[Reposting,PATCHv2,1/6] SLW: Add support for p9_stop_api

Message ID 1501558176-20783-1-git-send-email-akshay.adiga@linux.vnet.ibm.com
State Superseded
Headers show

Commit Message

Akshay Adiga Aug. 1, 2017, 3:29 a.m.
p9_stop_api's are used to SPR state on a core wakeup form a deeper state.
p9_stop_api uses  low level platform formware and self-restore microcode
to restore the sprs to requested values.

Code is taken from :
https://github.com/open-power/hostboot/tree/master/src/import/chips/p9/procedures/utils/stopreg

Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
---
Changes in v2 Reposting :
- Removed "This code is under development" from commit message

 include/p9_stop_api.H                    |  163 +++++
 libpore/Makefile.inc                     |    2 +-
 libpore/p9_cpu_reg_restore_instruction.H |   76 +++
 libpore/p9_hcd_header_defs.H             |  152 +++++
 libpore/p9_hcd_memmap_base.H             |  516 +++++++++++++++
 libpore/p9_stop_api.C                    | 1028 ++++++++++++++++++++++++++++++
 libpore/p9_stop_api.H                    |  163 +++++
 libpore/p9_stop_data_struct.H            |  149 +++++
 libpore/p9_stop_util.C                   |  187 ++++++
 libpore/p9_stop_util.H                   |  145 +++++
 10 files changed, 2580 insertions(+), 1 deletion(-)
 create mode 100644 include/p9_stop_api.H
 create mode 100644 libpore/p9_cpu_reg_restore_instruction.H
 create mode 100644 libpore/p9_hcd_header_defs.H
 create mode 100644 libpore/p9_hcd_memmap_base.H
 create mode 100644 libpore/p9_stop_api.C
 create mode 100644 libpore/p9_stop_api.H
 create mode 100644 libpore/p9_stop_data_struct.H
 create mode 100644 libpore/p9_stop_util.C
 create mode 100644 libpore/p9_stop_util.H

Patch

diff --git a/include/p9_stop_api.H b/include/p9_stop_api.H
new file mode 100644
index 0000000..79abd00
--- /dev/null
+++ b/include/p9_stop_api.H
@@ -0,0 +1,163 @@ 
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/import/chips/p9/procedures/utils/stopreg/p9_stop_api.H $  */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2017                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+#ifndef __P9_STOP_IMAGE_API_
+#define __P9_STOP_IMAGE_API_
+
+#include <stdint.h>
+
+#ifdef __SKIBOOT__
+    #include <skiboot.h>
+#endif
+
+///
+/// @file   p9_stop_api.H
+/// @brief  describes STOP API which  create/manipulate STOP image.
+///
+// *HWP HW Owner    :  Greg Still <stillgs@us.ibm.com>
+// *HWP FW Owner    :  Prem Shanker Jha <premjha2@in.ibm.com>
+// *HWP Team        :  PM
+// *HWP Level       :  2
+// *HWP Consumed by :  HB:HYP
+
+#ifdef __cplusplus
+namespace stopImageSection
+{
+#endif
+
+/**
+ * @brief   all SPRs and MSR for which register restore is to be supported.
+ * @note    STOP API design has built in support to accomodate 8 register of
+ *          scope core and thread each.
+ */
+typedef enum
+{
+    P9_STOP_SPR_DAWR    =    180,   // thread register
+    P9_STOP_SPR_HSPRG0  =    304,   // thread register
+    P9_STOP_SPR_HRMOR   =    313,   // core register
+    P9_STOP_SPR_LPCR    =    318,   // thread register
+    P9_STOP_SPR_HMEER   =    337,   // core register
+    P9_STOP_SPR_LDBAR   =    850,   // thread register
+    P9_STOP_SPR_PSSCR   =    855,   // thread register
+    P9_STOP_SPR_PMCR    =    884,   // core register
+    P9_STOP_SPR_HID     =   1008,   // core register
+    P9_STOP_SPR_MSR     =   2000,   // thread register
+} CpuReg_t;
+
+/**
+ * @brief lists all the bad error codes.
+ */
+typedef enum
+{
+    STOP_SAVE_SUCCESS                    = 0,
+    STOP_SAVE_ARG_INVALID_IMG            = 1,
+    STOP_SAVE_ARG_INVALID_REG            = 2,
+    STOP_SAVE_ARG_INVALID_THREAD         = 3,
+    STOP_SAVE_ARG_INVALID_MODE           = 4,
+    STOP_SAVE_ARG_INVALID_CORE           = 5,
+    STOP_SAVE_SPR_ENTRY_NOT_FOUND        = 6,
+    STOP_SAVE_SPR_ENTRY_UPDATE_FAILED    = 7,
+    STOP_SAVE_SCOM_INVALID_OPERATION     = 8,
+    STOP_SAVE_SCOM_INVALID_SECTION       = 9,
+    STOP_SAVE_SCOM_INVALID_ADDRESS       = 10,
+    STOP_SAVE_SCOM_INVALID_CHIPLET       = 11,
+    STOP_SAVE_SCOM_ENTRY_UPDATE_FAILED   = 12,
+    STOP_SAVE_INVALID_FUSED_CORE_STATUS  = 13,
+    STOP_SAVE_FAIL                       = 14,  // for internal failure within firmware.
+} StopReturnCode_t;
+
+/**
+ * @brief summarizes all operations supported on scom entries of STOP image.
+ */
+typedef enum
+{
+    P9_STOP_SCOM_OP_MIN     = 0,
+    P9_STOP_SCOM_APPEND     = 1,
+    P9_STOP_SCOM_REPLACE    = 2,
+    P9_STOP_SCOM_OR         = 3,
+    P9_STOP_SCOM_AND        = 4,
+    P9_STOP_SCOM_NOOP       = 5,
+    P9_STOP_SCOM_RESET      = 6,
+    P9_STOP_SCOM_OR_APPEND  = 7,
+    P9_STOP_SCOM_AND_APPEND = 8,
+    P9_STOP_SCOM_OP_MAX     = 9
+} ScomOperation_t;
+
+/**
+ * @brief All subsections that contain scom entries in a STOP image.
+ */
+typedef enum
+{
+    P9_STOP_SECTION_MIN         = 0,
+    P9_STOP_SECTION_CORE_SCOM   = 1,
+    P9_STOP_SECTION_EQ_SCOM     = 2,
+    P9_STOP_SECTION_L2          = 3,
+    P9_STOP_SECTION_L3          = 4,
+    P9_STOP_SECTION_MAX         = 5
+} ScomSection_t;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+/**
+ * @brief   Updates STOP image entry associated with CPU register.
+ * @param[in]   i_pImage    start address of homer image associated with processor.
+ * @param[in]   i_regId     id of SPR for which STOP image needs to be updated.
+ * @param[in]   i_regData   data to be restored in SPR register.
+ * @param[in]   i_pir       value of processor identification register (PIR)
+ * @return      STOP_SAVE_SUCCESS SUCCESS if image is updated successfully, error
+ *              code otherwise.
+ */
+
+StopReturnCode_t p9_stop_save_cpureg(  void* const i_pImage,
+                                       const CpuReg_t  i_regId,
+                                       const uint64_t  i_regData,
+                                       const uint64_t  i_pir );
+
+/**
+ * @brief   Updates scom image entry associated with given core or cache in
+ *          STOP section of homer image.
+ * @param[in]   i_pImage        start address of homer image of P9 chip.
+ * @param[in]   i_scomAddress   fully qualified address of SCOM register.
+ * @param[in]   i_scomData      data associated with SCOM register.
+ * @param[in]   i_operation     operation to be done on SCOM image entry.
+ * @param[in]   i_section       area to which given SCOM entry belongs.
+ * @return      STOP_SAVE_SUCCESS if image is updated successfully, error code
+ *              otherwise.
+ * @note        API is intended to update SCOM image entry associated with given
+ *              core or given part of a cache section. API doesn't validate if
+ *              a given SCOM address really belongs to given section.
+ */
+StopReturnCode_t p9_stop_save_scom( void* const   i_pImage,
+                                    const uint32_t i_scomAddress,
+                                    const uint64_t i_scomData,
+                                    const ScomOperation_t i_operation,
+                                    const ScomSection_t i_section );
+
+#ifdef __cplusplus
+} // extern "C"
+};  // namespace stopImageSection ends
+#endif //__cplusplus
+
+#endif //__P9_STOP_IMAGE_API_
diff --git a/libpore/Makefile.inc b/libpore/Makefile.inc
index 2eac595..cc89127 100644
--- a/libpore/Makefile.inc
+++ b/libpore/Makefile.inc
@@ -1,4 +1,4 @@ 
-LIBPORE_SRCS = p8_pore_table_gen_api_fixed.C
+LIBPORE_SRCS = p8_pore_table_gen_api_fixed.C p9_stop_api.C p9_stop_util.C
 LIBPORE_SRCS += p8_pore_table_static_data.c sbe_xip_image.c pore_inline_assembler.c
 LIBPORE_OBJS_1 = $(LIBPORE_SRCS:%.c=%.o)
 LIBPORE_OBJS = $(LIBPORE_OBJS_1:%.C=%.o)
diff --git a/libpore/p9_cpu_reg_restore_instruction.H b/libpore/p9_cpu_reg_restore_instruction.H
new file mode 100644
index 0000000..e5689ae
--- /dev/null
+++ b/libpore/p9_cpu_reg_restore_instruction.H
@@ -0,0 +1,76 @@ 
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/import/chips/p9/procedures/utils/stopreg/p9_cpu_reg_restore_instruction.H $ */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2017                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+
+///
+/// @file   p9_cpu_reg_restore_instruction.H
+/// @brief  enumerates all the opcodes used for SPR restoration.
+///
+// *HWP HW Owner    :  Greg Still <stillgs@us.ibm.com>
+// *HWP FW Owner    :  Prem Shanker Jha <premjha2@in.ibm.com>
+// *HWP Team        :  PM
+// *HWP Level       :  2
+// *HWP Consumed by :  HB:HYP
+
+#ifndef __REG_RESTORE_INSTRUCTION_H
+#define __REG_RESTORE_INSTRUCTION_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+
+namespace stopImageSection
+{
+#endif
+
+/**
+ * @brief enumerates opcodes for few instructions.
+ */
+enum
+{
+    ORI_OPCODE        = 24,
+    RFI_OPCODE        = 19,
+    RFI_CONST         = 50,
+    ORIS_OPCODE       = 25,
+    OPCODE_31         = 31,
+    XOR_CONST         = 316,
+    RLDICR_OPCODE     = 30,
+    RLDICR_CONST      = 1,
+    MTSPR_CONST1      = 467,
+    MTMSRD_CONST1     = 178,
+    MR_R0_TO_R10      = 0x7c0a0378, //mr r10, r0
+    MR_R0_TO_R21      = 0x7c150378, //mr r21, r0
+    BLR_INST          = 0x4e800020,
+    MTSPR_BASE_OPCODE = 0x7c0003a6,
+    ATTN_OPCODE       = 0x00000200,
+};
+
+#ifdef __cplusplus
+} // namespace stopImageSection ends
+
+} // extern "C"
+#endif //__cplusplus
+
+#endif //__REG_RESTORE_INSTRUCTION_H
diff --git a/libpore/p9_hcd_header_defs.H b/libpore/p9_hcd_header_defs.H
new file mode 100644
index 0000000..49c814a
--- /dev/null
+++ b/libpore/p9_hcd_header_defs.H
@@ -0,0 +1,152 @@ 
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/import/chips/p9/procedures/hwp/lib/p9_hcd_header_defs.H $ */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2016,2017                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+///
+/// @file  p9_hcd_header_defs.H
+/// @brief defines header constants based on file types
+///
+/// This header contains those cpp manifest constants required for processing
+/// the linker scripts used to generate OCC code images.  As these are used
+/// by linker scripts as well as by C++ code, these cannot be solely be put
+/// into a namespace. Prefixing these with the region name is the attempt
+/// to make these globally unique when this header is included in C++ code.
+///
+//  *HWP HWP Owner:        David Du   <daviddu@us.ibm.com>
+//  *HWP Backup HWP Owner: Greg Still <stillgs@us.ibm.com>
+//  *HWP FW Owner:         Prem Jha <premjha2@in.ibm.com>
+//  *HWP Team:             PM
+//  *HWP Level:            2
+//  *HWP Consumed by:      PM
+//
+
+#ifndef __HCD_HEADER_DEFS_H__
+#define __HCD_HEADER_DEFS_H__
+
+/// Macros for generating an Hcode header section
+///
+/// The CPP macros HCD_HDR_UINTxx generate equivalent code depending on
+/// whether they are being called from assembler (where they actually
+/// create the header section data) or from C (where they specifiy a
+/// C-structure form of the contents of the header section.
