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Efi_block_io.readblocks(), Readblocks(), Func – Intel Extensible Firmware Interface User Manual

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Protocols

— Bootable Image Support

Version 1.10

12/01/02

11-45

EFI_BLOCK_IO.ReadBlocks()

Summary

Reads the requested number of blocks from the device.

Prototype

EFI_STATUS

(EFIAPI *EFI_BLOCK_READ) (

IN

EFI_BLOCK_IO

*This,

IN

UINT32

MediaId,

IN

EFI_LBA

LBA,

IN

UINTN

BufferSize,

OUT

VOID

*Buffer

);

Parameters

This

Indicates a pointer to the calling context. Type

EFI_BLOCK_IO

is

defined in the

BLOCK_IO

protocol description.

MediaId

The media ID that the read request is for.

LBA

The starting logical block address to read from on the device. Type

EFI_LBA

is defined in the

BLOCK_IO

protocol description.

BufferSize

The size of the

Buffer

in bytes. This must be a multiple of the intrinsic

block size of the device.

Buffer

A pointer to the destination buffer for the data. The caller is responsible
for either having implicit or explicit ownership of the buffer.

Description

The

ReadBlocks()

function reads the requested number of blocks from the device. All the

blocks are read, or an error is returned.

If there is no media in the device, the function returns

EFI_NO_MEDIA

. If the

MediaId

is not

the ID for the current media in the device, the function returns

EFI_MEDIA_CHANGED

.