Intel Extensible Firmware Interface Specification page 443

DB
#pragma pack(1)
typedef struct s_pxe_db_get_init_info {
// Minimum length of locked memory buffer that must be given to
// the Initialize command.
// generally give better performance.
// If MemoryRequired is zero, the UNDI does not need and will not
// use system memory to receive and transmit packets.
PXE_UINT32 MemoryRequired;
// Maximum frame data length for Tx/Rx excluding the media
// header.
//
PXE_UINT32 FrameDataLen;
// Supported link speeds are in units of mega bits.
// ethernet values are 10, 100 and 1000.
// entries are zero filled.
PXE_UINT32 LinkSpeeds[4];
// Number of non-volatile storage items.
PXE_UINT32 NvCount;
// Width of non-volatile storage item in bytes.
PXE_UINT16 NvWidth;
// Media header length.
// for this UNDI.
// receive and transmit buffers.
PXE_UINT16 MediaHeaderLen;
Version 1.02
Giving UNDI more memory will
This is the typical media header length
This information is needed when allocating
12/12/00
32/64-bit UNDI Specification
Common
Unused LinkSpeeds[]
0, 1, 2 or 4
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