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/*=============================================================================
//
//      hal_cygm.S
//
//      SPARClite and CygMon play nice: vector service routines
//
//=============================================================================
// ####ECOSGPLCOPYRIGHTBEGIN####                                            
// -------------------------------------------                              
// This file is part of eCos, the Embedded Configurable Operating System.   
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
//
// eCos is free software; you can redistribute it and/or modify it under    
// the terms of the GNU General Public License as published by the Free     
// Software Foundation; either version 2 or (at your option) any later      
// version.                                                                 
//
// eCos is distributed in the hope that it will be useful, but WITHOUT      
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or    
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License    
// for more details.                                                        
//
// You should have received a copy of the GNU General Public License        
// along with eCos; if not, write to the Free Software Foundation, Inc.,    
// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            
//
// As a special exception, if other files instantiate templates or use      
// macros or inline functions from this file, or you compile this file      
// and link it with other works to produce a work based on this file,       
// this file does not by itself cause the resulting work to be covered by   
// the GNU General Public License. However the source code for this file    
// must still be made available in accordance with section (3) of the GNU   
// General Public License v2.                                               
//
// This exception does not invalidate any other reasons why a work based    
// on this file might be covered by the GNU General Public License.         
// -------------------------------------------                              
// ####ECOSGPLCOPYRIGHTEND####                                              
//=============================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):   hmt
// Contributors:hmt
// Date:        1998-02-24
// Purpose:     SPARClite vectors for interworking with CygMon
// Description: see vectors.S and hal_priv.c; these VSRs are installed to
//              interwork with CygMon.
//
//####DESCRIPTIONEND####
//
//===========================================================================*/

!-----------------------------------------------------------------------------

//      .file   "hal_cygm.S"

!-----------------------------------------------------------------------------

#include <pkgconf/system.h>
#include <pkgconf/hal.h>
#include <pkgconf/hal_sparclite.h>
#include <pkgconf/hal_sparclite_sleb.h>

!------------------------------------------------------------------------

#include <cyg/hal/vectors.h>    // eCos vector number et al
#include <cyg/hal/hal_cygm.h>   // CygMon vector number et al
        
#define DELAYS_AFTER_WRPSR_SAME_WINDOW
#define DELAYS_AFTER_WRWIM

!------------------------------------------------------------------------

        .text

!---------------------------------------------------------------------------

#ifdef CYG_HAL_USE_ROM_MONITOR_CYGMON

        .global hal_user_trap_to_cygmon_vsr
hal_user_trap_to_cygmon_vsr:
        ! here,locals have been set up as follows:
        ! %l0 = psr (with this CWP/window-level in it)
        ! %l1 = pc
        ! %l2 = npc
        ! %l3 = vector number (1-15 for interrupts)
        ! and we are in our own register window, though it is likely that
        ! the next one will need to be saved before we can use it:
        ! ie. this one is the invalid register window.

        rd      %tbr, %l4               ! Get the trap type
        srl     %l4, 4, %l4             ! into the bottom byte
        and     %l4, 0xff, %l4          ! actual trap number

        ! we deal with traps 1,3,8(+128) and 255 here.
        ! ta 1  => tt 129       :       breakpoint
        ! ta 3  => tt 131       :       flush windows (unneccessary, JIC)
        ! ta 8  => tt 136       :       syscall (apparently)
        ! ta 127 -OR- Debug Support Unit trap
        !       => tt 255       :       debug trap
        ! others bounce through to eCos handler, of course.

        cmp     %l4, 129
        beq     bounce_to_cygmon
        mov     BSP_EXC_BREAK, %l5

        ! ta 2 is a "skipped" breakpoint, we increment the PC, NPC
        ! ourselves to permit continuation.
        cmp     %l4, 130
        bne     1f
        nop
        mov     %l2, %l1
        add     %l2, 4, %l2
        b       bounce_to_cygmon
        mov     BSP_EXC_BREAK, %l5

1:      
        cmp     %l4, 131
        beq     bounce_to_cygmon
        mov     BSP_EXC_WINFLUSH, %l5
        
        cmp     %l4, 136
        beq     bounce_to_cygmon
        mov     BSP_EXC_SYSCALL, %l5
        
        cmp     %l4, 255
        beq     bounce_to_cygmon
        mov     BSP_EXC_DEBUG, %l5

        ! if we are here, it~s not a recognized trap to feed to CygMon, so
        ! call the eCos default trap VSR:
        .extern hal_default_exception_vsr
        ba      hal_default_exception_vsr       ! should be in range
        nop                                     ! does not return


        .global hal_nofpcp_trap_to_cygmon_vsr
hal_nofpcp_trap_to_cygmon_vsr:
        rd      %tbr, %l4               ! Get the trap type
        srl     %l4, 4, %l4             ! into the bottom byte
        and     %l4, 0xff, %l4          ! actual trap number
        ! we deal with trap types 4 and 36 here.

        cmp     %l4, 4
        beq     bounce_to_cygmon
        mov     BSP_EXC_FPDIS, %l5
        
        cmp     %l4, 36
        beq     bounce_to_cygmon
        mov     BSP_EXC_CPDIS, %l5

        ! we really should not be here otherwise, but for best debugging...
        b       bounce_to_cygmon        
        mov     BSP_EXC_TRAP, %l5
        
bounce_to_cygmon:
        ! here we have decided to jump over CygMon, the CygMon vector
        ! number to use is in %l5.
        set     CYGMON_VECTOR_TABLE_BASE, %l6
        sll     %l5, 2, %l5             ! to a word offset
        ! our calling convention is the same, so...
        ld      [ %l6 + %l5 ], %l6
        jmp     %l6
        nop


// Now a handler for INT15 (NMI) to assist in debugging; we have to ack and
// clear the interrupt, after waiting for the source to go away, I guess...
        .global hal_nmi_handler
hal_nmi_handler:
        ! here,locals have been set up as follows:
        ! %l0 = psr (with this CWP/window-level in it)
        ! %l1 = pc
        ! %l2 = npc
        ! %l3 = vector number (1-15 for interrupts)
        ! and we are in our own register window, though it is likely that
        ! the next one will need to be saved before we can use it:
        ! ie. this one is the invalid register window.
        
#define TRGM0   0
#define TRGM1   4           
#define REQSNS  8
#define REQCLR 12
#define IMASK  16
#define IRLAT  20
#define IMODE  24

#define NMIBIT 0x80000000

        sethi   %hi( 0x10000000 ), %l4  ! base address of the 86940 companion

10:     
        add     %l4, REQCLR, %l5        ! Request clear register
        set     NMIBIT, %l6
        sta     %l6, [ %l5 ] 4          ! Clear INT15

        add     %l4, REQSNS, %l5        ! Request sense register
        lda     [ %l5 ] 4, %l7
        andcc   %l6, %l7, %g0           ! test the sense bit

        sethi   %hi( 0x02000000 ), %l6  ! Pump it out to the LED
        srl     %l7, 24, %l7
        stb     %l7, [ %l6 + 3 ]

        bne     10b                     ! poll until the request is gone
        nop
        nop
        nop

        set     0x00100000, %l6         ! clear the latch
        add     %l4, IRLAT, %l5
        sta     %l6, [ %l5 ] 4

        nop
        nop
        nop

        b       bounce_to_cygmon
        mov     BSP_EXC_INT15, %l5
        

        
        
        
#endif // CYG_HAL_USE_ROM_MONITOR_CYGMON
                
! end of hal_cygm.S