Intel Extensible Firmware Interface - Manual (Page 624)

Extensible Firmware Interface Specification
15-18 12/01/02 Version 1.10
EFI_SIMPLE_NETWORK.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 )
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.