Some prefixes (e.g. .lkrn) allow a command line to be passed in to
iPXE.  At present, this command line is ignored.

If a command line is provided, treat it as an embedded script (without
an explicit "#!ipxe" magic marker).  This allows for patterns of
invocation such as

  title  iPXE
  kernel /boot/ipxe.lkrn dhcp && \
         sanboot iscsi:10.0.4.1::::iqn.2010-04.org.ipxe.dolphin:storage

Here GRUB is instructed to load ipxe.lkrn with an embedded script
equivalent to

  #!ipxe
  dhcp
  sanboot iscsi:10.0.4.1::::iqn.2010-04.org.ipxe.dolphin:storage

This can be used to effectively vary the embedded script without
having to rebuild ipxe.lkrn.

Originally-implemented-by: Dave Hansen <dave@sr71.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

Refactor the {load,exec} image operations as {probe,exec}.  This makes
the probe mechanism cleaner, eliminates some forward declarations,
avoids holding magic state in image->priv, eliminates the possibility
of screwing up between the "load" and "exec" stages, and makes the
documentation simpler since the concept of "loading" (as distinct from
"executing") no longer needs to be explained.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Since more reference-counted structures than embedded images might
want to mark themselves unfreeable, expose a dummy ref_no_free().

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Standardise on using ref_init() to initialise an embedded reference
count, to match the coding style used by other embedded objects.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain.  Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.

Also update README, LOG and COPYRIGHTS to remove obsolete information.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Add FILE_LICENCE declarations to almost all files that make up the
various standard builds of gPXE.

Having a default script containing

  #!gpxe
  autoboot

can cause problems when entering commands to load and start a kernel
manually; the default script image will still be present when the
kernel is started and so will be treated as an initrd.  It is possible
to work around this by typing "imgfree" before any other commands, but
this is counter-intuitive.

Fix by allowing the embedded image list to be empty (in which case we
just call autoboot()), and making this the default.

Reported by alkisg@gmail.com.

This patch extends the embedded image feature to allow multiple
embedded images instead of just one.

gPXE now always boots the first embedded image on startup instead of
doing the hardcoded DHCP boot (aka autoboot).

Based heavily upon a patch by Stefan Hajnoczi <stefanha@gmail.com>.

OpenBSD throws compiler warnings that we can't reproduce on Linux, for
some reason.

Original patch from Dewey Hylton <dewey@hyltown.com>.

When the embedded image is a script, the unregister_image() performed by
image/script.c corrupts memory, since image/embedded.c omitted the call
to register_image().

This is the first bug fixed using Stefan Hajnoczi's gdb stub for gPXE.