Retro68/gcc/libgloss/sparc_leon/etrap.S
2012-03-27 01:51:53 +02:00

114 lines
3.7 KiB
ArmAsm

/*
* 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.
*/
#include <asm-leon/leonstack.h>
#include <asm-leon/winmacros.h>
/* Registers to not touch at all. */
#define t_psr l0 /* Set by caller */
#define t_pc l1 /* Set by caller */
#define t_npc l2 /* Set by caller */
#define t_wim l3 /* Set by caller */
#define t_twinmask l4 /* Set at beginning of this entry routine. */
#define t_kstack l5 /* Set right before pt_regs frame is built */
#define t_retpc l6 /* If you change this, change winmacro.h header file */
#define t_systable l7 /* Never touch this, could be the syscall table ptr. */
#define curptr g6 /* Set after pt_regs frame is built */
/* Number of register windows */
.global _nwindows_min1, _nwindows
.text
.align 4
.globl leonbare_trapsetup
leonbare_trapsetup:
#ifdef _FLAT
restore
RW_STORE(sp)
save
#endif
#ifndef _SOFT_FLOAT
/* build a pt_regs trap frame. */
sub %fp, (SF_REGS_SZ + PT_REGS_SZ + FW_REGS_SZ), %t_kstack
PT_STORE_ALL(t_kstack, t_psr, t_pc, t_npc, g2)
/* build a fp_regs trap frame. */
sethi %hi(fpustate_current), %g2
ld [%g2+%lo(fpustate_current)], %g3
st %g3,[%t_kstack + (SF_REGS_SZ + PT_REGS_SZ + FW_REGS_SZ - 4)]
add %t_kstack,SF_REGS_SZ + PT_REGS_SZ,%g3
st %g3, [%g2+%lo(fpustate_current)]
#else
/* build a pt_regs trap frame.
*/
sub %fp, (SF_REGS_SZ + PT_REGS_SZ), %t_kstack
PT_STORE_ALL(t_kstack, t_psr, t_pc, t_npc, g2)
#endif
#ifndef _FLAT
/* See if we are in the trap window. */
mov 1, %t_twinmask
sll %t_twinmask, %t_psr, %t_twinmask ! t_twinmask = (1 << psr)
andcc %t_twinmask, %t_wim, %g0
beq 1f ! in trap window, clean up
nop
/*-------------------------------------------------*/
/* Spill , adjust %wim and go. */
srl %t_wim, 0x1, %g2 ! begin computation of new %wim
sethi %hi(_nwindows_min1), %g3
ld [%g3+%lo(_nwindows_min1)], %g3
sll %t_wim, %g3, %t_wim ! NWINDOWS-1
or %t_wim, %g2, %g2
and %g2, 0xff, %g2
save %g0, %g0, %g0 ! get in window to be saved
/* Set new %wim value */
wr %g2, 0x0, %wim
/* Save the kernel window onto the corresponding stack. */
RW_STORE(sp)
restore %g0, %g0, %g0
/*-------------------------------------------------*/
1:
#endif
/* Trap from kernel with a window available.
* Just do it...
*/
jmpl %t_retpc + 0x8, %g0 ! return to caller
mov %t_kstack, %sp ! jump onto new stack