2.2.4.5 Format of the message.rpmsg Attachment

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As specified in section 2.2.3.1 and section 3.1.4.1.2, the original message is stored in a message attachment called message.rpmsg. The attachment MUST contain a prefix that is formatted as follows:

CHAR STRING prefix - Value is "\x76\xE8\x04\x60\xC4\x11\xE3\x86" in little-endian format.

The prefix is followed by one or more blocks of data. The uncompressed content is divided into segments of 4,096 bytes. Each block of the compressed stream contains the fields specified in the following table.

Field name

Format

Description

ULCheck

DWORD ([MS-DTYP])

Marks the beginning of the attachment prefix. The value of this block is 0x00000FA0.

SizeAfterInflation

DWORD

Size of the uncompressed data segment. Usually 4,096; the last block can be less.

SizeBeforeInflation

DWORD

Size of the compressed data segment.

CompressedDataSegment

Specified in [RFC1950]

The compressed bits of the storage container that is specified in section 3.1.4.

The client compresses the bits for each successive block, as specified in [RFC1950] and [RFC1951].