New patch to review for coreboot: b0c4c33 sandybridge: Make build possible without descriptor.bin

[Nico Huber]

Nico Huber ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3524

-gerrit

commit b0c4c339566ddad4aabf8a893eaa2d82c1f043a3
Author: Nico Huber 
Date:   Wed Jun 19 16:16:05 2013 +0200

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, build without the real IFD. However,
    with such a build, one has to make sure he doesn't overwrite the real
    IFD on it's flash ROM (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 
---
 Makefile.inc                               |  8 ++++-
 src/southbridge/intel/bd82x6x/Kconfig      | 51 +++++++++++++++++++++++++++---
 src/southbridge/intel/bd82x6x/Makefile.inc | 24 ++++++++++++--
 3 files changed, 75 insertions(+), 8 deletions(-)

diff --git a/Makefile.inc b/Makefile.inc
index da350d1..69ad3a1 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -212,7 +212,8 @@ CFLAGS += -Werror
 endif
 CFLAGS += -fno-common -ffreestanding -fno-builtin -fomit-frame-pointer

-additional-dirs := $(objutil)/cbfstool $(objutil)/romcc $(objutil)/ifdtool $(objutil)/options
+additional-dirs := $(objutil)/cbfstool $(objutil)/romcc $(objutil)/ifdtool \
+		   $(objutil)/ifdfake $(objutil)/options

#######################################################################
 # generate build support files
@@ -275,6 +276,11 @@ $(IFDTOOL): $(top)/util/ifdtool/ifdtool.c
    @printf "    HOSTCC     $(subst $(obj)/,,$(@))\n"
    $(HOSTCC) $(HOSTCFLAGS) -o $@ $<

+IFDFAKE:=$(objutil)/ifdfake/ifdfake
+$(IFDFAKE): $(top)/util/ifdfake/ifdfake.c
+	@printf "    HOSTCC     $(subst $(obj)/,,$(@))\n"
+	$(HOSTCC) $(HOSTCFLAGS) -o $@ $<
+
 #######################################################################
 # needed objects that every mainboard uses
 # Creation of these is architecture and mainboard independent
diff --git a/src/southbridge/intel/bd82x6x/Kconfig b/src/southbridge/intel/bd82x6x/Kconfig
index 1d544de..0be875e 100644
--- a/src/southbridge/intel/bd82x6x/Kconfig
+++ b/src/southbridge/intel/bd82x6x/Kconfig
@@ -59,6 +59,52 @@ config HPET_MIN_TICKS
    hex
    default 0x80

+config HAVE_IFD_BIN
+	bool
+	default y
+
+config BUILD_WITH_FAKE_IFD
+	bool "Build with a fake IFD"
+	default y if !HAVE_IFD_BIN
+	help
+	  If you don't have an Intel Firmware Descriptor (ifd.bin) for your
+	  board, you can select this option and coreboot will build without it.
+	  Though, the resulting coreboot.rom will not contain all parts required
+	  to get coreboot running on your board. You can however write only the
+	  BIOS section to your board's flash ROM and keep the other sections
+	  untouched. Unfortunately the current version of flashrom doesn't
+	  support this yet. But there is a patch pending [1].
+
+	  WARNING: Never write a complete coreboot.rom to your flash ROM if it
+		   was built with a fake IFD. It just won't work.
+
+          [1] http://www.flashrom.org/pipermail/flashrom/2013-June/011083.html
+
+config IFD_BIOS_SECTION
+	depends on BUILD_WITH_FAKE_IFD
+	string
+	default ""
+
+config IFD_ME_SECTION
+	depends on BUILD_WITH_FAKE_IFD
+	string
+	default ""
+
+config IFD_GBE_SECTION
+	depends on BUILD_WITH_FAKE_IFD
+	string
+	default ""
+
+config IFD_PLATFORM_SECTION
+	depends on BUILD_WITH_FAKE_IFD
+	string
+	default ""
+
+config IFD_BIN_PATH
+	string "Path to intel firmware descriptor"
+	depends on !BUILD_WITH_FAKE_IFD
+	default "3rdparty/mainboard/$(MAINBOARDDIR)/descriptor.bin"
+
 config HAVE_GBE_BIN
    bool "Add gigabit ethernet firmware"
    default n
@@ -88,12 +134,9 @@ config ME_BIN_PATH
    depends on HAVE_ME_BIN
    default "3rdparty/mainboard/$(MAINBOARDDIR)/me.bin"

-config IFD_BIN_PATH
-	string "Path to intel firmware descriptor"
-	default "3rdparty/mainboard/$(MAINBOARDDIR)/descriptor.bin"
-
 config LOCK_MANAGEMENT_ENGINE
    bool "Lock Management Engine section"
+	depends on !BUILD_WITH_FAKE_IFD
    default n
    help
      The Intel Management Engine supports preventing write accesses
diff --git a/src/southbridge/intel/bd82x6x/Makefile.inc b/src/southbridge/intel/bd82x6x/Makefile.inc
index 73948d2..0c45c64 100644
--- a/src/southbridge/intel/bd82x6x/Makefile.inc
+++ b/src/southbridge/intel/bd82x6x/Makefile.inc
@@ -52,9 +52,27 @@ smm-$(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
 ifeq ($(CONFIG_HAVE_ME_BIN),y)
    printf "    IFDTOOL    me.bin -> coreboot.pre\n"
@@ -74,7 +92,7 @@ ifeq ($(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