gcc 4.4 defaults to using .cfi assembler directives for debugging
information, which causes unneeded .eh_frame sections to be generated.
These sections are already stripped out by our linker script, so don't
affect the final build, but do distort the output of "size" when run
on individual .o files; the .eh_frame size is included within the size
reported for .text.  This makes it difficult to accurately judge the
effects of source code changes upon object code size.

Fix by adding -fno-dwarf2-cfi-asm to CFLAGS if we detect that this
option is supported by the gcc that we are compiling with.

Tested-by: Daniel Verkamp <daniel@drv.nu>

It is now possible to run e.g.

  make bin/rtl8139.dsk.licence

in order to see a licensing assessment for any given gPXE build.  The
assessment will either produce a single overall licence for the build
(based on combining all the licences used within the source files for
that build), or will exit with an error stating why a licence
assessment is not possible (for example, if there are files involved
that do not yet contain an explicit FILE_LICENCE() declaration).

You can now type e.g.

  make bin/rtl8139.rom.sizes

in order to see the (uncompressed) sizes of all of the object files
linked in to bin/rtl8139.rom.  This should make it easier to identify
relevant code bloat.

Now that there are no remaining multiple-object source files, kill off
the mechanism in order to simplify the Makefile.

You can now type e.g.

  make bin/rtl8139.rom.deps

to see a list of the source files included in the build of
bin/rtl8139.rom.  This is intended to assist with copyright vetting.

Other new debugging targets include

  make bin/rtl8139.rom.objs

to see a list of object files linked in to bin/rtl8139.rom, and

  make bin/rtl8139.rom.nodeps

to see a list of the source files that are *not* required for the
build of bin/rtl8139.rom.

QEMU will silently round down a disk or ROM image file to the nearest
512 bytes.  Fix by always padding .rom, .dsk and .hd images to the
nearest 512-byte boundary.

Originally-fixed-by: Stefan Hajnoczi <stefanha@gmail.com>

The "seq" command is GNU-specific; a BSD userland will not have it.
Use POSIX-conforming "awk" instead.

Reported-by: Joshua Oreman <oremanj@rwcr.net>
Suggested-by: Stefan Hajnoczi <stefanha@gmail.com>

On Mac OS X, it is necessary to build binutils manually; the system
does not provide bfd.h or the libbfd or libiberty libraries.

Originally-fixed-by: Joshua Oreman <oremanj@rwcr.net>

Some builds of the GNU assembler will treat a '/' character as a
comment delimiter.  Adding "--divide" will cause it to be treated as a
division operator, as we expect.  The "--divide" option is not
available in all gas versions, so apply it only conditionally.

Suggested-by: Joshua Oreman <oremanj@rwcr.net>

bin/embedded.o has a build dependency on bin/.embedded.list, which
gets generated automatically by the Makefile.  However, if the
EMBEDDED_IMAGE list is empty, bin/.embedded.list will never be
created, and so bin/embedded.o will be rebuilt every time due to a
missing dependency.

Fix by forcing bin/.embedded.list to be created even if the list is
empty.

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>.

Add --fatal-warnings to ASFLAGS; this is the equivalent of -Werror in
CFLAGS (which we have used since July 2007).

elf2efi converts a suitable ELF executable (containing relocation
information, and with appropriate virtual addresses) into an EFI
executable.  It is less tightly coupled with the gPXE build process
and, in particular, does not require the use of a hand-crafted PE
image header in efiprefix.S.

elf2efi correctly handles .bss sections, which significantly reduces
the size of the gPXE EFI executable.

On some systems, libbfd is supplied only as a static library; linking
will fail unless -liberty is also specified.

FreeBSD requires the object format to be specified as elf_i386_fbsd,
rather than elf_i386.

Based on a patch from Eygene Ryabinkin <rea-fbsd@codelabs.ru>

We have EFI APIs for CPU I/O, PCI I/O, timers, console I/O, user
access and user memory allocation.

EFI executables are created using the vanilla GNU toolchain, with the
EXE header handcrafted in assembly and relocations generated by a
custom efilink utility.

-Wformat-nonliteral is not enabled by -Wall and needs to be explicitly
 specified.

Modified the few files that use nonliteral format strings to work with
this new setting in place.

Inspired by a patch from Carl Karsten <carl@personnelware.com> and an
identical patch from Rorschach <r0rschach@lavabit.com>.

Allow for the build CPU architecture and platform to be specified as part
of the make command goals.  For example:

  make bin/rtl8139.rom      # Standard i386 PC-BIOS build

  make bin-efi/rtl8139.efi  # i386 EFI build

The generic syntax is "bin[-[arch-]platform]", with the default
architecture being "i386" (regardless of the host architecture) and the
default platform being "pcbios".

Non-path targets such as "srcs" can be specified using e.g.

  make bin-efi srcs

Note that this changeset is merely Makefile restructuring to allow the
build architecture and platform to be determined by the make command
goals, and to export these to compiled code via the ARCH and PLATFORM
defines.  It doesn't actually introduce any new build platforms.

Some older versions of gcc don't complain about unknown compiler flags
unless you ask them to actually compile; asking them to merely
preprocess won't trigger the error.

Fix the -fno-stack-protector test by making it attempt to compile an
empty file, rather than preprocess an empty file.

?= in a Makefile means that that variable can be overridden by the
environment.  This is confusing to users, especially with a generic
name like "ARCH".

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Use "-include" rather than "include" for the generated Makefile
fragments, in order to suppress the long list of warnings that
otherwise appears at the start of a clean build.

Contributed by Edward Waugh <ewaugh@netxen.com>

Remove src/Config as it has no more users, and conflicts with
src/config on case-deficient filesystems.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

This "+" should be removed when a tarball release is done.

Revert "Use .SECONDARY instead of .PRECIOUS for bin/%.tmp targets."

This reverts commit de29e5a39c.

.SECONDARY doesn't seem to work properly with the target patterns of
implicit rules.  In particular, a "make clean ; make bin/rtl8139.dsk"
will correctly leave the bin/rtl8139.dsk.tmp file present when .PRECIOUS
is used, but not when .SECONDARY is used.

This is slightly irritating since we don't want the
"do-not-delete-if-interrupted" semantics of .PRECIOUS, but it seems to be
the best compromise.

During development it is often handy to change the config.h options from
their defaults, for example to enable debugging features.

To prevent accidental commits of debugging config.h changes, mdc
suggested having a config-local.h that is excluded from source control.
This file acts as a temporary config.h and can override any of the
defaults.

This commit is an attempt to implement the config-local.h feature.

The config.h file now has the following as its last line:
/* @TRYSOURCE config-local.h */

The @TRYSOURCE directive causes config-local.h to be included at that
point in the file.  If config-local.h does not exist, no error will be
printed and parsing will continue as normal.  Therefore, mkconfig.pl is
"trying" to "source" config-local.h.

ROMs will refuse to build unless pci_vendor_id and pci_device_id are
defined.  We probably ought to fix up the Makefile (and the ROM prefix) so
that they're required only for PCI ROMs, but this will do for now.

Using -MM strips out any system header files from the dependency list,
which means that we could safely use an external stdarg.h if we wanted
to.

Deleting bin/deps after "make veryclean" keeps deps from being
regenerated in the tarball.

Added 'install' and 'configure' targets for those who are used
to other build setups.

src/bin/%.tmp files can be useful for debugging, so let's keep them.

for "echo -e" on the host system.

suitable "echo -e" substitute.

implement the -e option.

(Thanks to Jim McQuillan for this suggestion.)