diff --git a/tools/firmware/hvmloader/Makefile b/tools/firmware/hvmloader/Makefile
index 043da50..920b0d0 100644
--- a/tools/firmware/hvmloader/Makefile
+++ b/tools/firmware/hvmloader/Makefile
@@ -99,7 +99,8 @@ smbios.o: CFLAGS += -D__SMBIOS_DATE__="\"$(SMBIOS_REL_DATE)\""
 ACPI_PATH = $(XEN_ROOT)/tools/firmware/hvmloader/acpi
 ACPI_FILES = dsdt_anycpu.c dsdt_15cpu.c dsdt_anycpu_qemu_xen.c build.c static_tables.c
 ACPI_OBJS = $(patsubst %.c,%.o,$(ACPI_FILES))
-$(ACPI_OBJS): CFLAGS += -I$(ACPI_PATH) -I.
+$(ACPI_OBJS): CFLAGS += -I. -DSTDUTILS=\"../util.h\"
+CFLAGS += -I$(ACPI_PATH)
 vpath build.c $(ACPI_PATH)/
 vpath static_tables.c $(ACPI_PATH)/
 OBJS += $(ACPI_OBJS)
diff --git a/tools/firmware/hvmloader/acpi/README b/tools/firmware/hvmloader/acpi/README
index 210d5ba..1d603ea 100644
--- a/tools/firmware/hvmloader/acpi/README
+++ b/tools/firmware/hvmloader/acpi/README
@@ -1,11 +1,19 @@
-ACPI Table for domain firmware
+ACPI builder for domain firmware
 
 
-INSTALL
+BUILDING ACPI
 -----------------
-Simply make is OK.
-# make 
+Users of ACPI builder are expected to provide an include file that defines
+the following:
+* strncpy
+* printf
+* NULL
+* test_bit
+* offsetof
 
+When compiling build.c, the name of this include file should be given to
+compiler as -DSTDUTILS=\"<filename>\". See tools/firmware/hvmloader/Makefile
+for an example.
 
 Note on DSDT Table
 ------------------
@@ -22,3 +30,4 @@ DSDT compiler "iasl" is needed. By default, it will be downloaded
 using wget in Makefile. if it failed, please download manually from 
 http://developer.intel.com/technology/iapc/acpi/downloads.htm. 
 then compile and install iasl
+
diff --git a/tools/firmware/hvmloader/acpi/build.c b/tools/firmware/hvmloader/acpi/build.c
index 4b0302c..290f005 100644
--- a/tools/firmware/hvmloader/acpi/build.c
+++ b/tools/firmware/hvmloader/acpi/build.c
@@ -15,15 +15,14 @@
  * this program; If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include STDUTILS
 #include "acpi2_0.h"
 #include "libacpi.h"
 #include "ssdt_s3.h"
 #include "ssdt_s4.h"
 #include "ssdt_tpm.h"
 #include "ssdt_pm.h"
-#include "../config.h"
-#include "../util.h"
-#include "../vnuma.h"
+#include "x86.h"
 #include <xen/hvm/hvm_xs_strings.h>
 #include <xen/hvm/params.h>
 
diff --git a/tools/firmware/hvmloader/acpi/x86.h b/tools/firmware/hvmloader/acpi/x86.h
new file mode 100644
index 0000000..21cad0d
--- /dev/null
+++ b/tools/firmware/hvmloader/acpi/x86.h
@@ -0,0 +1,38 @@
+/******************************************************************************
+ * x86.h
+ *
+ * x86-specific interfaces used by ACPI builder and its callers
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
+ */
+
+#ifndef __ACPI_X86_H__
+#define __ACPI_X86_H__
+
+#define IOAPIC_BASE_ADDRESS 0xfec00000
+#define IOAPIC_ID           0x01
+
+#define LAPIC_BASE_ADDRESS  0xfee00000
+#define LAPIC_ID(vcpu_id)   ((vcpu_id) * 2)
+
+#define PCI_ISA_IRQ_MASK    0x0c20U /* ISA IRQs 5,10,11 are PCI connected */
+
+#endif /* __ACPI_X86_H__ */
diff --git a/tools/firmware/hvmloader/config.h b/tools/firmware/hvmloader/config.h
index c7460fb..d847b86 100644
--- a/tools/firmware/hvmloader/config.h
+++ b/tools/firmware/hvmloader/config.h
@@ -42,15 +42,9 @@ extern struct bios_config ovmf_config;
 #define PAGE_SHIFT 12
 #define PAGE_SIZE  (1ul << PAGE_SHIFT)
 
-#define IOAPIC_BASE_ADDRESS 0xfec00000
-#define IOAPIC_ID           0x01
 #define IOAPIC_VERSION      0x11
 
-#define LAPIC_BASE_ADDRESS  0xfee00000
-#define LAPIC_ID(vcpu_id)   ((vcpu_id) * 2)
-
 #define PCI_ISA_DEVFN       0x08    /* dev 1, fn 0 */
-#define PCI_ISA_IRQ_MASK    0x0c20U /* ISA IRQs 5,10,11 are PCI connected */
 