+///
+/// In assembler each invocation also creates space in the header section
+
+#ifdef __ASSEMBLER__
+
+// *INDENT-OFF*
+    .macro  hcd_header_uint64, symbol:req, value = 0
+    .global \symbol
+\symbol\():
+    .quad (\value)
+    .endm
+
+    .macro  hcd_header_uint32, symbol:req, value = 0
+    .global \symbol
+    \symbol\():
+    .long (\value)
+    .endm
+
+    .macro  hcd_header_uint16, symbol:req, value = 0
+    .global \symbol
+\symbol\():
+    .short (\value)
+    .endm
+
+    .macro  hcd_header_uint8, symbol:req, value = 0
+    .global \symbol
+\symbol\():
+    .byte (\value)
+    .endm
+
+    .macro  hcd_header_uint8_vec, symbol:req, number:req, value = 0
+    .global \symbol
+\symbol\():
+    .rept (\number)
+    .byte (\value)
+    .endr
+    .endm
+
+    .macro  hcd_header_attn, symbol:req, number = 1
+    .global \symbol
+\symbol\():
+    .rept (\number)
+    .long 0x00000200
+    .endr
+    .endm
+
+    .macro  hcd_header_attn_pad, align:req
+    .balignl (\align), 0x00000200
+    .endm
+
+     .macro  hcd_header_pad, align:req
+     .balignl (\align), 0
+     .endm
+// *INDENT-ON*
+
+#define ULL(x) x
+#define HCD_CONST(name, expr)   .set name, expr;
+#define HCD_CONST64(name, expr) .set name, expr;
+
+#define HCD_HDR_UINT64(symbol, value) hcd_header_uint64 symbol value
+#define HCD_HDR_UINT32(symbol, value) hcd_header_uint32 symbol value
+#define HCD_HDR_UINT16(symbol, value) hcd_header_uint16 symbol value
+#define HCD_HDR_UINT8(symbol, value)  hcd_header_uint8  symbol value
+#define HCD_HDR_UINT8_VEC(symbol, number, value)  hcd_header_uint8_vec  symbol number value
+#define HCD_HDR_ATTN(symbol, number)  hcd_header_attn symbol number
+#define HCD_HDR_ATTN_PAD(align)       hcd_header_attn_pad align
+#define HCD_HDR_PAD(align)            hcd_header_pad      align
+
+#else // NOT __ASSEMBLER__
+
+#ifdef __LINKERSCRIPT__
+
+    #define ULL(x) x
+    #define POUND_DEFINE #define
+    #define HCD_CONST(name, expr)   POUND_DEFINE name expr
+    #define HCD_CONST64(name, expr) POUND_DEFINE name expr
+
+#else
+
+    #define ULL(x) x##ull
+    #define HCD_CONST(name, expr)   enum { name = expr };
+    #define HCD_CONST64(name, expr) enum { name = expr };
+
+    #define HCD_HDR_UINT64(symbol, value) uint64_t symbol
+    #define HCD_HDR_UINT32(symbol, value) uint32_t symbol
+    #define HCD_HDR_UINT16(symbol, value) uint16_t symbol
+    #define HCD_HDR_UINT8(symbol, value)  uint8_t  symbol
+    #define HCD_HDR_UINT8_VEC(symbol, number, value) uint8_t  symbol[number]
+    #define HCD_HDR_ATTN(symbol, number)  uint32_t symbol[number]
+    #define HCD_HDR_ATTN_PAD(align)
+    #define HCD_HDR_PAD(align)
+
+#endif // __LINKERSCRIPT__
+#endif // __ASSEMBLER__
+
+// Stringification
+
+#define STR_HELPER(x) #x
+#define STR(x) STR_HELPER(x)
+
+#endif // __HCD_HEADER_DEFS_H__
diff --git a/libpore/p9_hcd_memmap_base.H b/libpore/p9_hcd_memmap_base.H
new file mode 100644
index 0000000..1b7fa49
--- /dev/null
+++ b/libpore/p9_hcd_memmap_base.H
@@ -0,0 +1,516 @@ 
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/import/chips/p9/procedures/hwp/lib/p9_hcd_memmap_base.H $ */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2017                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+///
+/// @file   p9_hcd_memmap_base.H
+/// @brief  defines region constants shared by different memory components.
+///
+
+// *HWP HWP Owner:        David Du   <daviddu@us.ibm.com>
+// *HWP Backup HWP Owner: Greg Still <stillgs@us.ibm.com>
+// *HWP FW Owner:         Prem S Jha <premjha2@in.ibm.com>
+// *HWP Team:             PM
+// *HWP Level:            2
+// *HWP Consumed by:      PM:Hostboot:Phyp
+
+#ifndef __HCD_MEMMAP_BASE_H__
+#define __HCD_MEMMAP_BASE_H__
+
+#include <p9_hcd_header_defs.H>
+
+// -------------------------------------------------------------------
+// Note: There can be NO semicolons(";") at end of macros in this file
+//       There can ONLY have HCD_CONST/HCD_CONST64 macros in this file
+// -------------------------------------------------------------------
+
+/// Image Magic Numbers
+
+HCD_CONST64(CPMR_MAGIC_NUMBER,                  ULL(0x43504d525f312e30))  // CPMR_1.0
+HCD_CONST64(CME_MAGIC_NUMBER ,                  ULL(0x434d455f5f312e30))  // CME__1.0
+
+HCD_CONST64(QPMR_MAGIC_NUMBER,                  ULL(0x51504d525f312e30))  // QPMR_1.0
+HCD_CONST64(SGPE_MAGIC_NUMBER,                  ULL(0x534750455f312e30))  // SGPE_1.0
+
+HCD_CONST64(PPMR_MAGIC_NUMBER,                  ULL(0x50504d525f312e30))  // PPMR_1.0
+HCD_CONST64(PGPE_MAGIC_NUMBER,                  ULL(0x504750455F312E30))  // PGPE_1.0
+
+HCD_CONST(CME_BUILD_VERSION,                    0x001) // CME__1.0
+HCD_CONST(SGPE_BUILD_VERSION,                   0x001) // SGPE_1.0
+HCD_CONST(PGPE_BUILD_VERSION,                   0x001) // PGPE_1.0
+
+HCD_CONST64(CPMR_MAGIC_NUMBER_BASE,                  ULL(0x43504d525f302e30))  // CPMR_0.0
+HCD_CONST(CPMR_REGION_CHECK_WORD,                    (0x43504d52))          // CPMR
+HCD_CONST64(CME_MAGIC_NUMBER_BASE ,                  ULL(0x434d455f5f302e30))  // CME__0.0
+HCD_CONST64(QPMR_MAGIC_NUMBER_BASE,                  ULL(0x51504d525f302e30))  // QPMR_0.0
+HCD_CONST64(SGPE_MAGIC_NUMBER_BASE,                  ULL(0x534750455f302e30))  // SGPE_0.0
+HCD_CONST64(PPMR_MAGIC_NUMBER_BASE,                  ULL(0x50504d525f302e30))  // PPMR_0.0
+HCD_CONST64(PGPE_MAGIC_NUMBER_BASE,                  ULL(0x504750455F302E30))  // PGPE_0.0
+
+/// Size constants
+
+HCD_CONST(HALF_KB,                              512)
+HCD_CONST(ONE_KB,                               1024)
+HCD_CONST(HALF_MB,                              (1024 * 512))
+HCD_CONST(ONE_MB,                               (1024 * 1024))
+HCD_CONST(TWO_MB,                               (2 * 1024 * 1024))
+
+/// Memory constants
+
+HCD_CONST(CME_SRAM_SIZE,                        (32 * ONE_KB))
+HCD_CONST(OCC_SRAM_SIZE,                        (768 * ONE_KB))
+
+HCD_CONST(HOMER_MEMORY_SIZE,                    (4 * ONE_MB))
+HCD_CONST(HOMER_OPMR_REGION_NUM,                0)
+HCD_CONST(HOMER_QPMR_REGION_NUM,                1)
+HCD_CONST(HOMER_CPMR_REGION_NUM,                2)
+HCD_CONST(HOMER_PPMR_REGION_NUM,                3)
+
+/// Chip constants
+
+HCD_CONST(MAX_THREADS_PER_CORE,                 4)
+HCD_CONST(MAX_CORES_PER_CHIP,                   24)
+
+HCD_CONST(MAX_CMES_PER_CHIP,                    12)
+HCD_CONST(MAX_EXES_PER_CHIP,                    12)
+
+HCD_CONST(MAX_QUADS_PER_CHIP,                   6)
+HCD_CONST(MAX_CACHES_PER_CHIP,                  6)
+
+HCD_CONST(MAX_CORES_PER_CME,                    2)
+HCD_CONST(MAX_CORES_PER_EX,                     2)
+
+HCD_CONST(MAX_CMES_PER_QUAD,                    2)
+HCD_CONST(MAX_EXES_PER_QUAD,                    2)
+
+HCD_CONST(CACHE0_CHIPLET_ID,                    0x10)
+HCD_CONST(CACHE_CHIPLET_ID_MIN,                 0x10)
+HCD_CONST(CACHE_CHIPLET_ID_MAX,                 0x15)
+
+HCD_CONST(CORE0_CHIPLET_ID,                     0x20)
+HCD_CONST(CORE_CHIPLET_ID_MIN,                  0x20)
+HCD_CONST(CORE_CHIPLET_ID_MAX,                  0x37)
+
+HCD_CONST(MAX_QUAD_ID_SUPPORTED,                5)
+HCD_CONST(MAX_CORE_ID_SUPPORTED,                23)
+HCD_CONST(MAX_THREAD_ID_SUPPORTED,              3)
+
+/// Image build constants
+
+HCD_CONST(HARDWARE_IMG_SIZE,                    ONE_MB)
+
+HCD_CONST(FUSED_CORE_MODE,                      0xBB)
+HCD_CONST(NONFUSED_CORE_MODE,                   0xAA)
+
+HCD_CONST(SELF_RESTORE_BLR_INST,                0x4e800020)
+HCD_CONST(CORE_RESTORE_PAD_OPCODE,              0x00000200) //ATTN Opcode
+
+HCD_CONST(SCOM_RESTORE_PAD_OPCODE,              0x00000000) //zero pads
+HCD_CONST(SCOM_RESTORE_ENTRY_SIZE,              16)         //4B pad,4B address,8B data
+
+HCD_CONST(CME_BLOCK_READ_LEN,                   32)
+HCD_CONST(CME_BLK_SIZE_SHIFT,                   0x05)
+
+HCD_CONST(RING_ALIGN_BOUNDARY,                  0x08)
+HCD_CONST64(DARN_BAR_EN_POS,                    ULL(0x8000000000000000))
+
+//---------------------------------------------------------------------------------------
+
+/// OPMR
+
+HCD_CONST(OCC_HOST_AREA_SIZE,                   ONE_MB)
+HCD_CONST(OPMR_OCC_IMAGE_SIZE,                  HALF_MB)
+HCD_CONST(OPMR_HOST_AREA_SIZE,                  HALF_MB)
+
+//---------------------------------------------------------------------------------------
+
+/// QPMR Header
+
+HCD_CONST(QPMR_HOMER_OFFSET,                    (HOMER_QPMR_REGION_NUM* ONE_MB))
+HCD_CONST(QPMR_HEADER_SIZE,                     512)
+
+HCD_CONST(QPMR_MAGIC_NUMBER_BYTE,               0x00)
+HCD_CONST(QPMR_BOOT_COPIER_OFFSET_BYTE,         0x08)
+HCD_CONST(QPMR_BOOT_LOADER_OFFSET_BYTE,         0x10)
+HCD_CONST(QPMR_BOOT_LOADER_LENGTH_BYTE,         0x14)
+HCD_CONST(QPMR_BUILD_DATE_BYTE,                 0x18)
+HCD_CONST(QPMR_BUILD_VER_BYTE,                  0x1C)
+HCD_CONST(QPMR_SGPE_HCODE_OFFSET_BYTE,          0x28)
+HCD_CONST(QPMR_SGPE_HCODE_LENGTH_BYTE,          0x2C)
+HCD_CONST(QPMR_QUAD_COMMON_RINGS_OFFSET_BYTE,   0x30)
+HCD_CONST(QPMR_QUAD_COMMON_RINGS_LENGTH_BYTE,   0x34)
+HCD_CONST(QPMR_QUAD_OVERRIDE_RINGS_OFFSET_BYTE, 0x38)
+HCD_CONST(QPMR_QUAD_OVERRIDE_RINGS_LENGTH_BYTE, 0x3C)
+HCD_CONST(QPMR_QUAD_SPECIFIC_RINGS_OFFSET_BYTE, 0x40)
+HCD_CONST(QPMR_QUAD_SPECIFIC_RINGS_LENGTH_BYTE, 0x44)
+HCD_CONST(QPMR_QUAD_SCOM_RESTORE_OFFSET_BYTE,   0x48)
+HCD_CONST(QPMR_QUAD_SCOM_RESTORE_LENGTH_BYTE,   0x4C)
+HCD_CONST(QPMR_AUX_DATA_OFFSET_BYTE,            0x50)
+HCD_CONST(QPMR_AUX_DATA_LENGTH_BYTE,            0x54)
+HCD_CONST(QPMR_STOP_FFDC_OFFSET_BYTE,           0x58)
+HCD_CONST(QPMR_STOP_FFDC_LENGTH_BYTE,           0x5C)
+HCD_CONST(QPMR_SGPE_BOOT_PROG_CODE,             0x60)
+HCD_CONST(QPMR_SGPE_IMAGE_SIZE,                 0x64)
+
+/// SGPE Boot
+
+HCD_CONST(SGPE_BOOT_COPIER_QPMR_OFFSET,         QPMR_HEADER_SIZE)
+HCD_CONST(SGPE_BOOT_COPIER_SIZE,                ONE_KB)
+
+HCD_CONST(SGPE_BOOT_LOADER_QPMR_OFFSET,
+          (SGPE_BOOT_COPIER_QPMR_OFFSET + SGPE_BOOT_COPIER_SIZE))
+HCD_CONST(SGPE_BOOT_LOADER_SIZE,                ONE_KB)
+HCD_CONST(SGPE_BOOT_LOADER_RESET_ADDR_VAL,      0x40)
+
+HCD_CONST(SGPE_INSTRUMENTATION_SIZE,            (2 * ONE_KB))
+
+/// SGPE Image
+
+HCD_CONST(SGPE_IMAGE_QPMR_OFFSET,
+          (SGPE_BOOT_LOADER_QPMR_OFFSET + SGPE_BOOT_LOADER_SIZE))
+HCD_CONST(SGPE_IMAGE_SIZE,                      (80 * ONE_KB)) //RTC158543
+HCD_CONST(SGPE_INT_VECTOR_SIZE,                 384)
+HCD_CONST(SGPE_HCODE_RESET_ADDR_VAL,            0x40)
+
+/// SGPE Header
+
+HCD_CONST(SGPE_HEADER_QPMR_OFFSET,
+          (SGPE_IMAGE_QPMR_OFFSET + SGPE_INT_VECTOR_SIZE))
+HCD_CONST(SGPE_HEADER_IMAGE_OFFSET,             SGPE_INT_VECTOR_SIZE)
+HCD_CONST(SGPE_HEADER_SIZE,                     128)
+
+HCD_CONST(SGPE_MAGIC_NUMBER_BYTE,               0x00)
+HCD_CONST(SGPE_SYSTEM_RESET_ADDR_BYTE,          0x08)
+HCD_CONST(SGPE_IVPR_ADDR_BYTE,                  0x10)
+HCD_CONST(SGPE_BUILD_DATE_BYTE,                 0x18)
+HCD_CONST(SGPE_BUILD_VER_BYTE,                  0x1C)
+HCD_CONST(SGPE_STOP_FLAGS_BYTE,                 0x20)
+HCD_CONST(SGPE_LOCATION_ID_BYTE,                0x24)
+HCD_CONST(SGPE_QUAD_COMMON_RING_SRAM_OFF_BYTE,  0x28)
+HCD_CONST(SGPE_QUAD_OVERRIDE_RING_SRAM_OFF_BYTE, 0x2C)
+HCD_CONST(SGPE_QUAD_SPECIFIC_RING_SRAM_OFF_BYTE, 0x30)
+HCD_CONST(SGPE_QUAD_SCOM_RESTORE_SRAM_OFF_BYTE, 0x34)
+HCD_CONST(SGPE_QUAD_SCOM_RESTORE_MEM_OFF_BYTE,  0x38)
+HCD_CONST(SGPE_QUAD_SCOM_RESTORE_LENGTH_BYTE,   0x3C)
+HCD_CONST(SGPE_AUX_DATA_OFFSET_BYTE,            0x40)
+HCD_CONST(SGPE_AUX_DATA_LENGTH_BYTE,            0x44)
+HCD_CONST(SGPE_AUX_CTRL_BYTE,                   0x48)
+HCD_CONST(SGPE_CHTM_MEM_CFG_BYTE,               0x50)
+
+HCD_CONST(SGPE_RESET_ADDR_IMAGE_OFFSET,         (SGPE_HEADER_IMAGE_OFFSET + SGPE_SYSTEM_RESET_ADDR_BYTE))
+HCD_CONST(SGPE_BUILD_DATE_IMAGE_OFFSET,         (SGPE_HEADER_IMAGE_OFFSET + SGPE_BUILD_DATE_BYTE))
+HCD_CONST(SGPE_BUILD_VER_IMAGE_OFFSET,          (SGPE_HEADER_IMAGE_OFFSET + SGPE_BUILD_VER_BYTE))
+
+HCD_CONST(SGPE_STOP_4_TO_2_BIT_POS,             0x80000000)
+HCD_CONST(SGPE_STOP_5_TO_4_BIT_POS,             0x40000000)
+HCD_CONST(SGPE_STOP_8_TO_5_BIT_POS,             0x20000000)
+HCD_CONST(SGPE_STOP_11_TO_8_BIT_POS,            0x10000000)
+HCD_CONST(SGPE_ENABLE_CME_TRACE_ARRAY_BIT_POS,  0x08000000)
+HCD_CONST(SGPE_ENABLE_CHTM_TRACE_CME_BIT_POS,   0x04000000)
+HCD_CONST(SGPE_VDM_ENABLE_BIT_POS,              0x04000000)
+HCD_CONST(SGPE_PROC_FAB_PUMP_MODE_BIT_POS,      0x00004000)
+
+///24x7
+HCD_CONST(QPMR_AUX_OFFSET,                     (512 * ONE_KB))
+HCD_CONST(QPMR_AUX_LENGTH,                     (64  * ONE_KB))
+/// SGPE Hcode
+
+HCD_CONST(SGPE_HCODE_IMAGE_OFFSET,              (SGPE_INT_VECTOR_SIZE + SGPE_HEADER_SIZE))
+HCD_CONST(SGPE_HCODE_SIZE,                      ((45 * ONE_KB) + HALF_KB)) //RTC158543
+HCD_CONST(SGPE_DEBUG_PTRS_OFFSET,               0x200)
+HCD_CONST(SGPE_DEBUG_PTRS_SIZE,                 0x24)
+HCD_CONST(SGPE_DBG_PTR_AREA_SIZE,               64)
+
+/// Quad Scan
+
+// 400B * 9 rings * 3 types (base, RL, CC)
+HCD_CONST(QUAD_COMMON_RING_SIZE,                (13 * ONE_KB))
+// 300B * 9 rings
+HCD_CONST(QUAD_OVERRIDE_RING_SIZE,              (3 * ONE_KB))
+// 1KB/ring * 5 rings/cache
+HCD_CONST(QUAD_SPECIFIC_RING_SIZE_PER_QUAD,     ((3 * ONE_KB) + HALF_KB))
+HCD_CONST(QUAD_SPECIFIC_RING_SIZE_TOTAL,        (19 * ONE_KB)) //checkme?
+
+/// Quad Scom
+
+HCD_CONST(QUAD_SCOM_RESTORE_QPMR_OFFSET,        (128 * ONE_KB))
+HCD_CONST(QUAD_SCOM_RESTORE_HOMER_OFFSET,
+          (QUAD_SCOM_RESTORE_QPMR_OFFSET + QPMR_HOMER_OFFSET))
+
+HCD_CONST(MAX_L2_SCOM_ENTRIES,                  16)
+HCD_CONST(MAX_L3_SCOM_ENTRIES,                  16)
+HCD_CONST(MAX_EQ_SCOM_ENTRIES,                  15)
+HCD_CONST(QUAD_SCOM_RESTORE_REGS_PER_QUAD,
+          (MAX_EQ_SCOM_ENTRIES + MAX_L2_SCOM_ENTRIES + MAX_L3_SCOM_ENTRIES + 1))
+
+HCD_CONST(QUAD_SCOM_RESTORE_SIZE_PER_QUAD,
+          (SCOM_RESTORE_ENTRY_SIZE* QUAD_SCOM_RESTORE_REGS_PER_QUAD))
+
+HCD_CONST(QUAD_SCOM_RESTORE_SIZE_TOTAL,         (6 * ONE_KB)) //rounded to 6KB
+
+//---------------------------------------------------------------------------------------
+
+/// CPMR Header
+
+HCD_CONST(CPMR_HOMER_OFFSET,                    (HOMER_CPMR_REGION_NUM* ONE_MB))
+HCD_CONST(CPMR_HEADER_SIZE,                     256)
+
+HCD_CONST(CPMR_ATTN_WORD0_BYTE,                 0x00)
+HCD_CONST(CPMR_ATTN_WORD1_BYTE,                 0x04)
+HCD_CONST(CPMR_MAGIC_NUMBER_BYTE,               0x08)
+HCD_CONST(CPMR_BUILD_DATE_BYTE,                 0x10)
+HCD_CONST(CPMR_BUILD_VER_BYTE,                  0x14)
+HCD_CONST(CPMR_CME_HCODE_OFFSET_BYTE,           0x20)
+HCD_CONST(CPMR_CME_HCODE_LENGTH_BYTE,           0x24)
+HCD_CONST(CPMR_CORE_COMMON_RING_OFFSET_BYTE,    0x28)
+HCD_CONST(CPMR_CORE_COMMON_RING_LENGTH_BYTE,    0x2C)
+HCD_CONST(CPMR_CME_LOCAL_PSTATE_OFFSET_BYTE,    0x30)
+HCD_CONST(CPMR_CME_LOCAL_PSTATE_LENGTH_BYTE,    0x34)
+HCD_CONST(CPMR_CORE_SPECIFIC_RING_OFFSET_BYTE,  0x38)
+HCD_CONST(CPMR_CORE_SPECIFIC_RING_LENGTH_BYTE,  0x3C)
+HCD_CONST(CPMR_CORE_SCOM_RESTORE_OFFSET_BYTE,   0x40)
+HCD_CONST(CPMR_CORE_SCOM_RESTORE_LENGTH_BYTE,   0x44)
+HCD_CONST(CPMR_SELF_RESTORE_OFFSET_BYTE,        0x48)
+HCD_CONST(CPMR_SELF_RESTORE_LENGTH_BYTE,        0x4C)
+
+/// Self Restore
+
+HCD_CONST(SELF_RESTORE_CPMR_OFFSET,             CPMR_HEADER_SIZE)
+HCD_CONST(SELF_RESTORE_INT_SIZE,                (8 * ONE_KB))
+HCD_CONST(THREAD_LAUNCHER_SIZE,                 256)
+HCD_CONST(SELF_RESTORE_CODE_SIZE,
+          (SELF_RESTORE_INT_SIZE + THREAD_LAUNCHER_SIZE))
+
+HCD_CONST(CORE_RESTORE_THREAD_AREA_SIZE,        (ONE_KB))
+HCD_CONST(CORE_RESTORE_CORE_AREA_SIZE,          (ONE_KB))
+HCD_CONST(CORE_RESTORE_SIZE_PER_THREAD,
+          (CORE_RESTORE_THREAD_AREA_SIZE + CORE_RESTORE_CORE_AREA_SIZE))
+HCD_CONST(SELF_RESTORE_CORE_REGS_SIZE,
+          (CORE_RESTORE_SIZE_PER_THREAD*
+           MAX_THREADS_PER_CORE* MAX_CORES_PER_CHIP))
+
+HCD_CONST(SELF_RESTORE_SIZE_TOTAL,
+          (SELF_RESTORE_CODE_SIZE + SELF_RESTORE_CORE_REGS_SIZE))
+
+
+/// Core Scom
+
+HCD_CONST(CORE_SCOM_RESTORE_CPMR_OFFSET,        (256 * ONE_KB))
+HCD_CONST(CORE_SCOM_RESTORE_HOMER_OFFSET,
+          (CORE_SCOM_RESTORE_CPMR_OFFSET + CPMR_HOMER_OFFSET))
+
+HCD_CONST(MAX_CORE_SCOM_ENTRIES,                15)
+HCD_CONST(CORE_SCOM_RESTORE_REGS_PER_CORE,      (MAX_CORE_SCOM_ENTRIES + 1))
+
+HCD_CONST(CORE_SCOM_RESTORE_SIZE_PER_CORE,
+          (SCOM_RESTORE_ENTRY_SIZE* CORE_SCOM_RESTORE_REGS_PER_CORE)) // 16*16=256
+HCD_CONST(CORE_SCOM_RESTORE_SIZE_PER_CME,
+          (CORE_SCOM_RESTORE_SIZE_PER_CORE* MAX_CORES_PER_CME))       // 256*2=512
+
+HCD_CONST(CORE_SCOM_RESTORE_SIZE_TOTAL,
+          (CORE_SCOM_RESTORE_SIZE_PER_CME* MAX_CMES_PER_CHIP))        // 512*12=6K
+
+/// CME Image
+
+HCD_CONST(CME_IMAGE_CPMR_OFFSET,
+          (CORE_SCOM_RESTORE_CPMR_OFFSET + CORE_SCOM_RESTORE_SIZE_TOTAL))
+//HCD_CONST(CME_IMAGE_SIZE,                       0)
+HCD_CONST(CME_INT_VECTOR_SIZE,                  384)
+
+/// CME Header
+
+HCD_CONST(CME_HEADER_CPMR_OFFSET,
+          (CME_IMAGE_CPMR_OFFSET + CME_INT_VECTOR_SIZE))
+HCD_CONST(CME_HEADER_IMAGE_OFFSET,              CME_INT_VECTOR_SIZE)
+HCD_CONST(CME_HEADER_SIZE,                      128)
+
+HCD_CONST(CME_MAGIC_NUMBER_BYTE,                0x00)
+HCD_CONST(CME_HCODE_OFFSET_BYTE,                0x08)
+HCD_CONST(CME_HCODE_LENGTH_BYTE,                0x0C)
+HCD_CONST(CME_CORE_COMMON_RING_OFFSET_BYTE,     0x10)
+HCD_CONST(CME_CORE_OVERRIDE_RING_OFFSET_BYTE,   0x14)
+HCD_CONST(CME_CORE_COMMON_RING_LENGTH_BYTE,     0x18)
+HCD_CONST(CME_LOCAL_PSTATE_OFFSET_BYTE,         0x1C)
+HCD_CONST(CME_LOCAL_PSTATE_LENGTH_BYTE,         0x20)
+HCD_CONST(CME_CORE_SPECIFIC_RING_OFFSET_BYTE,   0x24)
+HCD_CONST(CME_CORE_SPECIFIC_RING_LENGTH_BYTE,   0x28)
+HCD_CONST(CME_CORE_SCOM_RESTORE_OFFSET_BYTE,    0x2C)
+HCD_CONST(CME_CORE_SCOM_RESTORE_LENGTH_BYTE,    0x30)
+HCD_CONST(CME_STOP_FLAGS_BYTE,                  0x34)
+HCD_CONST(CME_LOCATION_ID_BYTE,                 0x38)
+HCD_CONST(CME_QM_FLAGS_BYTE,                    0x3A)
+HCD_CONST(CME_HOMER_ADDRESS_BYTE,               0x40)
+
+HCD_CONST(CME_HCODE_OFF_IMAGE_OFFSET,           (CME_HEADER_IMAGE_OFFSET + CME_HCODE_OFFSET_BYTE))
