/*
* systrap.S
*
* This file contains emulated system calls using software trap 0.
* The following calls are supported:
*
* + SYS_exit (halt)
* + SYS_irqdis (disable interrupts)
* + SYS_irqset (set interrupt level)
*
* COPYRIGHT:
*
* COPYRIGHT (c) 1995. European Space Agency.
*
* This terms of the RTEMS license apply to this file.
*
*/
#include <rtems/asm.h>
#include "syscall.h"
.seg "text"
/*
* system call
*
* On entry:
*
* l0 = psr (from trap table)
* l1 = pc
* l2 = npc
* g1 = system call id
*
* System Call 1 (exit):
* g2 = additional exit code 1
* g3 = additional exit code 2
*/
.align 32 ! Align to 32-byte cache-line
PUBLIC(syscall)
SYM(syscall):
! "subcc, %g1, 3, %g0" done in trap table
bne 2f ! syscall 3? enable interrupt
and %i0, SPARC_PSR_PIL_MASK, %l4
andn %l0, SPARC_PSR_PIL_MASK, %l5
wr %l4, %l5, %psr ! Update PSR according to syscall 3
1: ! leave, with 3 inst PSR-write delay
mov 0, %g1 ! clear %g1
or %l0, SPARC_PSR_ET_MASK, %i0 ! return old psr with ET=1. No
! effect on syscall 3
jmpl %l2, %g0
rett %l2 + 4
2: or %l0, 0x0f00, %l4 ! set PIL=15
subcc %g1, 2, %g0 ! syscall 2? disable interrupts
beq,a 1b ! Annul delay-slot for syscall 1
mov %l4, %psr ! Update PSR according to Syscall 2
ta 0 ! syscall 1 (not 2 or 3), halt
PUBLIC(sparc_disable_interrupts)
SYM(sparc_disable_interrupts):
mov SYS_irqdis, %g1
retl
ta 0
PUBLIC(sparc_enable_interrupts)
SYM(sparc_enable_interrupts):
mov SYS_irqen, %g1
retl
ta 0
PUBLIC(sparc_syscall_exit)
SYM(sparc_syscall_exit):
mov SYS_exit, %g1
mov %o0, %g2 ! Additional exit code 1
mov %o1, %g3 ! Additional exit code 2
ta 0
#if defined(RTEMS_PARAVIRT)
PUBLIC(_SPARC_Get_PSR)
SYM(_SPARC_Get_PSR):
retl
rd %psr, %o0
PUBLIC(_SPARC_Set_PSR)
SYM(_SPARC_Set_PSR):
mov %o0, %psr
nop
nop
nop
retl
nop
PUBLIC(_SPARC_Get_TBR)
SYM(_SPARC_Get_TBR):
retl
rd %tbr, %o0
PUBLIC(_SPARC_Set_TBR)
SYM(_SPARC_Set_TBR):
retl
wr %o0, 0, %tbr
#endif /* defined(RTEMS_PARAVIRT) */
/* end of file */
