diff --git a/arch/powerpc/cpu/mpc85xx/cpu_init.c b/arch/powerpc/cpu/mpc85xx/cpu_init.c
index 6f256cf..aafb007 100644
--- a/arch/powerpc/cpu/mpc85xx/cpu_init.c
+++ b/arch/powerpc/cpu/mpc85xx/cpu_init.c
@@ -239,6 +239,13 @@ void cpu_init_f (void)
 	disable_tlb(14);
 	disable_tlb(15);
 
+#ifdef CONFIG_SYS_ESBC_FLASH
+	/* Disable the LAW created for NOR flash by the PBI commands */
+	struct law_entry law = find_law(CONFIG_SYS_PBI_FLASH_BASE);
+	if (law.index != -1)
+		disable_law(law.index);
+#endif
+
 #ifdef CONFIG_CPM2
 	config_8560_ioports((ccsr_cpm_t *)CONFIG_SYS_MPC85xx_CPM_ADDR);
 #endif
diff --git a/arch/powerpc/cpu/mpc85xx/cpu_init_early.c b/arch/powerpc/cpu/mpc85xx/cpu_init_early.c
index 32aa94b..58397ec 100644
--- a/arch/powerpc/cpu/mpc85xx/cpu_init_early.c
+++ b/arch/powerpc/cpu/mpc85xx/cpu_init_early.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2009 Freescale Semiconductor, Inc
+ * Copyright 2009-2011 Freescale Semiconductor, Inc
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -108,5 +108,13 @@ void cpu_init_early_f(void)
 
 	init_laws();
 	invalidate_tlb(0);
+
+#if defined(CONFIG_SECURE_BOOT)
+/* Disable the TLBs created by ISBC */
+	for (i = CONFIG_SYS_ISBC_START_TLB;
+	     i < CONFIG_SYS_ISBC_START_TLB + CONFIG_SYS_ISBC_NUM_TLBS; i++)
+			disable_tlb(i);
+#endif
+
 	init_tlbs();
 }
diff --git a/arch/powerpc/cpu/mpc85xx/start.S b/arch/powerpc/cpu/mpc85xx/start.S
index 5777493..0caa336 100644
--- a/arch/powerpc/cpu/mpc85xx/start.S
+++ b/arch/powerpc/cpu/mpc85xx/start.S
@@ -88,6 +88,45 @@
 
 _start_e500:
 
+#ifdef CONFIG_SECURE_BOOT
+	/* ISBC uses L2 as stack.
+	Disable L2 cache here so that u-boot can enable it later
+	as part of it's normal flow
+	*/
+
+	/* Check if L2 is enabled */
+	mfspr	r3, SPRN_L2CSR0
+	lis	r2, L2CSR0_L2E@h
+	ori	r2, r2, L2CSR0_L2E@l
+	and.	r4, r3, r2
+	beq	l2_disabled
+
+	mfspr r3, SPRN_L2CSR0
+	/* Flush L2 cache */
+	lis     r2,(L2CSR0_L2FL)@h
+	ori     r2, r2, (L2CSR0_L2FL)@l
+	or      r3, r2, r3
+	sync
+	isync
+	mtspr   SPRN_L2CSR0,r3
+	isync
+1:
+	mfspr r3, SPRN_L2CSR0
+	and. r1, r3, r2
+	bne 1b
+
+	mfspr r3, SPRN_L2CSR0
+	lis r2, L2CSR0_L2E@h
+	ori r2, r2, L2CSR0_L2E@l
+	andc r4, r3, r2
+	sync
+	isync
+	mtspr SPRN_L2CSR0,r4
+	isync
+
+l2_disabled:
+#endif
+
 /* clear registers/arrays not reset by hardware */
 
 	/* L1 */
@@ -287,7 +326,7 @@ _start_e500:
 	lis     r6,FSL_BOOKE_MAS0(1, 15, 0)@h
 	ori     r6,r6,FSL_BOOKE_MAS0(1, 15, 0)@l
 