+HCD_CONST(CME_HCODE_LEN_IMAGE_OFFSET,           (CME_HEADER_IMAGE_OFFSET + CME_HCODE_LENGTH_BYTE))
+
+HCD_CONST(CME_STOP_3_TO_2_BIT_POS,              0x80000000)
+HCD_CONST(CME_STOP_4_TO_2_BIT_POS,              0x40000000)
+HCD_CONST(CME_STOP_5_TO_4_BIT_POS,              0x20000000)
+HCD_CONST(CME_STOP_8_TO_5_BIT_POS,              0x10000000)
+HCD_CONST(CME_STOP_11_TO_8_BIT_POS,             0x08000000)
+HCD_CONST(CME_VDM_ENABLE_BIT_POS,               0x04000000)
+HCD_CONST(CME_STOP_MAPPING_DISABLE_BIT_POS,     0x00000004)
+HCD_CONST(CME_QUEUED_SCAN_DISABLE_BIT_POS,      0x00000002)
+HCD_CONST(CME_SKIP_CORE_POWEROFF_BIT_POS,       0x00000001)
+HCD_CONST(CME_QM_FLAG_RESCLK_ENABLE,            0x8000)
+HCD_CONST(CME_QM_FLAG_SYS_IVRM_ENABLE,          0x4000)
+HCD_CONST(CME_QM_FLAG_SYS_VDM_ENABLE,           0x2000)
+HCD_CONST(CME_QM_FLAG_SYS_WOF_ENABLE,           0x1000)
+
+/// CME Hcode
+
+HCD_CONST(CME_HCODE_IMAGE_OFFSET,               (CME_INT_VECTOR_SIZE + CME_HEADER_SIZE))
+//HCD_CONST(CME_HCODE_SIZE,                       0)
+HCD_CONST(CME_DEBUG_PTRS_OFFSET,                0x200)
+HCD_CONST(CME_DEBUG_PTRS_SIZE,                  0x24)
+HCD_CONST(CME_INSTRUMENTATION_SIZE,             HALF_KB)
+HCD_CONST(CME_SRAM_HCODE_OFFSET,                0)
+
+/// Core Scan
+
+HCD_CONST(CORE_COMMON_RING_SIZE,                (2 * ONE_KB))
+HCD_CONST(CORE_OVERRIDE_RING_SIZE,              (1 * ONE_KB))
+HCD_CONST(CORE_SPECIFIC_RING_SIZE_PER_CORE,     (1 * ONE_KB))
+HCD_CONST(CORE_SPECIFIC_RING_SIZE_TOTAL,        (32 * ONE_KB)) // rounded to 32K
+
+/// Quad P-State
+
+HCD_CONST(CME_QUAD_PSTATE_SIZE,                 HALF_KB)
+
+// CME Hcode + Core Scan + Pstate
+
+HCD_CONST(CME_REGION_SIZE,                      (64 * ONE_KB))
+
+// Debug
+
+HCD_CONST(CPMR_TRACE_REGION_OFFSET,             (512 * ONE_KB))
+HCD_CONST(CME_TRACE_REGION_SIZE,                (16 * ONE_KB))
+HCD_CONST(CPMR_TRACE_REGION_SIZE,               (CME_TRACE_REGION_SIZE* MAX_CMES_PER_CHIP)) // 192K
+HCD_CONST(CPMR_DEBUG_REGION_OFFSET,             CPMR_TRACE_REGION_OFFSET + CPMR_TRACE_REGION_SIZE)
+HCD_CONST(CPMR_DEBUG_REGION_SIZE,               (64 * ONE_KB)) // 192K + 64K = 256K
+
+
+
+//---------------------------------------------------------------------------------------
+
+/// PPMR Header
+
+HCD_CONST(PPMR_HOMER_OFFSET,                    (HOMER_PPMR_REGION_NUM* ONE_MB))
+HCD_CONST(PPMR_HEADER_SIZE,                     512)
+
+HCD_CONST(PPMR_MAGIC_NUMBER_BYTE,               0x00)
+HCD_CONST(PPMR_BOOT_COPIER_OFFSET_BYTE,         0x08)
+HCD_CONST(PPMR_BOOT_LOADER_OFFSET_BYTE,         0x10)
+HCD_CONST(PPMR_BOOT_LOADER_LENGTH_BYTE,         0x14)
+HCD_CONST(PPMR_BUILD_DATE_BYTE,                 0x18)
+HCD_CONST(PPMR_BUILD_VER_BYTE,                  0x1C)
+HCD_CONST(PPMR_PGPE_HCODE_OFFSET_BYTE,          0x28)
+HCD_CONST(PPMR_PGPE_HCODE_LENGTH_BYTE,          0x2C)
+HCD_CONST(PPMR_GLOBAL_PSTATE_OFFSET_BYTE,       0x30)
+HCD_CONST(PPMR_GLOBAL_PSTATE_LENGTH_BYTE,       0x34)
+HCD_CONST(PPMR_LOCAL_PSTATE_OFFSET_BYTE,        0x38)
+HCD_CONST(PPMR_LOCAL_PSTATE_LENGTH_BYTE,        0x3C)
+HCD_CONST(PPMR_OCC_PSTATE_OFFSET_BYTE,          0x40)
+HCD_CONST(PPMR_OCC_PSTATE_LENGTH_BYTE,          0x44)
+HCD_CONST(PPMR_PSTATE_TABLE_OFFSET_BYTE,        0x48)
+HCD_CONST(PPMR_PSTATE_TABLE_LENGTH_BYTE,        0x4C)
+HCD_CONST(PPMR_PGPE_SRAM_IMAGE_SIZE_BYTE,       0x50)
+HCD_CONST(PPMR_PGPE_BOOT_PROG_CODE_BYTE,        0x54)
+
+/// PGPE Boot
+
+HCD_CONST(PGPE_BOOT_COPIER_PPMR_OFFSET,         PPMR_HEADER_SIZE)
+HCD_CONST(PGPE_BOOT_COPIER_SIZE,                ONE_KB)
+
+HCD_CONST(PGPE_BOOT_LOADER_PPMR_OFFSET,
+          (PGPE_BOOT_COPIER_PPMR_OFFSET + PGPE_BOOT_COPIER_SIZE))
+HCD_CONST(PGPE_BOOT_LOADER_SIZE,                ONE_KB)
+HCD_CONST(PGPE_BOOT_LOADER_RESET_ADDR_VAL,      0x40)
+
+HCD_CONST(PGPE_INSTRUMENTATION_SIZE,            (2 * ONE_KB))
+
+/// PGPE Image
+
+HCD_CONST(PGPE_IMAGE_PPMR_OFFSET,
+          (PGPE_BOOT_LOADER_PPMR_OFFSET + PGPE_BOOT_LOADER_SIZE))
+HCD_CONST(PGPE_IMAGE_SIZE,                      (48 * ONE_KB)) //RTC158543
+HCD_CONST(PGPE_INT_VECTOR_SIZE,                 384)
+HCD_CONST(PGPE_HCODE_RESET_ADDR_VAL,            0x40)
+
+/// PGPE Header
+
+HCD_CONST(PGPE_HEADER_IMAGE_OFFSET,             PGPE_INT_VECTOR_SIZE)
+HCD_CONST(PGPE_HEADER_PPMR_OFFSET,
+          (PGPE_IMAGE_PPMR_OFFSET + PGPE_INT_VECTOR_SIZE))
+HCD_CONST(PGPE_HEADER_SIZE,                     128)
+
+HCD_CONST(PGPE_MAGIC_NUMBER_BYTE,               0x00)
+HCD_CONST(PGPE_SYSTEM_RESET_ADDR_BYTE,          0x08)
+HCD_CONST(PGPE_SHARED_SRAM_ADDR_BYTE,           0x0C)
+HCD_CONST(PGPE_IVPR_ADDR_BYTE,                  0x10)
+HCD_CONST(PGPE_SHARED_SRAM_LENGTH_BYTE,         0x14)
+HCD_CONST(PGPE_BUILD_DATE_BYTE,                 0x18)
+HCD_CONST(PGPE_BUILD_VER_BYTE,                  0x1C)
+HCD_CONST(PGPE_PGPE_FLAGS_BYTE,                 0x20)
+HCD_CONST(PGPE_GLOBAL_PSTATE_SRAM_ADDR_BYTE,    0x28)
+HCD_CONST(PGPE_GLOBAL_PSTATE_MEM_OFFSET_BYTE,   0x30)
+HCD_CONST(PGPE_GLOBAL_PSTATE_PPB_SIZE_BYTE,     0x34)
+HCD_CONST(PGPE_GEN_PSTATE_TABLE_MEM_OFFSET_BYTE, 0x38)
+HCD_CONST(PGPE_GEN_PSTATE_TABLE_SIZE_BYTE,      0x3C)
+HCD_CONST(PGPE_OCC_PSTATE_TABLE_MEM_OFFSET_BYTE, 0x40)
+HCD_CONST(PGPE_OCC_PSTATE_TABLE_SIZE_BYTE,      0x44)
+HCD_CONST(PGPE_BEACON_ADDR_BYTE,                0x48)
+HCD_CONST(PGPE_ACTUAL_QUAD_STATUS_ADDR_BYTE,    0x4C)
+HCD_CONST(PGPE_WOF_TABLE_ADDR_BYTE,             0x50)
+HCD_CONST(PGPE_WOF_TABLE_LENGTH_BYTE,           0x54)
+
+HCD_CONST(PGPE_RESET_ADDR_IMAGE_OFFSET,         (PGPE_HEADER_IMAGE_OFFSET + PGPE_SYSTEM_RESET_ADDR_BYTE))
+HCD_CONST(PGPE_BUILD_DATE_IMAGE_OFFSET,         (PGPE_HEADER_IMAGE_OFFSET + PGPE_BUILD_DATE_BYTE))
+HCD_CONST(PGPE_BUILD_VER_IMAGE_OFFSET,          (PGPE_HEADER_IMAGE_OFFSET + PGPE_BUILD_VER_BYTE))
+
+/// PGPE Hcode
+
+//HCD_CONST(PGPE_HCODE_SIZE,                      (32 * ONE_KB)) //RTC158543
+HCD_CONST(PGPE_DBG_PTR_AREA_SIZE,               64)
+HCD_CONST(PGPE_GLOBAL_PSTATE_PARAM_BLOCK_SIZE,  (4 * ONE_KB))
+
+/// Pstate Parameter Block + Pstate Table
+
+HCD_CONST(OCC_PSTATE_PARAM_BLOCK_PPMR_OFFSET,   (128 * ONE_KB))
+HCD_CONST(OCC_PSTATE_PARAM_BLOCK_SIZE,          (8 * ONE_KB))
+HCD_CONST(OCC_PSTATE_PARAM_BLOCK_REGION_SIZE,   (16 * ONE_KB))
+
+HCD_CONST(PGPE_PSTATE_OUTPUT_TABLES_PPMR_OFFSET, (144 * ONE_KB))
+HCD_CONST(PGPE_PSTATE_OUTPUT_TABLES_SIZE,       (8 * ONE_KB))
+HCD_CONST(PGPE_PSTATE_OUTPUT_TABLES_REGION_SIZE, (16 * ONE_KB))
+
+HCD_CONST(OCC_WOF_TABLES_PPMR_OFFSET,           (768 * ONE_KB))
+HCD_CONST(OCC_WOF_TABLES_SIZE,                  (256 * ONE_KB))
+
+HCD_CONST(WOF_TABLE_RESERVE,
+          OCC_WOF_TABLES_PPMR_OFFSET - (PGPE_PSTATE_OUTPUT_TABLES_PPMR_OFFSET + PGPE_PSTATE_OUTPUT_TABLES_REGION_SIZE))
+HCD_CONST(PGPE_IMAGE_RESERVE_SIZE,
+          (OCC_PSTATE_PARAM_BLOCK_PPMR_OFFSET - PGPE_IMAGE_PPMR_OFFSET - PGPE_IMAGE_SIZE))
+
+#endif /* __HCD_MEMMAP_BASE_H__ */
diff --git a/libpore/p9_stop_api.C b/libpore/p9_stop_api.C
new file mode 100644
index 0000000..26a14bb
--- /dev/null
+++ b/libpore/p9_stop_api.C
@@ -0,0 +1,1028 @@ 
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/import/chips/p9/procedures/utils/stopreg/p9_stop_api.C $  */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2017                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+
+///
+/// @file   p9_stop_api.C
+/// @brief  implements STOP API which  create/manipulate STOP image.
+///
+// *HWP HW Owner    :  Greg Still <stillgs@us.ibm.com>
+// *HWP FW Owner    :  Prem Shanker Jha <premjha2@in.ibm.com>
+// *HWP Team        :  PM
+// *HWP Level       :  2
+// *HWP Consumed by :  HB:HYP
+
+#include "p9_stop_api.H"
+#include "p9_cpu_reg_restore_instruction.H"
+#include "p9_stop_data_struct.H"
+#include <string.h>
+#include "p9_stop_util.H"
+#include <stdio.h>
+
+#ifdef __FAPI_2_
+    #include <fapi2.H>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+
+namespace stopImageSection
+{
+#endif
+// a true in the table below means register is of scope thread
+// whereas a false meanse register is of scope core.
+
+const StopSprReg_t g_sprRegister[] =
+{
+    { P9_STOP_SPR_HSPRG0,    true  },
+    { P9_STOP_SPR_HRMOR,     false },
+    { P9_STOP_SPR_LPCR,      true  },
+    { P9_STOP_SPR_HMEER,     false },
+    { P9_STOP_SPR_LDBAR,     true  },
+    { P9_STOP_SPR_PSSCR,     true  },
+    { P9_STOP_SPR_PMCR,      false },
+    { P9_STOP_SPR_HID,       false },
+    { P9_STOP_SPR_MSR,       true  },
+    { P9_STOP_SPR_DAWR,      true  },
+};
+
+const uint32_t MAX_SPR_SUPPORTED =
+    sizeof ( g_sprRegister ) / sizeof( StopSprReg_t );
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief   validates input arguments provided by STOP API caller.
+ * @param[in]       i_pImage    pointer to beginning of chip's HOMER image.
+ * @param[in]       i_regId             SPR register id
+ * @param[in]       i_coreId            core id
+ * @param[in|out]   i_pThreadId         points to thread id
+ * @param[in|out]   i_pThreadLevelReg   points to scope information of SPR
+ * @return  STOP_SAVE_SUCCESS if arguments found valid, error code otherwise.
+ * @note    for register of scope core, function shall force io_threadId to
+ *          zero.
