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
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