MFC Loader Fixes Final: r327612,r327703,r327704,r327878,r327879,r327881,
r328007,r328029,r328030,r328031,r328061,r328156,r328169,r328288,r328289,
r328290,r328291,r328292,r328411,r328536,r328603,r328614,r328642,r328769,
r328779,r328780,r328781,r328782,r328783,r328806,r328808,r328826,r328835,
r328911,r328986,r328987,r328990,r328999,r329000,r329019,r329050,r329054,
r329060

r327612: Invent new #defines for the biospci_{read,write}_config function

r327703: Define __dmadat after #include'ing ufsread.c.

r327704: Fix printf missing format variables warnings.

r327878: Add GUID for UEFI boot manager variables.

r327879: Report the boot order and where we are in that boot order.

r327881: Allow this file to be included

r328007: Fix booting on some arm64 systems after r327879 by fixing the call
to utf8_to_ucs2

r328029: When returning an error and freeing allocated memory from
ucs2_to_utf8, NULL the return pointer.

r328030: Check the return value from utf8_to_ucs2 instead of whether or not
uv is NULL.

r328031: Need to free uv after we're done using it.

r328061: utf8_to_ucs2() should check for malloc failure

r328156: stand: Move sections around to fix stand/ build with ld.lld on
armv7

r328169: Remove extra copy of bootinfo.c. It's a bit rotted copy of the one
in efi/loader.

r328288: Fix some resource leaks.

r328289: Don't leak memory when displaying help.

r328290: On malloc failure, be sure to close the include file that triggered
it.

r328291: getenv does not return tainted data in the boot loader. Attempt to
clue Coverity into that fact.

r328292: There's no tainted data here, tag it as such to avoid false
positives.

r328411: loader.efi: add missing EFI GUIDs

r328536: loader: support for mixed-endianness ELF/loader and POWER8

r328603: Add missing non-POWERPC case to give the scr value something
non-zero.

r328614: Move libstand.3 to libsa.3. Update libsa.3 to include functions

r328642: Break out the interpreters (simple and forth) w/o ifdefs.

r328769: Centralize several variables.

r328779: Retire pnp.4th and the code needed only for 4th words used here.

r328780: These 4th words were an attempt to allow integration into the boot
loader scripts. However, that path won't be taken after all it
seems.

r328781: Remove pcibios forth support.

r328782: Now that we no longer conditionally compile some files outside of
ficl

r328783: Invent new LDR_INTERP for the loader interpreter to use.

r328806: We need more heap space to properly load newer powerpc kernels.

r328808: Implement strcoll as strcmp.

r328826: Make cross-endian loader changes apply only to powerpc

r328835: Fix regression introduced in r328806, preventing boot on many
platforms.

r328911: Ignore relocation tables for non-memory-resident sections.

r328986: Fix relative location of USB sources after recent move.

r328987: A more definitions to kernel emulation shim in order to build
stand/usb.

r328990: Move the stand/usb test loader into its own directory.

r328999: Fix indentation to FreeBSD standard for interp files

r329000: Move simple interpreter 'perform' into interp.c and call it

r329019: Move to tabs for indentation and to 8-space notches, per style(9).

r329050: Fix build of userboot.so

r329054: Set script.lang in the environment to either 'forth' or 'simple' to
reflect what scripting language was compiled into the loader.

r329060: loader: fix endianness conversion

PR: 225323

MFC r325834,r325997,326502: Move sys/boot to stand/

This is effectively a direct commit to stable/11, due to differences between
stable/11 and head. Changes to DTS in sys/boot/fdt/dts were often
accompanied by kernel changes. Many of these were also risc-v updates that
likely had many more dependencies to MFC.

Because of this, sys/boot/fdt/dts remains as-is while everything else in
sys/boot relocates to stand/.

r325834: Move sys/boot to stand. Fix all references to new location

r325997: Remove empty directories.

r326502: Document the sys/boot -> stand move in hier.7 and the top-level README.

