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1 | /** @file\r |
2 | AsmCpuidEx function.\r |
3 | \r |
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4 | Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>\r |
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5 | This program and the accompanying materials\r |
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6 | are licensed and made available under the terms and conditions of the BSD License\r |
7 | which accompanies this distribution. The full text of the license may be found at\r |
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8 | http://opensource.org/licenses/bsd-license.php.\r |
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9 | \r |
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r |
12 | \r |
13 | **/\r |
14 | \r |
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15 | /**\r |
16 | Retrieves CPUID information using an extended leaf identifier.\r |
17 | \r |
18 | Executes the CPUID instruction with EAX set to the value specified by Index\r |
19 | and ECX set to the value specified by SubIndex. This function always returns\r |
20 | Index. This function is only available on IA-32 and x64.\r |
21 | \r |
22 | If Eax is not NULL, then the value of EAX after CPUID is returned in Eax.\r |
23 | If Ebx is not NULL, then the value of EBX after CPUID is returned in Ebx.\r |
24 | If Ecx is not NULL, then the value of ECX after CPUID is returned in Ecx.\r |
25 | If Edx is not NULL, then the value of EDX after CPUID is returned in Edx.\r |
26 | \r |
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27 | @param Index The 32-bit value to load into EAX prior to invoking the\r |
28 | CPUID instruction.\r |
29 | @param SubIndex The 32-bit value to load into ECX prior to invoking the\r |
30 | CPUID instruction.\r |
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31 | @param RegisterEax A pointer to the 32-bit EAX value returned by the CPUID\r |
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32 | instruction. This is an optional parameter that may be\r |
33 | NULL.\r |
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34 | @param RegisterEbx A pointer to the 32-bit EBX value returned by the CPUID\r |
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35 | instruction. This is an optional parameter that may be\r |
36 | NULL.\r |
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37 | @param RegisterEcx A pointer to the 32-bit ECX value returned by the CPUID\r |
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38 | instruction. This is an optional parameter that may be\r |
39 | NULL.\r |
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40 | @param RegisterEdx A pointer to the 32-bit EDX value returned by the CPUID\r |
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41 | instruction. This is an optional parameter that may be\r |
42 | NULL.\r |
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43 | \r |
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44 | @return Index.\r |
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45 | \r |
46 | **/\r |
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47 | UINT32\r |
48 | EFIAPI\r |
49 | AsmCpuidEx (\r |
50 | IN UINT32 Index,\r |
51 | IN UINT32 SubIndex,\r |
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52 | OUT UINT32 *RegisterEax, OPTIONAL\r |
53 | OUT UINT32 *RegisterEbx, OPTIONAL\r |
54 | OUT UINT32 *RegisterEcx, OPTIONAL\r |
55 | OUT UINT32 *RegisterEdx OPTIONAL\r |
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56 | )\r |
57 | {\r |
58 | _asm {\r |
59 | mov eax, Index\r |
60 | mov ecx, SubIndex\r |
61 | cpuid\r |
62 | push ecx\r |
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63 | mov ecx, RegisterEax\r |
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64 | jecxz SkipEax\r |
65 | mov [ecx], eax\r |
66 | SkipEax:\r |
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67 | mov ecx, RegisterEbx\r |
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68 | jecxz SkipEbx\r |
69 | mov [ecx], ebx\r |
70 | SkipEbx:\r |
71 | pop eax\r |
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72 | mov ecx, RegisterEcx\r |
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73 | jecxz SkipEcx\r |
74 | mov [ecx], eax\r |
75 | SkipEcx:\r |
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76 | mov ecx, RegisterEdx\r |
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77 | jecxz SkipEdx\r |
78 | mov [ecx], edx\r |
79 | SkipEdx:\r |
80 | mov eax, Index\r |
81 | }\r |
82 | }\r |