hi, i'm trying to dissassemble my old P3 mainboard bios for understanding the compatibility issue with a modern graphics card. I'm using IDA disassembler. Can someone tell me what I/O port EB refers to and also help me understand the purpose of the assembly instructions (start of bootblock) given below?
seg001:E45C mov al, 0BDh ;
seg001:E45E mov ah, al
seg001:E460 out 70h, al ; CMOS Memory:
seg001:E460 ;
seg001:E462 out 0EBh, al
seg001:E464 mov al, 55h ;
seg001:E466 out 71h, al ; CMOS Memory:
seg001:E466 ;
seg001:E468 xchg ah, al
seg001:E46A out 70h, al ; CMOS Memory:
seg001:E45C mov al, 0BDh ;
seg001:E45E mov ah, al
seg001:E460 out 70h, al ; CMOS Memory:
seg001:E460 ;
seg001:E462 out 0EBh, al
seg001:E464 mov al, 55h ;
seg001:E466 out 71h, al ; CMOS Memory:
seg001:E466 ;
seg001:E468 xchg ah, al
seg001:E46A out 70h, al ; CMOS Memory: