NetBSD/usr.sbin/cpuctl/arch/i386-asm.S
ad 51e7ff401b PR port-amd64/37461 x86 cpu dmesg output is noisy
Port identifycpu() to userspace. The kernel lies and reports on cpuN while
actually using the values from cpu0, but this attempts to bind itself to the
requested CPU if running as root. That doesn't work properly yet due to
kern/38588, but will do once that's fixed.
2008-05-05 17:54:14 +00:00

161 lines
3.9 KiB
ArmAsm

/* $NetBSD: i386-asm.S,v 1.1 2008/05/05 17:54:14 ad Exp $ */
/*-
* Copyright (c) 1998, 2000, 2004, 2006, 2007 The NetBSD Foundation, Inc.
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include <machine/asm.h>
#include <machine/cputypes.h>
#include <machine/psl.h>
.data
_C_LABEL(cpu):
.long 0
.globl _C_LABEL(cpu)
_C_LABEL(cpu_info_level):
.long -1
.globl _C_LABEL(cpu_info_level)
.text
ENTRY(x86_cpuid2)
pushl %ebx
pushl %edi
movl 12(%esp), %eax
movl 16(%esp), %ecx
movl 20(%esp), %edi
cpuid
movl %eax, 0(%edi)
movl %ebx, 4(%edi)
movl %ecx, 8(%edi)
movl %edx, 12(%edi)
popl %edi
popl %ebx
ret
END(x86_cpuid2)
ENTRY(x86_identify)
pushl %ebx
/* Try to toggle alignment check flag; does not exist on 386. */
pushfl
popl %eax
movl %eax,%ecx
orl $PSL_AC,%eax
pushl %eax
popfl
pushfl
popl %eax
xorl %ecx,%eax
andl $PSL_AC,%eax
pushl %ecx
popfl
testl %eax,%eax
jnz try486
/*
* Try the test of a NexGen CPU -- ZF will not change on a DIV
* instruction on a NexGen, it will on an i386. Documented in
* Nx586 Processor Recognition Application Note, NexGen, Inc.
*/
movl $0x5555,%eax
xorl %edx,%edx
movl $2,%ecx
divl %ecx
jnz is386
isnx586:
/*
* Don't try cpuid, as Nx586s reportedly don't support the
* PSL_ID bit.
*/
movl $CPU_NX586,_C_LABEL(cpu)
jmp 2f
is386:
movl $CPU_386,_C_LABEL(cpu)
jmp 2f
try486: /* Try to toggle identification flag; does not exist on early 486s. */
pushfl
popl %eax
movl %eax,%ecx
xorl $PSL_ID,%eax
pushl %eax
popfl
pushfl
popl %eax
xorl %ecx,%eax
andl $PSL_ID,%eax
pushl %ecx
popfl
testl %eax,%eax
jnz try586
is486: movl $CPU_486,_C_LABEL(cpu)
/*
* Check Cyrix CPU
* Cyrix CPUs do not change the undefined flags following
* execution of the divide instruction which divides 5 by 2.
*
* Note: CPUID is enabled on M2, so it passes another way.
*/
pushfl
movl $0x5555, %eax
xorl %edx, %edx
movl $2, %ecx
clc
divl %ecx
jnc trycyrix486
popfl
jmp 2f
trycyrix486:
movl $CPU_6x86,_C_LABEL(cpu) # set CPU type
/*
* Check for Cyrix 486 CPU by seeing if the flags change during a
* divide. This is documented in the Cx486SLC/e SMM Programmer's
* Guide.
*/
xorl %edx,%edx
cmpl %edx,%edx # set flags to known state
pushfl
popl %ecx # store flags in ecx
movl $-1,%eax
movl $4,%ebx
divl %ebx # do a long division
pushfl
popl %eax
xorl %ecx,%eax # are the flags different?
testl $0x8d5,%eax # only check C|PF|AF|Z|N|V
jne 2f # yes; must be Cyrix 6x86 CPU
movl $CPU_486DLC,_C_LABEL(cpu)# set CPU type
jmp 2f
try586: /* Use the `cpuid' instruction. */
xorl %eax,%eax
cpuid
movl %eax,_C_LABEL(cpu_info_level)
2:
popl %ebx
ret