03-06-2017, 02:41 PM
Hello everyone,
I've recently decided to try and mess with my laptop's BIOS. It's a HP Elitebook 8760w, and since I dropped in an extreme processor, I feel I should be able to overclock it (it also has the usual whitelist issues and a dreaded 1333MHz limit on RAM speed, but one problem at a time).
So, I read that these BIOSes are RSA encrypted, however I was able to unpack the ROM file with PhoenixTool and disassemble it with ndisasm. The installer package does have RSAcrypt files in a separate folder, it may be that HP checks it when flashing. The ROM itself doesn't seem to be encrypted from what I can tell.
What I'm looking for is a module where bit 63 (3f?) of register 0x610 is set - it's responsible for locking the Turbo Power Limit settings, which is the most important part of overclocking an extreme Sandy Bridge.
My knowledge of Assembly is limited, I looked for any mov/bts/btr/or operations involving 0x610 - there are a few of them, but I don't see a clear mov then bts anywhere. I'm not sure what other ways could be used to set the bits.
It is possible that it's not even the BIOS responsible for this, but the Intel Management Engine firmware, but I'd like to make sure.
If anyone can look into it and advise, point me in the right direction, I'd be really grateful.
I have attached the BIOS file itself.
The full package can be downloaded from HP's site: http://h20564.www2.hp.com/hpsc/swd/publi...nvOid=4061
Thank you!
I've recently decided to try and mess with my laptop's BIOS. It's a HP Elitebook 8760w, and since I dropped in an extreme processor, I feel I should be able to overclock it (it also has the usual whitelist issues and a dreaded 1333MHz limit on RAM speed, but one problem at a time).
So, I read that these BIOSes are RSA encrypted, however I was able to unpack the ROM file with PhoenixTool and disassemble it with ndisasm. The installer package does have RSAcrypt files in a separate folder, it may be that HP checks it when flashing. The ROM itself doesn't seem to be encrypted from what I can tell.
What I'm looking for is a module where bit 63 (3f?) of register 0x610 is set - it's responsible for locking the Turbo Power Limit settings, which is the most important part of overclocking an extreme Sandy Bridge.
My knowledge of Assembly is limited, I looked for any mov/bts/btr/or operations involving 0x610 - there are a few of them, but I don't see a clear mov then bts anywhere. I'm not sure what other ways could be used to set the bits.
It is possible that it's not even the BIOS responsible for this, but the Intel Management Engine firmware, but I'd like to make sure.
If anyone can look into it and advise, point me in the right direction, I'd be really grateful.
I have attached the BIOS file itself.
The full package can be downloaded from HP's site: http://h20564.www2.hp.com/hpsc/swd/publi...nvOid=4061
Thank you!