IPv4 may not always be dragged into the link, so add a specific
configuration option for it.

Convert DHCP option applicators in dns.c and iscsi.c to settings
applicators.

Kill off DHCP option applicators.

Add the notion of the settings hierarchy, complete with
register/unregister routines.

Rename set->store and get->fetch to avoid naming conflicts with get/put
as used in reference counting.

Add the concept of an abstract configuration setting, comprising a (DHCP)
tag value and an associated byte sequence.

Add the concept of a settings namespace.

Add functions for extracting string, IPv4 address, and signed and
unsigned integer values from configuration settings (analogous to
dhcp_snprintf(), dhcp_ipv4_option(), etc.).

Update functions for parsing and formatting named/typed options to work
with new settings API.

Update NVO commands and config UI to use new settings API.

Allow setting names such as "ip:hex".

Timers are sometimes required before the call to initialise(), so we
cannot rely on initialise() to set up the timers before use.

Also fix a potential integer overflow issue in generic_currticks_udelay()

Add missing comments to timer code.

Lock system if no suitable timer source is found.

Fix initialisation order so that timers are initialised before code that
needs to use them.

Allow encapsulated options to be specified as e.g. "175.3".  As a
side-effect, change the separator character for the type field from "." to
":"; for example, the IP address pseudo-option is now "175.3:ipv4".

Add parse and display routines for 16-bit and 32-bit integer configuration
settings.

Add parse and display routines for hex-string configuration settings.

Assume hex-string as a configuration setting type if no type is explicitly
specified.

strtoul() was accepting the characters immediately above ASCII 0..9 as
valid hex digits, due to a missing comparison.

show_setting() and related functions now return an "actual length" in the
style of snprintf().  This is to allow consumers to allocate buffers large
enough to hold the formatted setting.

Replace a printf with a DBG in timer_rtdsc.c
Replace a printf in timer.c with assert
Return proper error codes from timer drivers

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>

	Timer subsystem initialization code in core/timer.c

	Split the BIOS and RTDSC timer drivers from i386_timer.c

	Split arch/i386/firmware/pcbios/bios.c into the RTSDC
	timer driver and arch/i386/core/nap.c

	Split the headers properly:
		include/unistd.h - delay functions to be used by the
					gPXE core and drivers.

		include/gpxe/timer.h - the fimer subsystem interface
					to be used by the timer drivers
					and currticks() to be used by
					the code gPXE subsystems.

		include/latch.h	- removed
		include/timer.h - scheduled for removal. Some driver
					are using currticks, which is
					only for core subsystems.

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>

separate xfer method.

Add missing .alloc_iob entries to several xfer_interface_operations
structures.

implemented smbios_get_uuid().

No Microsoft intellectual property was harmed in the production of
this code.

executing any image, not just a script.  (This will enable pxelinux to
use relative URIs, should it wish to.)

wasn't meant for my local "master" branch ;)
This reverts commit 373022108b.

Some shuffling around of the image management code; this needs tidying up.