Eric W. Biederman wrote: >>>This depends on your southbridge and superio chipset. For SiS 630 it does jump >>> >>>to F segment as its first instruction.The chipset will decode F segment >>> >>address >> >>>to the Flash socket. >>> > >Is there any reason we need to make a far call? My gut reaction is that >it is easier to make a near call and use the high alias. For the normal >LinuxBIOS case this works quite well. >
I forgot the specific reason for this decision, it may be historical (just follow what normal BIOS do). But I think it should be that accessing DoC requires a lot of trasaction to the DoC window and making DS == CS helps a little bit in coding. Actually I am asking the same question myself recently. > >>BTW, after everything is done. The nvram_on in southbridge.c make the F segment >>mapped >>to RAM (for DoC cases). This is because LinuxKernel look F segment for PIRQ >>table. >> > >Nice. Ollie if you are regularly doing this that makes at least >one thing easier. If Ron keeps playing with pcbios compatibility I'll >have to move the linuxbios table to segment F. > I think I should, or where can I put PIRQ table ?? P.S. Now I think the main reason for far jump is that hand asm it is easier. How is the opcode for "near jmp -4KB" ?? Ollie
