arm: recognize instruction fetch pagefault

	. an instruction fetch pagefault generates a prefetch
	  abort exception, this should also be a source of
	  a pagefault event
	. the saved_lr argument to the C exception handler was
	  sometimes an address, sometimes a pointer to that address;
	  the kernel sometimes dereferences it, so it should always be
	  an in-kernel address, never a userspace address. fix in mpx.S
	  makes it always a pointer.
	. move dumping of all processes over serial out of
	  the arch-specific arch_system.c
mkfs: only complain about failing stat with -d

mkfs -d is a feature that needs a stat() of the mkfs binary, which
often fails (as mkfs is often not invoked with a full path or from
the same directory). it makes setup look a bit messy as the error
is always printed while installing the system, for each created FS,
even though the situation is harmless. This change only complains
when the stat is actually needed (-d).

Change-Id: I54ac01505aa97c1cbe40456c04a35aed5a7ee953
Fix symlink issue when generating an ARM image

A few symlinks were pointing to a nonexistent file named '(null)'
instead of their intended target. This was only seen when using the
arm_sdimage.sh script.

There is two ways of specifying links and directories. the first one
using an entry in one of the mtree files, and the second one in
/etc/Makefile.

Those entries where doubled, and one of them would specify some rights,
while the other had the target.

By removing those entries, I make sure there is only one definition of
these symlinks, which solves the problem I was seeing on an ARM image.

These symlinks are still present on a generated system, as they are
required.

Change-Id: I9ced8860f72d7c4d686a09720de4d8257d6e04fa
usr.sbin/mkfs: Allow -b SIZE with proto file

Previously, if a proto file was given, the -b argument would be ignored.

Also added:
 - if the number of inodes is not given, then an estimation is used.
 - sanity checks where moved from one special case to the general case.

Change-Id: I2abfa52bf34206c9087c64b5bfc26af866eb47cb
releasetools/arm_sdimage.sh: Improvements

 - Added the possibility to define the number of parallel jobs from the
   command line with (example, default is 1):
   $ JOBS=8 ./releasetools/arm_sdimage.sh

 - Generate filesystem filling the reserved partition area, instead of
   being smaller.

 - Added a possibility to specify additional parameter to the build.sh
   script from the command line with (example):
   $ BUILDVARS='-N0 -V MYVAR=yes' ./releasetools/arm_sdimage.sh

Change-Id: I5c34268ebf7d45a8d3408b45b1dc5051d775826c
arm:build generate uEnv.txt

Generate uEnv.txt to allow to generate an uEnv containing commands
to boot over the network.

Change-Id: I8bcd831ee474d837411568bf1c1e2c2d96ec931b
arm:add DDM37XX cflag

We are planning on using the NetBSD config system to perform build
system configuration when targeting different hardware variants.
This functionality however is not integrated yet and we currently
rely on using ifdef's in the code. This commit add the DDM37XX flag.

Change-Id: Ia25dfa520c7df4b648f4d1a583808de774acff63
arm:kernel simplify the in kernel serial.

Simplify the in kernel serial header to a minimum. The driver doing
the real handling is the tty driver.

Change-Id: I5d487d71a3d22906313aa8af5e9d84b0751a6868
arm:remove hardcoded base address for the in kernel serial.

Removed hardcoded base address for in kernel serial. This will ease
porting to different boards and allow us to remap i/o at later stage.

Change-Id: I4a4e00ed2aa2f94dfe928dc43a6816d3b94576b7
arm:keep kernel and modules in the first 256MB of memory.

Keep kernel and modules in the first 256MB of memory in preparation
for the beaglebone. That target only has 256 MB of memory.

Change-Id: I3d92247b5d4e5d3aab7388fe01c2f5713d6a4593
arm:add AM335X serial

Change-Id: I728622ddd4f59529d15e8ac2499c41fa815eee3b
arm:interupt handling remove hardcoded base address.

Remove hardcoded base address for the omap interrupt handler and add
interrupt names for AM335X in omap_intr.h.

Change-Id: Ie606d8612f55990d55f9db655583052f53950e8e
arm:configure tick per ms to reflect the free running clock.

Change-Id: Ifc02658d6ae48dd01a868bfaa3d60f77bc6cc800
arm:omap timers remove hardcoded base address.

Omap timers remove hardcoded base address and add some initial
support for the beaglebone's timers. Frclock_util will need
refactoring to remain independent of the ARM flavour.

Change-Id: I2b5d04e930364262c81b5686de634c0a51796b23
arm:build also generate cmdline.txt

Also generate cmdline.txt as we need to use a different serial
for the AM335X boards.

Change-Id: I18c1b5911b5d7238d4a765e0aa01613908d9f2e6
arm:adapt tty driver for AM335X.

Change-Id: Ic861d68d0576c2abcdcb265a450c013ea2b28499
arm:mmc only compile mmchs when targeting arm.

Change-Id: Ie8d0b6461b58c2a7becda98401dece81be607a01
arm:adapt MMC driver to also work on the AM335X platform.

Change-Id: I30e69b7bfd377d1dd2b0b458dd00ee411b060285
arm:also use 1MB sections for mapping AM335X device memory.

Change-Id: Idc0b285fcbabe8ec4c0be9a600b6a720c0bd3ffc
arm:build add flags for AM335X

Change-Id: I1fd25d5ada52972fd2f6ec5057ff273544c65390