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| author | Sami Mujawar <sami.mujawar@arm.com> | 2020-08-04 12:46:02 +0100 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2020-08-13 18:00:06 +0000 |
| commit | 7f293b25d600b673b0bd59c24aec9a887d7a5f4a (patch) | |
| tree | f74331ad83d09b97aec1502975f79caf41348322 /DynamicTablesPkg/Library/Common/AmlLib/Stream/AmlStream.c | |
| parent | ca04956e1b7790101a4bd774de60642acc15d695 (diff) | |
| download | edk2-7f293b25d600b673b0bd59c24aec9a887d7a5f4a.tar.gz edk2-7f293b25d600b673b0bd59c24aec9a887d7a5f4a.tar.bz2 edk2-7f293b25d600b673b0bd59c24aec9a887d7a5f4a.zip | |
DynamicTablesPkg: AML stream interface
Dynamic AML involves parsing/packing of AML opcode and
data into AML byte streams. The AML stream interface
provides safe buffer management as well as supports
forward and reverse streams. It provides functions to
create, read, write, clone and compare AML streams.
Co-authored-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
Diffstat (limited to 'DynamicTablesPkg/Library/Common/AmlLib/Stream/AmlStream.c')
| -rw-r--r-- | DynamicTablesPkg/Library/Common/AmlLib/Stream/AmlStream.c | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/DynamicTablesPkg/Library/Common/AmlLib/Stream/AmlStream.c b/DynamicTablesPkg/Library/Common/AmlLib/Stream/AmlStream.c new file mode 100644 index 0000000000..419e796e50 --- /dev/null +++ b/DynamicTablesPkg/Library/Common/AmlLib/Stream/AmlStream.c @@ -0,0 +1,665 @@ +/** @file
+ AML Stream.
+
+ Copyright (c) 2019 - 2020, Arm Limited. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Stream/AmlStream.h>
+
+/** Initialize a stream.
+
+ @param [in, out] Stream Pointer to the stream to initialize.
+ @param [in] Buffer Buffer to initialize Stream with.
+ Point to the beginning of the Buffer.
+ @param [in] MaxBufferSize Maximum size of Buffer.
+ @param [in] Direction Direction Stream is progressing
+ (forward, backward).
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamInit (
+ IN OUT AML_STREAM * Stream,
+ IN UINT8 * Buffer,
+ IN UINT32 MaxBufferSize,
+ IN EAML_STREAM_DIRECTION Direction
+ )
+{
+ if ((Stream == NULL) ||
+ (Buffer == NULL) ||
+ (MaxBufferSize == 0) ||
+ ((Direction != EAmlStreamDirectionForward) &&
+ (Direction != EAmlStreamDirectionBackward))) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Stream->Buffer = Buffer;
+ Stream->MaxBufferSize = MaxBufferSize;
+ Stream->Index = 0;
+ Stream->Direction = Direction;
+
+ return EFI_SUCCESS;
+}
+
+/** Clone a stream.
+
+ Cloning a stream means copying all the values of the input Stream
+ in the ClonedStream.
+
+ @param [in] Stream Pointer to the stream to clone.
+ @param [in] ClonedStream Pointer to the stream to initialize.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamClone (
+ IN CONST AML_STREAM * Stream,
+ OUT AML_STREAM * ClonedStream
+ )
+{
+ if (!IS_STREAM (Stream) ||
+ (ClonedStream == NULL)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ ClonedStream->Buffer = Stream->Buffer;
+ ClonedStream->MaxBufferSize = Stream->MaxBufferSize;
+ ClonedStream->Index = Stream->Index;
+ ClonedStream->Direction = Stream->Direction;
+
+ return EFI_SUCCESS;
+}
+
+/** Initialize a sub-stream from a stream.
