[edk2-devel] [PATCH 1/1] EmbeddedPkg/AcpiLib: Add more helper functions

Nhi Pham via groups.io nhi=os.amperecomputing.com at groups.io
Fri Sep 3 13:34:40 UTC 2021


Hi Abner,

Thank you so much for reviewing this patch.

On 22/08/2021 21:42, Chang, Abner (HPS SW/FW Technologist) wrote:
> Hi Pham,
> First at all, you have to update the copyright. Other comments are in below,
Will update.
>> -----Original Message-----
>> From: Nhi Pham [mailto:nhi at os.amperecomputing.com]
>> Sent: Tuesday, August 17, 2021 9:24 PM
>> To:devel at edk2.groups.io
>> Cc:patches at amperecomputing.com; Nhi Pham
>> <nhi at os.amperecomputing.com>; Leif Lindholm<leif at nuviainc.com>; Ard
>> Biesheuvel<ardb+tianocore at kernel.org>; Chang, Abner (HPS SW/FW
>> Technologist)<abner.chang at hpe.com>; Schaefer, Daniel
>> <daniel.schaefer at hpe.com>
>> Subject: [PATCH 1/1] EmbeddedPkg/AcpiLib: Add more helper functions
>>
>> This adds more helper functions that assist in calculating the checksum,
>> locating an ACPI table by signature, and updating an AML integer object.
>>
>> Cc: Leif Lindholm<leif at nuviainc.com>
>> Cc: Ard Biesheuvel<ardb+tianocore at kernel.org>
>> Cc: Abner Chang<abner.chang at hpe.com>
>> Cc: Daniel Schaefer<daniel.schaefer at hpe.com>
>> Signed-off-by: Nhi Pham<nhi at os.amperecomputing.com>
>> ---
>>   EmbeddedPkg/Library/AcpiLib/AcpiLib.inf |   2 +
>>   EmbeddedPkg/Include/Library/AcpiLib.h   |  68 ++++++++
>>   EmbeddedPkg/Library/AcpiLib/AcpiLib.c   | 183 ++++++++++++++++++++
>>   3 files changed, 253 insertions(+)
>>
>> diff --git a/EmbeddedPkg/Library/AcpiLib/AcpiLib.inf
>> b/EmbeddedPkg/Library/AcpiLib/AcpiLib.inf
>> index 538fe09cca29..154cb1eebc80 100644
>> --- a/EmbeddedPkg/Library/AcpiLib/AcpiLib.inf
>> +++ b/EmbeddedPkg/Library/AcpiLib/AcpiLib.inf
>> @@ -23,6 +23,8 @@ [Packages]
>>     EmbeddedPkg/EmbeddedPkg.dec
>>
>>   [LibraryClasses]
>> +  BaseLib
>> +  BaseMemoryLib
>>     DebugLib
>>     UefiBootServicesTableLib
>>
>> diff --git a/EmbeddedPkg/Include/Library/AcpiLib.h
>> b/EmbeddedPkg/Include/Library/AcpiLib.h
>> index c142446d9d59..cdb6ea410c54 100644
>> --- a/EmbeddedPkg/Include/Library/AcpiLib.h
>> +++ b/EmbeddedPkg/Include/Library/AcpiLib.h
>> @@ -13,6 +13,7 @@
>>   #include <Uefi.h>
>>
>>   #include <IndustryStandard/Acpi10.h>
>> +#include <Protocol/AcpiSystemDescriptionTable.h>
>>
>>   //
>>   // Macros for the Generic Address Space
>> @@ -128,4 +129,71 @@ LocateAndInstallAcpiFromFv (
>>     IN CONST EFI_GUID* AcpiFile
>>     );
>>
>> +/**
>> +  This function calculates and updates an UINT8 checksum.
>> +
>> +  @param  Buffer          Pointer to buffer to checksum
>> +  @param  Size            Number of bytes to checksum
>> +
>> +  @retval EFI_SUCCESS             The function completed successfully.
>> +  @retval EFI_INVALID_PARAMETER   Invalid parameter.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +AcpiUpdateChecksum (
>> +  IN UINT8      *Buffer,
>> +  IN UINTN      Size
>> +  );
>> +
>> +/**
>> +  This function uses the ACPI SDT protocol to locate an ACPI table
>> +  with a given signature that only have a single instance.
>> +
>> +  Caution: This function does not act correctly with tables having
>> +  more than 2 instances like SSDT table.
>> +
>> +  @param  AcpiTableSdtProtocol    Pointer to ACPI SDT protocol.
>> +  @param  TableSignature          ACPI table signature.
>> +  @param  Table                   Pointer to the table.
>> +  @param  TableKey                Pointer to the table key.
>> +
>> +  @return EFI_SUCCESS             The function completed successfully.
>> +  @return EFI_INVALID_PARAMETER   At least one of parameters is invalid.
>> +  @retval EFI_NOT_FOUND           The requested index is too large and a
>> table was not found.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +AcpiLocateTableBySignature (
>> +  IN  EFI_ACPI_SDT_PROTOCOL           *AcpiSdtProtocol,
>> +  IN  UINT32                          TableSignature,
>> +  OUT EFI_ACPI_DESCRIPTION_HEADER     **Table,
>> +  OUT UINTN                           *TableKey
>> +  );
>> +
>> +/**
