build: Mark bootblock files on x86 as IBB

* Add cbfsoption --ibb to mark files as IBB
* Will be used by "Legacy FIT TXT" boot

Change-Id: I83313f035e7fb7e1eb484b323862522e28cb73d4
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31497
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>

Makefile.inc

@@ -678,6 +678,18 @@ find-class = $(if $(filter $(1),$(basename $(1))),$(if $(CC_$(1)), $(1), $(call
 # the linker marked it NOBITS automatically because there are only zeroes in it.
 preserve-bss-flags := --set-section-flags .bss=load,alloc,data --set-section-flags .data=load,alloc,data
 
+# For Intel TXT files in the CBFS needs to be marked as 'Initial Boot Block'.
+# As CBFS attributes aren't cheap, only mark them if TXT is enabled.
+ifeq ($(CONFIG_INTEL_TXT),y)
+
+TXTIBB := --ibb
+
+else
+
+TXTIBB :=
+
+endif
+
 ifeq ($(CONFIG_COMPRESS_BOOTBLOCK),y)
 
 $(objcbfs)/bootblock.lz4: $(objcbfs)/bootblock.elf $(objutil)/cbfstool/cbfs-compression-tool
@@ -1031,6 +1043,7 @@ ifeq ($(CONFIG_ARCH_X86),y)
 		-f $(objcbfs)/bootblock.bin \
 		-n bootblock \
 		-t bootblock \
+		$(TXTIBB) \
 		-b -$(call file-size,$(objcbfs)/bootblock.bin) $(cbfs-autogen-attributes) \
 		$(TS_OPTIONS)
 else # ifeq ($(CONFIG_ARCH_X86),y)
@@ -1168,6 +1181,9 @@ endif    # CONFIG_NO_FIXED_XIP_ROM_SIZE
 
 endif   # CONFIG_NO_XIP_EARLY_STAGES
 endif   # CONFIG_ARCH_ROMSTAGE_X86_32 / CONFIG_ARCH_ROMSTAGE_X86_64
+ifeq ($(CONFIG_VBOOT_STARTS_IN_ROMSTAGE),y)
+$(CONFIG_CBFS_PREFIX)/romstage-options += $(TXTIBB)
+endif
 
 cbfs-files-$(CONFIG_HAVE_RAMSTAGE) += $(CONFIG_CBFS_PREFIX)/ramstage
 $(CONFIG_CBFS_PREFIX)/ramstage-file := $(RAMSTAGE)