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/* Check if CPU has some minimum CPUID bits
This runs in 16bit mode so that the caller can still use the BIOS
to output errors on the screen */
#include <asm/cpufeature.h>
#include <asm/msr.h>
verify_cpu:
pushfl # Save caller passed flags
pushl $0 # Kill any dangerous flags
popfl
#if CONFIG_X86_MINIMUM_CPU_FAMILY >= 4
pushfl
pop %eax
orl $(1<<18),%eax # try setting AC
push %eax
popfl
pushfl
popl %eax
testl $(1<<18),%eax
jz bad
#endif
#if REQUIRED_MASK0 != 0
pushfl # standard way to check for cpuid
popl %eax
movl %eax,%ebx
xorl $0x200000,%eax
pushl %eax
popfl
pushfl
popl %eax
cmpl %eax,%ebx
pushfl # standard way to check for cpuid
popl %eax
movl %eax,%ebx
xorl $0x200000,%eax
pushl %eax
popfl
pushfl
popl %eax
cmpl %eax,%ebx
jz bad # REQUIRED_MASK0 != 0 requires CPUID
movl $0x0,%eax # See if cpuid 1 is implemented
cpuid
cmpl $0x1,%eax
jb bad # no cpuid 1
#if REQUIRED_MASK0 & NEED_CMPXCHG64
/* Some VIA C3s need magic MSRs to enable CX64. Do this here */
cmpl $0x746e6543,%ebx # Cent
jne 1f
cmpl $0x48727561,%edx # aurH
jne 1f
cmpl $0x736c7561,%ecx # auls
jne 1f
movl $1,%eax # check model
cpuid
movl %eax,%ebx
shr $8,%ebx
andl $0xf,%ebx
cmp $6,%ebx # check family == 6
jne 1f
shr $4,%eax
andl $0xf,%eax
cmpl $6,%eax # check model >= 6
jb 1f
# assume models >= 6 all support this MSR
movl $MSR_VIA_FCR,%ecx
rdmsr
orl $((1<<1)|(1<<7)),%eax # enable CMPXCHG64 and PGE
wrmsr
1:
#endif
movl $0x1,%eax # Does the cpu have what it takes
cpuid
#if CONFIG_X86_MINIMUM_CPU_FAMILY > 4
#error add proper model checking here
#endif
andl $REQUIRED_MASK0,%edx
xorl $REQUIRED_MASK0,%edx
jnz bad
#endif /* REQUIRED_MASK0 */
popfl
xor %eax,%eax
ret
bad:
popfl
movl $1,%eax
ret
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