+ */
+static StopReturnCode_t validateSprImageInputs( void*   const i_pImage,
+        const CpuReg_t i_regId,
+        const uint32_t  i_coreId,
+        uint32_t*     i_pThreadId,
+        bool* i_pThreadLevelReg )
+{
+    uint32_t index = 0;
+    StopReturnCode_t l_rc = STOP_SAVE_SUCCESS;
+    bool sprSupported = false;
+    *i_pThreadLevelReg = false;
+
+    do
+    {
+        if( NULL == i_pImage )
+        {
+            // Error: HOMER image start location is not valid
+            // Cannot proceed further. So, let us exit.
+            l_rc = STOP_SAVE_ARG_INVALID_IMG;
+            MY_ERR( "invalid image location " );
+
+            break;
+        }
+
+        // STOP API manages STOP image based on physical core Id. PIR value
+        // is interpreted to calculate the physical core number and virtual
+        // thread number.
+        if( MAX_CORE_ID_SUPPORTED < i_coreId )
+        {
+            // Error: invalid core number. given core number exceeds maximum
+            // cores supported by chip.
+
+            // Physical core number is calculated based on following formula:
+            // core id = 4 * quad id (0..5) + core no within quad ( 0..3)
+            l_rc = STOP_SAVE_ARG_INVALID_CORE;
+            MY_ERR( "invalid core id " );
+            break;
+        }
+
+        if( MAX_THREAD_ID_SUPPORTED < *i_pThreadId )
+        {
+            //Error: invalid core thread. Given core thread exceeds maximum
+            //threads supported in a core.
+
+            // 64 bit PIR value is interpreted to calculate virtual thread
+            // Id. In fuse mode, b61 and b62 gives virtual thread id whereas in
+            // non fuse mode, b62 and b63 is read to determine the same.
+
+            l_rc = STOP_SAVE_ARG_INVALID_THREAD;
+            MY_ERR( "invalid thread " );
+            break;
+        }
+
+        for( index = 0; index < MAX_SPR_SUPPORTED; ++index )
+        {
+            if( i_regId == (CpuReg_t )g_sprRegister[index].sprId )
+            {
+                // given register is in the list of register supported
+                sprSupported = true;
+                *i_pThreadLevelReg = g_sprRegister[index].isThreadScope;
+                *i_pThreadId = *i_pThreadLevelReg ? *i_pThreadId : 0;
+                break;
+            }
+        }
+
+        if( !sprSupported )
+        {
+            // Following SPRs are supported
+            // trace out all registers supported
+            MY_ERR("Register not supported" );
+            // error code to caller.
+            l_rc = STOP_SAVE_ARG_INVALID_REG;
+            break;
+        }
+
+    }
+    while(0);
+
+    if( l_rc )
+    {
+        MY_ERR( "image 0x%08x, regId %08d, coreId %d, "
+                "threadId %d return code 0x%08x", i_pImage, i_regId,
+                i_coreId, *i_pThreadId, l_rc  );
+    }
+
+    return l_rc;
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief generates ori instruction code.
+ * @param[in]   i_Rs    Source register number
+ * @param[in]   i_Ra    destination register number
+ * @param[in]   i_data  16 bit immediate data
+ * @return  returns 32 bit number representing ori instruction.
+ */
+static uint32_t getOriInstruction( const uint16_t i_Rs, const uint16_t i_Ra,
+                                   const uint16_t i_data )
+{
+    uint32_t oriInstOpcode = 0;
+    oriInstOpcode = 0;
+    oriInstOpcode = ORI_OPCODE << 26;
+    oriInstOpcode |= i_Rs << 21;
+    oriInstOpcode |= i_Ra << 16;
+    oriInstOpcode |= i_data;
+
+    return SWIZZLE_4_BYTE(oriInstOpcode);
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief generates 32 bit key used for SPR lookup in core section.
+ */
+static uint32_t genKeyForSprLookup( const CpuReg_t i_regId )
+{
+    return getOriInstruction( 0, 0, (uint16_t) i_regId );
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief generates xor instruction code.
+ * @param[in] i_Rs  source register number for xor operation
+ * @param[in] i_Ra  destination register number for xor operation result
+ * @param[in] i_Rb source register number for xor operation
+ * @return returns 32 bit number representing xor  immediate instruction.
+ */
+static uint32_t getXorInstruction( const uint16_t i_Ra, const uint16_t i_Rs,
+                                   const uint16_t i_Rb )
+{
+    uint32_t xorRegInstOpcode;
+    xorRegInstOpcode = XOR_CONST << 1;
+    xorRegInstOpcode |= OPCODE_31 << 26;
+    xorRegInstOpcode |= i_Rs << 21;
+    xorRegInstOpcode |= i_Ra << 16;
+    xorRegInstOpcode |= i_Rb << 11;
+
+    return SWIZZLE_4_BYTE(xorRegInstOpcode);
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief generates oris instruction code.
+ * @param[in] i_Rs      source register number
+ * @param[in] i_Ra      destination register number
+ * @param[in] i_data    16 bit immediate data
+ * @return returns 32 bit number representing oris  immediate instruction.
+ */
+static uint32_t getOrisInstruction( const uint16_t i_Rs, const uint16_t i_Ra,
+                                    const uint16_t i_data )
+{
+    uint32_t orisInstOpcode;
+    orisInstOpcode = 0;
+    orisInstOpcode = ORIS_OPCODE << 26;
+    orisInstOpcode |= ( i_Rs & 0x001F ) << 21 | ( i_Ra & 0x001F ) << 16;
+    orisInstOpcode |= i_data;
+
+    return SWIZZLE_4_BYTE(orisInstOpcode);
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief generates instruction for mtspr
+ * @param[in] i_Rs      source register number
+ * @param[in] i_Spr represents spr where data is to be moved.
+ * @return returns 32 bit number representing mtspr instruction.
+ */
+static uint32_t getMtsprInstruction( const uint16_t i_Rs, const uint16_t i_Spr )
+{
+    uint32_t mtsprInstOpcode = 0;
+    uint32_t temp = (( i_Spr & 0x03FF ) << 11);
+    mtsprInstOpcode = (uint8_t)i_Rs << 21;
+    mtsprInstOpcode = ( temp  & 0x0000F800 ) << 5;
+    mtsprInstOpcode |= ( temp & 0x001F0000 ) >> 5;
+    mtsprInstOpcode |= MTSPR_BASE_OPCODE;
+
+    return SWIZZLE_4_BYTE(mtsprInstOpcode);
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief generates rldicr instruction.
+ * @param[in] i_Rs      source register number
+ * @param[in] i_Ra      destination register number
+ * @param[in] i_sh      bit position by which contents of i_Rs are to be shifted
+ * @param[in] i_me      bit position up to which mask should be 1.
+ * @return returns 32 bit number representing rldicr instruction.
+ */
+static uint32_t getRldicrInstruction( const uint16_t i_Ra, const uint16_t i_Rs,
+                                      const uint16_t i_sh, uint16_t i_me )
+{
+    uint32_t rldicrInstOpcode = 0;
+    rldicrInstOpcode = 0;
+    rldicrInstOpcode = ((RLDICR_OPCODE << 26 ) | ( i_Rs << 21 ) | ( i_Ra << 16 ));
+    rldicrInstOpcode |= ( ( i_sh & 0x001F ) << 11 ) | (RLDICR_CONST << 2 );
+    rldicrInstOpcode |= (( i_sh & 0x0020 ) >> 4);
+    rldicrInstOpcode |= (i_me & 0x001F ) << 6;
+    rldicrInstOpcode |= (i_me & 0x0020 );
+    return SWIZZLE_4_BYTE(rldicrInstOpcode);
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief looks up entry for given SPR in given thread/core section.
+ * @param[in]   i_pThreadSectLoc    start of given thread section or core section.
+ * @param[in]   i_lookUpKey         search key for lookup of given SPR entry.
+ * @param[in]   i_isCoreReg         true if register is of scope core, false
+ *                                  otherwise.
+ * @param[in|out] io_pSprEntryLoc   Input:  NULL
+ *                                  Output: location of given entry or end of table.
+ * @return      STOP_SAVE_SUCCESS if entry is found, STOP_SAVE_FAIL in case of
+ *              an error.
+ */
+static StopReturnCode_t lookUpSprInImage( uint32_t* i_pThreadSectLoc,
+        const uint32_t i_lookUpKey,
+        const bool i_isCoreReg,
+        void** io_pSprEntryLoc )
+{
+    StopReturnCode_t l_rc = STOP_SAVE_FAIL;
+    uint32_t temp = i_isCoreReg ? (uint32_t)(CORE_RESTORE_CORE_AREA_SIZE) :
+                    (uint32_t)(CORE_RESTORE_THREAD_AREA_SIZE);
+    uint32_t* i_threadSectEnd = i_pThreadSectLoc + temp;
+    uint32_t bctr_inst = SWIZZLE_4_BYTE(BLR_INST);
+    *io_pSprEntryLoc = NULL;
+
+    do
+    {
+        if( !i_pThreadSectLoc )
+        {
+            break;
+        }
+
+        temp = 0;
+
+        while( ( i_pThreadSectLoc <= i_threadSectEnd ) &&
+               ( temp != bctr_inst ) )
+        {
+            temp = *i_pThreadSectLoc;
+
+            if( ( temp == i_lookUpKey ) || ( temp == bctr_inst ) )
+            {
+                *io_pSprEntryLoc = i_pThreadSectLoc;
+                l_rc = STOP_SAVE_SUCCESS;
+                break;
+            }
+
+            i_pThreadSectLoc = i_pThreadSectLoc + SIZE_PER_SPR_RESTORE_INST;
+        }
+
+    }
+    while(0);
+
+    return l_rc;
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief updates an SPR STOP image entry.
+ * @param[in] i_pSprEntryLocation location of entry.
+ * @param[in] i_regId       register Id associated with SPR.
+ * @param[in] i_regData     data needs to be written to SPR entry.
+ * @return    STOP_SAVE_SUCCESS if update works, STOP_SAVE_FAIL otherwise.
+ */
+static StopReturnCode_t updateSprEntryInImage( uint32_t* i_pSprEntryLocation,
+        const CpuReg_t i_regId,
+        const uint64_t i_regData )
+{
+    StopReturnCode_t l_rc = STOP_SAVE_SUCCESS;
+    uint32_t tempInst = 0;
+    uint64_t tempRegData = 0;
+    bool newEntry  = true;
+    uint16_t regRs = 0; //to use R0 for SPR restore insruction generation
+    uint16_t regRa = 0;
+
+    do
+    {
+        if( !i_pSprEntryLocation )
+        {
+            MY_ERR("invalid location of SPR image entry" );
+            l_rc = STOP_SAVE_FAIL;
+            break;
+        }
+
+        tempInst = genKeyForSprLookup( i_regId );
+
+        if( *i_pSprEntryLocation == tempInst )
+        {
+            newEntry = false;
+        }
+
+        //Add SPR search instruction i.e. "ori r0, r0, SPRID"
+        *i_pSprEntryLocation = tempInst;
+        i_pSprEntryLocation += SIZE_PER_SPR_RESTORE_INST;
+
+        //clear R0 i.e. "xor ra, rs, rb"
+        tempInst = getXorInstruction( regRs, regRs, regRs );
+        *i_pSprEntryLocation = tempInst;
+        i_pSprEntryLocation += SIZE_PER_SPR_RESTORE_INST;
+
+        tempRegData = i_regData >> 48;
+        //get lower order 16 bits of SPR restore value in R0
+        tempInst = getOrisInstruction( regRs, regRa, (uint16_t)tempRegData );
+        *i_pSprEntryLocation = tempInst;
+        i_pSprEntryLocation += SIZE_PER_SPR_RESTORE_INST;
+
+        tempRegData = ((i_regData >> 32) & 0x0000FFFF );
+        //get bit b16-b31 of SPR restore value in R0
+        tempInst = getOriInstruction( regRs, regRa, (uint16_t)tempRegData );
+        *i_pSprEntryLocation = tempInst;
+        i_pSprEntryLocation += SIZE_PER_SPR_RESTORE_INST;
+
+        //Rotate R0 to left by  32 bit position and zero lower order 32 bits.
+        //Place the result in R0
+        tempInst = getRldicrInstruction(regRa, regRs, 32, 31);
+        *i_pSprEntryLocation = tempInst;
+        i_pSprEntryLocation += SIZE_PER_SPR_RESTORE_INST;
+
+        tempRegData = ((i_regData >> 16) & 0x000000FFFF );
+        //get bit b32-b47 of SPR restore value to R0
+        tempInst = getOrisInstruction( regRs, regRa, (uint16_t)tempRegData );
+        *i_pSprEntryLocation = tempInst;
+        i_pSprEntryLocation += SIZE_PER_SPR_RESTORE_INST;
+
+        tempRegData = (uint16_t)i_regData;
+        //get bit b48-b63 of SPR restore value to R0
+        tempInst = getOriInstruction( regRs, regRa, (uint16_t)i_regData );
+        *i_pSprEntryLocation = tempInst;
+        i_pSprEntryLocation += SIZE_PER_SPR_RESTORE_INST;
+
+        if( P9_STOP_SPR_MSR == i_regId )
+        {
+            //MSR cannot be restored completely with mtmsrd instruction.
+            //as it does not update ME, LE and HV bits. In self restore code
+            //inorder to restore MSR, contents of R21 is moved to SRR1. It also
+            //executes an RFID which causes contents of SRR1 to be copied to
+            //MSR. This allows copy of LE bit which are specifically interested
+            //in. Instruction below moves contents of MSR Value (in R0 ) to R21.
+            tempInst = SWIZZLE_4_BYTE( MR_R0_TO_R21 );
+        }
+        else if (P9_STOP_SPR_HRMOR == i_regId )
+        {
+            //Case HRMOR, move contents of R0 to a placeholder GPR (R10)
+            //Thread Launcher expects HRMOR value in R10
+            tempInst = SWIZZLE_4_BYTE( MR_R0_TO_R10 );
+        }
+        else
+        {
+            // Case other SPRs, move contents of R0 to SPR
+            tempInst =
+                getMtsprInstruction( 0, (uint16_t)i_regId );
+        }
+
+        *i_pSprEntryLocation = tempInst;
+
+        if( newEntry )
+        {
+            i_pSprEntryLocation += SIZE_PER_SPR_RESTORE_INST;
+            //at the end of SPR restore, add instruction BLR to go back to thread
+            //launcher.
