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562
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1 /*
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2 getcpucpuflags: get cpuflags for ia32
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3
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4 copyright ?-2006 by the mpg123 project - free software under the terms of the LGPL 2.1
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5 see COPYING and AUTHORS files in distribution or http:#mpg123.org
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6 initially written by KIMURA Takuhiro (for 3DNow!)
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7 extended for general use by Thomas Orgis
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8
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9 extern int getcpuid(struct cpuflags*)
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10 or just
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11 extern int getcpuid(unsigned int*)
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12 where there is memory for 4 ints
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13 -> the first set of idflags (basic cpu family info)
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14 and the idflags, stdflags, std2flags, extflags written to the parameter
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15 -> 0x00000000 (CPUID instruction not supported)
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16 */
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17
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18 #include "mangle.h"
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19
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20 .text
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21 ALIGN4
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22
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23 .globl ASM_NAME(getcpuflags)
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24 /* .type ASM_NAME(getcpuflags),@function */
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25 ASM_NAME(getcpuflags):
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26 pushl %ebp
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27 movl %esp,%ebp
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28 pushl %edx
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29 pushl %ecx
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30 pushl %ebx
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31 pushl %esi
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32 /* get the int pointer for storing the flags */
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33 movl 8(%ebp), %esi
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34 /* does that one make sense? */
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35 movl $0x80000000,%eax
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36 /* now save the flags and do a check for cpuid availability */
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37 pushfl
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38 pushfl
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39 popl %eax
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40 movl %eax,%ebx
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41 /* set that bit... */
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42 xorl $0x00200000,%eax
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43 pushl %eax
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44 popfl
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45 /* ...and read back the flags to see if it is understood */
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46 pushfl
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47 popl %eax
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48 popfl
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49 cmpl %ebx,%eax
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50 je .Lnocpuid
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51 /* In principle, I would have to check the CPU's identify first to be sure how to interpret the extended flags. */
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52 /* now get the info, first extended */
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53 movl $0x0, 12(%esi) /* clear value */
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54 /* only if supported... */
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55 movl $0x80000000, %eax
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56 cpuid
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57 /* IDT CPUs should not change EAX, generally I hope that non-3DNow cpus do not set a bogus support level here. */
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58 cmpl $0x80000001, %eax
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59 jb .Lnoextended /* Skip ext check without minimal support level. */
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60 /* is supported, get flags value */
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61 movl $0x80000001,%eax
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62 cpuid
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63 movl %edx,12(%esi)
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64 .Lnoextended:
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65 /* then the other ones, called last to get the id flags in %eax for ret */
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66 movl $0x00000001,%eax
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67 cpuid
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68 movl %eax, (%esi)
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69 movl %ecx, 4(%esi)
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70 movl %edx, 8(%esi)
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71 jmp .Lend
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72 ALIGN4
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73 .Lnocpuid:
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74 /* error: set everything to zero */
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75 movl $0, %eax
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76 movl $0, (%esi)
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77 movl $0, 4(%esi)
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78 movl $0, 8(%esi)
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79 movl $0, 12(%esi)
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80 ALIGN4
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81 .Lend:
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82 /* return value are the id flags, still stored in %eax */
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83 popl %esi
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84 popl %ebx
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85 popl %ecx
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86 popl %edx
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87 movl %ebp,%esp
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88 popl %ebp
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89 ret
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90
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91 /* Mark non-executable stack. */
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92 #if defined(__linux__) && defined(__ELF__)
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93 .section .note.GNU-stack,"",%progbits
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94 #endif
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