1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
#include <stdint.h>
#include <string.h>
#include <cpu.h>
/** @file
*
* CPU identification
*
*/
/**
* Test to see if CPU flag is changeable
*
* @v flag Flag to test
* @ret can_change Flag is changeable
*/
static inline int flag_is_changeable ( unsigned int flag ) {
uint32_t f1, f2;
__asm__ ( "pushfl\n\t"
"pushfl\n\t"
"popl %0\n\t"
"movl %0,%1\n\t"
"xorl %2,%0\n\t"
"pushl %0\n\t"
"popfl\n\t"
"pushfl\n\t"
"popl %0\n\t"
"popfl\n\t"
: "=&r" ( f1 ), "=&r" ( f2 )
: "ir" ( flag ) );
return ( ( ( f1 ^ f2 ) & flag ) != 0 );
}
/**
* Get CPU information
*
* @v cpu CPU information structure to fill in
*/
void get_cpuinfo ( struct cpuinfo_x86 *cpu ) {
unsigned int cpuid_level;
unsigned int cpuid_extlevel;
unsigned int discard_1, discard_2, discard_3;
memset ( cpu, 0, sizeof ( *cpu ) );
/* Check for CPUID instruction */
if ( ! flag_is_changeable ( X86_EFLAGS_ID ) ) {
DBG ( "CPUID not supported\n" );
return;
}
/* Get features, if present */
cpuid ( 0x00000000, &cpuid_level, &discard_1,
&discard_2, &discard_3 );
if ( cpuid_level >= 0x00000001 ) {
cpuid ( 0x00000001, &discard_1, &discard_2,
&discard_3, &cpu->features );
} else {
DBG ( "CPUID cannot return capabilities\n" );
}
/* Get 64-bit features, if present */
cpuid ( 0x80000000, &cpuid_extlevel, &discard_1,
&discard_2, &discard_3 );
if ( ( cpuid_extlevel & 0xffff0000 ) == 0x80000000 ) {
if ( cpuid_extlevel >= 0x80000001 ) {
cpuid ( 0x80000001, &discard_1, &discard_2,
&discard_3, &cpu->amd_features );
}
}
}
|
