diff --git a/src/arch/arm/armv7/bootblock.S b/src/arch/arm/armv7/bootblock.S
index f18a3556ba..bac49fea02 100644
--- a/src/arch/arm/armv7/bootblock.S
+++ b/src/arch/arm/armv7/bootblock.S
@@ -31,17 +31,7 @@
 
 .section ".start", "a", %progbits
 .globl _start
-_start: b	reset
-	.balignl 16,0xdeadbeef
-
-_cbfs_master_header:
-	/* The CBFS master header is inserted by cbfstool at the first
-	 * aligned offset after the above anchor string is found.
-	 * Hence, we leave some space for it.
-	 */
-	.skip 128			@ Assumes 64-byte alignment
-
-reset:
+_start:
 	/*
 	 * Set the cpu to System mode with IRQ and FIQ disabled. Prefetch/Data
 	 * aborts may happen early and crash before the abort handlers are
diff --git a/src/soc/samsung/exynos5250/Kconfig b/src/soc/samsung/exynos5250/Kconfig
index f61da9354c..00d9e81122 100644
--- a/src/soc/samsung/exynos5250/Kconfig
+++ b/src/soc/samsung/exynos5250/Kconfig
@@ -17,21 +17,22 @@ if CPU_SAMSUNG_EXYNOS5250
 #
 # 0x0000: vendor-provided BL1 (8k).
 # 0x2000: bootblock
-#  0x2010-0x2090: reserved for CBFS master header.
-# 0xA000: Free for CBFS data.
+# 0x9FFC-0xA000: BL2 checksum
+# 0xA000-0xA080: reserved for CBFS master header.
+# 0xA080: Free for CBFS data.
 
 config BOOTBLOCK_ROM_OFFSET
 	hex
-	default 0x2000
+	default 0
 
 config CBFS_HEADER_ROM_OFFSET
 	hex "offset of master CBFS header in ROM"
-	default 0x2010
+	default 0x9F80
 
 config CBFS_ROM_OFFSET
 	# Calculated by BOOTBLOCK_ROM_OFFSET + max bootblock size.
 	hex "offset of CBFS data in ROM"
-	default 0x0A000
+	default 0x0A080
 
 config SYS_SDRAM_BASE
 	hex
diff --git a/src/soc/samsung/exynos5250/Makefile.inc b/src/soc/samsung/exynos5250/Makefile.inc
index 22bfa66b44..01a075c8e9 100644
--- a/src/soc/samsung/exynos5250/Makefile.inc
+++ b/src/soc/samsung/exynos5250/Makefile.inc
@@ -50,13 +50,10 @@ ramstage-y += fb.c
 ramstage-y += usb.c
 ramstage-y += cbmem.c
 
-# Run an intermediate step when producing coreboot.rom
-# that adds additional components to the final firmware
-# image outside of CBFS
-.PHONY: exynos5250_add_bl1
-$(obj)/coreboot.rom: exynos5250_add_bl1
-exynos5250_add_bl1: $(obj)/coreboot.pre
-	printf "    DD         Adding Samsung Exynos5250 BL1\n"
-	# TODO(hungte) Change this 'cpu' to soc when build scripts are changed.
-	dd if=3rdparty/cpu/samsung/exynos5250/bl1.bin \
-		of=$(obj)/coreboot.pre conv=notrunc >/dev/null 2>&1
+$(objcbfs)/bootblock.raw.elf: $(objcbfs)/bootblock.elf
+	cp $< $@
+
+$(objcbfs)/bootblock.bin: $(objcbfs)/bootblock.raw.bin
+	@printf "    BL1, CKSUM $(subst $(obj)/,,$(@))\n"
+	util/exynos/fixed_cksum.py $< $<.cksum 32768
+	cat 3rdparty/cpu/samsung/exynos5250/bl1.bin $<.cksum > $@
diff --git a/src/soc/samsung/exynos5420/Kconfig b/src/soc/samsung/exynos5420/Kconfig
index 19e19f9871..b74849d99f 100644
--- a/src/soc/samsung/exynos5420/Kconfig
+++ b/src/soc/samsung/exynos5420/Kconfig
@@ -19,16 +19,16 @@ if CPU_SAMSUNG_EXYNOS5420
 # 0x0000: vendor-provided BL1 (8k).
 # 0x2000: variable length bootblock checksum header
 # 0x2010: bootblock
-#  0x2020-0x20A0: reserved for CBFS master header.
+#  0x9F80-0xA000: reserved for CBFS master header.
 # 0xA000: Free for CBFS data.
 