MFC Loader Fixes 2017q4p6: r324649,r324650,r324651,r324652,r324653,r324654,
r324700,r324702,r324709,r324717,r324719,r324841,r324842,r324843,r324845,
r324850,r324876,r324877,r324878,r324879,r324880,r324881,r324883,r324980,
r324981,r324982,r324995,r325014,r325093,r325094,r325114,r325170,r325171,
r325172,r325173,r325174,r325175,r325176,r325248,r325286,r325310,r325332,
r325338,r325339,r325376,r325377,r325379,r325380,r325382,r325478,r325479,
r325480,r325482,r325483,r325484,r325485,r325556,r325641,r325681,r325685,
r325686,r325687,r325688,r325689,r325690,r325691,r325692,r325693,r325694,
r325743,r325744,r325748,r325775,r325779,r325780

r324649: Move common/Makefile.inc to sys/boot/loader.mk.

r324650: tweak style

r324651: create defs.mk for common definitions

r324652: Move all the ficl common code into ficl.mk

r324653: LOADER_foo_SUPPORTED

r324654: Explicitly inlcude SYSDIR in the include path

r324700: loader: initialize dv_cleanup in md.c to eliminate clang warning

r324702: We need to include disk.o in libuboot.a when we're building with
support for disk access.

r324709: Revert "Unify boot1 with loader" change r324646

r324717: libsa/ip.c: misplaced comment, ip_v is half char, not ip_p

r324719: libsa/ip: stop read loop on bad fragments

r324841: Use BOOTDIR more consistently in defs.mk rather than repeat
sys/boot.

r324842: Introduce BOOTOBJ: The top level object directory for the boot tree

r324843: Stopgap fix to the mistmatch between LOADER_GELI_SUPPORT and
LOADER_NO_GELI_SUPPORT.

r324845: Use BOOTOBJ and BOOTDIR to find geli includes and libraries.

r324850: Define LIBSA32 to LIBSA on i386 to fix build.

r324876: Move fdt and uboot defines into common uboot.mk.

r324877: End source directories with SRC rather than a hodgepodge of names

r324878: Make at91 boot loader compile again.

r324879: Prefer SRCTOP paths for bits we're grabbing from libc.

r324880: Use BOOTSRC here.

r324881: Use SYSDIR instead of ${.CURDIR}/../..<etc>/sys.

r324883: Use preferred defined paths, rather than relative paths in fdt.

r324980: Use BOOTDIR consistently.

r324981: Move BINDIR definition to defs.mk, and override where it isn't
/boot

r324982: Remove sys/boot/arm/at91 and ixp425

r324995: loader.efi: Make framebuffer commands available for arm64

r325014: Add a 'place holder' arm struct efi_fb until a real one comes

r325093: Define new EFI variables

r325094: Cleanup non-arch Makefiles

r325114: Use defs.mk defins in most MD code

r325170: Use defs.mk values for userboot

r325171: Use defs.mk name and prefer bsd.init.mk

r325172: Remove the -nostdlib stuff I added. Instead, fix LDFLAGS to be
honored correctly with the new Makefile.inc include order.

r325173: We don't need to build a special ficl for userboot.

r325174: Minor cleanup

r325175: For amd64, compile both zfs and zfs32 libraries.

r325176: Actually add zfs32/Makefile

r325248: loader ptblread() is broken with >512B sectors

r325286: efipart_strategy is using wrong offset with >512B sectors

r325310: zfs.c:vdev_read() needs to be careful about large sectors

r325332: loader: re-enable gzip support for x86

r325338: loader: fix BOOTSRC -> BOOTOBJ in a library path

r325339: This used to have bzip2 support too.

r325376: WIP: centralize machine links

r325377: mostly libsa

r325379: Revert "mostly libsa"

r325380: Revert "WIP: centralize machine links"

r325382: Cleanup stray libstand names to be libsa names.

r325478: Powerpc is a 32-bit boot loader.

r325479: Define LIBFICL32 to be libficl.a on i386 and libficl32.a on amd64.

r325480: Use DO32 for all the places that we need to flag we're building a
32-bit version of a library.

r325482: Move machine and other link creation to defs.mk

r325483: MACHINE can never be powerpc64, so cleanup code that thinks it can.

