pass errno through switch to protected mode.

Fix typo (s/supress/suppress/).

branches: 1.10.60;
Support booting from GPT-partioned disks on PC-BIOS-compatible systems.

Much of the work in this commit was done by Mike Volokhov during GSoC 2009.

branches: 1.9.14; 1.9.22;
Remove clause 3 and 4 from TNF licenses

branches: 1.8.74; 1.8.76; 1.8.78;
merge ktrace-lwp.

Increase space for boot parameters - needed for specifying serial port
IO address and long keyboard translation map.

Rename bootparams to boot_params for consistency.

Change interface between bootxx.S and boot1() - always linked together.
This allows boot1() to change the sector number (of the boot partition)
that bootxx.S passes through to boot2().
This means that boot2() will find the correct partition when boot1()
reads /boot from the 'a' partition instead of the mbr boot partition.
This all happens when you update a system that used a small 'wd0h' partition
to boot a raid1 set to the new bootcode. Deleting /boot from the 'wd0h'
partition will make the new bootcode find /boot and the root filesystem
inside the raid set.

Report errno value from boot1() - even though the standalone FS code
seems to translate everything into ENOENT.

Pick up X86_BOOT_MAGIC_* from bootblock.h
Move boot_params.S to lib (seems useful to use it in pxeboot).

Overhaul MBR handling (part 1):

<sys/bootblock.h>:
* Added definitions for the Master Boot Record (MBR) used by
a variety of systems (primarily i386), including the format
of the BIOS Parameter Block (BPB).
This information was cribbed from a variety of sources
including <sys/disklabel_mbr.h> which this is a superset of.

As part of this, some data structure elements and #defines
were renamed to be more "namespace friendly" and consistent
with other bootblocks and MBR documentation.
Update all uses of the old names to the new names.

<sys/disklabel_mbr.h>:
* Deprecated in favor of <sys/bootblock.h> (the latter is more
"host tool" friendly).

amd64 & i386:
* Renamed /usr/mdec/bootxx_dosfs to /usr/mdec/bootxx_msdos, to
be consistent with the naming convention of the msdosfs tools.

* Removed /usr/mdec/bootxx_ufs, as it's equivalent to bootxx_ffsv1
and it's confusing to have two functionally equivalent bootblocks,
especially given that "ufs" has multiple meanings (it could be
a synonym for "ffs", or the group of ffs/lfs/ext2fs file systems).

* Rework pbr.S (the first sector of bootxx_*):
+ Ensure that BPB (bytes 11..89) and the partition table
(bytes 446..509) do not contain code.
+ Add support for booting from FAT partitions if BOOT_FROM_FAT
is defined. (Only set for bootxx_msdos).
+ Remove "dummy" partition 3; if people want to installboot(8)
these to the start of the disk they can use fdisk(8) to
create a real MBR partition table...
+ Compile with TERSE_ERROR so it fits because of the above.
Whilst this is less user friendly, I feel it's important
to have a valid partition table and BPB in the MBR/PBR.

* Renamed /usr/mdec/biosboot to /usr/mdec/boot, to be consistent
with other platforms.

* Enable SUPPORT_DOSFS in /usr/mdec/boot (stage2), so that
we can boot off FAT partitions.

* Crank version of /usr/mdec/boot to 3.1, and fix some of the other
entries in the version file.

installboot(8) (i386):
* Read the existing MBR of the filesystem and retain the BIOS
Parameter Block (BPB) in bytes 11..89 and the MBR partition
table in bytes 446..509. (Previously installboot(8) would
trash those two sections of the MBR.)

mbrlabel(8):
* Use sys/lib/libkern/xlat_mbr_fstype.c instead of homegrown code
to map the MBR partition type to the NetBSD disklabel type.


Test built "make release" for i386, and new bootblocks verified to work
(even off FAT!).

branches: 1.1.2;
bootxx: bootstrap code - installable by MI installboot.
Loads /boot using filesystem accesses (rather than a list of block numbers)