-#ifndef CONFIG_SYS_RAMBOOT
+#if !defined(CONFIG_SYS_RAMBOOT) && !defined(CONFIG_SECURE_BOOT)
 	/* create a temp mapping in AS=1 to the 4M boot window */
 	lis     r7,FSL_BOOKE_MAS1(1, 1, 0, 1, BOOKE_PAGESZ_4M)@h
 	ori     r7,r7,FSL_BOOKE_MAS1(1, 1, 0, 1, BOOKE_PAGESZ_4M)@l
@@ -298,6 +337,18 @@ _start_e500:
 	/* The 85xx has the default boot window 0xff800000 - 0xffffffff */
 	lis     r9,FSL_BOOKE_MAS3(0xffc00000, 0, (MAS3_SX|MAS3_SW|MAS3_SR))@h
 	ori     r9,r9,FSL_BOOKE_MAS3(0xffc00000, 0, (MAS3_SX|MAS3_SW|MAS3_SR))@l
+#elif defined(CONFIG_SECURE_BOOT)
+	/* create a temp mapping in AS = 1 for Flash mapping
+	 * created by PBL for ISBC code
+	*/
+	lis     r7,FSL_BOOKE_MAS1(1, 1, 0, 1, BOOKE_PAGESZ_1M)@h
+	ori     r7,r7,FSL_BOOKE_MAS1(1, 1, 0, 1, BOOKE_PAGESZ_1M)@l
+
+	lis     r8,FSL_BOOKE_MAS2(CONFIG_SYS_MONITOR_BASE, (MAS2_I|MAS2_G))@h
+	ori     r8,r8,FSL_BOOKE_MAS2(CONFIG_SYS_MONITOR_BASE, (MAS2_I|MAS2_G))@l
+
+	lis     r9,FSL_BOOKE_MAS3(CONFIG_SYS_PBI_FLASH_WINDOW, 0, (MAS3_SX|MAS3_SW|MAS3_SR))@h
+	ori     r9,r9,FSL_BOOKE_MAS3(CONFIG_SYS_PBI_FLASH_WINDOW, 0, (MAS3_SX|MAS3_SW|MAS3_SR))@l
 #else
 	/*
 	 * create a temp mapping in AS=1 to the 1M CONFIG_SYS_MONITOR_BASE space, the main
diff --git a/arch/powerpc/include/asm/fsl_secure_boot.h b/arch/powerpc/include/asm/fsl_secure_boot.h
new file mode 100644
index 0000000..786a98e
--- /dev/null
+++ b/arch/powerpc/include/asm/fsl_secure_boot.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2010-2011 Freescale Semiconductor, Inc.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __FSL_SECURE_BOOT_H
+#define __FSL_SECURE_BOOT_H
+
+/* This define indicates that u-boot's code is executing from flash
+ * after ISBC Validation */
+#define CONFIG_SYS_ESBC_FLASH
+
+/*Starting TLB number for the TLB entried for 3.5 G space created by ISBC */
+#define CONFIG_SYS_ISBC_START_TLB		3
+
+/* Number fo TLB's created by ISBC */
+#define CONFIG_SYS_ISBC_NUM_TLBS		5
+
+/* Address map where flash lies as done by PBI commands */
+#define CONFIG_SYS_PBI_FLASH_BASE		0xc0000000
+#define CONFIG_SYS_PBI_FLASH_WINDOW		0xcff80000
+
+#endif
diff --git a/boards.cfg b/boards.cfg
index cc1ae6c..6ffcd96 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -545,6 +545,7 @@ P2020RDB_SDCARD              powerpc     mpc85xx     p1_p2_rdb           freesca
 P2020RDB_SPIFLASH            powerpc     mpc85xx     p1_p2_rdb           freescale      -           P1_P2_RDB:P2020RDB,SPIFLASH
 P4080DS                      powerpc     mpc85xx     corenet_ds          freescale
 P4080DS_RAMBOOT_PBL          powerpc     mpc85xx     corenet_ds          freescale      -           P4080DS:RAMBOOT_PBL,SYS_TEXT_BASE=0xFFF80000
+P4080DS_SECURE_BOOT          powerpc     mpc85xx     corenet_ds          freescale      -           P4080DS:SECURE_BOOT
 mpq101                       powerpc     mpc85xx     mpq101              mercury        -           mpq101
 stxgp3                       powerpc     mpc85xx     stxgp3              stx
 stxssa                       powerpc     mpc85xx     stxssa              stx            -           stxssa
diff --git a/include/configs/corenet_ds.h b/include/configs/corenet_ds.h
index 2bd2553..9bc9017 100644
--- a/include/configs/corenet_ds.h
+++ b/include/configs/corenet_ds.h
@@ -607,4 +607,8 @@
 
 #define CONFIG_BOOTCOMMAND		CONFIG_HDBOOT
 
+#ifdef CONFIG_SECURE_BOOT
+#include <asm/fsl_secure_boot.h>
+#endif
+
 #endif	/* __CONFIG_H */