+            tempInst = SWIZZLE_4_BYTE(BLR_INST);
+            *i_pSprEntryLocation = tempInst;
+        }
+    }
+    while(0);
+
+    return l_rc;
+}
+
+//-----------------------------------------------------------------------------
+
+StopReturnCode_t p9_stop_save_cpureg(  void* const i_pImage,
+                                       const CpuReg_t  i_regId,
+                                       const uint64_t  i_regData,
+                                       const uint64_t  i_pir )
+{
+    StopReturnCode_t l_rc = STOP_SAVE_SUCCESS;    // procedure return code
+    HomerSection_t* chipHomer = NULL;
+
+    do
+    {
+        uint32_t threadId = 0;
+        uint32_t coreId   = 0;
+        uint32_t lookUpKey = 0;
+        void* pSprEntryLocation = NULL;   // an offset w.r.t. to start of image
+        void* pThreadLocation = NULL;
+        bool threadScopeReg = false;
+
+        l_rc = getCoreAndThread( i_pImage, i_pir, &coreId, &threadId );
+
+        if( l_rc )
+        {
+            MY_ERR("Failed to determine Core Id and Thread Id from PIR 0x%016llx",
+                   i_pir);
+            break;
+        }
+
+        MY_INF( " PIR 0x%016llx coreId %d threadid %d "
+                " registerId %d", i_pir, coreId,
+                threadId, i_regId );
+
+        // First of all let us validate all input arguments.
+        l_rc =  validateSprImageInputs( i_pImage,
+                                        i_regId,
+                                        coreId,
+                                        &threadId,
+                                        &threadScopeReg );
+
+        if( l_rc )
+        {
+            // Error: bad argument traces out error code
+            MY_ERR("Bad input argument rc %d", l_rc );
+
+            break;
+        }
+
+        chipHomer = ( HomerSection_t*)i_pImage;
+
+        if( threadScopeReg )
+        {
+            pThreadLocation =
+                &(chipHomer->coreThreadRestore[coreId][threadId].threadArea[0]);
+        }
+        else
+        {
+            pThreadLocation =
+                &(chipHomer->coreThreadRestore[coreId][threadId].coreArea[0]);
+        }
+
+        if( ( SWIZZLE_4_BYTE(BLR_INST) == *(uint32_t*)pThreadLocation ) ||
+            ( SWIZZLE_4_BYTE(ATTN_OPCODE) == *(uint32_t*) pThreadLocation ) )
+        {
+            // table for given core id doesn't exit. It needs to be
+            // defined.
+            pSprEntryLocation = pThreadLocation;
+        }
+        else
+        {
+            // an SPR restore section for given core already exists
+            lookUpKey = genKeyForSprLookup( i_regId );
+            l_rc = lookUpSprInImage( (uint32_t*)pThreadLocation,
+                                     lookUpKey,
+                                     threadScopeReg,
+                                     &pSprEntryLocation );
+        }
+
+        if( l_rc )
+        {
+            MY_ERR("Invalid or corrupt SPR entry. CoreId 0x%08x threadId ",
+                   "0x%08x regId 0x%08x lookUpKey 0x%08x pThreadLocation 0x%08x"
+                   , coreId, threadId, i_regId, lookUpKey, pThreadLocation );
+            break;
+        }
+
+        l_rc = updateSprEntryInImage( (uint32_t*) pSprEntryLocation,
+                                      i_regId,
+                                      i_regData );
+
+        if( l_rc )
+        {
+            MY_ERR( " Failed to update the SPR entry of PIR 0x%08x reg"
+                    "0x%08x", i_pir, i_regId );
+            break;
+        }
+
+    }
+    while(0);
+
+    return l_rc;
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief validates all the input arguments.
+ * @param[in]   i_pImage       pointer to start of HOMER of image for proc chip.
+ * @param[in]   i_scomAddress SCOM address of register.
+ * @param[in]   i_chipletId   core or cache chiplet id
+ * @param[in]   i_operation   operation requested for SCOM entry.
+ * @param[in]   i_section     image section on which operation is to be performed
+ * @return      STOP_SAVE_SUCCESS if arguments found valid, error code otherwise.
+ * @note        Function does not validate that the given SCOM address really
+ *              belongs to the given section.
+ */
+static StopReturnCode_t validateScomImageInputs( void* const i_pImage,
+        const uint32_t i_scomAddress,
+        const uint8_t i_chipletId,
+        const ScomOperation_t i_operation,
+        const ScomSection_t i_section )
+{
+    StopReturnCode_t l_rc = STOP_SAVE_SUCCESS;
+
+    do
+    {
+        if( !i_pImage )
+        {
+            //Error Invalid image pointer
+            l_rc = STOP_SAVE_ARG_INVALID_IMG;
+            MY_ERR("invalid image location ");
+            break;
+        }
+
+        if( 0 == i_scomAddress )
+        {
+            l_rc = STOP_SAVE_SCOM_INVALID_ADDRESS;
+            MY_ERR("invalid SCOM address");
+            break;
+        }
+
+        if(( CACHE_CHIPLET_ID_MIN > i_chipletId ) ||
+           ( CORE_CHIPLET_ID_MAX < i_chipletId ))
+        {
+            l_rc = STOP_SAVE_SCOM_INVALID_CHIPLET;
+            MY_ERR("chiplet id not in range");
+            break;
+        }
+
+        if(( CORE_CHIPLET_ID_MIN >  i_chipletId ) &&
+           ( CACHE_CHIPLET_ID_MAX < i_chipletId ))
+        {
+            l_rc = STOP_SAVE_SCOM_INVALID_CHIPLET;
+            MY_ERR("chiplet id not valid");
+            break;
+        }
+
+        if(( P9_STOP_SCOM_OP_MIN >= i_operation ) ||
+           ( P9_STOP_SCOM_OP_MAX <= i_operation ))
+        {
+            //invalid SCOM image operation requested
+            l_rc = STOP_SAVE_SCOM_INVALID_OPERATION;
+            MY_ERR("invalid SCOM image operation");
+            break;
+        }
+
+        if(( P9_STOP_SECTION_MIN >= i_section ) ||
+           ( P9_STOP_SECTION_MAX <= i_section ))
+        {
+            // invalid cache sub section specified
+            l_rc = STOP_SAVE_SCOM_INVALID_SECTION;
+            MY_ERR("invalid section");
+            break;
+        }
+
+        if(( i_operation == P9_STOP_SCOM_RESET ) &&
+           ( i_chipletId <  CORE_CHIPLET_ID_MIN ))
+        {
+            // replace requested with a cache chiplet Id
+            l_rc = STOP_SAVE_SCOM_INVALID_OPERATION;
+            MY_ERR( "reset not supported for cache. chiplet Id 0x%08x",
+                    i_chipletId );
+            break;
+        }
+
+    }
+    while(0);
+
+    if( l_rc )
+    {
+        MY_ERR("image 0x%08x SCOMAddress 0x%08x chipletId 0x%08x operation"
+               "0x%08x section 0x%08x", i_pImage, i_scomAddress, i_chipletId,
+               i_operation, i_section );
+    }
+
+    return l_rc;
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief   edit SCOM entry associated with the given core.
+ * @param[in]   i_scomAddr       SCOM address of register.
+ * @param[in]   i_scomData      data associated with SCOM register.
+ * @param[in]   i_pEntryLocation points to a SCOM entry in HOMER image.
+ * @param[in]   i_operation     operation to be performed on SCOM entry.
+ * @return      STOP_SAVE_SUCCESS if existing entry is updated, STOP_SAVE_FAIL
+ *              otherwise.
+ */
+static StopReturnCode_t editScomEntry( uint32_t i_scomAddr, uint64_t i_scomData,
+                                       ScomEntry_t* i_pEntryLocation,
+                                       uint32_t i_operation )
+{
+    StopReturnCode_t l_rc = STOP_SAVE_SUCCESS;
+
+    do
+    {
+        if( !i_pEntryLocation )
+        {
+            //Error: location of SCOM entry is not known
+            //therefore no point moving forward
+            MY_ERR("SCOM entry location not valid");
+            l_rc = STOP_SAVE_FAIL;
+            break;
+        }
+
+        switch( i_operation )
+        {
+            case P9_STOP_SCOM_OR:
+                i_pEntryLocation->scomEntryData |= i_scomData;
+                break;
+
+            case P9_STOP_SCOM_AND:
+                i_pEntryLocation->scomEntryData &= i_scomData;
+                break;
+
+            case P9_STOP_SCOM_NOOP:
+                {
+                    uint32_t nopInst = getOriInstruction( 0, 0, 0 );
+                    i_pEntryLocation->scomEntryHeader = SWIZZLE_4_BYTE(SCOM_ENTRY_START);
+                    i_pEntryLocation->scomEntryData = nopInst;
+                    i_pEntryLocation->scomEntryAddress = nopInst;
+                }
+                break;
+
+            case P9_STOP_SCOM_APPEND:
+                i_pEntryLocation->scomEntryHeader = SWIZZLE_4_BYTE(SCOM_ENTRY_START);
+                i_pEntryLocation->scomEntryData = i_scomData;
+                i_pEntryLocation->scomEntryAddress = i_scomAddr;
+                break;
+        }
+
+    }
+    while(0);
+
+    return l_rc;
+}
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @brief   update SCOM entry associated with the given core.
+ * @param[in]   i_scomAddr   SCOM address of register.
+ * @param[in]   i_scomData   data associated with SCOM register.
+ * @param[in]   i_scomEntry  points to a SCOM entry in cache section of HOMER image.
+ * @return      STOP_SAVE_SUCCESS if new  entry is added, STOP_SAVE_FAIL otherwise.
+ * @note        adds an entry at a given location. It can be used to add entry in
+ *              place of NOP, at the end of table or as first entry of the cache
+ *              sub-section(L2, L3 or EQ ).
+ */
+static StopReturnCode_t updateScomEntry( uint32_t i_scomAddr, uint64_t i_scomData,
+        ScomEntry_t* i_scomEntry   )
+{
+    StopReturnCode_t l_rc = STOP_SAVE_SUCCESS;
+
+    do
+    {
+        if( !i_scomEntry )
+        {
+            MY_ERR( "cache entry cannot be located");
+            l_rc = STOP_SAVE_SCOM_ENTRY_UPDATE_FAILED;
+            break;
+        }
+
+        i_scomEntry->scomEntryHeader = SWIZZLE_4_BYTE(SCOM_ENTRY_START); // done for now
+        i_scomEntry->scomEntryAddress = i_scomAddr;
+        i_scomEntry->scomEntryData = i_scomData;
+
+    }
+    while(0);
+
+    return l_rc;
+}
+
+//-----------------------------------------------------------------------------
+
+StopReturnCode_t p9_stop_save_scom( void* const   i_pImage,
+                                    const uint32_t i_scomAddress,
+                                    const uint64_t i_scomData,
+                                    const ScomOperation_t i_operation,
+                                    const ScomSection_t i_section )
+{
+    StopReturnCode_t l_rc = STOP_SAVE_SUCCESS;
+    StopCacheSection_t* pStopCacheScomStart = NULL;
+    ScomEntry_t* pScomEntry = NULL;
+    uint32_t entryLimit = 0;
+    uint8_t chipletId = 0;
+
+    uint32_t nopInst;
+    ScomEntry_t* pEntryLocation = NULL;
+    ScomEntry_t* pNopLocation = NULL;
+    ScomEntry_t* pTableEndLocationtable = NULL;
+    uint32_t swizzleAddr;
+    uint64_t swizzleData;
+    uint32_t swizzleAttn;
+    uint32_t swizzleEntry;
+    uint32_t index = 0;
+    uint32_t swizzleBlr = SWIZZLE_4_BYTE(BLR_INST);
+
+    do
+    {
+        chipletId = i_scomAddress >> 24;
+        chipletId = chipletId & 0x3F;
+
+        l_rc = validateScomImageInputs( i_pImage,
+                                        i_scomAddress,
+                                        chipletId,
+                                        i_operation,
+                                        i_section );
+
+        if( l_rc )
+        {
+            MY_ERR( "invalid argument: aborting");
+            break;
+        }
+
+        if( chipletId >= CORE_CHIPLET_ID_MIN )
+        {
+            // chiplet is core. So, let us find the start address of SCOM area
+            // pertaining to a core in STOP image.
+            pScomEntry = CORE_ID_SCOM_START(i_pImage,
+                                            chipletId )
+                         entryLimit = MAX_CORE_SCOM_ENTRIES;
+        }
+        else
+        {
+            // chiplet is a cache. let us find start address of cache section
+            // associated with given chiplet. A cache section associated with
+            // given chiplet is split in to L2, L3 and EQ area.
+            pStopCacheScomStart = CACHE_SECTN_START(i_pImage,
+                                                    chipletId);
+        }
+
+        if(( !pStopCacheScomStart ) && ( !pScomEntry) )
+        {
+            //Error invalid pointer to SCOM entry in cache or core section
+            //of STOP image.
+            MY_ERR("invalid start location for chiplet %d",
+                   chipletId );
+            break;
+        }
+
+        switch( i_section )
+        {
+            case P9_STOP_SECTION_EQ_SCOM:
+                pScomEntry = pStopCacheScomStart->nonCacheArea;
+                entryLimit = MAX_EQ_SCOM_ENTRIES;
+                break;
+
+            case P9_STOP_SECTION_L2:
+                pScomEntry = pStopCacheScomStart->l2CacheArea;
+                entryLimit = MAX_L2_SCOM_ENTRIES;
+                break;
+
+            case P9_STOP_SECTION_L3:
+                pScomEntry = pStopCacheScomStart->l3CacheArea;
+                entryLimit = MAX_L3_SCOM_ENTRIES;
+                break;
+
+            case P9_STOP_SECTION_CORE_SCOM:
+                //macro CORE_ID_SCOM_START already gives start of scom
+                //entry for given core. entry limit too is assigned thereafter.
