diff options
Diffstat (limited to 'MdePkg/Include')
| -rw-r--r-- | MdePkg/Include/Ppi/Pcd.h | 24 | ||||
| -rw-r--r-- | MdePkg/Include/Protocol/Pcd.h | 25 |
2 files changed, 32 insertions, 17 deletions
diff --git a/MdePkg/Include/Ppi/Pcd.h b/MdePkg/Include/Ppi/Pcd.h index 73f027b5e7..def6b46e0b 100644 --- a/MdePkg/Include/Ppi/Pcd.h +++ b/MdePkg/Include/Ppi/Pcd.h @@ -750,18 +750,24 @@ EFI_STATUS /**
- Retrieves the next valid PCD token for a given namespace.
+ Retrieves the next valid token number in a given namespace.
- If the input token namespace or token number does not exist on the platform, an error is
- returned and the value of *TokenNumber is undefined. To retrieve the "first" token,
- have the pointer reference a TokenNumber value of 0.
- If the input token number is 0 and there is no valid token number for this token namespace,
- *TokenNumber will be assigned to 0 and the function return EFI_SUCCESS.
- If the token number is the last valid token number, *TokenNumber will be assigned to 0 and
- the function return EFI_SUCCESS.
+ This is useful since the PCD infrastructure contains a sparse list of token numbers,
+ and one cannot a priori know what token numbers are valid in the database.
+
+ If TokenNumber is 0 and Guid is not NULL, then the first token from the token space specified by Guid is returned.
+ If TokenNumber is not 0 and Guid is not NULL, then the next token in the token space specified by Guid is returned.
+ If TokenNumber is 0 and Guid is NULL, then the first token in the default token space is returned.
+ If TokenNumber is not 0 and Guid is NULL, then the next token in the default token space is returned.
+ The token numbers in the default token space may not be related to token numbers in token spaces that are named by Guid.
+ If the next token number can be retrieved, then it is returned in TokenNumber, and EFI_SUCCESS is returned.
+ If TokenNumber represents the last token number in the token space specified by Guid, then EFI_NOT_FOUND is returned.
+ If TokenNumber is not present in the token space specified by Guid, then EFI_NOT_FOUND is returned.
- @param[in] Guid The 128-bit unique value that designates the namespace from which to extract the value.
+ @param[in] Guid The 128-bit unique value that designates the namespace from which to extract the value.
+ This is an optional parameter that may be NULL. If this parameter is NULL, then a request
+ is being made to retrieve tokens from the default token space.
@param[in, out] TokenNumber A pointer to the PCD token number to use to find the subsequent token number.
@retval EFI_SUCCESS The PCD service has retrieved the next valid token number.
diff --git a/MdePkg/Include/Protocol/Pcd.h b/MdePkg/Include/Protocol/Pcd.h index 40e436434e..3cf1049556 100644 --- a/MdePkg/Include/Protocol/Pcd.h +++ b/MdePkg/Include/Protocol/Pcd.h @@ -759,17 +759,26 @@ EFI_STATUS /**
- Retrieves the next valid PCD token for a given namespace.
+ Retrieves the next valid token number in a given namespace.
+
+ This is useful since the PCD infrastructure contains a sparse list of token numbers,
+ and one cannot a priori know what token numbers are valid in the database.
+
+ If TokenNumber is 0 and Guid is not NULL, then the first token from the token space specified by Guid is returned.
+ If TokenNumber is not 0 and Guid is not NULL, then the next token in the token space specified by Guid is returned.
+ If TokenNumber is 0 and Guid is NULL, then the first token in the default token space is returned.
+ If TokenNumber is not 0 and Guid is NULL, then the next token in the default token space is returned.
+ The token numbers in the default token space may not be related to token numbers in token spaces that are named by Guid.
+ If the next token number can be retrieved, then it is returned in TokenNumber, and EFI_SUCCESS is returned.
+ If TokenNumber represents the last token number in the token space specified by Guid, then EFI_NOT_FOUND is returned.
+ If TokenNumber is not present in the token space specified by Guid, then EFI_NOT_FOUND is returned.
+
- @param[in] Guid The 128-bit unique value that designates the namespace from which to extract the value.
+ @param[in] Guid The 128-bit unique value that designates the namespace from which to retrieve the next token.
+ This is an optional parameter that may be NULL. If this parameter is NULL, then a request is
+ being made to retrieve tokens from the default token space.
@param[in,out] TokenNumber
A pointer to the PCD token number to use to find the subsequent token number.
- If the input token namespace or token number does not exist on the platform,
- an error is returned and the value of *TokenNumber is undefined. To retrieve the "first" token,
- have the pointer reference a TokenNumber value of 0. If the input token number is 0 and
- there is no valid token number for this token namespace, *TokenNumber will be assigned to
- 0 and the function return EFI_SUCCESS. If the token number is the last valid token number,
- *TokenNumber will be assigned to 0 and the function return EFI_SUCCESS.
@retval EFI_SUCCESS The PCD service retrieved the next valid token number. Or the input token number
is already the last valid token number in the PCD database.
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