About Gate A20. GRUB supports only the traditional approach (i.e. using the keyboard controller) to enable/disable Gate A20 at the moment. This is not enough.
Until now, at least two persons have problems because of this. One is Zinx, who reported a problem via the Debian Bug Tracking System: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=139774&repeatmerged=yes The other is Daniel. His report is here: http://www.mail-archive.com/bug-grub%40gnu.org/msg05653.html In his case, it was difficult to figure out that his problem was related to Gate A20. I and he investigated it privately, and it turned out that enabling Gate A20 via the keyboard controller made his USB keyboard unworkable, but doing that via System Control Port A worked quite well. I guess that's because the BIOS keyboard support somewhat relies on the status of the keyboard contoller output port. Those implies that GRUB needs to support using System Control Port A, but according to <http://www.win.tue.nl/~aeb/linux/kbd/A20.html>, some systems seem to crash, if System Control Port A is used. In that web site, a suggestion is recorded, but it is unknown whether the suggestion overcomes the crash problem or not. Therefore, syslinux uses BIOS as the first way, the keyboard controller as the second, and System Control Port A as the last. This may be good for syslinux, but not good for GRUB, because GRUB must support interactive operations using a keyboard even after loading an OS image, unlike syslinux. In Daniel's system, as using the keyboard controller spoils the BIOS support for an USB keyboard, System Control Port A _must_ be used before the keyboard controller. Incidentally, his system doesn't support the BIOS calls (INT 15H, AX=240x) unfortunately. I'm not sure how we should solve all this problem. Do you have any ideas or suggestions? Okuji _______________________________________________ Bug-grub mailing list [EMAIL PROTECTED] http://mail.gnu.org/mailman/listinfo/bug-grub