>> +  This function updates the integer value of an AML Object.
>> +
>> +  @param  AcpiTableSdtProtocol    Pointer to ACPI SDT protocol.
>> +  @param  TableHandle             Points to the table representing the starting
>> point
>> +                                  for the object path search.
>> +  @param  AsciiObjectPath         Pointer to the ACPI path of the object being
>> updated.
>> +  @param  Value                   New value to write to the object.
>> +
>> +  @return EFI_SUCCESS             The function completed successfully.
>> +  @return EFI_INVALID_PARAMETER   At least one of parameters is invalid
>> or the data type
>> +                                  of the ACPI object is not an integer value.
>> +  @retval EFI_NOT_FOUND           The object is not found with the given path.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +AcpiAmlObjectUpdateInteger (
>> +  IN  EFI_ACPI_SDT_PROTOCOL           *AcpiSdtProtocol,
>> +  IN  EFI_ACPI_HANDLE                 TableHandle,
>> +  IN  CHAR8                           *AsciiObjectPath,
>> +  IN  UINTN                           Value
>> +  );
>> +
>>   #endif // __ACPI_LIB_H__
>> diff --git a/EmbeddedPkg/Library/AcpiLib/AcpiLib.c
>> b/EmbeddedPkg/Library/AcpiLib/AcpiLib.c
>> index ff7d678433d5..e07919ae323f 100644
>> --- a/EmbeddedPkg/Library/AcpiLib/AcpiLib.c
>> +++ b/EmbeddedPkg/Library/AcpiLib/AcpiLib.c
>> @@ -9,9 +9,12 @@
>>   #include <Uefi.h>
>>
>>   #include <Library/AcpiLib.h>
>> +#include <Library/BaseLib.h>
>> +#include <Library/BaseMemoryLib.h>
>>   #include <Library/DebugLib.h>
>>   #include <Library/UefiBootServicesTableLib.h>
>>
>> +#include <Protocol/AcpiSystemDescriptionTable.h>
>>   #include <Protocol/AcpiTable.h>
>>   #include <Protocol/FirmwareVolume2.h>
>>
>> @@ -170,3 +173,183 @@ LocateAndInstallAcpiFromFv (
>>   {
>>     return LocateAndInstallAcpiFromFvConditional (AcpiFile, NULL);
>>   }
>> +
>> +/**
>> +  This function calculates and updates an UINT8 checksum.
>> +
>> +  @param  Buffer          Pointer to buffer to checksum
>> +  @param  Size            Number of bytes to checksum
>> +
>> +  @retval EFI_SUCCESS             The function completed successfully.
>> +  @retval EFI_INVALID_PARAMETER   Invalid parameter.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +AcpiUpdateChecksum (
>> +  IN UINT8      *Buffer,
>> +  IN UINTN      Size
>> +  )
>> +{
>> +  UINTN ChecksumOffset;
>> +
>> +  if (Buffer == NULL || Size == 0) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  ChecksumOffset = OFFSET_OF (EFI_ACPI_DESCRIPTION_HEADER,
>> Checksum);
>> +
>> +  //
>> +  // Set checksum to 0 first
>> +  //
>> +  Buffer[ChecksumOffset] = 0;
>> +
>> +  //
>> +  // Update checksum value
>> +  //
>> +  Buffer[ChecksumOffset] = CalculateCheckSum8 (Buffer, Size);
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +  This function uses the ACPI SDT protocol to locate an ACPI table
>> +  with a given signature that only have a single instance.
>> +
>> +  Caution: This function does not act correctly with tables having
>> +  more than 2 instances like SSDT table.
> Instead of having this caution, why not returning an array of table pointers and TableKeys, also another new parameter indicates how many tables are matched to the signature?
> How to use the array depends on the caller.
Thank you for a good idea. So, I was intended to add a new 
EFI_ACPI_TABLE_WITH_KEY structure your suggestion. But it looks more 
complicated in consuming. Only the SSDT table is happy with that. Well, 
now my idea is that, to remove the caution, I want to add one more 
IN/OUT parameter "*Index", which is the ACPI table index where to 
search, to this API function. So, consumers can rely on this index to 
search continuously the tables if there are multiple ACPI table 
instances installed like SSDT. Does it look good to you?
>> +
>> +  @param  AcpiTableSdtProtocol    Pointer to ACPI SDT protocol.
>> +  @param  TableSignature          ACPI table signature.
>> +  @param  Table                   Pointer to the table.
>> +  @param  TableKey                Pointer to the table key.
>> +
