1/* Check if CPU has some minimum CPUID bits 2 This runs in 16bit mode so that the caller can still use the BIOS 3 to output errors on the screen */ 4#include <asm/cpufeature.h> 5#include <asm/msr.h> 6 7verify_cpu: 8 pushfl # Save caller passed flags 9 pushl $0 # Kill any dangerous flags 10 popfl 11 12#if CONFIG_X86_MINIMUM_CPU_MODEL >= 4 13 pushfl 14 pop %eax 15 orl $(1<<18),%eax # try setting AC 16 push %eax 17 popfl 18 pushfl 19 popl %eax 20 testl $(1<<18),%eax 21 jz bad 22#endif 23#if REQUIRED_MASK1 != 0 24 pushfl # standard way to check for cpuid 25 popl %eax 26 movl %eax,%ebx 27 xorl $0x200000,%eax 28 pushl %eax 29 popfl 30 pushfl 31 popl %eax 32 cmpl %eax,%ebx 33 pushfl # standard way to check for cpuid 34 popl %eax 35 movl %eax,%ebx 36 xorl $0x200000,%eax 37 pushl %eax 38 popfl 39 pushfl 40 popl %eax 41 cmpl %eax,%ebx 42 jz bad # REQUIRED_MASK1 != 0 requires CPUID 43 44 movl $0x0,%eax # See if cpuid 1 is implemented 45 cpuid 46 cmpl $0x1,%eax 47 jb bad # no cpuid 1 48 49#if REQUIRED_MASK1 & NEED_CMPXCHG64 50 /* Some VIA C3s need magic MSRs to enable CX64. Do this here */ 51 cmpl $0x746e6543,%ebx # Cent 52 jne 1f 53 cmpl $0x48727561,%edx # aurH 54 jne 1f 55 cmpl $0x736c7561,%ecx # auls 56 jne 1f 57 movl $1,%eax # check model 58 cpuid 59 movl %eax,%ebx 60 shr $8,%ebx 61 andl $0xf,%ebx 62 cmp $6,%ebx # check family == 6 63 jne 1f 64 shr $4,%eax 65 andl $0xf,%eax 66 cmpl $6,%eax # check model >= 6 67 jb 1f 68 # assume models >= 6 all support this MSR 69 movl $MSR_VIA_FCR,%ecx 70 rdmsr 71 orl $((1<<1)|(1<<7)),%eax # enable CMPXCHG64 and PGE 72 wrmsr 731: 74#endif 75 movl $0x1,%eax # Does the cpu have what it takes 76 cpuid 77 78#if CONFIG_X86_MINIMUM_CPU_MODEL > 4 79#error add proper model checking here 80#endif 81 82 andl $REQUIRED_MASK1,%edx 83 xorl $REQUIRED_MASK1,%edx 84 jnz bad 85#endif /* REQUIRED_MASK1 */ 86 87 popfl 88 xor %eax,%eax 89 ret 90 91bad: 92 popfl 93 movl $1,%eax 94 ret 95