+                //Handling for core and cache segment is different for scom
+                //entries. It is because scom entries are organized differently
+                //in core and cache segment.
+                break;
+
+            default:
+                l_rc = STOP_SAVE_SCOM_INVALID_SECTION;
+                break;
+        }
+
+        if(( !pScomEntry ) || ( l_rc ) )
+        {
+            // Error Invalid pointer to cache entry
+            MY_ERR("invalid subsection %d or internal firmware failure",
+                   i_section );
+            l_rc = STOP_SAVE_FAIL;
+            break;
+        }
+
+        nopInst = getOriInstruction( 0, 0, 0 );
+        pEntryLocation = NULL;
+        pNopLocation = NULL;
+        pTableEndLocationtable = NULL;
+        swizzleAddr = SWIZZLE_4_BYTE(i_scomAddress);
+        swizzleData = SWIZZLE_8_BYTE(i_scomData);
+        swizzleAttn = SWIZZLE_4_BYTE(ATTN_OPCODE);
+        swizzleEntry = SWIZZLE_4_BYTE(SCOM_ENTRY_START);
+
+        for( index = 0; index < entryLimit; ++index )
+        {
+            uint32_t entrySwzAddress = pScomEntry[index].scomEntryAddress;
+
+            if( ( swizzleAddr == entrySwzAddress ) && ( !pEntryLocation ) )
+
+            {
+                pEntryLocation = &pScomEntry[index];
+            }
+
+            if( (( nopInst == entrySwzAddress ) ||
+                 ( swizzleAttn == entrySwzAddress ) ||
+                 ( swizzleBlr == entrySwzAddress )) && ( !pNopLocation ) )
+            {
+                pNopLocation = &pScomEntry[index];
+            }
+
+            if( swizzleEntry == pScomEntry[index].scomEntryHeader )
+            {
+                continue;
+            }
+
+            pTableEndLocationtable = &pScomEntry[index];
+            break;
+        }
+
+        if( ( !pEntryLocation ) && ( !pTableEndLocationtable ) )
+        {
+            MY_ERR(" exhausted all location available for section"
+                   "0x%08x scom address 0x%08x",
+                   i_section, i_scomAddress );
+            l_rc = STOP_SAVE_SCOM_ENTRY_UPDATE_FAILED;
+            break;
+        }
+
+        switch( i_operation )
+        {
+            case P9_STOP_SCOM_APPEND:
+                {
+                    ScomEntry_t* pScomAppend = NULL;
+
+                    if( pNopLocation )
+                    {
+                        pScomAppend = pNopLocation;
+                    }
+                    else
+                    {
+                        pScomAppend = pTableEndLocationtable;
+                    }
+
+                    l_rc = updateScomEntry ( swizzleAddr,
+                                             swizzleData, pScomAppend );
+                }
+                break;
+
+            case P9_STOP_SCOM_REPLACE:
+                {
+                    ScomEntry_t* scomReplace = NULL;
+
+                    if( pEntryLocation )
+                    {
+                        scomReplace = pEntryLocation;
+                    }
+                    else
+                    {
+                        scomReplace = pTableEndLocationtable;
+                    }
+
+                    l_rc = updateScomEntry( swizzleAddr,
+                                            swizzleData, scomReplace );
+                }
+                break;
+
+            case P9_STOP_SCOM_OR:
+            case P9_STOP_SCOM_AND:
+            case P9_STOP_SCOM_NOOP:
+
+                if( pEntryLocation )
+                {
+                    l_rc = editScomEntry( swizzleAddr,
+                                          swizzleData,
+                                          pEntryLocation,
+                                          i_operation );
+                }
+                else
+                {
+                    //Invalid operation requested.
+                    MY_ERR( "entry not found edit chiplet Id 0x%08x "
+                            "swizzle addr 0x%08x ",
+                            chipletId, swizzleAddr );
+
+                    l_rc = STOP_SAVE_SCOM_INVALID_OPERATION;
+                }
+
+                break;
+
+            case P9_STOP_SCOM_RESET:
+
+                if( P9_STOP_SECTION_CORE_SCOM ==  i_section )
+                {
+                    memset( pScomEntry, 0x00, CORE_SCOM_RESTORE_SIZE_PER_CORE );
+                }
+
+                break;
+
+            case P9_STOP_SCOM_OR_APPEND:
+            case P9_STOP_SCOM_AND_APPEND:
+                {
+                    uint32_t tempOperation = P9_STOP_SCOM_APPEND;
+                    ScomEntry_t* editAppend = NULL;
+
+                    if( NULL == pEntryLocation )
+                    {
+                        editAppend = pTableEndLocationtable;
+                    }
+                    else
+                    {
+                        editAppend = pEntryLocation;
+
+                        if( P9_STOP_SCOM_OR_APPEND == i_operation )
+                        {
+                            tempOperation = P9_STOP_SCOM_OR;
+                        }
+                        else
+                        {
+                            tempOperation = P9_STOP_SCOM_AND;
+                        }
+                    }
+
+                    l_rc = editScomEntry( swizzleAddr,
+                                          swizzleData,
+                                          editAppend,
+                                          tempOperation );
+                }
+                break;
+
+            default:
+                l_rc = STOP_SAVE_SCOM_INVALID_OPERATION;
+                break;
+        }
+
+    }
+    while(0);
+
+    if( l_rc )
+    {
+        MY_ERR("SCOM image operation 0x%08x failed for chiplet 0x%08x addr"
+               "0x%08x", i_operation, chipletId ,
+               i_scomAddress );
+    }
+
+    return l_rc;
+}
+
+
+#ifdef __cplusplus
+} //namespace stopImageSection ends
+
+}  //extern "C"
+#endif
diff --git a/libpore/p9_stop_api.H b/libpore/p9_stop_api.H
new file mode 100644
index 0000000..79abd00
--- /dev/null
+++ b/libpore/p9_stop_api.H
@@ -0,0 +1,163 @@ 
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/import/chips/p9/procedures/utils/stopreg/p9_stop_api.H $  */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2017                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+#ifndef __P9_STOP_IMAGE_API_
+#define __P9_STOP_IMAGE_API_
+
+#include <stdint.h>
+
+#ifdef __SKIBOOT__
+    #include <skiboot.h>
+#endif
+
+///
+/// @file   p9_stop_api.H
+/// @brief  describes STOP API which  create/manipulate STOP image.
+///
+// *HWP HW Owner    :  Greg Still <stillgs@us.ibm.com>
+// *HWP FW Owner    :  Prem Shanker Jha <premjha2@in.ibm.com>
+// *HWP Team        :  PM
+// *HWP Level       :  2
+// *HWP Consumed by :  HB:HYP
+
+#ifdef __cplusplus
+namespace stopImageSection
+{
+#endif
+
+/**
+ * @brief   all SPRs and MSR for which register restore is to be supported.
+ * @note    STOP API design has built in support to accomodate 8 register of
+ *          scope core and thread each.
+ */
+typedef enum
+{
+    P9_STOP_SPR_DAWR    =    180,   // thread register
+    P9_STOP_SPR_HSPRG0  =    304,   // thread register
+    P9_STOP_SPR_HRMOR   =    313,   // core register
+    P9_STOP_SPR_LPCR    =    318,   // thread register
+    P9_STOP_SPR_HMEER   =    337,   // core register
+    P9_STOP_SPR_LDBAR   =    850,   // thread register
+    P9_STOP_SPR_PSSCR   =    855,   // thread register
+    P9_STOP_SPR_PMCR    =    884,   // core register
+    P9_STOP_SPR_HID     =   1008,   // core register
+    P9_STOP_SPR_MSR     =   2000,   // thread register
+} CpuReg_t;
+
+/**
+ * @brief lists all the bad error codes.
+ */
+typedef enum
+{
+    STOP_SAVE_SUCCESS                    = 0,
+    STOP_SAVE_ARG_INVALID_IMG            = 1,
+    STOP_SAVE_ARG_INVALID_REG            = 2,
+    STOP_SAVE_ARG_INVALID_THREAD         = 3,
+    STOP_SAVE_ARG_INVALID_MODE           = 4,
+    STOP_SAVE_ARG_INVALID_CORE           = 5,
+    STOP_SAVE_SPR_ENTRY_NOT_FOUND        = 6,
+    STOP_SAVE_SPR_ENTRY_UPDATE_FAILED    = 7,
+    STOP_SAVE_SCOM_INVALID_OPERATION     = 8,
+    STOP_SAVE_SCOM_INVALID_SECTION       = 9,
+    STOP_SAVE_SCOM_INVALID_ADDRESS       = 10,
+    STOP_SAVE_SCOM_INVALID_CHIPLET       = 11,
+    STOP_SAVE_SCOM_ENTRY_UPDATE_FAILED   = 12,
+    STOP_SAVE_INVALID_FUSED_CORE_STATUS  = 13,
+    STOP_SAVE_FAIL                       = 14,  // for internal failure within firmware.
+} StopReturnCode_t;
+
+/**
+ * @brief summarizes all operations supported on scom entries of STOP image.
+ */
+typedef enum
+{
+    P9_STOP_SCOM_OP_MIN     = 0,
+    P9_STOP_SCOM_APPEND     = 1,
+    P9_STOP_SCOM_REPLACE    = 2,
+    P9_STOP_SCOM_OR         = 3,
+    P9_STOP_SCOM_AND        = 4,
+    P9_STOP_SCOM_NOOP       = 5,
+    P9_STOP_SCOM_RESET      = 6,
+    P9_STOP_SCOM_OR_APPEND  = 7,
+    P9_STOP_SCOM_AND_APPEND = 8,
+    P9_STOP_SCOM_OP_MAX     = 9
+} ScomOperation_t;
+
+/**
+ * @brief All subsections that contain scom entries in a STOP image.
+ */
+typedef enum
+{
+    P9_STOP_SECTION_MIN         = 0,
+    P9_STOP_SECTION_CORE_SCOM   = 1,
+    P9_STOP_SECTION_EQ_SCOM     = 2,
+    P9_STOP_SECTION_L2          = 3,
+    P9_STOP_SECTION_L3          = 4,
+    P9_STOP_SECTION_MAX         = 5
+} ScomSection_t;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+/**
+ * @brief   Updates STOP image entry associated with CPU register.
+ * @param[in]   i_pImage    start address of homer image associated with processor.
+ * @param[in]   i_regId     id of SPR for which STOP image needs to be updated.
+ * @param[in]   i_regData   data to be restored in SPR register.
+ * @param[in]   i_pir       value of processor identification register (PIR)
+ * @return      STOP_SAVE_SUCCESS SUCCESS if image is updated successfully, error
+ *              code otherwise.
+ */
+
+StopReturnCode_t p9_stop_save_cpureg(  void* const i_pImage,
+                                       const CpuReg_t  i_regId,
+                                       const uint64_t  i_regData,
+                                       const uint64_t  i_pir );
+
+/**
+ * @brief   Updates scom image entry associated with given core or cache in
+ *          STOP section of homer image.
+ * @param[in]   i_pImage        start address of homer image of P9 chip.
+ * @param[in]   i_scomAddress   fully qualified address of SCOM register.
+ * @param[in]   i_scomData      data associated with SCOM register.
+ * @param[in]   i_operation     operation to be done on SCOM image entry.
+ * @param[in]   i_section       area to which given SCOM entry belongs.
+ * @return      STOP_SAVE_SUCCESS if image is updated successfully, error code
+ *              otherwise.
+ * @note        API is intended to update SCOM image entry associated with given
+ *              core or given part of a cache section. API doesn't validate if
+ *              a given SCOM address really belongs to given section.
+ */
+StopReturnCode_t p9_stop_save_scom( void* const   i_pImage,
+                                    const uint32_t i_scomAddress,
+                                    const uint64_t i_scomData,
+                                    const ScomOperation_t i_operation,
+                                    const ScomSection_t i_section );
+
+#ifdef __cplusplus
+} // extern "C"
+};  // namespace stopImageSection ends
+#endif //__cplusplus
+
+#endif //__P9_STOP_IMAGE_API_
diff --git a/libpore/p9_stop_data_struct.H b/libpore/p9_stop_data_struct.H
new file mode 100644
index 0000000..2201021
--- /dev/null
+++ b/libpore/p9_stop_data_struct.H
@@ -0,0 +1,149 @@ 
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/import/chips/p9/procedures/utils/stopreg/p9_stop_data_struct.H $ */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2017                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+
+///
+/// @file   p9_stop_data_struct.H
+/// @brief  describes data structures internal to STOP API.
+///
+// *HWP HW Owner    :  Greg Still <stillgs@us.ibm.com>
+// *HWP FW Owner    :  Prem Shanker Jha <premjha2@in.ibm.com>
+// *HWP Team        :  PM
+// *HWP Level       :  2
+// *HWP Consumed by :  HB:HYP
+#ifndef __STOP_DATA_STRUCT_
+#define __STOP_DATA_STRUCT_
+
+#ifndef  _AIX
+    #include <endian.h>
+#endif
+
+#include "p9_hcd_memmap_base.H"
+
+#ifdef __SKIBOOT__
+    #include <skiboot.h>
+#endif
+
+#ifdef __FAPI_2_
+    #include <fapi2.H>
+#endif
+
+
+#ifdef __cplusplus
+extern "C" {
+namespace stopImageSection
+{
+#endif
+
+enum
+{
+    MAX_SPR_RESTORE_INST = 0x08,
+    SIZE_PER_SPR_RESTORE_INST = ((4 * sizeof(uint8_t)) / sizeof(uint32_t)),
+};
+
+typedef struct
+{
+    uint32_t scomEntryHeader;
+    uint32_t scomEntryAddress;
+    uint64_t scomEntryData;
+} ScomEntry_t;
+
+/**
+ * @brief models a CPU register restoration area in STOP section of homer image.
