Date: Sat, 28 Jul 2001 09:58:12 -0600 From: Warner Losh <imp@harmony.village.org> To: Mike Smith <msmith@FreeBSD.ORG> Cc: freebsd-stable@FreeBSD.ORG Subject: Re: FreeBSD 4.3 and 6G RAM Message-ID: <200107281558.f6SFwCw22612@harmony.village.org> In-Reply-To: Your message of "Sat, 21 Jul 2001 14:39:30 PDT." <200107212139.f6LLdVm01080@mass.dis.org> References: <200107212139.f6LLdVm01080@mass.dis.org>
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In message <200107212139.f6LLdVm01080@mass.dis.org> Mike Smith writes: : > Can the NetBSD stuff be fairly easily ported to FreeBSD, or is their VM : > system too funky? : : It's just different. But no, the NetBSD work doesn't immediately : translate. The work that NetBSD did for ka64 isn't directly translatable either since the pae support appears to be in the ka64 pmap. Their i386 (aka ia32) pmap doesn't support this yet. At least I'm not seeing 64bit addresses and the like in my viewing of the code. It does look like the ka64 pmap does have what you need, but my gut tells me that it would be hard to port to NetBSD/i386's pmap. Or at least labor intensive. However, there's a further wrinkle with NetBSD. Its bus_space_dma macros are more advanced than FreeBSD's when it comes to network drivers. All its network drivers use them (nearly all), while almost none (none?) of FreeBSD's drivers use our bus_space_dma macros. So we'd have to rewrite all of them (well, the pci ones) to handle running in 36 bits. And there are likely other issues as well that will surprise us on any port. It is a big can of worms that no one has yet tackled. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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