Date: Fri, 12 May 2000 11:28:01 -0600 From: Warner Losh <imp@village.org> To: FreeBSD MAIL <freebsd@mauibuilt.com> Cc: freebsd-hackers@FreeBSD.ORG, freebsd-questions@FreeBSD.ORG Subject: Re: BROKEN_KEYBOARD_RESET Message-ID: <200005121728.LAA12536@harmony.village.org> In-Reply-To: Your message of "Fri, 12 May 2000 04:29:40 -1000." <200005121429.EAA13692@mauibuilt.com> References: <200005121429.EAA13692@mauibuilt.com>
next in thread | previous in thread | raw e-mail | index | archive | help
In message <200005121429.EAA13692@mauibuilt.com> FreeBSD MAIL writes: : Is this the kernel setting to dislable ctrl-alt-delete from resetting : a systtem? If so it seems to be broken in 4.0-RELEASE. : is there another way of doing this? remaping keyboard perhaps? : : # BROKEN_KEYBOARD_RESET disables the use of the keyboard controller to : # reset the CPU for reboot. This is needed on some systems with broken : # keyboard controllers. No. The hot key squence CAD will reboot the system. Or rather it will cause the init process to get a signal that causes it to reboot the system. BROKEN_KEYBOARD_RESET does something different. In the IBM PC and newer compatible machines, the keyboard controller part is connected to a lot of different things, including the reset line to the CPU. Generally one can get a fairly clean reset of the CPU by telling the keyboard controller micro controller to reset the CPU with a nice pulse downt he reset line. Some keyboard controllers didn't think this was important enough to get right, so they don't implement this proplerly. These controllers are generally on the 386 and 486 class of machines and some pentium laptops (exceptions to the rule exist) where the keyboard controller was still a 8042 microcontroller programmed to talk to the keyboard. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200005121728.LAA12536>