Date: Thu, 03 Jun 2004 00:39:44 +0200 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: Nate Lawson <nate@root.org> Cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/boot/i386/boot2 boot1.S Message-ID: <5101.1086215984@critter.freebsd.dk> In-Reply-To: Your message of "Wed, 02 Jun 2004 09:36:20 PDT." <20040602093149.D35427@root.org>
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In message <20040602093149.D35427@root.org>, Nate Lawson writes: >By removing the callw/retw and moving the jmp to the end, A20 enable can't >be called as a subroutine from elsewhere. Will it be needed elsewhere? Not that I could find. >> /* >> * Enable A20 so we can access memory above 1 meg. >> + * Use the zero-valued %cx as a timeout for embedded hardware which do not >> + * have a keyboard controller. >> */ >> seta20: cli # Disable interrupts >> -seta20.1: inb $0x64,%al # Get status > >Should be a "movw TIMEOUT, %cx" here. (Or whatever the timeout constant >is.) Uhm, you are aware that space is very limited, right ? Please see the constant above for how we get the TIMEOUT value. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.
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