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Marcel Moolenaar f2c49dd248 Revamp of the syscall path, exception and context handling. The
prime objectives are:
o  Implement a syscall path based on the epc inststruction (see
   sys/ia64/ia64/syscall.s).
o  Revisit the places were we need to save and restore registers
   and define those contexts in terms of the register sets (see
   sys/ia64/include/_regset.h).

Secundairy objectives:
o  Remove the requirement to use contigmalloc for kernel stacks.
o  Better handling of the high FP registers for SMP systems.
o  Switch to the new cpu_switch() and cpu_throw() semantics.
o  Add a good unwinder to reconstruct contexts for the rare
   cases we need to (see sys/contrib/ia64/libuwx)

Many files are affected by this change. Functionally it boils
down to:
o  The EPC syscall doesn't preserve registers it does not need
   to preserve and places the arguments differently on the stack.
   This affects libc and truss.
o  The address of the kernel page directory (kptdir) had to
   be unstaticized for use by the nested TLB fault handler.
   The name has been changed to ia64_kptdir to avoid conflicts.
   The renaming affects libkvm.
o  The trapframe only contains the special registers and the
   scratch registers. For syscalls using the EPC syscall path
   no scratch registers are saved. This affects all places where
   the trapframe is accessed. Most notably the unaligned access
   handler, the signal delivery code and the debugger.
o  Context switching only partly saves the special registers
   and the preserved registers. This affects cpu_switch() and
   triggered the move to the new semantics, which additionally
   affects cpu_throw().
o  The high FP registers are either in the PCB or on some
   CPU. context switching for them is done lazily. This affects
   trap().
o  The mcontext has room for all registers, but not all of them
   have to be defined in all cases. This mostly affects signal
   delivery code now. The *context syscalls are as of yet still
   unimplemented.

Many details went into the removal of the requirement to use
contigmalloc for kernel stacks. The details are mostly CPU
specific and limited to exception_save() and exception_restore().
The few places where we create, destroy or switch stacks were
mostly simplified by not having to construct physical addresses
and additionally saving the virtual addresses for later use.

Besides more efficient context saving and restoring, which of
course yields a noticable speedup, this also fixes the dreaded
SMP bootup problem as a side-effect. The details of which are
still not fully understood.

This change includes all the necessary backward compatibility
code to have it handle older userland binaries that use the
break instruction for syscalls. Support for break-based syscalls
has been pessimized in favor of a clean implementation. Due to
the overall better performance of the kernel, this will still
be notived as an improvement if it's noticed at all.

Approved by: re@ (jhb)
2003-05-16 21:26:42 +00:00
bin mdoc(7) police: A better version of the same. 2003-05-16 21:19:32 +00:00
contrib Fix up external variables named "debug" that have a horrible habit 2003-05-11 18:17:00 +00:00
crypto Revert unnecessary part of previous commit. 2003-05-13 10:18:49 +00:00
etc Add new directories from the XFree86 4.3.0 update. 2003-05-14 07:23:54 +00:00
games mdoc(7) police: Added "rot13" to the NAME section. 2003-05-16 21:26:39 +00:00
gnu Set the binutils arch for as/nm correctly on the amd64 platform. 2003-05-08 06:39:31 +00:00
include Centralize _PATH_* definitions. 2003-05-05 22:49:23 +00:00
kerberos5 Remove some KRB4 scraps, and allow NOSHARED make worlds to 2003-05-11 18:49:29 +00:00
lib Revamp of the syscall path, exception and context handling. The 2003-05-16 21:26:42 +00:00
libexec Allow a NOPIC "make world" to complete. 2003-05-11 18:48:29 +00:00
release Revision 1.49 broke snapshot building on older systems. 2003-05-16 13:59:12 +00:00
sbin Allow zero or more actions in an action list, rather than requiring 2003-05-15 02:23:32 +00:00
secure Turn MAKE_KERBEROS5 into NO_KERBEROS by negating the logic. Some extra 2003-05-05 07:58:44 +00:00
share Remove an extraneous .El' that was reported by groff -z`. 2003-05-16 19:57:38 +00:00
sys Revamp of the syscall path, exception and context handling. The 2003-05-16 21:26:42 +00:00
tools More configuration tweaks. Rename %CONFIGS to %SETUPS to make the code 2003-05-16 14:01:02 +00:00
usr.bin Revamp of the syscall path, exception and context handling. The 2003-05-16 21:26:42 +00:00
usr.sbin When getting back an NLM DENIED response for a requested lock from the 2003-05-15 03:19:30 +00:00
COPYRIGHT Update to add the July 22, 1999 addendum. 1999-09-05 21:33:47 +00:00
MAINTAINERS OBE 2003-04-27 05:51:12 +00:00
Makefile Kill upgrade target docs. It too is stale. 2003-04-03 05:34:36 +00:00
Makefile.inc1 Use the installed world's idea of OSRELDATE rather than the kernel. 2003-05-15 17:59:32 +00:00
README KerberosIV de-orbit burn continues. Disconnect from "make world". 2003-03-08 10:01:26 +00:00
UPDATING Announce the Kerberos5 changes. 2003-05-05 20:05:37 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on:
$FreeBSD$

For copyright information, please see the file COPYRIGHT in this
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The Makefile in this directory supports a number of targets for
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commonly used one being ``world'', which rebuilds and installs
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Building a kernel is a somewhat more involved process, documentation
for which can be found at:
   http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html
And in the config(8) man page.
Note: If you want to build and install the kernel with the
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The sample kernel configuration files reside in the sys/<arch>/conf
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kernel.  The file NOTES contains entries and documentation for all possible
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Source Roadmap:
---------------
bin		System/user commands.

contrib		Packages contributed by 3rd parties.

crypto		Cryptography stuff (see crypto/README).

etc		Template files for /etc.

games		Amusements.

gnu		Various commands and libraries under the GNU Public License.
		Please see gnu/COPYING* for more information.

include		System include files.

kerberos5	Kerberos5 (Heimdal) package.

lib		System libraries.

libexec		System daemons.

release		Release building Makefile & associated tools.

sbin		System commands.

secure		Cryptographic libraries and commands.

share		Shared resources.

sys		Kernel sources.

tools		Utilities for regression testing and miscellaneous tasks.

usr.bin		User commands.

usr.sbin	System administration commands.


For information on synchronizing your source tree with one or more of
the FreeBSD Project's development branches, please see:

  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html