[legal] Add a selection of FILE_LICENCE declarations

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

src/arch/i386/interface/pcbios/abft.c

@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <realmode.h>
 #include <gpxe/aoe.h>
 #include <gpxe/netdevice.h>

src/arch/i386/interface/pcbios/aoeboot.c

@@ -10,6 +10,8 @@
 #include <gpxe/abft.h>
 #include <int13.h>
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 static int aoeboot ( const char *root_path ) {
 	struct ata_device ata;
 	struct int13_drive drive;

src/arch/i386/interface/pcbios/bios_nap.c

@@ -1,6 +1,8 @@
 #include <gpxe/nap.h>
 #include <realmode.h>
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /**
  * Save power by halting the CPU until the next interrupt
  *

src/arch/i386/interface/pcbios/bios_smbios.c

@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <stdint.h>
 #include <string.h>
 #include <errno.h>

src/arch/i386/interface/pcbios/bios_timer.c

@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /** @file
  *
  * BIOS timer

src/arch/i386/interface/pcbios/biosint.c

@@ -7,6 +7,8 @@
  *
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /**
  * Hook INT vector
  *

src/arch/i386/interface/pcbios/ibft.c

@@ -25,6 +25,8 @@
  *
  */
 
+FILE_LICENCE ( BSD2 );
+
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>

src/arch/i386/interface/pcbios/int13.c

@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <stdint.h>
 #include <limits.h>
 #include <byteswap.h>

src/arch/i386/interface/pcbios/iscsiboot.c

@@ -13,6 +13,8 @@
 #include <int13.h>
 #include <usr/autoboot.h>
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 struct setting keep_san_setting __setting = {
 	.name = "keep-san",
 	.description = "Preserve SAN connection",

src/arch/i386/interface/pcbios/memtop_umalloc.c

@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /**
  * @file
  *

src/arch/i386/interface/pcbios/pcibios.c

@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <stdint.h>
 #include <gpxe/pci.h>
 #include <realmode.h>