source: trunk/libs/newlib/src/libgloss/sparc_leon/locore.S @ 450

/*
 * Copyright (c) 2011 Aeroflex Gaisler
 *
 * BSD license:
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

 
/* The traptable has to be the first code in a boot PROM. */

#include <asm-leon/head.h>
                
#define TRAP(H)  mov %psr, %l0; sethi %hi(H), %l4; jmp %l4+%lo(H); nop;
#define TRAPL(H)  nop; sethi %hi(H), %g1; jmp %g1+%lo(H); nop;
#define TRAP_ENTRY(H) rd %psr, %l0; b H; rd %wim, %l3; nop;

#define WIM_INIT 2
#ifdef _SOFT_FLOAT
#define PSR_INIT 0x0e0
#else
#define PSR_INIT 0x10e0
#endif

#define NUMREGWINDOWS 8

/* Unexcpected trap will halt the processor by forcing it to error state */
#define BAD_TRAP ta 0; nop; nop; nop;

/* Software trap. Treat as BAD_TRAP */
#define SOFT_TRAP BAD_TRAP

  .seg    "text"
  .global _trap_table, start, _start, cpuinit, leonbare_irq_entry, _hardreset
  .global _window_overflow, _window_underflow, _flush_windows, _fpdis_enable
  /*.global _nwindows, _leon_version, _nwindows_min1*/

        
!
! Startup code for standalone system. Wash IU and FPU (if present) registers.
! The registers have to be written to initiate the parity bits.
!
        .section .text
        /* ------- */
        .weak   _hardreset
        .set    _hardreset,_hardreset_libgloss
        /* ------- */
        
        .global _hardreset_custom_weak, _hardreset_real, _cleanregs_custom_weak, _hardreset_custom_svt_weak

_hardreset_real:
        nop
_hardreset_libgloss:
        set     _hardreset_custom_weak, %g1  ! possible mkprom init code here, default links to dummy _hardreset_custom_dummy
        call     %g1
         nop
        
        set     _trap_table, %g1        ! Initialize TBR
        mov     %g1, %tbr
        
        set     _hardreset_custom_svt_weak, %g1 ! give mkprom svt chance to reset tbr
        call     %g1
         nop
        
        set     _cleanregs_custom_weak, %g1
        call     %g1
         nop

#ifdef _FLAT
        mov     %g0, %wim
#else
/*      ! assume that %sp is correct use cwp of psr to set the next window as invalid
        mov     %psr, %g2    ! extract cwp
        and     0x1f, %g2,%g2
        set     0x1, %g3
        sll     %g3,%g2,%g3  ! the bit mask for cwp

        sll     %g3, 1, %g4  ! rotate one to left
        sethi %hi(_nwindows_min1), %g5  ! NWINDOWS-1
        ld [%g5+%lo(_nwindows_min1)], %g5
        srl  %g3, %g5, %g5
        or   %g5, %g4, %g5
        mov  %g5, %wim
        nop; nop; nop */
#endif
        
/*
        mov     %psr, %g2
        set     0x202, %g3
        sll     %g3, %g2, %g2
        mov     %g2, %wim
        nop; nop; nop
1:
*/
        ! -------------------------------
        ! only cpu 0 initializes
/*      mov     %psr, %g5
        srl     %g5, 24, %g5
        and     %g5, 3, %g5
        subcc   %g5, 3, %g0             ! leon2: 0 or 2, leon3: 3
        bne     callcpuinit
        nop
*/
        
        rd     %asr17,%g5
        srl    %g5,28,%g5
        cmp %g5,%g0
         bne slavego
        nop
        
callcpuinit:      
        call    cpuinit
         nop
        
        call    pnpinit
         nop
        
slavego:        
        ! -------------------------------
        
        sub     %sp, 0x40, %sp          ! room for main to save args
        call    _start
        nop

        mov     1, %g1
        ta      0                       ! Halt if _main would return ...
        nop

        .global _fpdis,_fpdis_svt
_fpdis_svt:
_fpdis:
        set     0x1000, %l4
        andcc   %l0, %l4, %l3
        bne,a   4f
        andn    %l0, %l4, %l0
        ta      0
4:
        mov      %l0, %psr              ! restore %psr
        nop; nop; nop
        jmp  %l2                        ! Jump to nPC
        rett  %l2 + 4

        
/*
!''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
        .section .bss
        .global _nwindows, _leon_version, _nwindows_min1
_nwindows:
        .word 8
_nwindows_min1: 
        .word 7
_leon_version:
        .word 3
*/