Byte_Recv = 1; byteTimeout = BYTE_TO_BYTE_TIMEOUT; if(Rx_count > (RX_RS485_SIZE-2)) /* Buffer overflow checking in case of junk receiving */ { Rx_count = 0; } } } ``` } # /\* - - Serial Port Initialization Program - ============================================================================================ \*/ void Serial\_Driver\_Port() { Serial\_Port\_fd = open(“/dev/ttyHSL1”, O\_RDWR | O\_NOCTTY | O\_NDELAY); if (Serial\_Port\_fd == -1) { /\* \* Could not open the port. \*/ ``` LE_ERROR("open_port: Unable to open /dev/ttyHSL1 - "); ``` } else { fcntl(Serial\_Port\_fd, F\_SETFL, 0); ``` le_tty_SetRaw(Serial_Port_fd, 0, 0); //ECHO is OFF le_tty_SetFraming(Serial_Port_fd, 'N', 8, 1); pthread_create(&MODBUS_Read_Thread_ID, (pthread_attr_t*)(0), &Modbus_Reading_Thread, (void*)(0)); sleep(1); LE_INFO("COM PORT HSL1 Opened"); ``` } } .cdef file ``` // Linux filesystem device paths. device: { // Get read and write access to the UART1 port. [rw] /dev/ttyHSL1 /dev/ttyHSL1 } ``` in .adef file sandbox : false I used uartMode set 2 app command for setting application mode, after system restart HSL1 disabled is coming in dmesg, while using uartMode get 2 command reports linux application ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [October 28, 2020, 5:29am UTC](https://forum.legato.io/t/uart2-linux-application-mode-is-not-working/5479/4 "2020-10-28T05:29:41Z")
once you set AT!MAPUART=17,2 , after reset, you should not see /dev/ttyHSL1 ---
**Author:** ![arun](https://avatars.discourse-cdn.com/v4/letter/a/ee7513/32.png) [@arun](https://forum.legato.io/u/arun)\ **Post date:** [October 28, 2020, 6:38am UTC](https://forum.legato.io/t/uart2-linux-application-mode-is-not-working/5479/5 "2020-10-28T06:38:56Z")
Hi, I performed the AT command set, and restarted , it showing as below root@swi-mdm9x28-wp:~# dmesg | grep tty [0.000000] Kernel command line: console=ttyHSL0,115200 console=ttyHSL1,115200 root=/dev/ram rootfs\_ro=true user1\_fs=ubifs verity=on ima\_ready=0 lkversion=SWI9X07Y\_02.28.03.03 androidboot.serialno=5c5d67dd androidboot.authorized\_kernel=true quiet androidboot.baseband=msm rootfstype=ubifs rootflags=bulk\_read [0.660730] ttyHS0 is reserved for AT service. [0.663953] 78b0000.uart: ttyHS0 at MMIO 0x78b0000 (irq = 49, base\_baud = 460800) is a MSM HS UART [0.666305] ttyHS1 could be used as generic serial port. [0.669063] 78af000.uart: ttyHS1 at MMIO 0x78af000 (irq = 48, base\_baud = 460800) is a MSM HS UART [0.671868] ttyHSL1 is disabled. [0.672155] ttyHSL0 is disabled. i have to use ttyHS1 for my application? ---
**Author:** ![arun](https://avatars.discourse-cdn.com/v4/letter/a/ee7513/32.png) [@arun](https://forum.legato.io/u/arun)\ **Post date:** [October 28, 2020, 7:12am UTC](https://forum.legato.io/t/uart2-linux-application-mode-is-not-working/5479/6 "2020-10-28T07:12:47Z")
Hi, Thanks for the support its working as expected, please find the working code sample below # /\* - - Receive MODBUS Packet Program - ============================================================================================ \*/ void\* Modbus\_Reading\_Thread(void\* object) { int res = 0; ``` uint8_t temp_buf[RX_RS485_SIZE] = {0}; LE_INFO("MODBUS Thread Started"); while(1) { res = read(Serial_Port_fd,temp_buf,RX_RS485_SIZE-2); if(res > 0) { if((Rx_count + res) > (RX_RS485_SIZE-2)) Rx_count = 0; memcpy(&Rx_Buffer[Rx_count],temp_buf,res); Rx_count += res; Byte_Recv = 1; byteTimeout = BYTE_TO_BYTE_TIMEOUT; if(Rx_count > (RX_RS485_SIZE-2)) /* Buffer overflow checking in case of junk receiving */ { Rx_count = 0; } } } ``` } # /\* - - Serial Port Initialization Program - ============================================================================================ \*/ void Serial\_Driver\_Port() { Serial\_Port\_fd = open(“/dev/ttyHS1”, O\_RDWR | O\_NOCTTY | O\_NDELAY); if (Serial\_Port\_fd == -1) { /\* \* Could not open the port. \*/ ``` LE_ERROR("open_port: Unable to open /dev/ttyHS1 - "); ``` } else { fcntl(Serial\_Port\_fd, F\_SETFL, 0); ``` le_tty_SetBaudRate(Serial_Port_fd,LE_TTY_SPEED_19200); le_tty_SetRaw(Serial_Port_fd, 0, 0); //ECHO is OFF le_tty_SetFraming(Serial_Port_fd, 'N', 8, 1); pthread_create(&MODBUS_Read_Thread_ID, (pthread_attr_t*)(0), &Modbus_Reading_Thread, (void*)(0)); sleep(1); LE_INFO("COM PORT HSL1 Opened"); ``` } } in .cdef file ``` // Linux filesystem device paths. device: { // Get read and write access to the UART1 port. [rw] /dev/ttyHS1 /dev/ttyHS1 } ```