>> +  @return EFI_SUCCESS             The function completed successfully.
>> +  @return EFI_INVALID_PARAMETER   At least one of parameters is invalid.
>> +  @retval EFI_NOT_FOUND           The requested index is too large and a
>> table was not found.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +AcpiLocateTableBySignature (
>> +  IN  EFI_ACPI_SDT_PROTOCOL           *AcpiSdtProtocol,
>> +  IN  UINT32                          TableSignature,
>> +  OUT EFI_ACPI_DESCRIPTION_HEADER     **Table,
>> +  OUT UINTN                           *TableKey
>> +  )
>> +{
>> +  EFI_STATUS              Status;
>> +  EFI_ACPI_SDT_HEADER     *TempTable;
>> +  EFI_ACPI_TABLE_VERSION  TableVersion;
>> +  UINTN                   TableIndex;
>> +
>> +  if (AcpiSdtProtocol == NULL
>> +      || Table == NULL
>> +      || TableKey == NULL) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  Status = EFI_SUCCESS;
>> +
>> +  //
>> +  // Search for ACPI Table with matching signature
>> +  //
>> +  TableVersion = 0;
>> +  TableIndex = 0;
>> +  while (!EFI_ERROR (Status)) {
>> +    Status = AcpiSdtProtocol->GetAcpiTable (
>> +                                TableIndex,
>> +                                &TempTable,
>> +                                &TableVersion,
>> +                                TableKey
>> +                                );
>> +    if (!EFI_ERROR (Status)) {
>> +      TableIndex++;
>> +
>> +      if (((EFI_ACPI_DESCRIPTION_HEADER *)TempTable)->Signature ==
>> TableSignature) {
>> +        *Table = (EFI_ACPI_DESCRIPTION_HEADER *)TempTable;
>> +        break;
>> +      }
>> +    }
>> +  }
>> +
>> +  return Status;
>> +}
>> +
>> +/**
>> +  This function updates the integer value of an AML Object.
>> +
>> +  @param  AcpiTableSdtProtocol    Pointer to ACPI SDT protocol.
>> +  @param  TableHandle             Points to the table representing the starting
>> point
>> +                                  for the object path search.
>> +  @param  AsciiObjectPath         Pointer to the ACPI path of the object being
>> updated.
>> +  @param  Value                   New value to write to the object.
>> +
>> +  @return EFI_SUCCESS             The function completed successfully.
>> +  @return EFI_INVALID_PARAMETER   At least one of parameters is invalid
>> or the data type
>> +                                  of the ACPI object is not an integer value.
>> +  @retval EFI_NOT_FOUND           The object is not found with the given path.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +AcpiAmlObjectUpdateInteger (
>> +  IN  EFI_ACPI_SDT_PROTOCOL           *AcpiSdtProtocol,
>> +  IN  EFI_ACPI_HANDLE                 TableHandle,
>> +  IN  CHAR8                           *AsciiObjectPath,
>> +  IN  UINTN                           Value
>> +  )
>> +{
>> +  EFI_STATUS            Status;
>> +  EFI_ACPI_HANDLE       ObjectHandle;
>> +  EFI_ACPI_DATA_TYPE    DataType;
>> +  UINT8                 *Buffer;
>> +  UINTN                 BufferSize;
>> +
>> +  if (AcpiSdtProtocol == NULL || AsciiObjectPath == NULL) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  Status = AcpiSdtProtocol->FindPath (TableHandle, AsciiObjectPath,
>> &ObjectHandle);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  Status = AcpiSdtProtocol->GetOption (ObjectHandle, 0, &DataType, (VOID
> We can use AML_OP_PARSE_INDEX_GET_OPCODE instead of '0', which is more readable.
I find the AML_OP_PARSE_INDEX_GET_OPCODE is defined for private use in 
the MdeModulePkg/Universal/Acpi/AcpiTableDxe module. Do we need to make 
a copy for usage in the AcpiLib?
>> *)&Buffer, &BufferSize);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  if (Buffer[0] != AML_NAME_OP) {
>> +    return EFI_NOT_FOUND;
>> +  }
>> +
>> +  switch (Buffer[5]) {
> After  getting the opcode from ACPI handle, the BufferSize suppose is in value of 1 or 2 if I interpret the code correctly. You can access to Buffer[5] because the buffer points the AML node.
> Below can be executed correctly but seems to me not quite proper. Furthermore, can we leverage AcpiSdtProtocol ->SetOpion for updating value instead of having below code block?

