[coreboot] Lenovo G505S - spkmodem console sound, is correct? Please listen and tell

Anac anac at rbox.co
Thu Sep 27 17:07:27 CEST 2018

On 09/27/2018 05:22 AM, Ivan Ivanov wrote:
> I suspect: despite that the "PC Speaker"-style beeping output is
> working fine at this laptop/speakers while we are using Linux or even
> some very simple OS like FreeDOS or Kolibri - that coreboot's spkmodem
> might be buggy at G505S laptop, since there are only a few distinct
> beeps (a couple of them are long enough to be visible at Soundcloud's
> waveform) - everything else sounds like maybe an encrypted message but
> could be just garbage (far from being similar to some morse code)

Hi Ivan,

sorry to say that I'm de facto illiterate when it comes to CoreBoot or 
even spkmodem.

What I can say, though, is that regarding transmitting hidden 
information through sound, the best way-to-go IMO would be piggybacking 
scattered, high-tuned and encrypted pieces of data on otherwise 
unsuspected waves. The frequencies would preferably be between what 
human ears can hear and what loudspeakers can transmit. Unfortunately, 
this is where compression algorithms come into play. So, any compressed 
file types (like ogg or mp3) may not convey sufficient suspicious data 
and therefore are no reliable grounds for checks/audits.

Directly seeing magnified waves seems to be required here. I'm not even 
sure if any software based tools like Audacity or any other 
vulnerable-to-attacks tools are suitable for those audits. Well, despite 
their huge budgets, **they** are sloppy or out-dated sometimes. So, 
using software based tools may be useful or not. Definitely better would 
be old-school analog oscilloscopes, and then go further from there.

Hoping I could be helpful in some way despite my illiteracy on CoreBoot.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.coreboot.org/pipermail/coreboot/attachments/20180927/3ddcce58/attachment.html>

More information about the coreboot mailing list