r325484: Prefer bsd.init.mk to src.opts.mk

r325485: Centralize all 32-bit builds on 64-bit platform stuff.

r325556: loader: set options before including bsd.init.mk

r325641: loader.efi: efi_devpath_is_prefix should return bool

r325681: boot1: avoid using NULL device path

r325685: libsa32 isn't needed for i386. It's already a 32-bit platform.

r325686: Simplify this if to a direct assignment.

r325687: Remove all the empty help files from the powerpc build.

r325688: FDT support doesn't make sense for ps3, remove it.

r325689: Remove LOADER_FDT_SUPPORT as a Makefile variable.

r325690: Remove LOADER_ZFS_SUPPORT as a Makefile variable

r325691: Remove useless PNP define here.

r325692: Replace LOADER_FIREWIRE_SUPPORT variable

r325693: Move LOADER_{NO,}_GELI_SUPPORT to MK_LOADER_GELI

r325694: Install the 4th files in sys/boot/forth instead of each loader

r325743: Make sure the proper loader.rc gets installed.

r325744: boot1: also check for NULL device

r325748: Use proper include file.

r325775: Add loader.conf to the list of files that are MD.

r325779: Add /boot/dts to the list of default modules.

r325780: Don't add /boot/dt*s* but /boot/dt*b*. Stupid think-o.

MFC r303555,r303556,r303936,r303962,r304317,r304532,r305026,r305107,r305132,
r305178,r305353,r305814,r306159,r306380,r306504: Loader fixes, 2016q3

r303555: bcache should support reads shorter than sector size

r303556: Improve boot loader quote parsing

r303936: Add kernel environment variables under smbios.system

r303962: Add the missing space between .asciz directive and opening quote
for some lines with #ifdef BTXLDR_VERBOSE/#endif

r304317: boot1.efi Free() should check for NULL to provide consistent
behavior

r304532: Replace sprintf -> snprintf for command_errbuf provisioned from
dynamic content.

r305026: Emulate efi_cons_poll when WaitForKey is not available

r305107: Create a hook 'post-initialize' for people that want to define
something to read in .conf files after all other .conf files for the purpose
of overriding.

r305132: Remove accidentally committed stray comment.

r305178: bd_int13probe() should check extended info if sector info is bad

r305353: Don't use -N to set the OMAGIC with data and text writeable and
data not page aligned.

r305814: ufsread: Do not cast struct direct from void *

r306159: Consistently declare getsecs(void) with proper return type and void
when no arguments are present.

r306380: loader command interpreter should reset command_errmsg

r306504: Fix a cluster of bugs in list EFI environment variables

PR: 204602, 211958, 211958
Relnotes: yes ("Improve boot loader quote parsing")

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Implement (ACFLAGS|CFLAGS|CXXFLAGS).SRC globally.

Sponsored by: EMC / Isilon Storage Division

META MODE: Update dependencies with 'the-lot' and add missing directories.

This is not properly respecting WITHOUT or ARCH dependencies in target/.
Doing so requires a massive effort to rework targets/ to do so. A
better approach will be to either include the SUBDIR Makefiles directly
and map to DIRDEPS or just dynamically lookup the SUBDIR. These lose
the benefit of having a userland/lib, userland/libexec, etc, though and
results in a massive package. The current implementation of targets/ is
very unmaintainable.

Currently rescue/rescue and sys/modules are still not connected.

Sponsored by: EMC / Isilon Storage Division

Revert r267233 for now. PIE support needs to be reworked.

1. 50+% of NO_PIE use is fixed by adding -fPIC to INTERNALLIB and other
build-only utility libraries.
2. Another 40% is fixed by generating _pic.a variants of various libraries.
3. Some of the NO_PIE use is a bit absurd as it is disabling PIE (and ASLR)
where it never would work anyhow, such as csu or loader. This suggests
there may be better ways of adding support to the tree. Many of these
cases can be fixed such that -fPIE will work but there is really no
reason to have it in those cases.
4. Some of the uses are working around hacks done to some Makefiles that are
really building libraries but have been using bsd.prog.mk because the code
is cleaner. Had they been using bsd.lib.mk then NO_PIE would not have
been needed.

