The BIOS Blog

Welcome to the dark corner of BIOS reverse engineering, code injection and various modification techniques only deemed by those immensely curious about BIOS

Saturday, July 23, 2016

UEFI Boot from Web

I think I've been living under a rock in these last few months and not exactly following UEFI development. Nonetheless, I managed to spot this stuff over at What's interesting is the SDK supports "Firmware Boot from Web" so to speak. This is the relevant excerpt:
The Intel® Server Board S1200RP UEFI Development Kit supports Pre-Execution Environment (PXE) boot for IPV4 and IPV6 networking using on-board and add-in networking devices. Because of added initialization time, network boot for the four onboard networking devices is disabled by default in firmware setup. Users can enable PXE boot for on-board networking by enabling the ’EFI Network’ setting in the firmware setup menu.
EDKII Menu -> Advanced -> Network Configuration
As of SDV.RP.B6, the Intel® Server Board S1200RP UEFI Development Kit supports UEFI HTTP and HTTPS boot. These features are described in whitepapers located on the Tianocore github wiki:
Well, it could be double-edged sword from security standpoint. It depends on who you ask and what it's being used for.

Anyway, this is my take on this:

  • My "educated" guess is: This stuff emerge from Intel collaboration with the so-called Hyperscalers--Hyperscalers is what some people call them ( The Hyperscalers (Google, Facebook, Amazon, Azure, Alibaba, Baidu, Tencent) are running lots of web servers. Therefore, it makes sense for them to make it possible for their machines to boot just off of the webservers instead of preparing another "PXE Boot server" due to the prevalent web server in their bit barns. I think that Intel wants to trickle-down the same stuff into the masses, but as the first step, the Enterprise sector is what Intel targets.
  • Present day flash (is it still Flash??) memory used for firmware storage is spacious enough to cram a (compressed?) HTTP/HTTPS client into it. It would hardly possible to do that just several years ago due to the space constraint in the firmware chip on the motherboard. I didn't say this is impossible years ago because I have worked with extremely limited firmware space in non-PC platform that somehow managed to cram HTTP server into space less than 1MB, along with hardware configuration software stuff. 
  • This made it possible to boot from the cloud if anyone wants to implement such a stuff. But, it would entails a huge security "nightmare" if you ask me.

Thursday, May 26, 2016

BIOS Disassembly Ninjutsu PDF Moved to GitHub

The primary download site for BIOS Disassembly Ninjutsu PDF (free) is now moved to  (direct download at The previous download at 4shared is a malware-invested place, thus the change.

The addendum to the book is also included in the GitHub repository.

Monday, April 18, 2016

Moving Winflashrom code to Github

I ported Coreboot (formerly LinuxBIOS) flashrom utility to Windows a long time ago as my activity in Google Summer of Code and named it winflashrom. Because will be shutdown this year, I moved the code to github:

This is old news because the code haven't been updated for years. However, it might still relevant for those who want to port flashrom or other similar utility to present day Windows. I haven't developed Windows driver anymore since Windows Server 2003. I'm not even sure if WDM-style driver is still in use in Windows. But, I might be returning to develop Windows driver this year. So, yeah, you (and I) never know.

Friday, January 1, 2016

Looking into The State of Firmware Security in Russia

I think every major industrialized country has its own policies in preventing malicious IT equipment and products to enter their premises, let alone being used within the country. In this post, we will look into one of Russian computer hardware maker, Kraftway ( This company might be a bit obscure to you. But, I think it serves quite a big chunk of the Russian and possibly CIS market. It was even visited by Dmitry Medvedev when he was still President.
This company is interesting for two things:
  • It is not just a "box" mover. It tailors the machines it made to meet the customer requirements. Among its in-house expertise is custom firmware, including UEFI firmware. If you look at this page:, at the end of it, you can see that it has in-house expertise to work on UEFI security modules and Trusted BIOS (whatever that might imply). Another thing that catches my attention is this: 
In 2010 the company signed an agreement with a telecom giant Cisco establishing a special procedure for the certification of Cisco products in Obninsk manufacturing facilities. Kraftway ensures that Cisco products comply with the requirement of the Federal Technical and Export Control Service on information security. Such certified products can be used in systems processing sensitive or confidential information. In 2012 Kraftway launched the production of Fujitsu PCs with a trusted BIOS and all-in-one PCs based on the Russian processor Elbrus.
I'm not so sure what does the statement meant by "requirements". Perhaps, it includes firmware-level compliance of some sort. You can look at the whole thing over here
  • The second thing is Kraftway also made PC based on the Russian homegrown Elbrus CPU ( Of course, in the process, it creates the firmware alongside experts from MCST. The premise for using Elbrus CPU is national security needs and "sensitive" computing needs. So, it's understandable. 
Well, I recall that Dell also did the very same thing as Kraftway with respect to firmware and hardware customization. Dell puts crypto-stuff in the firmware even before UEFI hits the market for some of its server product. Perhaps, that's not meant to be used by the masses, only certain customers.

Anyway, scrutinizing the firmware code or creating a custom ones is highly logical for "sensitive" (high-security) computing gear. Every major developed country do that. IIRC, Germany has its own Coreboot Laptop for that kind of purpose. Even China and Taiwan is doing that as well, albeit I haven't yet found writings on that.