Setting up Device Driver

[davidh at student.unsw.edu.au (David Hocking)]

Hi,

I'm currently writing a device driver for the MC68EZ328 to interface with the Siemens 81c91 Standalone Full-CAN controller. I'm new to writing device drivers and new to Rtems so it's been a steep learning curve.

So far i've written rtems_device_driver functions:

    can_init(major, minor, *arg);
    can_read(major, minor, *arg);
    can_write(major, minor, *arg);

However, i'm unsure where and how to set up the Device Driver Table. (Also the Configuration Table)

In the file console.h for example the entry appears:

    #define CONSOLE_DRIVER_TABLE_ENTRY \
              { console_initialize, console_open, console_close, \
                console_read, console_write, console_control }

In the user documentation an example of a typical declaration for a Device Driver Table appears:

    rtems_driver_address_table Driver_table[2] = {
        { tty_initialize, tty_open, tty_close,            /* major = 0 */
          tty_read, tty_write, tty_control
        }
        { lp_initialize, lp_open, lp_close,                /* major = 1 */
          NULL, lp_write, lp_control
        }
    };

I'm not sure where this declaration would occur and why this is the Driver table [2].

How are the major numbers defined ? It seems it is just the order that they appear above.

So how do you explain the CONSOLE_DRIVER_TABLE_ENTRY ?


I understand the the device driver functions correspond to the rtems_io_etc directives via the table. How then does the user know the correct major number for the device?

Thanks,

Dave.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://rtems.rtems.org/pipermail/rtems-users/attachments/19991002/f30f4d51/attachment.html