Commit Graph

10 Commits

Author SHA1 Message Date
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
Peter Wemm
66422f5b7a Initiate deorbit burn for the i386-only a.out related support. Moves are
under way to move the remnants of the a.out toolchain to ports.  As the
comment in src/Makefile said, this stuff is deprecated and one should not
expect this to remain beyond 4.0-REL.  It has already lasted WAY beyond
that.

Notable exceptions:
gcc - I have not touched the a.out generation stuff there.
ldd/ldconfig - still have some code to interface with a.out rtld.
old as/ld/etc - I have not removed these yet, pending their move to ports.
some includes - necessary for ldd/ldconfig for now.

Tested on: i386 (extensively), alpha
2002-09-17 01:49:00 +00:00
Marcel Moolenaar
dfef48964d Remove reference to the "Alpha Calling Standard". 2002-05-13 04:58:12 +00:00
Marcel Moolenaar
d8869cc205 o Revert previous commit in asm.h. There's no need to undefine
__FBSDID first, because it should not be defined at all,
o  Remove inclusion of cdefs.h in locore.s.

Pointed out by: peter
2002-03-27 02:20:09 +00:00
Marcel Moolenaar
9156494211 Undefine __FBSDID before defining it as it's already defined at
that point.
2002-03-24 10:28:04 +00:00
David E. O'Brien
439a4003ab ASM versions of __FBSDID. 2002-03-23 02:01:27 +00:00
Doug Rabson
47806f084a Implement MCOUNT hook for assembler. Probably doesn't work right. 2001-10-11 13:35:31 +00:00
Doug Rabson
8d9761debf Next round of fixes to the ia64 code. This includes simulated clock and
disk drivers along with a load of fixes to context switching, fork
handling and a load of other stuff I can't remember now. This takes us as
far as start_init() before it dies. I guess now I will have to finish off
the VM system and syscall handling :-).
2000-10-04 17:53:03 +00:00
Doug Rabson
431f3cb41d Next round of ia64 work, including fixes to context switching,
implementing cpu_fork(), copy*str(), bcopy(), copy{in,out}(). With these
changes, my test kernel reaches the mountroot prompt.
2000-09-30 17:48:44 +00:00
Doug Rabson
1ebcad5720 This is the first snapshot of the FreeBSD/ia64 kernel. This kernel will
not work on any real hardware (or fully work on any simulator). Much more
needs to happen before this is actually functional but its nice to see
the FreeBSD copyright message appear in the ia64 simulator.
2000-09-29 13:46:07 +00:00