3 Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>
4 Copyright (C) 2013, Red Hat, Inc.
5 Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
7 This program and the accompanying materials
8 are licensed and made available under the terms and conditions of the BSD License
9 which accompanies this distribution. The full text of the license may be found at
10 http://opensource.org/licenses/bsd-license.php
12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
18 #include <Library/BaseLib.h>
19 #include <Library/BaseMemoryLib.h>
20 #include <Library/DebugLib.h>
21 #include <Library/IoLib.h>
22 #include <Library/QemuFwCfgLib.h>
23 #include <Library/MemoryAllocationLib.h>
24 #include <Library/UefiBootServicesTableLib.h>
26 #include "QemuFwCfgLibInternal.h"
30 Selects a firmware configuration item for reading.
32 Following this call, any data read from this item will start from
33 the beginning of the configuration item's data.
35 @param[in] QemuFwCfgItem - Firmware Configuration item to read
41 IN FIRMWARE_CONFIG_ITEM QemuFwCfgItem
44 DEBUG ((EFI_D_INFO
, "Select Item: 0x%x\n", (UINT16
)(UINTN
) QemuFwCfgItem
));
45 IoWrite16 (FW_CFG_IO_SELECTOR
, (UINT16
)(UINTN
) QemuFwCfgItem
);
50 Transfer an array of bytes, or skip a number of bytes, using the DMA
53 @param[in] Size Size in bytes to transfer or skip.
55 @param[in,out] Buffer Buffer to read data into or write data from. Ignored,
56 and may be NULL, if Size is zero, or Control is
59 @param[in] Control One of the following:
60 FW_CFG_DMA_CTL_WRITE - write to fw_cfg from Buffer.
61 FW_CFG_DMA_CTL_READ - read from fw_cfg into Buffer.
62 FW_CFG_DMA_CTL_SKIP - skip bytes in fw_cfg.
65 InternalQemuFwCfgDmaBytes (
67 IN OUT VOID
*Buffer OPTIONAL
,
71 volatile FW_CFG_DMA_ACCESS Access
;
72 UINT32 AccessHigh
, AccessLow
;
75 ASSERT (Control
== FW_CFG_DMA_CTL_WRITE
|| Control
== FW_CFG_DMA_CTL_READ
||
76 Control
== FW_CFG_DMA_CTL_SKIP
);
82 Access
.Control
= SwapBytes32 (Control
);
83 Access
.Length
= SwapBytes32 (Size
);
84 Access
.Address
= SwapBytes64 ((UINTN
)Buffer
);
87 // Delimit the transfer from (a) modifications to Access, (b) in case of a
88 // write, from writes to Buffer by the caller.
93 // Start the transfer.
95 AccessHigh
= (UINT32
)RShiftU64 ((UINTN
)&Access
, 32);
96 AccessLow
= (UINT32
)(UINTN
)&Access
;
97 IoWrite32 (FW_CFG_IO_DMA_ADDRESS
, SwapBytes32 (AccessHigh
));
98 IoWrite32 (FW_CFG_IO_DMA_ADDRESS
+ 4, SwapBytes32 (AccessLow
));
101 // Don't look at Access.Control before starting the transfer.
106 // Wait for the transfer to complete.
109 Status
= SwapBytes32 (Access
.Control
);
110 ASSERT ((Status
& FW_CFG_DMA_CTL_ERROR
) == 0);
111 } while (Status
!= 0);
114 // After a read, the caller will want to use Buffer.
121 Reads firmware configuration bytes into a buffer
123 @param[in] Size - Size in bytes to read
124 @param[in] Buffer - Buffer to store data into (OPTIONAL if Size is 0)
129 InternalQemuFwCfgReadBytes (
131 IN VOID
*Buffer OPTIONAL
134 if (InternalQemuFwCfgDmaIsAvailable () && Size
<= MAX_UINT32
) {
135 InternalQemuFwCfgDmaBytes ((UINT32
)Size
, Buffer
, FW_CFG_DMA_CTL_READ
);
138 IoReadFifo8 (FW_CFG_IO_DATA
, Size
, Buffer
);
143 Reads firmware configuration bytes into a buffer
145 If called multiple times, then the data read will
146 continue at the offset of the firmware configuration
147 item where the previous read ended.
