diff options
Diffstat (limited to 'MdePkg/Library/BasePalLibNull/PalCall.c')
| -rw-r--r-- | MdePkg/Library/BasePalLibNull/PalCall.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/MdePkg/Library/BasePalLibNull/PalCall.c b/MdePkg/Library/BasePalLibNull/PalCall.c index 82db43cf65..a124336b20 100644 --- a/MdePkg/Library/BasePalLibNull/PalCall.c +++ b/MdePkg/Library/BasePalLibNull/PalCall.c @@ -20,14 +20,24 @@ /**
Makes a PAL procedure call.
- This is a wrapper function to make a PAL procedure call.
- This is just a template as simple instance. It does not
- make real PAL call. It directly reports error if called.
-
- @param Index The PAL procedure Index number.
- @param Arg2 The 2nd parameter for PAL procedure calls.
- @param Arg3 The 3rd parameter for PAL procedure calls.
- @param Arg4 The 4th parameter for PAL procedure calls.
+ This is a wrapper function to make a PAL procedure call. Based on the Index value,
+ this API will make static or stacked PAL call. Architected procedures may be designated
+ as required or optional. If a PAL procedure is specified as optional, a unique return
+ code of 0xFFFFFFFFFFFFFFFF is returned in the Status field of the PAL_CALL_RETURN structure.
+ This indicates that the procedure is not present in this PAL implementation. It is the
+ caller's responsibility to check for this return code after calling any optional PAL
+ procedure. No parameter checking is performed on the 4 input parameters, but there are
+ some common rules that the caller should follow when making a PAL call. Any address
+ passed to PAL as buffers for return parameters must be 8-byte aligned. Unaligned addresses
+ may cause undefined results. For those parameters defined as reserved or some fields
+ defined as reserved must be zero filled or the invalid argument return value may be
+ returned or undefined result may occur during the execution of the procedure.
+ This function is only available on IPF.
+
+ @param Index The PAL procedure Index number.
+ @param Arg2 The 2nd parameter for PAL procedure calls.
+ @param Arg3 The 3rd parameter for PAL procedure calls.
+ @param Arg4 The 4th parameter for PAL procedure calls.
@return Structure returned from the PAL Call procedure, including the status and return value.
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