written by chuck cranor. thanks to mycroft for helping me find the
one little line of code i accidentally deleted while merging it.
this is not enabled by default. `options MACHINE_NEW_NONCONTIG'
will use this code. eventually, this should go into <machine/vmparam.h>
insteaed of MACHINE_NONCONTIG.
- New variables: biosextmem, biosbasemem, nkpde
- Above can be set by using the options BIOSEXTMEM, BIOSBASEMEM,
and NKPDE respectively (EXTMEM_SIZE is now called BIOSEXTMEM).
When preset this way, they won't be filled in / calculated.
- Readable by sysctl using machdep.nkpde, machdep.biosbasemem
and machdep.biosextmem.
- nkpde is calculated as:
min(NKPDE_MAX, NKPDE_BASE + (biosextmem >> 10) * NKPDE_SCALE)
Where NKPDE_MAX is 31, NKPDE_BASE is 4, NKPDE_SCALE = 1.
Map kernel stacks only at unique addresses.
Use one TSS per process.
Add sysarch calls for modifying IOPL and the I/O permission bitmap.
Add a compacting GDT entry allocator, for TSS and LDT selectors.
Enable modifying %fs and %gs with PT_SETREGS.
Sanitize various bits of code.
* Inline some functions.
* Eliminate redundant calls to pmap_page_index().
* Reduce the number of TLB flushes in accordance with the i386 SSWG.
* Inline pmap_remove() in pmap_remove_all(). (Most if it is unnecessary.)
* Allocate pv_entry's in pages, and keep a list of free entries in each page,
and a list of pages with free entries. (Trying to reduce malloc() overhead,
and improve locality of reference.)
* Remove a couple of macros that aren't really useful.
* Remove pmap_kernel() completely.
cgd