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c90decb9 LE |
1 | /** @file\r |
2 | \r | |
3 | Stateless fw_cfg library implementation.\r | |
4 | \r | |
5 | Clients must call QemuFwCfgIsAvailable() first.\r | |
6 | \r | |
7 | Copyright (C) 2013, Red Hat, Inc.\r | |
8 | Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>\r | |
6264abc2 | 9 | Copyright (c) 2017, Advanced Micro Devices. All rights reserved.<BR>\r |
c90decb9 LE |
10 | \r |
11 | This program and the accompanying materials are licensed and made available\r | |
12 | under the terms and conditions of the BSD License which accompanies this\r | |
13 | distribution. The full text of the license may be found at\r | |
14 | http://opensource.org/licenses/bsd-license.php\r | |
15 | \r | |
16 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT\r | |
17 | WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
18 | **/\r | |
19 | \r | |
f6c909ae | 20 | #include <Library/BaseLib.h>\r |
c90decb9 LE |
21 | #include <Library/DebugLib.h>\r |
22 | #include <Library/QemuFwCfgLib.h>\r | |
23 | \r | |
5297c0bf | 24 | #include "QemuFwCfgLibInternal.h"\r |
c90decb9 LE |
25 | \r |
26 | /**\r | |
27 | Returns a boolean indicating if the firmware configuration interface\r | |
28 | is available or not.\r | |
29 | \r | |
30 | This function may change fw_cfg state.\r | |
31 | \r | |
32 | @retval TRUE The interface is available\r | |
33 | @retval FALSE The interface is not available\r | |
34 | \r | |
35 | **/\r | |
36 | BOOLEAN\r | |
37 | EFIAPI\r | |
38 | QemuFwCfgIsAvailable (\r | |
39 | VOID\r | |
40 | )\r | |
41 | {\r | |
42 | UINT32 Signature;\r | |
43 | UINT32 Revision;\r | |
44 | \r | |
45 | QemuFwCfgSelectItem (QemuFwCfgItemSignature);\r | |
46 | Signature = QemuFwCfgRead32 ();\r | |
47 | DEBUG ((EFI_D_INFO, "FW CFG Signature: 0x%x\n", Signature));\r | |
48 | QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);\r | |
49 | Revision = QemuFwCfgRead32 ();\r | |
50 | DEBUG ((EFI_D_INFO, "FW CFG Revision: 0x%x\n", Revision));\r | |
51 | if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||\r | |
52 | (Revision < 1)\r | |
53 | ) {\r | |
54 | DEBUG ((EFI_D_INFO, "QemuFwCfg interface not supported.\n"));\r | |
55 | return FALSE;\r | |
56 | }\r | |
57 | \r | |
58 | DEBUG ((EFI_D_INFO, "QemuFwCfg interface is supported.\n"));\r | |
59 | return TRUE;\r | |
60 | }\r | |
61 | \r | |
62 | \r | |
63 | /**\r | |
64 | Returns a boolean indicating if the firmware configuration interface is\r | |
65 | available for library-internal purposes.\r | |
66 | \r | |
67 | This function never changes fw_cfg state.\r | |
68 | \r | |
69 | @retval TRUE The interface is available internally.\r | |
70 | @retval FALSE The interface is not available internally.\r | |
71 | **/\r | |
72 | BOOLEAN\r | |
c90decb9 LE |
73 | InternalQemuFwCfgIsAvailable (\r |
74 | VOID\r | |
75 | )\r | |
76 | {\r | |
77 | //\r | |
78 | // We always return TRUE, because the consumer of this library ought to have\r | |
79 | // called QemuFwCfgIsAvailable before making other calls which would hit this\r | |
80 | // path.\r | |
81 | //\r | |
82 | return TRUE;\r | |
83 | }\r | |
2c8dcbc6 LE |
84 | \r |
85 | /**\r | |
86 | Returns a boolean indicating whether QEMU provides the DMA-like access method\r | |
87 | for fw_cfg.\r | |
88 | \r | |
89 | @retval TRUE The DMA-like access method is available.\r | |
90 | @retval FALSE The DMA-like access method is unavailable.\r | |
91 | **/\r | |
92 | BOOLEAN\r | |
93 | InternalQemuFwCfgDmaIsAvailable (\r | |
94 | VOID\r | |
95 | )\r | |
96 | {\r | |
97 | return FALSE;\r | |
98 | }\r | |
6264abc2 BS |
99 | \r |
100 | /**\r | |
f6c909ae BS |
101 | Transfer an array of bytes, or skip a number of bytes, using the DMA\r |
102 | interface.\r | |
6264abc2 | 103 | \r |
f6c909ae | 104 | @param[in] Size Size in bytes to transfer or skip.\r |
6264abc2 | 105 | \r |
f6c909ae BS |
106 | @param[in,out] Buffer Buffer to read data into or write data from. Ignored,\r |
107 | and may be NULL, if Size is zero, or Control is\r | |
108 | FW_CFG_DMA_CTL_SKIP.\r | |
6264abc2 | 109 | \r |
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110 | @param[in] Control One of the following:\r |
111 | FW_CFG_DMA_CTL_WRITE - write to fw_cfg from Buffer.\r | |
112 | FW_CFG_DMA_CTL_READ - read from fw_cfg into Buffer.\r | |
113 | FW_CFG_DMA_CTL_SKIP - skip bytes in fw_cfg.\r | |
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114 | **/\r |
115 | VOID\r | |
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116 | InternalQemuFwCfgDmaBytes (\r |
117 | IN UINT32 Size,\r | |
118 | IN OUT VOID *Buffer OPTIONAL,\r | |
119 | IN UINT32 Control\r | |
6264abc2 BS |
120 | )\r |
121 | {\r | |
122 | //\r | |
123 | // We should never reach here\r | |
124 | //\r | |
125 | ASSERT (FALSE);\r | |
f6c909ae | 126 | CpuDeadLoop ();\r |
6264abc2 | 127 | }\r |