kernel: Sync ldscript files wrt gnu.attributes and .note.GNU-stack

Bring the keeping of .gnu.attributes to all architectures. Also discard
.note.GNU-stack on all archtiectures. Plus delete obsolete comment that
was removed from i386 in 2010.

Sponsored by: Netflix
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D44069

ldscript.powerpc*: Only put .dynamic in PT_DYNAMIC

Currently there are a few output sections left as implicitly using
:kernel :dynamic before :kernel on its own is used again, which means
they end up in both the PT_LOAD and the PT_DYNAMIC segments, an unusual
situation which the new libelf-based kldxref initially treated as
invalid. Thus, hoist the :kernel to the very next section to ensure only
.dynamic is in PT_DYNAMIC, as is more normal.

Whilst here, sync ldscript.powerpc64le with ldscript.powerpc64 to pick
up various fixes that were presumably made between the start of the
powerpc64le port and it being committed and got missed.

Reviewed by: jhibbits, jhb
Differential Revision: https://reviews.freebsd.org/D43066

sys: Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

[PowerPC] kernel ifunc support for powerpc*, fix ppc64 relocation oddities.

This is a general cleanup of the relocatable kernel support on powerpc,
needed to enable kernel ifuncs.

* Fix some relocatable issues in the kernel linker, and change to using
a RELOCATABLE_KERNEL #define instead of #ifdef __powerpc__ for parts that
other platforms can use in the future if they wish to have ET_DYN kernels.

* Get rid of the DB_STOFFS hack now that the kernel is relocated to the DMAP
properly across the board on powerpc64.

* Add powerpc64 and powerpc32 ifunc functionality.

* Allow AIM64 virtual mode OF kernels to run from the DMAP like other AIM64
by implementing a virtual mode restart. This fixes the runtime address on
PowerMac G5.

* Fix symbol relocation problems on post-relocation kernels by relocating
the symbol table.

* Add an undocumented method for supplying kernel symbols on powernv and
other powerpc machines using linux-style kernel/initrd loading -- If
you pass the kernel in as the initrd as well, the copy resident in initrd
will be used as a source for symbols when initializing the debugger.
This method is subject to removal once we have a better way of doing this.

Approved by: jhibbits
Relnotes: yes
Sponsored by: Tag1 Consulting, Inc.
Differential Revision: https://reviews.freebsd.org/D23156

powerpc: Kernel fixes for ppc32 and powerpcspe w/ lld

Fix wrong section ordering that was causing a ".got is not contiguous with
other relro sections" lld error. This also brings ldscript.powerpc and
ldscript.powerpcspe closer to ldscript.powerpc64.

Also, remove unnecessary text relocs from the ppc32 AIM trap code.

Approved by: jhibbits (mentor)
Differential Revision: https://reviews.freebsd.org/D22349

Expose the kernel's build-ID through sysctl

After our migration (of certain architectures) to lld the kernel is built
with a unique build-ID. Make it available via a sysctl and uname(1) to
allow the user to identify their running kernel.

Submitted by: Ali Mashtizadeh <ali_mashtizadeh.com>
MFC after: 2 weeks
Relnotes: Yes
Event: Waterloo Hackathon 2019
Differential Revision: https://reviews.freebsd.org/D20326

remove CONSTRUCTORS from kernel linker scripts

The linker script CONSTRUCTORS keyword is only meaningful "when linking
object file formats which do not support arbitrary sections, such as
ECOFF and XCOFF"[1] and is ignored for other object file formats.

LLVM's lld does not yet accept (and ignore) CONSTRUCTORS, so just remove
CONSTRUCTORS from the linker scripts as it has no effect.

[1] https://sourceware.org/binutils/docs/ld/Output-Section-Keywords.html

Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D7343

Refactor PowerPC (especially AIM) init sequence to be less baroque.

MFC after: 2 months

Rename elf*-powerpc into elf*-powerpc-freebsd in binutils

The powerpc support was the only supported architecture not prepending the elf format name
with "-freebsd" in base this change makes it consistent with other architectures.
On newer version of binutils the powerpc format is also prepended with "-freebsd".

Also modify the kernel ldscripts in that regards.

As a result it is now possible cross build the kernel on powerpc using newer binutils

Differential Revision: https://reviews.freebsd.org/D926
Differential Revision: https://reviews.freebsd.org/D928

In fact, we don't need any of these __DYNAMIC. it is a.out leftover and commented out.

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

- Import the HEAD csup code which is the basis for the cvsmode work.

Avoid hardcoding the kernel link address in the linker script.
Use KERNBASE instead. While here, move the text sections
forward to the beginning of the text segment.

Page align the data segment.

The final commit for the first phase of PowerPC support.

This adds the config stuff needed to build kernels.

Reviewed by: obrien

Add $FreeBSD$
Make the alpha linker script more like the i386 version - delete the
/usr/local and egcs directories

Lots of changes, including:

* Support for AlphaStation 200, 250, 255, 400
* Untested support for UDB, Multia, AXPpci33 (Noname)
* Support for Personal Workstation 433a/433au, 500a/500au, 600a/600au (Miata)
* Some minor fixes and improvements to interrupt handling.

Submitted by: Andrew Gallatin <gallatin@cs.duke.edu> (AS200, Miata)
Obtained from: NetBSD (some code for AS200, Miata, Noname)

Change load address to 0xfffffc0000300000 to help support AS200.

Linker script for alpha kernel.