freebsd-dev/sys/i386
Konstantin Belousov 34c15db9cd 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
2015-04-13 15:22:45 +00:00
..
acpica Correct a comment brought over from amd64. i386 doesn't use long 2014-08-12 18:22:57 +00:00
bios Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
conf Apply r276208 to non-amd64 NOTES files as well to fix tinderbox builds 2015-03-25 15:51:41 +00:00
i386 Add config option PAE_TABLES for the i386 kernel. It switches pmap to 2015-04-13 15:22:45 +00:00
ibcs2 Remove the no-at variants of the kern_xx() syscall helpers. E.g., we 2014-11-13 18:01:51 +00:00
include Add config option PAE_TABLES for the i386 kernel. It switches pmap to 2015-04-13 15:22:45 +00:00
isa Remove write-only variable. 2015-03-12 20:14:48 +00:00
linux Regen after r276508, r276509. 2015-01-01 18:43:31 +00:00
pci Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
svr4 MFamd64: Move extern declaration of _ucodesel and _udatasel to 2014-11-02 21:40:32 +00:00
xbox After r261980, the local ptr variable in xbox_init() is no longer used, 2014-02-16 22:48:36 +00:00
xen Generalized parts of the XEN timer code into a generic pvclock 2015-02-04 08:26:43 +00:00
Makefile Delete duplicate tags entry I introduced in -r223901. 2011-07-15 17:27:26 +00:00