trouble with application programe of serial port (use bsp of pc386)

[zhoupeng]

Excuse me.
I will add a brief postscript to my question ,can i use rtems_io_open() ...directly?
I think ,in this situation , we may use arguments  just i give.
Thanks.




At 2012-02-16 21:37:51,"Joel Sherrill" <joel.sherrill at oarcorp.com> wrote:
The short answer is that you shouldn't be programming it at this level.
You should be doing something like this:

int fd;

fd = open( "/dev/xxx", ...);
write( fd, buffer, length );

It doesn't matter to you what the interface between the driver and
termios framework is. You should be using POSIX calls like open, read,
write, and ioctl. The Termios API is used for changing things like baud
rate, bits per character, etc.

I don't know how good this is but a google turned up this which doesn't
look too bad at first glance as an introduction to termios capabilities:

http://en.wikibooks.org/wiki/Serial_Programming/termios

--joel

On 02/16/2012 07:29 AM, zhoupeng wrote:

Hello guys,

I am a student. Now i have take part in a project which is based on x86 cpu. So i study BSP of PC386. Precently,i want to write a application program of serial port. Because,the BSP of PC386 is provide the serial port driver. So we can use the serial port driver directly.

The soruce code of this drive programe include tty_drv.c\ termios.c\ uart.c... Before i write the application programe , i made a analysis about this driver. Let's look some code whic is come out of these files.

rtems_device_driver
tty_read(rtems_device_major_number major,
             rtems_device_minor_number minor,
             void                      *arg)
{
  return rtems_termios_read (arg);
} /* tty_read */

rtems_status_code
rtems_termios_read (void *arg)
{
 rtems_libio_rw_args_t *args = arg;
 struct rtems_termios_tty *tty = args->iop->data1;
 uint32_t   count = args->count;
 char      *buffer = args->buffer;
 rtems_status_code sc; 

...}

we can find a important arguements *arg , it's a pointer point to a struct .This struct have three member ,they are

args->iop->data1 \ args->count \ args->buffer

who know their funcations??? I believe in application programe ,we have to provide these arguements!

Can you provide a test programe of serial port with this drive in bsp of pc386.?

Thanks so much!

Best wish!

zhoupeng






-- 
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
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