| /* 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_MODEL >= 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_MASK1 != 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_MASK1 != 0 requires CPUID |
| |
| movl $0x0,%eax # See if cpuid 1 is implemented |
| cpuid |
| cmpl $0x1,%eax |
| jb bad # no cpuid 1 |
| |
| #if REQUIRED_MASK1 & 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_MODEL > 4 |
| #error add proper model checking here |
| #endif |
| |
| andl $REQUIRED_MASK1,%edx |
| xorl $REQUIRED_MASK1,%edx |
| jnz bad |
| #endif /* REQUIRED_MASK1 */ |
| |
| popfl |
| xor %eax,%eax |
| ret |
| |
| bad: |
| popfl |
| movl $1,%eax |
| ret |
