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- #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 );
- }
- }
- }
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