We likely do want to enable PIE by default (opt-out) for non-tree consumers
(such as ports). For in-tree though we probably want to only enable PIE
(opt-in) for common attack targets such as remote service daemons and setuid
utilities. This is also a great performance compromise since ASLR is expected
to reduce performance. As such it does not make sense to enable it in all
utilities such as ls(1) that have little benefit to having it enabled.

Reported by: kib

In preparation for ASLR [1] support add WITH_PIE to support building with -fPIE.

This is currently an opt-in build flag. Once ASLR support is ready and stable
it should changed to opt-out and be enabled by default along with ASLR.

Each application Makefile uses opt-out to ensure that ASLR will be enabled by
default in new directories when the system is compiled with PIE/ASLR. [2]

Mark known build failures as NO_PIE for now.

The only known runtime failure was rtld.

[1] http://www.bsdcan.org/2014/schedule/events/452.en.html
Submitted by: Shawn Webb <lattera@gmail.com>
Discussed between: des@ and Shawn Webb [2]

NO_MAN= has been deprecated in favor of MAN= for some time, go ahead
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.

Sanitize the %eflags returned by BIOS routines. Some BIOS routines enter
protected mode and may leave protected-mode-specific flags like PSL_NT set
when they return to real mode. This can cause a fault when BTX re-enters
protected mode after the BIOS mode returns.

PR: amd64/182740
Reported by: Julian Pidancet <julian.pidancet@gmail.com>
Approved by: re (gjb)
MFC after: 1 week

When rebooting (exiting) from the BTX loader, make sure to restore the
GDT from the correct segment, otherwise a triple fault would be caused.
In some virtual environments (VMware, VirtualBox, etc) this could lead
to a unhandled error or hang in the guest emulation software.

Thanks to avg and jhb for a few hints in the right direction.

Noticed by: Jeremy Chadwick <jdc@koitsu.org> (and many others)
MFC after: 1 week

add detection of serial console presence to btx and boot2-like blocks

Note that this commit slightly increases size of boot blocks.

Reviewed by: jhb
Tested by: Olivier Cochard-Labbe <olivier@cochard.me>
MFC after: 26 days

btxldr: future-proof argument passing from boot1/2-ish to loader

Place the arguments at a fixed offset of 0x800 withing the argument area
(of size 0x1000). Allow variable size extended arguments first of which
should be a size of the extended arguments (including the size
parameter).

Consolidate all related definitions in a new i386/common/bootargs.h header.

Many thanks to jhb and bde for their guidance and reviews.

Reviewed by: jhb, bde
Approved by: jhb
MFC after: 1 month

Define several extra macros in bsd.sys.mk and sys/conf/kern.pre.mk, to
get rid of testing explicitly for clang (using ${CC:T:Mclang}) in
individual Makefiles.

Instead, use the following extra macros, for use with clang:
- NO_WERROR.clang (disables -Werror)
- NO_WCAST_ALIGN.clang (disables -Wcast-align)
- NO_WFORMAT.clang (disables -Wformat and friends)
- CLANG_NO_IAS (disables integrated assembler)
- CLANG_OPT_SMALL (adds flags for extra small size optimizations)

As a side effect, this enables setting CC/CXX/CPP in src.conf instead of
make.conf! For clang, use the following:

CC=clang
CXX=clang++
CPP=clang-cpp

MFC after: 2 weeks

Upgrade our copy of llvm/clang to r126079, from upstream's trunk.

This contains many improvements, primarily better C++ support, an
integrated assembler for x86 and support for -pg.

Use -Wl,-N instead of the undocumented -N option for GCC.

GCC forwards the -N flag directly to ld. This flag is not documented and
not supported by (for example) Clang. Just use -Wl,-N.

Submitted by: Pawel Worach

Fix some more issues with the real mode BTX.

