Dear friends, did you know that there is a Coreboot Open-Source BIOS project?
You are lucky - Coreboot supports your Lenovo G505S laptop!
This is a truly unlocked BIOS:
no limitations, no Wi-Fi whitelist, and because its open source you can modify its code as much as you want!
Who needs InsydeH20 proprietary crap, when you could have Coreboot open source master race?
http://www.coreboot.org/Board:lenovo/g505s - description page, although slightly outdated
http://www.coreboot.org/Download_coreboot - download page
http://www.coreboot.org/Build_HOWTO - build instructions
Note: I didn't know how to flash a produced 4MB BIOS image to SOIC-8 BIOS chip,
so I got a cheap USB SPI flasher + SOIC-8 test clip from China, costed less than $20...
Compilation: Just follow the instructions from Coreboot wiki at the links above
It seems that a Coreboot for this laptop is not a Libreboot yet, it still needs a closed source VGABIOS which weights 64KB and should be extracted from a stock BIOS:
http://www.coreboot.org/VGA_support - use this instruction for doing it; although it recommends extracting from vendor BIOS I've done it through "Retrieval via Linux kernel" way.
Everything in software world that is closed source, could potentially have the backdoors demanded by evil gov three-letter-agency which could be a very serious security risk...
However, you could enable YABEL option in coreboot's menuconfig to prevent the possible undocumented accesses of VGABIOS to other PCI devices of your laptop
Flashing:
I disconnected all the power sources: charger and battery, then teardown Lenovo G505S (it was really easy after watching photo/video instructions at the Internet)
Located a SOIC-8 BIOS chip on the laptop's motherboard, it looks square with 8 legs and a dot in corner marking first leg - for a correct SOIC-8 test clip installation.
In my case, BIOS chip had a cFeon label - not MXIC as specified on description page above - and it was located at the bottom closer side of the motherboard.
Carefully put SOIC-8 test clip on this chip, which was connected to USB SPI flasher which was inserted into other laptop, then I made a backup of proprietary crap BIOS
(just in case of failure). Flashed Coreboot 4MB image to this BIOS chip, then I disconnected SOIC-8 clip and assembled this laptop in reverse order of teardown...
Result: after installing Coreboot BIOS everything works perfectly, much more freedom, and boots so much faster than before!
P.S. Because this removes a whitelist, I think its appropriate to give here a good WiFi card advice:
Atheros AR9462 or Atheros AR9485 . These Atheros cards work very good, cost cheap, very stable WiFi,
and they work perfectly under Linux without needing any proprietary firmware drivers