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efibootmgr command?


Guest imi2003

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Guest JamieH02

This is interesting, I can't add much but I plugged in a USB Stick via OTG and Held the + volume key after I pressed the Power button, It comes up it can't boot due to Security policy and I don't know how to get into the BIOS to change it.

I wonder how someone could disable/Modify it to allow us.
I am no developer or Expert so I can't offer any more info.

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Guest imi2003

Hi Jamie

What did you try and boot from the USB stick? was it a windows bootable USB drive? I am still waiting for my cable to arrive. I was planing to test the following

windows 8.1 64bit

windows 8.1 32bit

Ubuntu Linux 32 and 64bit

I think the message you are seeing has something to do with the bios needing a sigined UEFI boot loader.

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Guest JamieH02

Hi Jamie

What did you try and boot from the USB stick? was it a windows bootable USB drive? I am still waiting for my cable to arrive. I was planing to test the following

windows 8.1 64bit

windows 8.1 32bit

Ubuntu Linux 32 and 64bit

I think the message you are seeing has something to do with the bios needing a sigined UEFI boot loader.

I was trying this: https://www.happyassassin.net/fedlet-a-fedora-remix-for-bay-trail-tablets/

I'm sure it was bootable because I use the same Software(to create the USB) to convert Chromebooks to Xubuntu.

It's not exactly made for device and It seemed the closest.

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Guest imi2003

i can confirm a bootable Windows 8.1 32bit wont boot, i get the same error message that cant boot due to secuirty policy.

I also tried unpluging the usb stick and pluging in a wireless keyboard and mouse while at that screen, a mouse icon appered i then pressed random keys and the hudl rebooted to the recovery screen.

Hope this helps anyone

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Guest imi2003

just a thought would it be possible to corrupt the cmos settings in the flash memory, so that like in a normal pc the boot process would halt and you have to press a key to go into bios to fix the settings 

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Guest BobNugget

Looks like the hudl 2 is operating in UEFI secure boot mode. The patch posted just after the hudl came out contains a UEFI update. This update looks like it has secure boot vendor keys in it, so hudl 2 is locked to booting Tesco signed code. We need to either replace the tesco keys in the NVRAM or somehow disable UEFI Secure boot mode (not easy as there doesn't appear to be a way to get into the UEFI settings).

 

This may well be achievable if someone has a UEFI flasher/editor for Android (I can't find one other than trying to patch our code into the Tesco update) or something that will let us edit the NVRAM and overwrite the keys in UEFI Secure mode (such a tool exists for linux, i think, but I can't see a build for Android anywhere).

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  • 7 months later...
Guest dennissingh99

Looks like the hudl 2 is operating in UEFI secure boot mode. The patch posted just after the hudl came out contains a UEFI update. This update looks like it has secure boot vendor keys in it, so hudl 2 is locked to booting Tesco signed code. We need to either replace the tesco keys in the NVRAM or somehow disable UEFI Secure boot mode (not easy as there doesn't appear to be a way to get into the UEFI settings).

 

This may well be achievable if someone has a UEFI flasher/editor for Android (I can't find one other than trying to patch our code into the Tesco update) or something that will let us edit the NVRAM and overwrite the keys in UEFI Secure mode (such a tool exists for linux, i think, but I can't see a build for Android anywhere).

Do you have a link for that update?

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