[config] Make PXE stack a compile-time option

For extremely tight space requirements and specific applications, it is
sometimes desirable to create gPXE images that cannot provide the PXE API
functionality to client programs. Add a configuration header option,
PXE_STACK, that can be removed to remove this stack. Also add PXE_MENU
to control the PXE boot menu, which most uses of gPXE do not need.

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

src/config/config.c

@@ -91,6 +91,17 @@ REQUIRE_OBJECT ( efi_console );
 REQUIRE_OBJECT ( ipv4 );
 #endif
 
+/*
+ * Drag in all requested PXE support
+ *
+ */
+#ifdef PXE_MENU
+REQUIRE_OBJECT ( pxemenu );
+#endif
+#ifdef PXE_STACK
+REQUIRE_OBJECT ( pxe_call );
+#endif
+
 /*
  * Drag in all requested download protocols
  *

src/config/config_romprefix.c

@@ -0,0 +1,24 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2, or (at
+ * your option) any later version.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <config/general.h>
+
+/** @file
+ *
+ * ROM prefix configuration options
+ *
+ */
+
+/*
+ * Provide UNDI loader if PXE stack is requested
+ *
+ */
+#ifdef PXE_STACK
+REQUIRE_OBJECT ( undiloader );
+#endif

src/config/defaults/pcbios.h

@@ -25,6 +25,8 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define IMAGE_BZIMAGE		/* Linux bzImage image support */
 #define IMAGE_COMBOOT		/* SYSLINUX COMBOOT image support */
 
+#define PXE_STACK		/* PXE stack in gPXE - required for PXELINUX */
+#define PXE_MENU		/* PXE menu booting */
 #define	PXE_CMD			/* PXE commands */
 
 #define	SANBOOT_PROTO_ISCSI	/* iSCSI protocol */

src/config/general.h

@@ -41,6 +41,13 @@ FILE_LICENCE ( GPL2_OR_LATER );
 
 #define	NET_PROTO_IPV4		/* IPv4 protocol */
 
+/*
+ * PXE support
+ *
+ */
+//#undef	PXE_STACK		/* PXE stack in gPXE - you want this! */
+//#undef	PXE_MENU		/* PXE menu booting */
+
 /*
  * Download protocols
  *