The old BTX passed the general purpose registers from the 32-bit client to
the routines called via virtual 86 mode. The new BTX did the same thing.
However, it turns out that some instructions behave differently in virtual 86
mode and real mode (even though this is under-documented). For example, the
LEAVE instruction will cause an exception in real mode if any of the upper
16-bits of %ebp are non-zero after it executes. In virtual 8086 mode the
upper 16-bits are simply ignored. This could cause faults in hardware
interrupt handlers that inherited an %ebp larger than 0xffff from the 32-bit
client (loader, boot2, etc.) while running in real mode.

To fix, when executing hardware interrupt handlers provide an explicit clean
state where all the general purpose and segment registers are zero upon
entry to the interrupt handler. While here, I attempted to simplify the
control flow in the 'intusr' code that sets up the various stack frames
and exits protected mode to invoke the requested routine via real mode.

A huge thanks to Tor Egge (tegge@) for debugging this issue.

Submitted by: tegge
Reviewed by: tegge
Tested by: bz
MFC after: 1 week

Fix the hangs reported with the real mode BTX:
- I had errantly assumed that all user requests should run with interrupts
enabled. User requests for software interrupts, however, need to disable
interrupts (and tracing) just like hardware interrupts.
- Disable alignment checking when emulating a hardware interrupt as well
(based on the description of the real mode operation of the 'INT'
instruction in the IA-32 manuals).
- Use constants for fields in %eflags.

Tested by: bz
MFC after: 3 days

Change the BTX kernel to drop all the way out to real mode to invoke BIOS
routines (V86 requests from the client and hardware interrupt handlers):
- Install trampoline real mode interrupt handlers at IDT vectors 0x20-0x2f
to handle hardware interrupts by invoking the appropriate vector (0x8-0xf
or 0x70-0x78). This allows the 8259As to use vectors 0x20-0x2f in real
mode as well as protected mode will ensuring that the master 8259A
doesn't share IDT space with CPU exceptions in protected mode.
- Since we don't need to reserve space for page tables and a page directory
anymore since dropping paging support, move the TSS and protected mode
IDT up by 16k. Grow the ring 1 link stack by 16k as a result.
- Repurpose the ring 1 link stack to be used as a real mode stack when
invoking real mode routines either via a V86 request or a hardware
interrupts. This simplifies a few things as we avoid disturbing the
original user stack.
- Add some more block comments to explain how the code interacts with the
V86 structure as this wasn't immediately obvious from the prior comments
(e.g. that we explicitly copy the seg regs for real mode out of the V86
struct onto the stack to be popped off when going into real mode, etc.).
Also, document some of the stack frames we create going to real mode and
back.
- Remove all of the virtual 86 related code including having to simulate
various instructions and BIOS calls on a trap from virtual 86 mode.
- Explicitly panic if a user client attempts to perform a V86 CALL
request that isn't a far call.
- Bump version to 1.2.

Assuming this works ok this should fix some of the long standing issues
with USB booting as well as etherboot.

MFC after: 2 weeks
Submitted by: kib (some parts from his original real mode patch)

Retire the support for using paging in BTX. It hasn't been used since
before 4.0.

Submitted by: kib

Ignore any breakpoint instructions (int 3) we encounter in vm86 mode
rather than treating them as a fatal exception and halting. At least one
storage BIOS (some newer mpt(4) parts) have a breakpoint instruction in
their disk read routine.

MFC after: 3 days

- Fix a couple of improper uses of leal in the previous space saving
commits. For some reason I thought the scale factor was a shift count
rather than the multiplicand (that is, I thought leal (%eax,%edx,4) was
going to generate %eax + %edx << 4 rather than %eax + %edx * 4). What
I need is to multiply by 16 to convert a real-mode (seg, offset) tuple
into a flat address. However, the max multiplicand for scaled/index
addressing on i386 is 8, so go back to using a shl and an add.
- Convert two more inter-register mov instructions where we don't need to
preserve the source register to xchg instructions to keep our space
savings.

Tested by: Ian FREISLICH if at hetzner.co.za
MFC after: 1 week

Tweak the code to handle intercepting BIOS calls to int 0x15 to shave
another 16 bytes off of BTX (and thus boot2):
- Compare against the value of %eax that is saved on the stack instead of
loading it into %eax (which requires saving the current %eax on the
stack).
- Use %ch to examine the keyboard flag state in the BIOS to see if
Ctrl-Alt-Del is pressed instead of %al so we don't have to save %eax on
the stack anymore.