Yes, thank you. Let me update it to use the SDT->SetOption function for 
updating the data object in an AML name object.

Best regards,

Nhi

>
> Abner
>
>> +  case AML_ZERO_OP:
>> +  case AML_ONE_OP:
>> +    Buffer[5] = (UINT8)Value;
>> +    break;
>> +
>> +  case AML_BYTE_PREFIX:
>> +    Buffer[6] = (UINT8)Value;
>> +    break;
>> +
>> +  case AML_WORD_PREFIX:
>> +    CopyMem ((VOID *)&Buffer[6], (VOID *)&Buffer, sizeof (UINT16));
>> +    break;
>> +
>> +  case AML_DWORD_PREFIX:
>> +    CopyMem ((VOID *)&Buffer[6], (VOID *)&Buffer, sizeof (UINT32));
>> +    break;
>> +
>> +  case AML_QWORD_PREFIX:
>> +    CopyMem ((VOID *)&Buffer[6], (VOID *)&Buffer, sizeof (UINT64));
>> +    break;
>> +
>> +  default:
>> +    // The data type of the ACPI object is not an integer value.
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  return Status;
>> +}
>> --
>> 2.17.1


-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#80236): https://edk2.groups.io/g/devel/message/80236
Mute This Topic: https://groups.io/mt/84947529/1813853
Group Owner: devel+owner at edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [edk2-devel-archive at redhat.com]
-=-=-=-=-=-=-=-=-=-=-=-





More information about the edk2-devel-archive mailing list