How to use Console Driver of RTEMS on MVME162

[Joel Sherrill]

Just use printf and regular C stdio.

--joel

On 8/2/2013 2:45 AM, AJAI KUMAR MEDHAVI wrote:
> Hi
>
>
> I am working on RTEMS 4.10.2 on MVME162-522A VME CPU Board. I wish to use
> RTEMS consloe driver (..\libbsp\m68k\mvme162\console) functions to read
> /write on both channels of CPU board.
>
>
> Here I have  following queries regarding console driver :
>
>
> 1. How to wish to directly use rtems_io_read and rtems_io_write, for
> writing/reading on channels,  by providng console/tty00/tty01 major and
> minor number and pointer to arg.
>
>
> here How should I know Console Major number. Because RTEMS itself
> registers console driver if we include
> "=define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER" in the application.
>
>
> To find out Console Major/Minor number pair , I have used following call
> in my application :
>
> /*----Get Console Device Major / Minor Number---------------------------*/
> 	status = rtems_io_lookup_name( "/dev/console",
> &Console_low_level_device_info );
> 	if(status != RTEMS_SUCCESSFUL)
> 		rtems_fatal_error_occurred(status);
>
> 	Console_device_major = Console_low_level_device_info.major;
> 	Console_device_minor = Console_low_level_device_info.minor;
>
> I have defined Console_device_major, Console_device_minor as global
> variables.
>
>
> printf("\n\nConsole Device Major No. : %d", (int)Console_device_major);
> 	printf("\nConsole Device Minor No. : %d", (int)Console_device_minor);
>
>
> but on printing Console Major/ Minor number is coming sometimes 0 / 0 and
> sometimes  different values other than 0 / 0 when I compile my application
> without making any changes in console.c and above system call in my
> application.
>
> When It major/monor comes 0 / 0 I am able to write on channel 0 bu using
> console Major no. (zero) and minor number (Zero).
>
>
> I am not able to understand why I am getting different values of Major /
> Minor Values.
>
>
> 2. Second, in console_initialize of
> (..\libbsp\m68k\mvme162\console\console.c)
>
> I have found following code :
>
>
> status = rtems_io_register_name(
> 		"/dev/console",
> 		major,
> 		(rtems_device_minor_number) 1
> 	);
>
> 	if (status != RTEMS_SUCCESSFUL)
> 		rtems_fatal_error_occurred(status);
>
> 	status = rtems_io_register_name(
> 		"/dev/tty00",
> 		major,
> 		(rtems_device_minor_number) 0
> 	);
>
> 	if (status != RTEMS_SUCCESSFUL)
> 		rtems_fatal_error_occurred(status);
>
> 	status = rtems_io_register_name(
> 		"/dev/tty01",
> 		major,
> 		(rtems_device_minor_number) 1
> 	);
>
>
> It means Console Minor number must be (One), then I am getting console
> minor number as zero, when comming correctly, and I am able to write on
> console channel by proving console Major: 0 and Console Minor :0 in
> rtems_io_write
>
>
> Here I am confused whether console channel is channel-0 or Channel-1 of
> Channels provided by Z85230 SCC Chip on MVME162 CPU Board. At present my
> PC COM1 is connected to Console Port/Serial Port1 of CPU board.
>
>
> Kindly let me know what are  exact channel number of Console/tty00/tty01.
> Please note that Z85230 SCC chip on MVME162 defines two channels CH-B
> (channel 0 ) and CH-A (channel-1)
>
>
> In brief , please let me know following :
>
> 1. how to find Console/tty00/tty01  Major/Minor number pair for using
>     in rtems_io_read and rtems_io_write
>
>
> 2. exact channel number of Console/tty00/tty01. Please note that Z85230
> SCC chip on MVME162 defines two channels CH-B (channel 0 ) and CH-A
> (channel-1)
> Whther minor number 1 corresponds to Channel 1 of SCC and minor number 0
> corresponds to channel number 0 of SCC.
>
>
> 3. Why Console Major/ Minor number is coming  as 0/0 while "/dev/console
> has been named as minor 1 in status =
> rtems_io_register_name("/dev/console",
> major, 	(rtems_device_minor_number) 1 )
>
>
> Also not always as 0/0, it is coming with different - different values
> like -1 / 444768 and 25768/25678 and so many values ....
>
>
> 4. when I set "Console_Is_Initialized" to 1 in console_initialize(...)
> then I get no printf on console as per following function in console.c
>
>
> void _BSP_output_char(char c)
> {
>    if(Console_Is_Initialized)
>      putchar(c);
>    else
>      _162Bug_output_char(c);
>
>    if ('\n' == c)
>      _BSP_output_char('\r');
> }
>
> What is exactly happening when I set Console_Is_Initialized to 1.
>
>
>
>
> Kindly reply me at the earliest.
>
>
> Thanks in advance
>
>
>
> Best regards
>
>
>
> AJAI KUMAR MEDHAVI
> SCIENTIFIC OFFICER
> RAJA RAMMANNA CENTRE FOR ADVANCED TECHNOLGY
> DEPARTMENT OF ATOMIC ENERGY, GOV. OF INDIA,
> PO : CAT, INDORE-452013, INDIA
> PH. 91-731-2488052
> Email : akmedhavi at rrcat.gov.in , akmedhavi at rediffmail.com
>
>
>
>
>


-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill at OARcorp.com        On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
Support Available                (256) 722-9985