ramdisk.c

nucleus 文件系统,内核和彩色图形系统,在小系统上非常好用

    UCOUNT *mem_address;

    /* Nucleus */
    if( NU_Alloc_Partition(NUF_RAMDISK_PARTITION,
                           (unsigned int **) &mem_address,
                           NU_NO_TIMEOUT) == NU_SUCCESS )
        return ((UTINY FAR *) mem_address);
    else
        return((UTINY FAR *)0);

#endif /*  PLUS  */
}

/*************************************************************************/
/*                                                                       */
/* FUNCTION                                      rd_free_page            */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function deallocates one page of memory from a Nucleus      */
/*      fixed partition.                                                 */
/*                                                                       */
/* AUTHOR                                                                */
/*                                                                       */
/*      Peter Van Oudenaren                                              */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      pc_rd_open                                                       */
/*      pc_rd_close                                                      */
/*                                                                       */
/* CALLS                                                                 */
/*                                                                       */
/*      NU_Deallocate_Partition (PLUS)                                   */
/*      NU_Change_Preemption (PLUS)                                      */
/*      free                                                             */
/*      NU_Dealloc_Partition (RTX)                                       */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      page - pointer to memory to be deallocated                       */
/*                                                                       */
/* OUTPUTS                                                               */
/*                                                                       */
/*      none                                                             */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*         NAME            DATE                    REMARKS               */
/*                                                                       */
/*         P. Van Oudenaren                        Initial Version       */
/*         N. Henderson    02/18/94                Cleanup               */
/*************************************************************************/

VOID   rd_free_page(UTINY FAR *page)           /* __fn__ */
{
#if (PLUS)
#if (RAMDISK_FROMPOOL)

    /*  If the input parameter is valid, deallocate.  */
    if (page)
        NU_Deallocate_Partition((VOID *)page);

#else

    /* Using free() instead of dealloc */
    OPTION      preempt_status;

    /*  Don't let anyone interfere with the malloc.  Anticpating DOS non-
        reentrancy.  */
    preempt_status = NU_Change_Preemption(NU_NO_PREEMPT);

    /*  If the input is valid, deallocate the page.  */
    if (page)
        free(page);

    /*  Others can take over now since the malloc is complete. */
    NU_Change_Preemption(preempt_status);

#endif

#else       /* RTX */

    /*  If the input is valid, deallocate the page.  */
    if (page)
        NU_Dealloc_Partition((unsigned  *)page);

#endif
}

/*************************************************************************/
/*                                                                       */
/* FUNCTION                                      pc_rd_ioctl             */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function doesn't do anything for the RAM Disk.  It is       */
/*      included for devtable consistency.                               */
/*                                                                       */
/* AUTHOR                                                                */
/*                                                                       */
/*      Peter Van Oudenaren                                              */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      none                                                             */
/*                                                                       */
/* CALLS                                                                 */
/*                                                                       */
/*      none                                                             */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      none                                                             */
/*                                                                       */
/* OUTPUTS                                                               */
/*                                                                       */
/*      none                                                             */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*         NAME            DATE                    REMARKS               */
/*                                                                       */
/*         P. Van Oudenaren                        Initial Version       */
/*         N. Henderson    02/18/94                Cleanup               */
/*************************************************************************/
BOOL pc_rd_ioctl(UCOUNT driveno, UCOUNT command, VOID *buffer)      /*__fn__*/
{
    driveno = driveno;
    command = command;
    buffer = buffer;
    return(NO);
}

/*************************************************************************/
/*                                                                       */
/* FUNCTION                                      pc_rd_raw_open          */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function doesn't do anything for the RAM Disk.  It is       */
/*      included for devtable consistency.                               */
/*                                                                       */
/* AUTHOR                                                                */
/*                                                                       */
/*      Peter Van Oudenaren                                              */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      none                                                             */
/*                                                                       */
/* CALLS                                                                 */
/*                                                                       */
/*      none                                                             */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      none                                                             */
/*                                                                       */
/* OUTPUTS                                                               */
/*                                                                       */
/*      none                                                             */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*         NAME            DATE                    REMARKS               */
/*                                                                       */
/*         P. Van Oudenaren                        Initial Version       */
/*         N. Henderson    02/18/94                Cleanup               */
/*************************************************************************/
BOOL pc_rd_raw_open(UCOUNT driveno)                                /*__fn__*/
{
    driveno = driveno;
    return(NO);
}

/*************************************************************************/
/*                                                                       */
/* FUNCTION                                      pc_rd_open              */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function prepares the RAM Disk for usage by allocating the  */
/*      pages necessary for usage.                                       */
/*                                                                       */
/* AUTHOR                                                                */
/*                                                                       */
/*      Peter Van Oudenaren                                              */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      Nucleus FILE                                                     */
/*                                                                       */
/* CALLS                                                                 */
/*                                                                       */
/*      rd_alloc_page                                                    */
/*      rd_free_page                                                     */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      driveno - the number assigned to the RAM Disk (not used)         */