On Mon, Apr 13, 2015 at 11:22 AM, Konstantin Belousov <k...@freebsd.org> wrote:
> Author: kib > Date: Mon Apr 13 15:22:45 2015 > New Revision: 281495 > URL: https://svnweb.freebsd.org/changeset/base/281495 > > Log: > Add config option PAE_TABLES for the i386 kernel. It switches pmap to > use PAE format for the page tables, but does not incur other > consequences of the full PAE config. In particular, vm_paddr_t and > bus_addr_t are left 32bit, and max supported memory is still limited > by 4GB. > > The option allows to have nx permissions for memory mappings on i386 > kernel, while keeping the usual i386 KBI and avoiding the kernel data > sizing problems typical for the PAE config. > > Intel documented that the PAE format for page tables is available > starting with the Pentium Pro, but it is possible that the plain > Pentium CPUs have the required support (Appendix H). The goal is to > enable the option and non-exec mappings on i386 for the GENERIC > kernel. Anybody wanting a useful system on 486, have to reconfigure > the modern i386 kernel anyway. > > Discussed with: alc, jhb > Sponsored by: The FreeBSD Foundation > MFC after: 2 weeks > relnotes: yes? -Ben _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
