BIOS mods – who's game?

[Iñigo Martinez Lasala]

I modified BIOS last night in order to enable extended options at BIOS menu (no mods) and installed via regular tool from Windows. Beautiful brick after reboot. 🙁

This weekend I will try to reflash via RaspPI…

 

[David]

Iñigo Martinez Lasala wrote:

I modified BIOS last night in order to enable extended options at BIOS menu (no mods) and installed via regular tool from Windows. Beautiful brick after reboot. <noscript></noscript>This weekend I will try to reflash via RaspPI…

Que version tienes Iñigo? La A5C6 o A5C8? Has metido la bios de tu version no? Habrá que investigar mas..

 

[Peter]

David wrote:

With this script can’t you flash the bios?

Only replace the bios (A5C6 dual boot) by the modified

EDIT: I open my bios with AMIBCP and on Intel IGD Configuration the setting to GFX Boost is disabled.

I could try to do that but if the UEFI Secure Boot has been fully implemented, flashing a non signed EFI will brick your tablet. If the official flasher from AMI tells you that what you are trying to flash does not pass the signature check, and the EFI boot is going to do the same check at boot (stopping any execution if it fails), it doesn’t make any sense IMHO to play with it.

I would recommend (if you’re so desperate to play this risky game) disabling any secure boot flags and secure flash options in the modded EFI before flashing it. Otherwise, the EFI execution will terminate as soon as it detects it is a mod.

Summarizing: MODERN UEFI SECURE FLASH IS DESIGNED TO AVOID MODIFIED EFIs TO BE EXECUTED http://www.uefi.org/sites/default/files/resources/UEFI_Plugfest_2012Q1_v3_AMI.pdf

[Iñigo Martinez Lasala]

A5C8. La saqué directamente del paquete de teclast (la misma que ya tenía) y la subí modificada. No sé si me reventó por la modificación o bien porque lo hice con el tablet a un 40% de batería y sin enchufar a la luz (no debería). Por lo que he leído hay un modo especial para meter la BIOS en modo “dnx” pero se necesita una imagen especial que se encarga de flashear la BIOS. Si no, via RaspPI, pero tengo que chequear qué voltajes usa.

I uploaded A5C8 (teclast official and the same I had previously) but modified by me. I don’t know if it failed because mod was incorrect or because I performed the upgrade only with battery at 40% and unplugged. I’ve read there is a special mode DNX that allows to upgrade BIOS but I would need an especial image that flashes the BIOS. If not work, I will proceed with RaspBI EEPROM mode but I have to check what voltages provides in order to not fry the chip.

[David]

Pues el problema es lo que ha dicho Peter, la firma de la bios, a ver si puedes probar una vez que tengas todo soldado y la recuperes, con la bios con todas las opciones relativas al secureboot deshabilitadas.

[Peter]

David wrote:

Pues el problema es lo que ha dicho Peter, la firma de la bios, a ver si puedes probar una vez que tengas todo soldado y la recuperes, con la bios con todas las opciones relativas al secureboot deshabilitadas.

SPANISH: Y no sólo eso, sino que además tendrá que cambiar el flag en la NVRAM antes de reiniciar. Por favor, escribid en Inglés y en Español (aunque sea googliano) antes de que el foro se desmadre.
ENGLISH: Not only will you have to disable all secure boot things in the modified EFI but change as well these flags in the NVRAM before rebooting.
http://www.intelsecurity.com/resources/pr-bios-secure-boot-attacks-uncovered.pdf

More info about flashing a modified bios with secureboot here https://www.techinferno.com/index.php?/forums/topic/1870-flash-modified-biosuefi-which-are-digitally-signed-circumvent-secure-flash/

Pretty please: If you are going to write a post in your own language, post a translation into English along with your message (even from the ugly Google translator). Otherwise this forum will become a mess instead of being a nice hub for Teclast tablets.

