sandybridge: Make build possible without descriptor.bin

On newer Intel systems, the flash ROM is shared between the host
processor (BIOS), it's Management Engine (ME) and an integrated ethernet
controller (GbE). The layout of the flash ROM (and other information) is
kept in the so called Intel Firmware Descriptor (IFD). If we only want
to build coreboot to update the BIOS section, all we need is the flash
layout.

This patch adds the option to specify the flash layout in the
mainboard's Kconfig, and thus, to build without the real IFD. However,
with such a build, one has to make sure that the IFD section on the
flash ROM won't be written over (nor any other section that hasn't been
included by coreboot). A patch to write selected sections of a flash ROM
with IFD has been sent to the flashrom mailing list [1].

[1] http://www.flashrom.org/pipermail/flashrom/2013-June/011083.html

Change-Id: Ia23e439a00a197fb54852263f8e206f16c3e8851
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/3524
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 21 insertions, 3 deletions

diff --git a/src/southbridge/intel/bd82x6x/Makefile.inc b/src/southbridge/intel/bd82x6x/Makefile.inc
index e277450a45..257bff5394 100644
--- a/src/southbridge/intel/bd82x6x/Makefile.inc
+++ b/src/southbridge/intel/bd82x6x/Makefile.inc
@@ -52,9 +52,27 @@ smm-$(CONFIG_USBDEBUG) += usb_debug.c
 romstage-y += reset.c
 romstage-y += early_spi.c
 
-bd82x6x_add_me: $(obj)/coreboot.pre $(IFDTOOL)
+ifeq ($(CONFIG_BUILD_WITH_FAKE_IFD),y)
+IFD_BIN_PATH := $(objgenerated)/ifdfake.bin
+IFD_SECTIONS := $(addprefix -b ,$(CONFIG_IFD_BIOS_SECTION:"%"=%)) \
+		$(addprefix -m ,$(CONFIG_IFD_ME_SECTION:"%"=%)) \
+		$(addprefix -g ,$(CONFIG_IFD_GBE_SECTION:"%"=%)) \
+		$(addprefix -p ,$(CONFIG_IFD_PLATFORM_SECTION:"%"=%))
+else
+IFD_BIN_PATH := $(CONFIG_IFD_BIN_PATH)
+endif
+
+bd82x6x_add_me: $(obj)/coreboot.pre $(IFDTOOL) $(IFDFAKE)
+ifeq ($(CONFIG_BUILD_WITH_FAKE_IFD),y)
+	printf "\n** WARNING **\n"
+	printf "Coreboot will be built with a fake Intel Firmware Descriptor (IFD).\n"
+	printf "Never write a complete coreboot.rom with a fake IFD to your board's\n"
+	printf "flash ROM! Make sure that you only write valid flash regions.\n\n"
+	printf "    IFDFAKE    Building a fake Intel Firmware Descriptor\n"
+	$(IFDFAKE) $(IFD_SECTIONS) $(IFD_BIN_PATH)
+endif
 	printf "    DD         Adding Intel Firmware Descriptor\n"
-	dd if=$(CONFIG_IFD_BIN_PATH) \
+	dd if=$(IFD_BIN_PATH) \
 		of=$(obj)/coreboot.pre conv=notrunc >/dev/null 2>&1
 	printf "    IFDTOOL    me.bin -> coreboot.pre\n"
 	$(objutil)/ifdtool/ifdtool \
@@ -72,7 +90,7 @@ ifeq ($(CONFIG_LOCK_MANAGEMENT_ENGINE),y)
 	printf "    IFDTOOL    Locking Management Engine\n"
 	$(objutil)/ifdtool/ifdtool -l $(obj)/coreboot.pre
 	mv $(obj)/coreboot.pre.new $(obj)/coreboot.pre
-else
+else ifneq ($(CONFIG_BUILD_WITH_FAKE_IFD),y)
 	printf "    IFDTOOL    Unlocking Management Engine\n"
 	$(objutil)/ifdtool/ifdtool -u $(obj)/coreboot.pre
 	mv $(obj)/coreboot.pre.new $(obj)/coreboot.pre