/* Clock_initialize * * This routine initializes the Timer/Counter on the Intel * 386ex evaluation board. * * The tick frequency is 1 millisecond. * * Input parameters: NONE * * Output parameters: NONE * * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994. * On-Line Applications Research Corporation (OAR). * All rights assigned to U.S. Government, 1994. * * This material may be reproduced by or for the U.S. Government pursuant * to the copyright license under the clause at DFARS 252.227-7013. This * notice must appear in all copies of this file and its derivatives. * * $Id$ */ #include #include #include volatile rtems_unsigned32 Clock_driver_ticks; rtems_unsigned32 Clock_isrs; /* ISRs until next tick */ rtems_isr_entry Old_ticker; rtems_device_driver Clock_initialize( rtems_device_major_number major, rtems_device_minor_number minor, void *pargp, rtems_id tid, rtems_unsigned32 *rval ) { Install_clock( Clock_isr ); } void ReInstall_clock( rtems_isr_entry clock_isr ) { rtems_unsigned32 isrlevel = 0; rtems_interrupt_disable( isrlevel ); (void) set_vector( clock_isr, 0x20, 1 ); /* was 0x38 */ rtems_interrupt_enable( isrlevel ); } void Install_clock( rtems_isr_entry clock_isr ) { Clock_driver_ticks = 0; Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000; if ( BSP_Configuration.ticks_per_timeslice ) { Old_ticker = ( rtems_isr_entry ) set_vector( clock_isr, 0x20, 1 ); /* was 0x38 */ /* The following is already set up in interns.s -> ( This is test code only... production code will move the TMRCFG stuff here ) */ #define TMR0 0xF040 #define TMR1 0xF041 #define TMR2 0xF042 #define TMRCON 0xF043 #define TMRCFG 0xF834 outport_byte ( TMRCFG , 0x80 ); outport_byte ( TMRCON , 0x34 ); outport_byte ( TMR0 , 0xA8 ); outport_byte ( TMR0 , 0x04 ); outport_byte ( TMRCFG , 0x00 ); } atexit( Clock_exit ); } void Clock_exit( void ) { if ( BSP_Configuration.ticks_per_timeslice ) { /* outport_byte( TBCR, 0x00 ); */ /* initial value */ /* outport_byte( IERA, 0x40 ); */ /* disable interrupt */ /* ??? Is "do not restore old vector" causing problems? */ } }