MFC after: 1 week

Optimize the int 15/87 handler for space to shave another 16 bytes off of
BTX (and thus boot2):
- Don't bother saving %eax, %ebx, or %ecx as it is not necessary.
- Use a more compact sequence to load the base value out of a GDT entry
by loading the contiguous low 24 bits into the upper 24 bits of %eax,
loading the high 8 bits into %al, and using a ror to rotate the bits
(2 mov's and a ror) rather than loading the pieces in smaller chunks
(3 mov's and a shl).
- Use movzwl + leal instead of movl + movw + shll + addl.
- Use 'xchgl %eax,%foo' rather than 'movl %eax,%foo' for cases where
it's ok to trash %eax. xchgl %eax, foo is a 1-byte opcode whereas the
mov is a 2-byte opcode.
- Use movzwl rather than xorl + movw.

MFC after: 1 week

A couple of simple tweaks that trim BTX by 6 bytes. Since BTX is
16-byte aligned within boot2 however, this actually trims boot2 by 16
bytes.

Emulate moving cr0, cr2, cr3, or cr4 into any i386 general register
rather than just emulating mov cr0, eax. This fixes some Compaq/HP BIOS
with DMA (as the BIOS tried to read cr3 so it could translate addresses
if paging was enabled).

MFC after: 1 week

Start the dreaded NOFOO -> NO_FOO conversion.

OK'ed by: core

Fix comments for serial I/O function prototypes that were broken in the
assembler to cpp(1) comment conversions. This allows btx to compile again
when BTX_SERIAL is defined.

Reported by: Danny Braniss danny at cs dot huji dot ac dot il
MFC after: 1 month

Back out last revision that unnecessarily changed valid assembler
line comments and damaged the CVS history.

Prompted by: bde, jhb

After talking to Bruce Evans and reading more standards specs,
switch to using C99-style comments everywhere in preprocessed
assembler. The reason is that lines starting with the regexp
'^[[:space:]]#' are treated as preprocessing directives, and
while it seems to work now with GCC, it's not necessarily has
to work. Use C99 comments `//' for the trailing comments to
save whitespace.

Use C (and CPP) style comments for assembler-with-cpp sources,
for lines that start with a comment.

Removed now redundant CLEANFILES assignments.

Not read enough of my patch by: obrien ;)

Use a more compact syntax for passing the "binary" options to 'ld'.

Simplify the building of our i386 'binary' boot components by directly
producing them using 'ld' options rather than post-processing with 'objcopy'.

Idea by: Ryan Sommers <ryans@gamersimpact.com>

Get rid of unnecessary use of m4(1) by using cpp(1) instead.
(John tells me there were problems when trying this before,
but it appears to be safe these day.)

OK'ed by: jhb
Repocopied by: joe

- Factor out -nostdlib to an upper level Makefile.inc.

- Now that bsd.prog.mk deals with programs linked with -nostdlib
better, and has a notion of an "internal" program, use PROG
where possible. This has a good impact on the contents of
.depend files and causes programs to be linked with cc(1).

XXX: boot2 couldn't be converted as it's actually two programs.

Tested on: i386, amd64

When rebooting the machine jump to 0xf000:0xfff0 instead of 0xffff:0x0.

While we end up the same place, we end up with two different CS register
values after the jump and 0xf000 is compatible with the hardware reset
value.

This makes a difference if the BIOS does a near jump before a far jump.

Detective work and patch by: Adrian Steinmann <ast@marabu.ch>

Revert MEM_USR back to 0xa000 for BTX clients. Instead, adjust boot2
to run at 0xc000 by changing its virtual start address from 0x1000 to
0x2000.

Tested by: phk

Move MEM_USR a page upwards to make space for larger UFS1 boot2.

Load 4 sectors more than we used to. This is harmless overhead for
the UFS1_ONLY case, but sufficient for boot2(UFS1+2).

Sponsored by: DARPA & NAI Labs

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

Whoops, missed these bits in the previous commit.

