armv7: Prevent CBFS data overlapping bootblock.

For arm/snow, current bootblock is larger than previously assigned CBFS offset
and will fail to boot. To prevent this happening again in future, cbfstool now
checks if CBFS will overlap bootblock.

A sample error message:
	E: Bootblock (0x0+0x71d4) overlap CBFS data (0x5000)
	E: Failed to create build/coreboot.pre1.tmp.

arm/snow offset is also enlarged and moved to Kconfig variable.

Change-Id: I4556aef27ff716556040312ae8ccb78078abc82d
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: http://review.coreboot.org/2295
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>

src/arch/armv7/Makefile.inc

@@ -45,10 +45,12 @@ prebuild-files = \
 	$(if $(call extract_nth,4,$(file)),-b $(call extract_nth,4,$(file))) &&)
 prebuilt-files = $(foreach file,$(cbfs-files), $(call extract_nth,1,$(file)))
 
-# TODO Change -b, -H, -o to Kconfig variables.
+# TODO Change -b to Kconfig variable.
 $(obj)/coreboot.pre1: $(objcbfs)/bootblock.bin $$(prebuilt-files) $(CBFSTOOL)
 	$(CBFSTOOL) $@.tmp create -m armv7 -s $(CONFIG_COREBOOT_ROMSIZE_KB)K \
-		-B $(objcbfs)/bootblock.bin -a 64 -b 0x0000 -H 0x2040 -o 0x5000
+		-B $(objcbfs)/bootblock.bin -a 64 -b 0x0000 \
+		-H $(CONFIG_CBFS_HEADER_ROM_OFFSET) \
+		-o $(CONFIG_CBFS_ROM_OFFSET)
 	$(prebuild-files) true
 	mv $@.tmp $@
 else

src/cpu/samsung/exynos5250/Kconfig

@@ -48,6 +48,11 @@ config ROMSTAGE_SIZE
 	hex
 	default 0x10000
 
+config CBFS_ROM_OFFSET
+	# Calculated by BL1 + max bootblock size.
+	hex "offset of CBFS data in ROM"
+	default 0x0A000
+
 # TODO Change this to some better address not overlapping bootblock when
 # cbfstool supports creating header in arbitrary location.
 config CBFS_HEADER_ROM_OFFSET

util/cbfstool/cbfs_image.c

@@ -174,6 +174,12 @@ int cbfs_image_create(struct cbfs_image *image,
 		      bootblock_offset, bootblock->size, size);
 		return -1;
 	}
+	if (entries_offset > bootblock_offset &&
+	    entries_offset < bootblock->size) {
+		ERROR("Bootblock (0x%x+0x%zx) overlap CBFS data (0x%x)\n",
+		      bootblock_offset, bootblock->size, entries_offset);
+		return -1;
+	}
 	memcpy(image->buffer.data + bootblock_offset, bootblock->data,
 	       bootblock->size);