source: mainline/arch/ia32/src/cpuid.s@ ca90d65

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since ca90d65 was f761f1eb, checked in by Jakub Jermar <jakub@…>, 20 years ago

Initial import

  • Property mode set to 100644
File size: 2.3 KB
Line 
1#
2# Copyright (C) 2001-2004 Jakub Jermar
3# All rights reserved.
4#
5# Redistribution and use in source and binary forms, with or without
6# modification, are permitted provided that the following conditions
7# are met:
8#
9# - Redistributions of source code must retain the above copyright
10# notice, this list of conditions and the following disclaimer.
11# - Redistributions in binary form must reproduce the above copyright
12# notice, this list of conditions and the following disclaimer in the
13# documentation and/or other materials provided with the distribution.
14# - The name of the author may not be used to endorse or promote products
15# derived from this software without specific prior written permission.
16#
17# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27#
28
29#
30# CPU identification functions.
31# The code below just interfaces the CPUID instruction.
32# CPU recognition logic is contained in higher-level functions.
33
34.text
35
36.global has_cpuid
37.global cpuid
38.global rdtsc
39
40has_cpuid:
41 push %ebx
42
43 pushf # store flags
44 popl %eax # read flags
45 movl %eax,%ebx # copy flags
46 btcl $21,%ebx # swap the ID bit
47 pushl %ebx
48 popf # propagate the change into flags
49 pushf
50 popl %ebx # read flags
51 andl $(1<<21),%eax # interested only in ID bit
52 andl $(1<<21),%ebx
53 xorl %ebx,%eax # 0 if not supported, 1 if supported
54
55 pop %ebx
56 ret
57
58# cpuid(__u32 cmd, struct cpu_info *info)
59cpuid:
60 pushl %ebp
61 movl %esp,%ebp
62 pusha
63
64 movl 8(%ebp),%eax # load the command into %eax
65 movl 12(%ebp),%esi # laod the address of the info struct
66
67 cpuid
68 movl %eax,0(%esi)
69 movl %ebx,4(%esi)
70 movl %ecx,8(%esi)
71 movl %edx,12(%esi)
72
73 popa
74 popl %ebp
75 ret
76
77rdtsc:
78 rdtsc
79 ret
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