freebsd-skq/sys/mips/mips/locore.S
jmallett ac880fa7c8 At the risk of reducing source compatibility with old NetBSD and Sprite:
o) Get rid of some unused macros related to features we don't intend to
   provide.
o) Get rid of macro definitions for MIPS-I CPUs.  We are not likely to
   support anything that predartes MIPS-III.
o) Respell MIPS3_* macros as MIPS_*, which is how most of them were being
   used already.
o) Eliminate a duplicate and mostly-unused set of exception vector macros.

There's still considerable duplication and lots more obsolete in our headers,
but this reduces one of the larger files to a size where one could reckon
about the correctness of its contents with a mere few hours of contemplation.

There is, of course, a question of whether we need definitions for fields,
registers and configurations that we are unlikely to ever use or implement,
even if they're not obsolete since 1991.  FreeBSD is not a processor
reference manual, and things that aren't used may be wrong, or may be
duplicated because nobody could possibly actually know whether they're
already defined.
2012-03-06 19:01:32 +00:00

188 lines
5.7 KiB
ArmAsm

/* $OpenBSD: locore.S,v 1.18 1998/09/15 10:58:53 pefo Exp $ */
/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Digital Equipment Corporation and Ralph Campbell.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Copyright (C) 1989 Digital Equipment Corporation.
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appears in all copies.
* Digital Equipment Corporation makes no representations about the
* suitability of this software for any purpose. It is provided "as is"
* without express or implied warranty.
*
* from: Header: /sprite/src/kernel/mach/ds3100.md/RCS/loMem.s,
* v 1.1 89/07/11 17:55:04 nelson Exp SPRITE (DECWRL)
* from: Header: /sprite/src/kernel/mach/ds3100.md/RCS/machAsm.s,
* v 9.2 90/01/29 18:00:39 shirriff Exp SPRITE (DECWRL)
* from: Header: /sprite/src/kernel/vm/ds3100.md/vmPmaxAsm.s,
* v 1.1 89/07/10 14:27:41 nelson Exp SPRITE (DECWRL)
*
* from: @(#)locore.s 8.5 (Berkeley) 1/4/94
* JNPR: locore.S,v 1.6.2.1 2007/08/29 12:24:49 girish
* $FreeBSD$
*/
/*
* FREEBSD_DEVELOPERS_FIXME
* The start routine below was written for a multi-core CPU
* with each core being hyperthreaded. This serves as an example
* for a complex CPU architecture. For a different CPU complex
* please make necessary changes to read CPU-ID etc.
* A clean solution would be to have a different locore file for
* each CPU type.
*/
/*
* Contains code that is the first executed at boot time plus
* assembly language support routines.
*/
#include <machine/asm.h>
#include <machine/cpu.h>
#include <machine/cpuregs.h>
#include <machine/regnum.h>
#include "assym.s"
.data
#ifdef YAMON
GLOBAL(fenvp)
.space 4 # Assumes mips32? Is that OK?
#endif
.set noreorder
.text
GLOBAL(btext)
ASM_ENTRY(_start)
VECTOR(_locore, unknown)
/* UNSAFE TO USE a0..a3, need to preserve the args from boot loader */
mtc0 zero, MIPS_COP_0_CAUSE # Clear soft interrupts
#if defined(CPU_CNMIPS)
/*
* t1: Bits to set explicitly:
* Enable FPU
*/
/* Set these bits */
li t1, (MIPS_SR_COP_0_BIT | MIPS_SR_PX | MIPS_SR_KX | MIPS_SR_UX | MIPS_SR_SX | MIPS_SR_BEV)
/* Reset these bits */
li t0, ~(MIPS_SR_DE | MIPS_SR_SR | MIPS_SR_ERL | MIPS_SR_EXL | MIPS_SR_INT_IE | MIPS_SR_COP_2_BIT)
#elif defined (CPU_RMI) || defined (CPU_NLM)
/* Set these bits */
li t1, (MIPS_SR_COP_2_BIT | MIPS_SR_COP_0_BIT | MIPS_SR_KX | MIPS_SR_UX)
/* Reset these bits */
li t0, ~(MIPS_SR_BEV | MIPS_SR_SR | MIPS_SR_INT_IE)
#else
/*
* t0: Bits to preserve if set:
* Soft reset
* Boot exception vectors (firmware-provided)
*/
li t0, (MIPS_SR_BEV | MIPS_SR_SR)
/*
* t1: Bits to set explicitly:
* Enable FPU
*/
li t1, MIPS_SR_COP_1_BIT
#ifdef __mips_n64
or t1, MIPS_SR_KX | MIPS_SR_SX | MIPS_SR_UX
#endif
#endif
/*
* Read coprocessor 0 status register, clear bits not
* preserved (namely, clearing interrupt bits), and set
* bits we want to explicitly set.
*/
mfc0 t2, MIPS_COP_0_STATUS
and t2, t0
or t2, t1
mtc0 t2, MIPS_COP_0_STATUS
COP0_SYNC
/* Make sure KSEG0 is cached */
li t0, MIPS_CCA_CACHED
mtc0 t0, MIPS_COP_0_CONFIG
COP0_SYNC
/*xxximp
* now that we pass a0...a3 to the platform_init routine, do we need
* to stash this stuff here?
*/
#ifdef YAMON
/* Save YAMON boot environment pointer */
sw a2, _C_LABEL(fenvp)
#endif
#if defined(CPU_CNMIPS) && defined(SMP)
.set push
.set mips32r2
rdhwr t2, $0
beqz t2, 1f
nop
j octeon_ap_wait
nop
.set pop
1:
#endif
/*
* Initialize stack and call machine startup.
*/
PTR_LA sp, _C_LABEL(pcpu_space)
PTR_ADDU sp, (PAGE_SIZE * 2) - CALLFRAME_SIZ
REG_S zero, CALLFRAME_RA(sp) # Zero out old ra for debugger
REG_S zero, CALLFRAME_SP(sp) # Zero out old fp for debugger
PTR_LA gp, _C_LABEL(_gp)
/* Call the platform-specific startup code. */
jal _C_LABEL(platform_start)
nop
PTR_LA sp, _C_LABEL(thread0)
PTR_L a0, TD_PCB(sp)
REG_LI t0, ~7
and a0, a0, t0
PTR_SUBU sp, a0, CALLFRAME_SIZ
jal _C_LABEL(mi_startup) # mi_startup(frame)
sw zero, CALLFRAME_SIZ - 8(sp) # Zero out old fp for debugger
PANIC("Startup failed!")
VECTOR_END(_locore)