What is blackbox log from display diagnostic?

What is blackbox log from display diagnostic? equipment S5700 V200R003C00SPC200

We often wonder what is black box and in which situation it usually it contains logging information.

for example:

=====================================================
===============display inspect black-box record 8 0 0 0===============
=====================================================

An error occured! File: pat_main.c, Line: 3794, ErrNo: 0x9002a02e.
Para: 5b5d5b2d 31383738 39303037 33315d
CallStack: 0x0133d4f8(VOS_ReportError) <-- 0x01ba5da8(VOS_AscToBin)
<-- 0x01b84f08(VOS_AscToBin) <-- 0x01b85130(VOS_AscToBin)
<-- 0x01b85718(VOS_AscToBin) <-- 0x01c6c158(VOS_AscToBin)
<-- 0x01c68384(VOS_AscToBin) <-- 0x01c68608(VOS_AscToBin)
<-- 0x01341bb0(AppInit) <-- 0x01359cc4(tskAllTaskEntry)
<-- 0x00db2260(0xdb2260)
<CpuID: 0, TaskID: 14, Sn: 0> [2015.06.20 00:45:32.940] Ver: 1.6.9.671

Normally the black box is fill in with info before a reboot/power off. Device will make some check up (the callstack function) and in case some data is not matching it will return some values into the black box.
Now, to be more precise, the values above refers to patch check up, there is no patch install or a wrong patch installed.