The Research For UEFI BIOS Power Management And Application

Since UEFI (Unified Extensible Firmware Interface) supports the application of new technology and promotes new usage model; and it is open and standardized compared with legacy closed BIOS (Basic Input Output System) system, so it gets support and promotion by many famous companies such as Intel, Microsoft, AMD, etc. But it has not solved the following 2 problems. First, UEFI and legacy BIOS do not support power management function under their own environment. Second, the switch time between UEFI/BIOS environment and operating system is too long. So the two problems brings obstacle to promote some new technology. The paper will combine the technology features of both hardware and software to create an innovational technology platform for new usage model. The two purposes of the paper are, 1) to research the methods on how to implementing system level power management feature under UEFI environment; 2) when the system is waken up from sleep state, to implement to go to the new created UEFI environment for support new usage model instead of back to operating system..The paper uses the laptop customer reference board of Intel as the development and verification platform. The main accomplishes are as follows. 1) It creates new UEFI environment after system is waken up from sleep state and runs into UEFI shell. After the work is done, it can exit the UEFI shell to continue previous boot progress. When system returns back to operating system, all devices work normally. 2) It implements the network stack under S3 UEFI status and can run FTP application to download data into the hard disk. 3) It implements the power management function to control devices by using software, such as processor, PCI devices, hard disk, etc. It optimizes the system power consumption under the specific network download usage model of the UEFI environment. 4) It requires measuring power consumption distribution of various components, including DC-DC converter on the motherboard to understand the device power consumption to system total power consumption ratio of various devices. 5) It compares total system power consumption of the S3 UEFI environment to other operating systems, such as the power consumption under Win7, WinXP and Linux at the same usage model. It provides data to prove that the total system power consumption of the UEFI environment is the lowest.The experiment result shows that the system power consumption based on the paper is at least 17% lower than other operating systems. And it also can switch software environment between UEFI and operating system in short time. So it can bring a new usage model for user. Because that this usage model can enable the business model that the brand computer companies can create new usage model independent of specific operating system. For example, under UEFI it can scan virus, download data from network, and backup local data to server. So it can get better power result to make the computer company to distinguish itself among other companies in the market. The open industry standard feature of UEFI, could support different companies'software, and is easy to promote more applications under the UEFI environment.