+
+ A sub-stream is a stream initialized at the current position of the input
+ stream:
+ - the Buffer field points to the current position of the input stream;
+ - the Index field is set to 0;
+ - the MaxBufferSize field is set to the remaining size of the input stream;
+ - the direction is conserved;
+
+ E.g.: For a forward stream:
+ +----------------+----------------+
+ |ABCD.........XYZ| Free Space |
+ +----------------+----------------+
+ ^ ^ ^
+ Stream: Buffer CurrPos EndOfBuff
+ Sub-stream: Buffer/CurrPos EndOfBuff
+
+ @param [in] Stream Pointer to the stream from which a sub-stream is
+ created.
+ @param [in] SubStream Pointer to the stream to initialize.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamInitSubStream (
+ IN CONST AML_STREAM * Stream,
+ OUT AML_STREAM * SubStream
+ )
+{
+ if (!IS_STREAM (Stream) ||
+ (SubStream == NULL)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (IS_STREAM_FORWARD (Stream)) {
+ SubStream->Buffer = AmlStreamGetCurrPos (Stream);
+ } else if (IS_STREAM_BACKWARD (Stream)) {
+ SubStream->Buffer = Stream->Buffer;
+ } else {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ SubStream->MaxBufferSize = AmlStreamGetFreeSpace (Stream);
+ SubStream->Index = 0;
+ SubStream->Direction = Stream->Direction;
+
+ return EFI_SUCCESS;
+}
+
+/** Get the buffer of a stream.
+
+ @param [in] Stream Pointer to a stream.
+
+ @return The stream's Buffer.
+ NULL otherwise.
+**/
+UINT8 *
+EFIAPI
+AmlStreamGetBuffer (
+ IN CONST AML_STREAM * Stream
+ )
+{
+ if (!IS_STREAM (Stream)) {
+ ASSERT (0);
+ return NULL;
+ }
+ return Stream->Buffer;
+}
+
+/** Get the size of Stream's Buffer.
+
+ @param [in] Stream Pointer to a stream.
+
+ @return The Size of Stream's Buffer.
+ Return 0 if Stream is invalid.
+**/
+UINT32
+EFIAPI
+AmlStreamGetMaxBufferSize (
+ IN CONST AML_STREAM * Stream
+ )
+{
+ if (!IS_STREAM (Stream)) {
+ ASSERT (0);
+ return 0;
+ }
+ return Stream->MaxBufferSize;
+}
+
+/** Reduce the maximal size of Stream's Buffer (MaxBufferSize field).
+
+ @param [in] Stream Pointer to a stream.
+ @param [in] Diff Value to subtract to the Stream's MaxBufferSize.
+ 0 < x < MaxBufferSize - Index.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamReduceMaxBufferSize (
+ IN AML_STREAM * Stream,
+ IN UINT32 Diff
+ )
+{
+ if (!IS_STREAM (Stream) ||
+ (Diff == 0) ||
+ ((Stream->MaxBufferSize - Diff) <= Stream->Index)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Stream->MaxBufferSize -= Diff;
+ return EFI_SUCCESS;
+}
+
+/** Get Stream's Index.
+
+ Stream's Index is incremented when writing data, reading data,
+ or moving the position in the Stream.
+ It can be seen as an index:
+ - starting at the beginning of Stream's Buffer if the stream goes forward;
+ - starting at the end of Stream's Buffer if the stream goes backward.
+
+ @param [in] Stream Pointer to a stream.
+
+ @return Stream's Index.
+ Return 0 if Stream is invalid.
+**/
+UINT32
+EFIAPI
+AmlStreamGetIndex (
+ IN CONST AML_STREAM * Stream
+ )
+{
+ if (!IS_STREAM (Stream)) {
+ ASSERT (0);
+ return 0;
+ }
+ return Stream->Index;
+}
+
+/** Get Stream's Direction.
+
+ @param [in] Stream Pointer to a stream.
+
+ @return Stream's Direction.
+ Return EAmlStreamDirectionUnknown if Stream is invalid.