149 @param[in] Size - Size in bytes to read
150 @param[in] Buffer - Buffer to store data into
160 if (InternalQemuFwCfgIsAvailable ()) {
161 InternalQemuFwCfgReadBytes (Size
, Buffer
);
163 ZeroMem (Buffer
, Size
);
168 Write firmware configuration bytes from a buffer
170 If called multiple times, then the data written will
171 continue at the offset of the firmware configuration
172 item where the previous write ended.
174 @param[in] Size - Size in bytes to write
175 @param[in] Buffer - Buffer to read data from
180 QemuFwCfgWriteBytes (
185 if (InternalQemuFwCfgIsAvailable ()) {
186 if (InternalQemuFwCfgDmaIsAvailable () && Size
<= MAX_UINT32
) {
187 InternalQemuFwCfgDmaBytes ((UINT32
)Size
, Buffer
, FW_CFG_DMA_CTL_WRITE
);
190 IoWriteFifo8 (FW_CFG_IO_DATA
, Size
, Buffer
);
196 Skip bytes in the firmware configuration item.
198 Increase the offset of the firmware configuration item without transferring
199 bytes between the item and a caller-provided buffer. Subsequent read, write
200 or skip operations will commence at the increased offset.
202 @param[in] Size Number of bytes to skip.
211 UINT8 SkipBuffer
[256];
213 if (!InternalQemuFwCfgIsAvailable ()) {
217 if (InternalQemuFwCfgDmaIsAvailable () && Size
<= MAX_UINT32
) {
218 InternalQemuFwCfgDmaBytes ((UINT32
)Size
, NULL
, FW_CFG_DMA_CTL_SKIP
);
223 // Emulate the skip by reading data in chunks, and throwing it away. The
224 // implementation below is suitable even for phases where RAM or dynamic
225 // allocation is not available or appropriate. It also doesn't affect the
226 // static data footprint for client modules. Large skips are not expected,
227 // therefore this fallback is not performance critical. The size of
228 // SkipBuffer is thought not to exert a large pressure on the stack in any
232 ChunkSize
= MIN (Size
, sizeof SkipBuffer
);
233 IoReadFifo8 (FW_CFG_IO_DATA
, ChunkSize
, SkipBuffer
);
240 Reads a UINT8 firmware configuration value
242 @return Value of Firmware Configuration item read
253 QemuFwCfgReadBytes (sizeof (Result
), &Result
);
260 Reads a UINT16 firmware configuration value
262 @return Value of Firmware Configuration item read
273 QemuFwCfgReadBytes (sizeof (Result
), &Result
);
280 Reads a UINT32 firmware configuration value
282 @return Value of Firmware Configuration item read
293 QemuFwCfgReadBytes (sizeof (Result
), &Result
);
300 Reads a UINT64 firmware configuration value
302 @return Value of Firmware Configuration item read
313 QemuFwCfgReadBytes (sizeof (Result
), &Result
);
320 Find the configuration item corresponding to the firmware configuration file.
322 @param[in] Name - Name of file to look up.
323 @param[out] Item - Configuration item corresponding to the file, to be passed
324 to QemuFwCfgSelectItem ().
325 @param[out] Size - Number of bytes in the file.
327 @return RETURN_SUCCESS If file is found.
328 RETURN_NOT_FOUND If file is not found.
329 RETURN_UNSUPPORTED If firmware configuration is unavailable.
335 IN CONST CHAR8
*Name
,
336 OUT FIRMWARE_CONFIG_ITEM
*Item
,
343 if (!InternalQemuFwCfgIsAvailable ()) {
344 return RETURN_UNSUPPORTED
;
347 QemuFwCfgSelectItem (QemuFwCfgItemFileDir
);
348 Count
= SwapBytes32 (QemuFwCfgRead32 ());
350 for (Idx
= 0; Idx
< Count
; ++Idx
) {
354 CHAR8 FName
[QEMU_FW_CFG_FNAME_SIZE
];
356 FileSize
= QemuFwCfgRead32 ();
357 FileSelect
= QemuFwCfgRead16 ();
358 FileReserved
= QemuFwCfgRead16 ();
359 (VOID
) FileReserved
; /* Force a do-nothing reference. */
360 InternalQemuFwCfgReadBytes (sizeof (FName
), FName
);
362 if (AsciiStrCmp (Name
, FName
) == 0) {
363 *Item
= SwapBytes16 (FileSelect
);
364 *Size
= SwapBytes32 (FileSize
);
365 return RETURN_SUCCESS
;
369 return RETURN_NOT_FOUND
;