Where data_size is an unsigned 8-byte big-endian binary value, and data is the fastboot packet. The 8-byte length is intended to provide future-proofing even though currently fastboot packets have a 4-byte maximum length.

Example
In this example the fastboot host queries the device for two variables, “version” and “none”.

Host    <connect to the device on port 5555>
Host    FB01
Device  FB01
Host    [0x00][0x00][0x00][0x00][0x00][0x00][0x00][0x0E]getvar:version
Device  [0x00][0x00][0x00][0x00][0x00][0x00][0x00][0x07]OKAY0.4
Host    [0x00][0x00][0x00][0x00][0x00][0x00][0x00][0x0B]getvar:none
Device  [0x00][0x00][0x00][0x00][0x00][0x00][0x00][0x14]FAILUnknown variable
Host    <disconnect>
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