[Iñigo Martinez Lasala]

Not only will you have to disable all secure boot things in the modified EFI but change as well these flags in the NVRAM before rebooting. http://www.intelsecurity.com/resources/pr-bios-secure-boot-attacks-uncovered.pdf More info about flashing a modified bios with secureboot here https://www.techinferno.com/index.php?/forums/topic/1870-flash-modified-biosuefi-which-are-digitally-signed-circumvent-secure-flash/ Pretty please: If you are going to write a post in your own language, post a translation into English along with your message (even from the ugly Google translator). Otherwise this forum will become a mess instead of being a nice hub for Teclast tablets.

In order to restore original BIOS, some questions:

• ROM file provided by vendor is unpacked? So, can I directy flash into BIOS without de-encapsulating?
• Since it would be original ROM, do I need to disable secure boot?

As a last option, using RaspBI with a logic level coverter (from 3.3 to 1.8V) seems more easy….

[Razer Spoon]

That will be painful buying a Pi just to flash it. We need a way to install with zero bricking. I got money to but not worth paying for 1 then never using it again after. High chances of them updating bios again may not happen. But again we need a way.

[Peter]

Iñigo Martinez Lasala wrote:

In order to restore original BIOS, some questions:

• ROM file provided by vendor is unpacked? So, can I directy flash into BIOS without de-encapsulating?
• Since it would be original ROM, do I need to disable secure boot?

As a last option, using RaspBI with a logic level coverter (from 3.3 to 1.8V) seems more easy….

Some time ago I recovered my Onda v975w flashing the original image BIOS with a flash clip and the CH341 programmer with the logic converter I previously mentioned. In my case, I just loaded the .bin file from the website into the very basic programming software which came with the programmer and it worked.

I guess you have saved a dump of your EFI before flashing the modified one, haven’t you? Just flash that dump.

[Iñigo Martinez Lasala]

Some time ago I recovered my Onda v975w flashing the original image BIOS with a flash clip and the CH341 programmer with the logic converter I previously mentioned. In my case, I just loaded the .bin file from the website into the very basic programming software which came with the programmer and it worked. I guess you have saved a dump of your EFI before flashing the modified one, haven’t you? Just flash that dump.

Negative. No EFI dump.

I’ve just asked for CH341 programmer. Level converter not yet. Yesterday I opened the tablet in order to verify winbond chip and, of course, 1.8v. (25QL).

 

[David]

http://www.win-raid.com/t286f16-Guide-Flashing-modified-AMI-Aptio-UEFI-using-AFU.html

I think that with this method the bios would work..

[Razer Spoon]

What needs to be done is bios modding. Then figuring out how to get it to flash on everyone’s with zero flashers. It be tricky but worth doing. Hopefully we can get somewhere. I would do if i already had a flasher and had some actual skill flashing with a flasher. Once i see a modded bios with everything unlocked then i can do my tweaks and such. And tell the creator of the bios tweak what to disable to avoid people touching a setting that will make unstable or bricking. This is why i need someone to do it. My tweak guide will benefit for this. I’m extremely experience in modding and overclocking. At some point i hope one day we can overclock on these chips. I do plan on mounting a slim designed heat sink with a fan with grills to protect it. Won’t be flushed with system might stick out a bit but will be nice to have proper cooling on these. Just want to help the community on bringing every drop of performance on these tablets. Might even make the manufactures let me help them design these things with little to no extra cost.

[Anonymous]

lol….You are flirting with disaster. Overclocking the Z8300/z8500 chipset. No wonder nobody commented!

30 minute battery life with a fan…lol

[Razer Spoon]

Well there is ways increasing the battery by upgrading it. Either way it’s all up in the air. Just want to get the bios mod where we all need it. So much performance we can gain from these Chinese devices. If we all pitch in with mods and tweaks it be a gain for everyone.

[Razer Spoon]

Any update on bios modding?

[Author]

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