Messages in this thread | | | Subject | Re: GGI Project Unhappy On Linux | From | (Eric W. Biederman) | Date | 27 Mar 1998 10:00:49 -0600 |
| |
>>>>> "HA" == H Peter Anvin <hpa@transmeta.com> writes:
>> As Alan Cox has stated, and as I know from personal experience[1]: you can >> go from a known video state to a known video state, and you can go from a >> known video state to an unknown (i.e., garbage) video state. You cannot, >> short of resetting the card (which typically takes a reboot), go from an >> unknown state to a known state. It simply doesn't work that way. Why? >> Because the people who designed the VGA video hardware were idiots (IMHO). >> That's why kernel-arbitrated video mode changing is needed, and that's what >> KGI is. As Varg pointed out so eloquently, KGI is a leetle teeny tiny >> piece of GGI that needs to be in the kernel. The rest doesn't. >>
HA> Actually, the people who designed VGA were actually very careful to HA> *not* make this mistake (that had previously been made in EGA); HA> unfortunately, some of the people that copied and extended their HA> design weren't that careful.
They were close except the index registers while resettable are not readable. So you can rest it from a unknown state but you can 100% reliably multitask access to the card.
Eric
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu
| |