+**/
+EAML_STREAM_DIRECTION
+EFIAPI
+AmlStreamGetDirection (
+ IN CONST AML_STREAM * Stream
+ )
+{
+ if (!IS_STREAM (Stream)) {
+ ASSERT (0);
+ return EAmlStreamDirectionInvalid;
+ }
+ return Stream->Direction;
+}
+
+/** Return a pointer to the current position in the stream.
+
+ @param [in] Stream Pointer to a stream.
+
+ @return The current position in the stream.
+ Return NULL if error.
+**/
+UINT8 *
+EFIAPI
+AmlStreamGetCurrPos (
+ IN CONST AML_STREAM * Stream
+ )
+{
+ if (!IS_STREAM (Stream)) {
+ ASSERT (0);
+ return NULL;
+ }
+
+ if (IS_STREAM_FORWARD (Stream)) {
+ return Stream->Buffer + Stream->Index;
+ } else if (IS_STREAM_BACKWARD (Stream)) {
+ return Stream->Buffer + (Stream->MaxBufferSize - 1) - Stream->Index;
+ } else {
+ ASSERT (0);
+ return NULL;
+ }
+}
+
+/** Get the space available in the stream.
+
+ @param [in] Stream Pointer to a stream.
+
+ @return Remaining space available in the stream.
+ Zero in case of error or if the stream is at its end.
+**/
+UINT32
+EFIAPI
+AmlStreamGetFreeSpace (
+ IN CONST AML_STREAM * Stream
+ )
+{
+ if (!IS_STREAM (Stream)) {
+ ASSERT (0);
+ return 0;
+ }
+
+ if (Stream->Index > Stream->MaxBufferSize) {
+ ASSERT (0);
+ return 0;
+ }
+
+ return Stream->MaxBufferSize - Stream->Index;
+}
+
+/** Move Stream by Offset bytes.
+
+ The stream current position is moved according to the stream direction
+ (forward, backward).
+
+ @param [in] Stream Pointer to a stream.
+ The stream must not be at its end.
+ @param [in] Offset Offset to move the stream of.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+ @retval EFI_BUFFER_TOO_SMALL No space left in the buffer.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamProgress (
+ IN AML_STREAM * Stream,
+ IN UINT32 Offset
+ )
+{
+ if (!IS_STREAM (Stream) ||
+ IS_END_OF_STREAM (Stream) ||
+ (Offset == 0)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (AmlStreamGetFreeSpace (Stream) < Offset) {
+ ASSERT (0);
+ return EFI_BUFFER_TOO_SMALL;
+ }
+
+ Stream->Index += Offset;
+
+ return EFI_SUCCESS;
+}
+
+/** Rewind Stream of Offset bytes.
+
+ The stream current position is rewound according to the stream direction
+ (forward, backward). A stream going forward will be rewound backward.
+
+ @param [in] Stream Pointer to a stream.
+ @param [in] Offset Offset to rewind the stream of.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+ @retval EFI_BUFFER_TOO_SMALL No space left in the buffer.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamRewind (
+ IN AML_STREAM * Stream,
+ IN UINT32 Offset
+ )
+{
+ if (!IS_STREAM (Stream) ||
+ (Offset == 0)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (AmlStreamGetIndex (Stream) < Offset) {
+ ASSERT (0);
+ return EFI_BUFFER_TOO_SMALL;
+ }
+
+ Stream->Index -= Offset;
+
+ return EFI_SUCCESS;
+}
+
+/** Reset the Stream (move the current position to the initial position).
+
+ @param [in] Stream Pointer to a stream.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamReset (
+ IN AML_STREAM * Stream
+ )
+{
+ if (!IS_STREAM (Stream)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Stream->Index = 0;
+
+ return EFI_SUCCESS;
+}
+
+/** Peek one byte at Stream's current position.
+
+ Stream's position is not moved when peeking.
+
+ @param [in] Stream Pointer to a stream.
