Express Gate is meant to be complementary to your traditional operating system for when you want to surf the Internet without fear of Windows attacks and when you don't want to wait for your computer to turn on. ASUS Express Gate also consumes less power than using a traditional operating system. We've been asked in the Phoronix Forums how this technology works, and this ASUS document did provide a brief technical overview.
Express Gate consists of two modules: the Core Engine (CE) and the Virtual Appliance Environment (VAE). The Core Engine is a "proprietary real-time operating environment" that is integrated inside the BIOS flash chip. The Core Engine can be as small as 64KB so that it can embed into current-generation BIOS flash chips. This Core Engine is made up of a multi-threaded operating system (Linux), a networking stack, and a set of drivers (LAN, USB, video, and audio).
To speed up the boot time, the Express Gate only does a minimized POST to initialize critical hardware, prepare the environment for the Core Engine, and then enter the Core Engine. This is opposed to a full-blown desktop BIOS POST that would generally take much longer.
The Virtual Appliance Environment is the second Express Gate / SplashTop module. The VAE is described as a "highly optimized Linux core" to allow the system to boot fast while maintaining support for the needed hardware and software functionalities. The Virtual Appliance Environment is intended to be a platform for all VAs (Virtual Appliances) in the future. The Express Gate VAs are packaged where they can be easily added or removed from a system and this package managing can be done by the end-user. While they refer to their Core Engine as a proprietary environment, they plan to open up the capabilities of the Virtual Appliances to the end-user. Below is how it was described on a slide.
We plan to enable users to personalize the VAE with their favorite instant-on virtual appliances in the future. Any of the existing thousands of Linux applications can be packaged into an instant-on VA, running on VAE.
One of the touted benefits of Express Gate / SplashTop was its optimized Linux core so that it's immune from Windows spyware and viruses. The VAE module is read-only and does not write anything to any attached hard disks so it's intended as being a safer environment and any personal files are isolated from the VAE. With the SplashTop Browser and related areas, to provide persistent storage of the user files there is a special user-data partition created on the on-board flash memory, which is only accessible by VAEs.
The ASUS R&D team is planning to implement more Express Gate features in 2008. Among the features is an ASUS Updater, which will allow you to update the system's BIOS within Express Gate. This should be terrific! We've long been waiting for a better OS-neutral environment to flash the BIOS on their motherboards without using a floppy disk or other media, and now we'll finally have it. Another feature being worked on is a CD/DVD player that can be used within Express Gate. On an earlier slide, various native applications were mentioned, among those that were listed was an embedded web browser, photo viewer, and an audio/video player. In order to make a photo viewer useful, Express Gate / SplashTop will need to support mounting external media devices. This is another item we mentioned in our earlier article that we had hoped they would tackle.
We were also told by our ASUS Taiwan lead that Express Gate originated from work on the Eee PC, the low-cost yet to be released Linux laptop, so we are expecting the Eee PC to offer a similar virtual environment. We'll have more information on DeviceVM's SplashTop on Wednesday.