You are peeking into data that should be sent to a device that understands ANSI sequences.
1B
is the HEX code for "ESC", (escape, character 27 in the ASCII table. The Unicode equivalent is u001B
, which might be why it is displayed in that manner.
[
is part of the introduction of ANSI sequences, when paired with ESC.
154
is a parameter, and G
tells the function to run with that parameter.
Type od -t x1z boot.log | less
to see the contents in hex and text formats, side by side.
Assuming that your terminal understands the sequence:
head -n 30 boot.log
should display the text formatted in the manner it was intended to be seen.