+ The stream must not be at its end.
+ @param [out] OutByte Pointer holding the byte value of
+ the stream current position.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+ @retval EFI_BUFFER_TOO_SMALL No space left in the buffer.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamPeekByte (
+ IN AML_STREAM * Stream,
+ OUT UINT8 * OutByte
+ )
+{
+ UINT8 * CurPos;
+
+ if (!IS_STREAM (Stream) ||
+ IS_END_OF_STREAM (Stream) ||
+ (OutByte == NULL)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ CurPos = AmlStreamGetCurrPos (Stream);
+ if (CurPos == NULL) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ *OutByte = *CurPos;
+ return EFI_SUCCESS;
+}
+
+/** Read one byte at Stream's current position.
+
+ The stream current position is moved when reading.
+
+ @param [in] Stream Pointer to a stream.
+ The stream must not be at its end.
+ @param [out] OutByte Pointer holding the byte value of
+ the stream current position.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+ @retval EFI_BUFFER_TOO_SMALL No space left in the buffer.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamReadByte (
+ IN AML_STREAM * Stream,
+ OUT UINT8 * OutByte
+ )
+{
+ EFI_STATUS Status;
+
+ if (!IS_STREAM (Stream) ||
+ IS_END_OF_STREAM (Stream) ||
+ (OutByte == NULL)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ // Stream is checked in the function call.
+ Status = AmlStreamPeekByte (Stream, OutByte);
+ if (EFI_ERROR (Status)) {
+ ASSERT (0);
+ return Status;
+ }
+
+ Status = AmlStreamProgress (Stream, 1);
+ ASSERT_EFI_ERROR (Status);
+ return Status;
+}
+
+/** Write Size bytes in the stream.
+
+ If the stream goes backward (toward lower addresses), the bytes written
+ to the stream are not reverted.
+ In the example below, writing "Hello" to the stream will not revert
+ the string. The end of the stream buffer will contain "Hello world!".
+ Stream buffer:
+ +---------------+-----+-----+-----+-----+-----+-----+---- +------+
+ | ..... | ' ' | 'w' | 'o' | 'r' | 'l' | 'd' | '!' | '\0' |
+ +---------------+-----+-----+-----+-----+-----+-----+---- +------+
+ ^
+ Current position.
+
+ @param [in] Stream Pointer to a stream.
+ The stream must not be at its end.
+ @param [in] Buffer Pointer to the data to write.
+ @param [in] Size Number of bytes to write.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+ @retval EFI_BUFFER_TOO_SMALL No space left in the buffer.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamWrite (
+ IN AML_STREAM * Stream,
+ IN CONST UINT8 * Buffer,
+ IN UINT32 Size
+ )
+{
+ UINT8 * CurrPos;
+
+ if (!IS_STREAM (Stream) ||
+ IS_END_OF_STREAM (Stream) ||
+ (Buffer == NULL) ||
+ (Size == 0)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (AmlStreamGetFreeSpace (Stream) < Size) {
+ ASSERT (0);
+ return EFI_BUFFER_TOO_SMALL;
+ }
+
+ CurrPos = AmlStreamGetCurrPos (Stream);
+
+ // If the Stream goes backward, prepare some space to copy the data.
+ if (IS_STREAM_BACKWARD (Stream)) {
+ CurrPos -= Size;
+ }
+
+ CopyMem (CurrPos, Buffer, Size);
+ Stream->Index += Size;
+
+ return EFI_SUCCESS;
+}
+
+/** Compare Size bytes between Stream1 and Stream2 from their
+ respective current position.
+
+ Stream1 and Stream2 must go in the same direction.
+ Stream1 and Stream2 are left unchanged.
+
+ @param [in] Stream1 First stream to compare.
+ The stream must not be at its end.
+ @param [in] Stream2 Second stream to compare.
+ The stream must not be at its end.
+ @param [in] Size Number of bytes to compare.
