It is often the case that some module of gPXE is only relevant if the
subsystem it depends on is already being included. For instance,
commands to manage wireless interfaces are quite useless if no
compiled-in driver has pulled in the wireless networking stack. There
may be a user-modifiable configuration options for these dependent
modules, but even if enabled, they should not be included when they
would be useless.

Solve this by allowing the creation of config_subsystem.c, for
configuration directives like those in the global config.c that should
only be considered when subsystem.c is included in the final gPXE
build.

For consistency, move core/config.c to the config/ directory, where
the other config_subsystem.c files will eventually reside.

Signed-off-by: Marty Connor <mdc@etherboot.org>

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

This is required for all modern 802.11 devices, and allows drivers
to be written for them with minimally more effort than is required
for a wired NIC.

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

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).

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>

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>

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.

EFI provides a copy of the SMBIOS table accessible via the EFI system
table, which we should use instead of manually scanning through the
F000:0000 segment.

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.

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.

The arch/i386/Config file has long been marked as deprecated.  Move all
the pertinent bits to arch/i386/Makefile instead and remove
arch/i386/Config.

[] are shell metacharacters, and they can get confused by files in the
local directory.

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

?= 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>

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>

stappers and xl0 pointed out that gnu make sets some variables, so ?=
is ineffective in some cases where we use it.. Cross-compilation
requires that some variables can be overridden in the
src/$(ARCH)/Config file, so include that file _after_ utility program
variables are set.

for "echo -e" on the host system.

suitable "echo -e" substitute.

implement the -e option.

(Thanks to Jim McQuillan for this suggestion.)

inside gPXE.

Experimentation reveals that gcc ignores -mrtd for the implicit
arithmetic functions (e.g. __udivdi3), but not for the implicit
memcpy() and memset() functions.  Mark the implicit arithmetic
functions with __attribute__((cdecl)) to compensate for this.

(Note: we cannot mark with with __cdecl, because we define __cdecl to
incorporate regparm(0) as well.)

Even though it is only currently used for rom-o-matic.net code,
it is good to make sure it gets built, and that the parsing code
is working.