+ */
+typedef struct
+{
+    uint8_t threadArea[CORE_RESTORE_THREAD_AREA_SIZE];
+    uint8_t coreArea[CORE_RESTORE_CORE_AREA_SIZE];
+} SprRestoreArea_t;
+
+/**
+ * @brief   models homer image of a chip.
+ * @note    sections not relevant for CPU register restoration have been
+ * abstracted using field 'reserve'.
+ */
+typedef struct
+{
+    uint8_t occ_host_sgpe_area[ TWO_MB ];  // CPU restore area starts at an offset of 2MB from chip HOMER
+    uint8_t interrruptHandler[SELF_RESTORE_INT_SIZE];
+    uint8_t threadLauncher[THREAD_LAUNCHER_SIZE];
+    SprRestoreArea_t coreThreadRestore[MAX_CORES_PER_CHIP][MAX_THREADS_PER_CORE];
+    uint8_t reserve[(ONE_KB * ONE_KB) - SELF_RESTORE_SIZE_TOTAL];
+} HomerSection_t;
+
+/**
+ * @brief models cache subsection in STOP section of a given homer image.
+ * @note    given the start of cache subsection associated with a given core,
+ *          the structure below represents what a cache subsection would look
+ *          like. Based on known start address, quick traversing can be done
+ *          within the cache subsection.
+ */
+typedef struct
+{
+    ScomEntry_t  nonCacheArea[MAX_EQ_SCOM_ENTRIES];
+    ScomEntry_t  l2CacheArea[MAX_L2_SCOM_ENTRIES];
+    ScomEntry_t  l3CacheArea[MAX_L3_SCOM_ENTRIES];
+} StopCacheSection_t;
+
+/**
+ * @brief summarizes attributes associated with a SPR register.
+ */
+typedef struct
+{
+    uint32_t sprId;
+    bool isThreadScope;
+} StopSprReg_t;
+
+enum
+{
+    SIZE_SCOM_ENTRY = sizeof( ScomEntry_t ),
+    SCOM_ENTRY_START = 0xDEADDEAD,
+};
+
+#ifdef __FAPI_2_
+    #define MY_ERR( _fmt_, _args_...)  FAPI_ERR(_fmt_, ##_args_)
+    #define MY_INF(_fmt_, _args_...) FAPI_INF(_fmt_, ##_args_)
+#else
+    #define MY_ERR( _fmt_, _args_...)
+    #define MY_INF(_fmt_, _args_...)
+#endif
+
+#define CORE_ID_SCOM_START(io_image,\
+                           i_chipletId) \
+((ScomEntry_t*)(((uint8_t*)(io_image)) + CORE_SCOM_RESTORE_HOMER_OFFSET +\
+                ((i_chipletId - CORE_CHIPLET_ID_MIN) * \
+                 CORE_SCOM_RESTORE_SIZE_PER_CORE)));
+
+#define CACHE_SECTN_START(io_image,\
+                          i_chipletId) \
+((StopCacheSection_t *)(((uint8_t *)(io_image)) + QUAD_SCOM_RESTORE_HOMER_OFFSET +\
+                        ((i_chipletId - CACHE_CHIPLET_ID_MIN) * \
+                         QUAD_SCOM_RESTORE_SIZE_PER_QUAD)));
+#ifdef __cplusplus
+}  // extern "C"
+
+} //namespace stopImageSection ends
+#endif //__cplusplus
+
+#endif
diff --git a/libpore/p9_stop_util.C b/libpore/p9_stop_util.C
new file mode 100644
index 0000000..f751594
--- /dev/null
+++ b/libpore/p9_stop_util.C
@@ -0,0 +1,187 @@ 
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/import/chips/p9/procedures/utils/stopreg/p9_stop_util.C $ */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2017                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+
+///
+/// @file   p9_stop_util.C
+/// @brief  implements some utilty functions for STOP API.
+///
+// *HWP HW Owner    :  Greg Still <stillgs@us.ibm.com>
+// *HWP FW Owner    :  Prem Shanker Jha <premjha2@in.ibm.com>
+// *HWP Team        :  PM
+// *HWP Level       :  2
+// *HWP Consumed by :  HB:HYP
+
+#include "p9_stop_api.H"
+#include "p9_stop_util.H"
+#include "p9_stop_data_struct.H"
+
+#ifdef __cplusplus
+namespace stopImageSection
+{
+#endif
+
+/**
+ * @brief   Returns proc chip's fuse mode status.
+ * @param   i_pImage    points to start of chip's HOMER image.
+ * @param   o_fusedMode  points to fuse mode information.
+ * @return  STOP_SAVE_SUCCESS if functions succeeds, error code otherwise.
+ */
+static StopReturnCode_t  isFusedMode( void* const i_pImage, bool* o_fusedMode )
+{ 
+    uint64_t cpmrCheckWord;
+    StopReturnCode_t l_rc = STOP_SAVE_SUCCESS;
+    *o_fusedMode = false;
+
+    do
+    {
+        HomerSection_t* pHomerDesc = ( HomerSection_t* ) i_pImage;
+        HomerImgDesc_t* pHomer =  (HomerImgDesc_t*)( pHomerDesc->interrruptHandler );
+
+        if( !i_pImage )
+        {
+            MY_ERR( "invalid pointer to HOMER image");
+            l_rc = STOP_SAVE_ARG_INVALID_IMG;
+            break;
+        }
+
+
+        cpmrCheckWord = SWIZZLE_8_BYTE(pHomer->cpmrMagicWord);
+        cpmrCheckWord = cpmrCheckWord >> 32;
+
+        if( CPMR_REGION_CHECK_WORD != cpmrCheckWord )
+        {
+            MY_ERR("corrupt or invalid HOMER image location 0x%016llx",
+                   SWIZZLE_8_BYTE(pHomer->cpmrMagicWord) );
+            l_rc = STOP_SAVE_ARG_INVALID_IMG;
+            break;
+        }
+
+        if( (uint8_t) FUSED_CORE_MODE == pHomer->fusedModeStatus )
+        {
+            *o_fusedMode = true;
+            break;
+        }
+
+        if( (uint8_t) NONFUSED_CORE_MODE == pHomer->fusedModeStatus )
+        {
+            break;
+        }
+
+        MY_ERR("Unexpected value 0x%08x for fused mode. Bad or corrupt "
+               "HOMER location", pHomer->fuseModeStatus );
+        l_rc = STOP_SAVE_INVALID_FUSED_CORE_STATUS ;
+
+    }
+    while(0);
+
+    return l_rc;
+}
+
+//----------------------------------------------------------------------
+
+StopReturnCode_t getCoreAndThread( void* const i_pImage, const uint64_t i_pir,
+                                   uint32_t* o_pCoreId, uint32_t* o_pThreadId )
+{
+    StopReturnCode_t l_rc = STOP_SAVE_SUCCESS;
+
+    do
+    {
+        // for SPR restore using 'Virtual Thread' and 'Physical Core' number
+        // In Fused Mode:
+        // bit b28 and b31 of PIR give physical core and b29 and b30 gives
+        // virtual thread id.
+        // In Non Fused Mode
+        // bit 28 and b29 of PIR give both logical and physical core number
+        // whereas b30 and b31 gives logical and virtual thread id.
+        bool fusedMode = false;
+        uint8_t coreThreadInfo = (uint8_t)i_pir;
+        *o_pCoreId = 0;
+        *o_pThreadId = 0;
+        l_rc = isFusedMode( i_pImage, &fusedMode );
+
+        if( l_rc )
+        {
+            MY_ERR(" Checking Fused mode. Read failed 0x%08x", l_rc );
+            break;
+        }
+
+        if( fusedMode )
+        {
+            if( coreThreadInfo & FUSED_CORE_BIT1 )
+            {
+                *o_pThreadId = 2;
+            }
+
+            if( coreThreadInfo & FUSED_CORE_BIT2 )
+            {
+                *o_pThreadId += 1;
+            }
+
+            if( coreThreadInfo & FUSED_CORE_BIT0 )
+            {
+                *o_pCoreId = 2;
+            }
+
+            if( coreThreadInfo & FUSED_CORE_BIT3 )
+            {
+                *o_pCoreId += 1;
+            }
+        }
+        else
+        {
+            if( coreThreadInfo & FUSED_CORE_BIT0 )
+            {
+                *o_pCoreId = 2;
+            }
+
+            if ( coreThreadInfo & FUSED_CORE_BIT1 )
+            {
+                *o_pCoreId += 1;
+            }
+
+            if( coreThreadInfo & FUSED_CORE_BIT2 )
+            {
+                *o_pThreadId = 2;
+            }
+
+            if( coreThreadInfo & FUSED_CORE_BIT3 )
+            {
+                *o_pThreadId += 1;
+            }
+        }
+
+        MY_INF("Core Type %s", fusedMode ? "Fused" : "Un-Fused" );
+        //quad field is not affected by fuse mode
+        *o_pCoreId += 4 * (( coreThreadInfo & 0x70 ) >> 4 );
+    }
+    while(0);
+
+    return l_rc;
+}
+
+#ifdef __cplusplus
+}//namespace stopImageSection ends
+#endif
+
diff --git a/libpore/p9_stop_util.H b/libpore/p9_stop_util.H
new file mode 100644
index 0000000..3266fde
--- /dev/null
+++ b/libpore/p9_stop_util.H
@@ -0,0 +1,145 @@ 
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/import/chips/p9/procedures/hwp/lib/p9_stop_util.H $       */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2016,2017                        */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+#ifndef __P9_STOP_UTIL_
+#define __P9_STOP_UTIL_
+
+#ifdef _AIX
+    #define __BYTE_ORDER __BIG_ENDIAN
+#elif __SKIBOOT__
+    #include <skiboot.h>
+#else
+    #include <endian.h>
+#endif
+
+#ifndef __PPE_PLAT
+    #include "p9_stop_api.H"
+#endif
+
+#ifdef FAPI_2
+    #include <fapi2.H>
+#endif
+
+///
+/// @file   p9_stop_util.H
+/// @brief  describes some utilty functions for STOP API.
+///
+// *HWP HW Owner    :  Greg Still <stillgs@us.ibm.com>
+// *HWP FW Owner    :  Prem Shanker Jha <premjha2@in.ibm.com>
+// *HWP Team        :  PM
+// *HWP Level       :  2
+// *HWP Consumed by :  HB:HYP
+#ifndef __PPE_PLAT
+#ifdef __cplusplus
+namespace stopImageSection
+{
+#endif
+#endif  //__PPE_PLAT
+/**
+ * @brief  helper function to swizzle given input data
+ * @note   swizles bytes to handle endianess issue.
+ */
+#if( __BYTE_ORDER == __BIG_ENDIAN )
+
+// NOP if it is a big endian system
+#define SWIZZLE_2_BYTE(WORD) WORD
+#define SWIZZLE_4_BYTE(WORD) WORD
+#define SWIZZLE_8_BYTE(WORD) WORD
+
+#else
+#define SWIZZLE_2_BYTE(WORD) \
+    ( (((WORD) >> 8) & 0x00FF) | (((WORD) << 8) & 0xFF00) )
+
+#define SWIZZLE_4_BYTE(WORD) \
+    ( (((WORD) >> 24) & 0x000000FF) | (((WORD) >>  8) & 0x0000FF00) | \
+      (((WORD) <<  8) & 0x00FF0000) | (((WORD) << 24) & 0xFF000000) )
+
+#define SWIZZLE_8_BYTE(WORD) \
+    ( (((WORD) >> 56) & 0x00000000000000FF) |  \
+      (((WORD) >> 40) & 0x000000000000FF00)| \
+      (((WORD) >> 24) & 0x0000000000FF0000) |  \
+      (((WORD) >>  8) & 0x00000000FF000000) |  \
+      (((WORD) <<  8) & 0x000000FF00000000) |  \
+      (((WORD) << 24) & 0x0000FF0000000000) | \
+      (((WORD) << 40) & 0x00FF000000000000) |  \
+      (((WORD) << 56) & 0xFF00000000000000) )
+#endif
+
+/**
+ * @brief   describes details of CPMR header in HOMER.
+ */
+typedef struct
+{
+    uint64_t attnOpcodes;
+    uint64_t cpmrMagicWord;
+    uint32_t buildDate;
+    uint32_t version;
+    uint8_t  reserve1[7];
+    uint8_t  fusedModeStatus;
+    uint32_t cmeImgOffset;
+    uint32_t cmeImgLength;
+    uint32_t cmeCommonRingOffset;
+    uint32_t cmeCommonRingLength;
+    uint32_t cmePstateOffset;
+    uint32_t cmePstateLength;
+    uint32_t coreSpecRingOffset;
+    uint32_t coreSpecRingLen;
+    uint32_t coreScomOffset;
+    uint32_t coreScomLength;
+    uint32_t reserve2[184];
+} HomerImgDesc_t;
+
+/**
+ * @brief enumerates bit(s) positions of interest for PIR.
+ */
+enum
+{
+    FUSED_CORE_BIT0 = 0x08,
+    FUSED_CORE_BIT1 = 0x04,
+    FUSED_CORE_BIT2 = 0x02,
+    FUSED_CORE_BIT3 = 0x01,
+    QUAD_BITS = 0x70
+};
+
+#ifndef __PPE_PLAT
+/**
+ * @brief   returns core id and thread id by parsing a given PIR.
+ * @param   i_pStopImage    points to STOP image associated with a proc chip.
+ * @param   i_pir           PIR associated with a core's thread.
+ * @param   o_coreId        points to core id value obtained from PIR.
+ * @param   o_threadId      points to thread id value obtained from PIR.
+ * @return  SUCCESS if function suceeds, error code otherwise.
+ */
+StopReturnCode_t getCoreAndThread( void* const i_pStopImage,
+                                   const uint64_t i_pir,
+                                   uint32_t* o_coreId,
+                                   uint32_t* o_threadId );
+#ifdef __cplusplus
+} // namespace stopImageSection ends
+
+#endif
+#endif //__PPE_PLAT
+#endif
+
+