+ Must be lower than the minimum remaining space of
+ Stream1 and Stream2.
+ Must be non-zero.
+
+ @retval TRUE If Stream1 and Stream2 have Size bytes equal,
+ from their respective current position.
+ The function completed successfully.
+ @retval FALSE Otherwise.
+**/
+BOOLEAN
+EFIAPI
+AmlStreamCmp (
+ IN CONST AML_STREAM * Stream1,
+ IN CONST AML_STREAM * Stream2,
+ IN UINT32 Size
+ )
+{
+ UINT32 MinSize;
+ UINT8 * CurrPosStream1;
+ UINT8 * CurrPosStream2;
+
+ if (!IS_STREAM (Stream1) ||
+ IS_END_OF_STREAM (Stream1) ||
+ !IS_STREAM (Stream2) ||
+ IS_END_OF_STREAM (Stream2) ||
+ (Stream1->Direction != Stream2->Direction) ||
+ (Size == 0)) {
+ ASSERT (0);
+ return FALSE;
+ }
+
+ // Check the Size is not longer than the remaining size of
+ // Stream1 and Stream2.
+ MinSize = MIN (
+ AmlStreamGetFreeSpace (Stream1),
+ AmlStreamGetFreeSpace (Stream2)
+ );
+ if (MinSize < Size) {
+ ASSERT (0);
+ return FALSE;
+ }
+
+ CurrPosStream1 = AmlStreamGetCurrPos (Stream1);
+ if (CurrPosStream1 == NULL) {
+ ASSERT (0);
+ return FALSE;
+ }
+ CurrPosStream2 = AmlStreamGetCurrPos (Stream2);
+ if (CurrPosStream2 == NULL) {
+ ASSERT (0);
+ return FALSE;
+ }
+
+ if (Stream1->Direction == EAmlStreamDirectionForward) {
+ return (0 == CompareMem (CurrPosStream1, CurrPosStream2, MinSize));
+ }
+
+ // The stream is already pointing on the last byte, thus the (-1).
+ // +---------------------+
+ // BStream | | | | | | | |M|E|T|0|
+ // +---------------------+
+ // ^
+ // CurrPos
+ return (0 == CompareMem (
+ CurrPosStream1 - (MinSize - 1),
+ CurrPosStream2 - (MinSize - 1),
+ MinSize
+ ));
+}
+
+/** Copy Size bytes of the stream's data to DstBuffer.
+
+ For a backward stream, the bytes are copied starting from the
+ current stream position.
+
+ @param [out] DstBuffer Destination Buffer to copy the data to.
+ @param [in] MaxDstBufferSize Maximum size of DstBuffer.
+ Must be non-zero.
+ @param [in] Stream Pointer to the stream to copy the data from.
+ @param [in] Size Number of bytes to copy from the stream
+ buffer.
+ Must be lower than MaxDstBufferSize.
+ Must be lower than Stream's MaxBufferSize.
+ Return success if zero.
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlStreamCpyS (
+ OUT CHAR8 * DstBuffer,
+ IN UINT32 MaxDstBufferSize,
+ IN AML_STREAM * Stream,
+ IN UINT32 Size
+ )
+{
+ CHAR8 * StreamBufferStart;
+
+ // Stream is checked in the function call.
+ if ((DstBuffer == NULL) ||
+ (MaxDstBufferSize == 0) ||
+ (Size > MaxDstBufferSize) ||
+ (Size > AmlStreamGetMaxBufferSize (Stream))) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (Size == 0) {
+ return EFI_SUCCESS;
+ }
+
+ // Find the address at which the data is starting.
+ StreamBufferStart = (CHAR8*)(IS_STREAM_FORWARD (Stream) ?
+ Stream->Buffer :
+ AmlStreamGetCurrPos (Stream));
+
+ CopyMem (DstBuffer, StreamBufferStart, Size);
+
+ return EFI_SUCCESS;
+}
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