Welcome to the dark corner of BIOS reverse engineering, code injection and various modification techniques only deemed by those immensely curious about BIOS
Sunday, January 29, 2012
BIOS-related code "abuse" the x86 segment descriptor cache for its own pusposes. Therefore, it pays to know the details of the x86 segment descriptor cache. Aside from information in section "3.4.3 Segment Registers" of the official Intel Software Developer Manual Volume 3A and 3B, this link: http://www.rcollins.org/ddj/Aug98/Aug98.html is also very useful and gives historical insight into this widely "abused" feature that Intel have to support due to its wide usage back to the i386 era.