Add support for sending messages to the serial console which is helpful
when debugging boot problems. It is not on by default but is enabled via
the BTX_SERIAL variable. The port and speed can be set via the same
variables used by boot2 and the loader.

Add support for outputting multiple lines when dumping memory during the
register dump. Change the default to bump 2 lines of output (32 bytes)
instead of 1 line (16 byte).

Add support for trace traps by returning from them just as for breakpoint
traps rather than halting. Ideally, we should avoid printing the
'BTX halted' message for debug register dumps.

Output a newline at the end of a dump so that there are blank lines between
dumps when using breakpoints or tracing.

Unset MAINTAINER.

Fix reboot buglet when BOOT_BTX_NOHANG is defined.

Submitted by: Umesh Krishnaswamy <umesh@juniper.net>

Always disable paging when exiting back to real mode after receiving a
fatal trap. Also, reload the GDT register to point to BTX's GDT before
playing around with the segment registers to return to real mode. This is
helpful if the kernel causes a fatal exception before it has setup its own
IDT and fault handlers. For example, if one happens to break mtx_init().
Without these changes BTX would recursively page fault (if paging was not
disabled) or triple fault and reset the CPU (without the GDT reload)
instead of providing a potentially useful register dump.

Reviewed by: rnordier

Set MAINTAINER.

Add a new compile-time tweak to BTX. If you set the make(1) variable
BOOT_BTX_NOHANG, then BTX will be compiled with the appropriate flags so
that it reboots after a fault instead of hanging forever.

Requested by: ps
Approved by: rnordier

Emulate the WBINVD instruction when it is called by the BIOS.

Change the fault message to say 'BTX halted' isntead of 'System halted' to
avoid confusion.

Submitted by: George Scott <George.Scott@its.monash.edu.au>

Rework the detecting of the rdmsr and wrmsr instructions in the v86
monitor so that the codepath is cleaner and easier to maintain in the
future.

Add support for emulating the RDMSR and WRMSR instructions into BTX. In
theory, this should allow the K7V Athlon motherboard to boot ok with boot
virus protection enabled. However, I have no hardware to test this. It
shouldn't break anything though. :)

Prodded by: Kelly Yancey <kbyanc@posi.net>

Clean up all of the 16-bit assembly code in the x86 bootstrap to work
with the new binutils. Now that we have a decent assembler, all the old
m4 macros are no longer needed. Instead, straight assembly can be used
since as(1) now understands 16-bit addressing, branches, etc. Also,
several bugs have been fixed in as(1), allowing boot0.s to be further
cleaned up.

Don't disable interrupts when calling a vm86 mode interrupt or routine
from user mode. Don't disable interrupts when returning from vm86 mode
to user mode either. Now, we only disable interrupts before calling a
hardware interrupt handler, which is the only time we _should_ be
disabling interrupts.

Because of this, err, feature, any routine that one called in vm86 mode
had to re-enable interrupts by setting the interrupt flag or interrupts
would remain disabled even after the routine returned. For example, I
have a simple debugging routine that uses a vm86 mode function to dump
any arbitrary memory word that I use to read the BIOS timer or any other
memory location. This function does 1 load instruction from memory and
then returns. Since it didn't re-enable interrupts, the first time I
called it to read the BIOS timer, it disabled interrupts. This also
affected the PXE bootstrap as it needs interrupts enabled while it is
processing. This patch fixes both of those situations so that those
functions do not worry about having to enable interrupts. Hardware
interrupt handlers worked fine with the old code because they always
enable interrupts as part of their routine.

If you have any problems with the loader after this commit, please
let me know. I'd like to MFC it in a week or two since PXE support
needs it.