 config BOOTBLOCK_ROM_OFFSET
 	hex
-	default 0x2010
+	default 0
 
 config CBFS_HEADER_ROM_OFFSET
 	hex "offset of master CBFS header in ROM"
-	default 0x2020
+	default 0x9F80
 
 config CBFS_ROM_OFFSET
 	# Calculated by BOOTBLOCK_ROM_OFFSET + max bootblock size.
diff --git a/src/soc/samsung/exynos5420/Makefile.inc b/src/soc/samsung/exynos5420/Makefile.inc
index 55868eb008..caacc21b54 100644
--- a/src/soc/samsung/exynos5420/Makefile.inc
+++ b/src/soc/samsung/exynos5420/Makefile.inc
@@ -56,13 +56,10 @@ rmodules-y += mct.c
 VBOOT_STUB_DEPS += $(obj)/soc/samsung/exynos5420/monotonic_timer.rmodules.o
 VBOOT_STUB_DEPS += $(obj)/soc/samsung/exynos5420/mct.rmodules.o
 
-# Run an intermediate step when producing coreboot.rom
-# that adds additional components to the final firmware
-# image outside of CBFS
-.PHONY: exynos5420_add_bl1
-$(obj)/coreboot.rom: exynos5420_add_bl1
-exynos5420_add_bl1: $(obj)/coreboot.pre
-	printf "    DD         Adding Samsung Exynos5420 BL1\n"
-	# TODO(hungte) Change this 'cpu' to soc when build scripts are changed.
-	dd if=3rdparty/cpu/samsung/exynos5420/bl1.bin \
-		of=$(obj)/coreboot.pre conv=notrunc >/dev/null 2>&1
+$(objcbfs)/bootblock.raw.elf: $(objcbfs)/bootblock.elf
+	cp $< $@
+
+$(objcbfs)/bootblock.bin: $(objcbfs)/bootblock.raw.bin
+	@printf "    BL1, CKSUM $(subst $(obj)/,,$(@))\n"
+	util/exynos/variable_cksum.py $< $<.cksum
+	cat 3rdparty/cpu/samsung/exynos5420/bl1.bin $<.cksum > $@
diff --git a/util/exynos/fixed_cksum.py b/util/exynos/fixed_cksum.py
new file mode 100755
index 0000000000..79a206a5c1
--- /dev/null
+++ b/util/exynos/fixed_cksum.py
@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+This utility computes and fills Exynos ROM checksum (for BL1 or BL2).
+(Algorithm from U-Boot: tools/mkexynosspl.c)
+
+Input: IN OUT DATA_SIZE
+
+Output:
+
+  IN padded out to DATA_SIZE, checksum at the end, written to OUT.
+"""
+
+import struct
+import sys
+
+def main(argv):
+  if len(argv) != 4:
+    exit('usage: %s IN OUT DATA_SIZE' % argv[0])
+
+  in_name, out_name = argv[1:3]
+  size = int(argv[3], 0)
+  checksum_format = "<I"
+  with open(in_name, "rb") as in_file, open(out_name, "wb") as out_file:
+    data = in_file.read()
+    checksum_size = struct.calcsize(checksum_format)
+    data_size = size - checksum_size
+    assert len(data) <= data_size
+    checksum = struct.pack(checksum_format, sum(map(ord, data)))
+    out_file.write(data + bytearray(data_size - len(data)) + checksum)
+
+
+if __name__ == '__main__':
+  main(sys.argv)
diff --git a/util/exynos/variable_cksum.py b/util/exynos/variable_cksum.py
new file mode 100755
index 0000000000..25c7c0aa0a
--- /dev/null
+++ b/util/exynos/variable_cksum.py
@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+This utility computes and fills Exynos ROM checksum (for BL1 or BL2).
+(Algorithm from U-Boot: tools/mkexynosspl.c)
+
+Input: IN OUT
+
+Output:
+
+  Checksum header added to IN and written to OUT.
+  Header: uint32_t size, checksum, reserved[2].
+"""
+
+import struct
+import sys
+
+def main(argv):
+  if len(argv) != 3:
+    exit('usage: %s IN OUT' % argv[0])
+
+  in_name, out_name = argv[1:3]
+  header_format = "<IIII"
+  with open(in_name, "rb") as in_file, open(out_name, "wb") as out_file:
+    data = in_file.read()
+    header = struct.pack(header_format,
+                         struct.calcsize(header_format) + len(data),
+                         sum(map(ord, data)),
+                         0, 0)
+    out_file.write(header + data)
+
+
+if __name__ == '__main__':
+  main(sys.argv)