Optimized Design Of Godson2E BIOS Based On PMON

Godson2E is a 64-bit high-performance universal RISC processor successfully developed in 2006 independently by Institute of Computing Technology,Chinese Academy of Sciences.Although BIOS is very small,it is responsible for POST(Power On Self Test),board-level initialization and loading Operating System Kernel. Godson2E BIOS is gotten by expanding, porting and perfecting PMON.Although PMON is like-BIOS bootloader used for embedded systems based on MIPS architecture, Godson BIOS is different from PMON, because Godson2E is different from general MIPS CPU. Also, both of the functions PMON implemented and the hardware it supports are very limited, moreover, the hardware it supports is old-fashioned. Therefore, it is very necessary to expand and strengthen existing functions of PMON,and optimize initial flow in order to support more hardware devices on the market and quickly initialize them.Meanwhile, PMON is based on MIPS architecture, so it does not support X86 graphic card whose expanded ROM stores X86 binary codes. By VGA BIOS simulator PMON initializes X86 graphic card. But the graphic card the original VGA BIOS simulator supported is very limited and also old-fashioned. Furthermore, VGA BIOS simulator's initial is very slow. Therefore, it is also very necessary to port VGA BIOS simulator to support more graphic cards on the market, and quickly initialize it by optimization.Based on deficiencies existing in PMON, this thesis puts forward a new solution of optimizing initial flow and porting VGA BIOS simulator. By optimizing BIOS initial flow, BIOS POST becomes faster than ever before. Also, by successfully porting VGA BIOS simulator, more graphic cards on the market have already been supported. The typical graphic cards Godson2E BIOS has already successfully supported include RAGE PRO, RAGE XL, and RADEON7000 of ATI. Experimental results indicate that the systematical performance is very well after adopting the above new solution. It not only speeds up Godson2E BIOS POST, but also supports more graphic cards on the market. So it will bring more potential customers for Godson2E. And it is very beneficial for Godson2E's industrialization.