Noticed by: ps, Michael Johnston <michael.johnston@intel.com>

This patch to BTX fixes several small things:

1) Fix a bug in the int15 function 87 emulation where we only copied half
of what the BIOS asked for. This caused the Mylex RAID adapter to go
haywire and start trashing memory when you tried to boot from it.
2) Don't use interrupt 19 to reboot. Instead, set the reboot flag to a warm
boot and jump to the BIOS's reboot handler. int 19 doesn't clear memory
or restore the interrupt vector table, and thus really isn't safe. For
example, when booting off of PXE, the PXE BIOS eats up a chunk of memory
for its internal data and structures. Since we rebooted via int 19,
using the 'reboot' command in the loader resulted in that memory not
being reclaimed by the BIOS. Thus, after a few PXE boots, the system
was out of lower memory.
3) Catch any int 19 calls made by a BTX client or a user pressing
Ctrl-Alt-Delete and shutdown BTX and reboot the machine cleanly. This
fixes Ctrl-Alt-Delete in the loader and in boot2 instead of presenting
the user with a BTX fault.

Approved by: jkh
Found by: 1) by msmith

Fix brokenness introduced with the PAGING conditional variable. The value
of %cr0 wasn't reloaded into %eax before being modified to turn protected
mode off if PAGING was not defined. The result was that the processor did
not exit protected mode, so when it tried to jump to segment 0x0 in the
next instruction to clear the prefetch cache like one should when leaving
protected mode, it actually tried to jump to a null selector, causing a
GPF.

If PAGING is defined then actually turn it on when entering protected
mode.

aThis patch updates the BTX to emulate the BIOS function "Copy Extended
Memory" called as function 0x87 of interrupt 0x15. Since the Mylex RAID
adapter's BIOS used this function to access memory (actually PCI bus
space) beyond 16 MB, this patch also allows BTX to address all 4 Gig of
possible address space on i386+. Since the loader does not have room for
4 MB of page tables, this was done by turning off paging.

Paging was turned off via a compile time setting which defaults to off.
To enable paging, simply define the make variable PAGING.

rnordier might want to clean this up later.

Submitted by: W. Gerald Hicks <wghicks@bellsouth.net>,
Bosko Milekic <bmilekic@ares.dsuper.net>
Reviewed by: msmith
Required by: Mylex RAID adapter's BIOS

$Id$ -> $FreeBSD$

Emulate a V86 "movl %cr0,%eax" instruction.

Feedback and testing: Kurt Hopfensperger <kjhmdjd@ix.netcom.com>

Push version numbers up to 1.00. This is just intended to reflect
that the BTX code can be regarded as stable: there are no associated
code changes.

Suggested by: obrien

Revise a few comments.

Ignore, rather than emulate, an i386 'hlt' instruction (though for
most practical purposes, this should be indistinguishable from a
more strictly correct approach).

Feedback and testing: msmith

Don't use an absolute path to objcopy.
Noticed by: Scott Mace <smace@intt.org>

Allocate space for storing of arguments at the end of conventional
memory.

For system calls, reboot without prompting; for exceptions, display
message and await reset.

Map all BTX system pages readable at ring 3.
This resolves the firmware problem first raised in connection
with PR 8105, although unrelated.

Make these compile when there is an obj dir.

Initial integration of the i386 bootloader and BTX.

- Discard large amounts of BIOS-related code in favour of the more compact
BTX vm86 interface.
- Build the loader module as ELF, although the resulting object is a.out,
make gensetdefs 32/64-bit sensitive and use a single copy of it.
- Throw away installboot, as it's no longer required.
- Use direct bcopy operations in the i386_copy module, as BTX
maps the first 16M of memory. Check operations against the
detected size of actual memory.

Add exec syscall.

Resynch with working sources before BTX integration.

- Use format-independant module allocator.
- Conditionalise ISA PnP support.
- Simplify PnP enumerator interface.
- Improve module/object searching.
- Add missing depend/install targets in BTX makefiles.
- Pass the kernel environment and module data in extended bootinfo fields.
- Add a pointer to the end of the kernel + modules in bootinfo.
- Fix parsing of old-style kernel arguments.

Enable client entry point support.

This commit was generated by cvs2svn to compensate for changes in r39088,
which included commits to RCS files with non-trunk default branches.

BTX (aka the boot extender) is an i386 kernel that hosts 32-bit
bootstrap programs, and provides page-level protection, hardware
interrupt reflection, a virtual-8086 mode interface to BIOS, etc.