Intel Extensible Firmware Interface, Specification

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Extensible Firmware Interface Specification
294 12/12/00 Version 1.02
15.1.10 EFI_SIMPLE_NETWO RK.NvData()
Summary
Performs read and write operations on the NVRAM device attached to a network interface.
Prototype
EFI_STATUS
(EFIAPI *EFI_SIMPLE_NETWORK_NVDATA) (
IN EFI_SIMPLE_NETWORK *This
IN BOOLEAN ReadWrite,
IN UINTN Offset,
IN UINTN BufferSize,
IN OUT VOID *Buffer
);
Parameters
This
A pointer to the
EFI_SIMPLE_NETWORK
instance.
ReadWrite TRUE
for read operations,
FALSE
for write operations.
Offset
Byte offset in the NVRAM device at which to start the read or
write operation. This must be a multiple of
NvRamAccessSize
and less than
NvRamSize
. (See
EFI_SIMPLE_NETWORK_MODE
in “Related Definitions” in
Section 15.1.)
BufferSize
The number of bytes to read or write from the NVRAM device.
This must also be a multiple of
NvramAccessSize
.
Buffer
A pointer to the data buffer.
Description
This function performs read and write operations on the NVRAM device attached to a network
interface. If
ReadWrite
is TRUE, a read operation is performed. If
ReadWrite
is FALSE, a
write operation is performed.
Offset
specifies the byte offset at which to start either operation.
Offset
must be a multiple of
NvRamAccessSize
, and it must have a value between zero and
NvRamSize
.
BufferSize
specifies the length of the read or write operation.
BufferSize
must also be a
multiple of
NvRamAccessSize
, and
Offset
+
BufferSize
must not exceed
NvRamSize
.
If any of the above conditions is not met, then
EFI_INVALID_PARAMETER
will be returned.
If all the conditions are met and the operation is “read”, the NVRAM device attached to the
network interface will be read into
Buffer
and
EFI_SUCCESS
will be returned. If this is a write
operation, the contents of
Buffer
will be used to update the contents of the NVRAM device
attached to the network interface and
EFI_SUCCESS
will be returned.