 /* MMIO hole: Hardcoded defaults, which can be dynamically expanded. */
 #define PCI_MEM_END         0xfc000000
diff --git a/tools/firmware/hvmloader/hvmloader.c b/tools/firmware/hvmloader/hvmloader.c
index 716d03c..06a1665 100644
--- a/tools/firmware/hvmloader/hvmloader.c
+++ b/tools/firmware/hvmloader/hvmloader.c
@@ -24,8 +24,9 @@
 #include "config.h"
 #include "pci_regs.h"
 #include "apic_regs.h"
-#include "acpi/acpi2_0.h"
+#include "acpi2_0.h"
 #include "vnuma.h"
+#include "x86.h"
 #include <xen/version.h>
 #include <xen/hvm/params.h>
 
diff --git a/tools/firmware/hvmloader/mp_tables.c b/tools/firmware/hvmloader/mp_tables.c
index 69c2885..4d21304 100644
--- a/tools/firmware/hvmloader/mp_tables.c
+++ b/tools/firmware/hvmloader/mp_tables.c
@@ -29,6 +29,7 @@
 
 #include <stdint.h>
 #include "config.h"
+#include "x86.h"
 
 /* number of non-processor MP table entries */
 #define NR_NONPROC_ENTRIES     18
diff --git a/tools/firmware/hvmloader/ovmf.c b/tools/firmware/hvmloader/ovmf.c
index 74fec56..e7c48a5 100644
--- a/tools/firmware/hvmloader/ovmf.c
+++ b/tools/firmware/hvmloader/ovmf.c
@@ -23,7 +23,7 @@
 
 #include "config.h"
 #include "smbios_types.h"
-#include "acpi/acpi2_0.h"
+#include "acpi2_0.h"
 #include "apic_regs.h"
 #include "../rombios/config.h"
 #include "util.h"
diff --git a/tools/firmware/hvmloader/pci.c b/tools/firmware/hvmloader/pci.c
index 4eb1a31..d265109 100644
--- a/tools/firmware/hvmloader/pci.c
+++ b/tools/firmware/hvmloader/pci.c
@@ -23,6 +23,7 @@
 #include "hypercall.h"
 #include "config.h"
 #include "pci_regs.h"
+#include "x86.h"
 
 #include <xen/memory.h>
 #include <xen/hvm/ioreq.h>
diff --git a/tools/firmware/hvmloader/pir.c b/tools/firmware/hvmloader/pir.c
index cc420dd..f95bcea 100644
--- a/tools/firmware/hvmloader/pir.c
+++ b/tools/firmware/hvmloader/pir.c
@@ -16,6 +16,7 @@
 #include "config.h"
 #include "pir_types.h"
 #include "util.h"
+#include "x86.h"
 
 /*
  * The structure of these tables is described in
diff --git a/tools/firmware/hvmloader/rombios.c b/tools/firmware/hvmloader/rombios.c
index 1f8fc2d..863c1a7 100644
--- a/tools/firmware/hvmloader/rombios.c
+++ b/tools/firmware/hvmloader/rombios.c
@@ -24,7 +24,7 @@
 #include "../rombios/config.h"
 
 #include "smbios_types.h"
-#include "acpi/acpi2_0.h"
+#include "acpi2_0.h"
 #include "pci_regs.h"
 #include "util.h"
 #include "hypercall.h"
diff --git a/tools/firmware/hvmloader/seabios.c b/tools/firmware/hvmloader/seabios.c
index 2fbc3af..aadae30 100644
--- a/tools/firmware/hvmloader/seabios.c
+++ b/tools/firmware/hvmloader/seabios.c
@@ -25,8 +25,8 @@
 #include "util.h"
 
 #include "smbios_types.h"
-#include "acpi/acpi2_0.h"
-#include "acpi/libacpi.h"
+#include "acpi2_0.h"
+#include "libacpi.h"
 
 #define ROM_INCLUDE_SEABIOS
 #include "roms.inc"
diff --git a/tools/firmware/hvmloader/smp.c b/tools/firmware/hvmloader/smp.c
index 082b17f..4c6c3c6 100644
--- a/tools/firmware/hvmloader/smp.c
+++ b/tools/firmware/hvmloader/smp.c
@@ -22,6 +22,7 @@
 #include "util.h"
 #include "config.h"
 #include "apic_regs.h"
+#include "x86.h"
 
 #define AP_BOOT_EIP 0x1000
 extern char ap_boot_start[], ap_boot_end[];
diff --git a/tools/firmware/hvmloader/util.c b/tools/firmware/hvmloader/util.c
index 9438571..b7c9ff2 100644
--- a/tools/firmware/hvmloader/util.c
+++ b/tools/firmware/hvmloader/util.c
@@ -22,8 +22,9 @@
 #include "hypercall.h"
 #include "ctype.h"
 #include "vnuma.h"
-#include "acpi/acpi2_0.h"
-#include "acpi/libacpi.h"
+#include "acpi2_0.h"
+#include "libacpi.h"
+#include "x86.h"
 #include <stdint.h>
 #include <xen/xen.h>
 #include <xen/memory.h>
