diff --git a/arch/powerpc/cpu/ppc4xx/cpu_init.c b/arch/powerpc/cpu/ppc4xx/cpu_init.c
index bf208ad..2f3a802 100644
--- a/arch/powerpc/cpu/ppc4xx/cpu_init.c
+++ b/arch/powerpc/cpu/ppc4xx/cpu_init.c
@@ -221,6 +221,66 @@ void reconfigure_pll(u32 new_cpu_freq)
 #endif
 }
 
+#ifdef CONFIG_SYS_4xx_CHIP_21_ERRATA
+void
+chip_21_errata(void)
+{
+	/*
+	 * See rev 1.09 of the 405EX/405EXr errata.  CHIP_21 says that
+	 * sometimes reading the PVR and/or SDR0_ECID results in incorrect
+	 * values.  Since the rev-D chip uses the SDR0_ECID bits to control
+	 * internal features, that means the second PCIe or ethernet of an EX
+	 * variant could fail to work.  Also, security features of both EX and
+	 * EXr might be incorrectly disabled.
+	 *
+	 * The suggested workaround is as follows (covering rev-C and rev-D):
+	 *
+	 * 1.Read the PVR and SDR0_ECID3.
+	 *
+	 * 2.If the PVR matches an expected Revision C PVR value AND if
+	 * SDR0_ECID3[12:15] is different from PVR[28:31], then – processor is
+	 * Revision C: continue executing the initialization code (no reset
+	 * required).  else – go to step 3.
+	 *
+	 * 3.If the PVR matches an expected Revision D PVR value AND if
+	 * SDR0_ECID3[10:11] matches its expected value, then – continue
+	 * executing initialization code, no reset required.  else – write
+	 * DBCR0[RST] = 0b11 to generate a SysReset.
+	 */
+
+	u32 pvr;
+	u32 pvr_28_31;
+	u32 ecid3;
+	u32 ecid3_10_11;
+	u32 ecid3_12_15;
+
+	/* Step 1: */
+	pvr = get_pvr();
+	mfsdr(SDR0_ECID3, ecid3);
+
+	/* Step 2: */
+	pvr_28_31 = pvr & 0xf;
+	ecid3_10_11 = (ecid3 >> 20) & 0x3;
+	ecid3_12_15 = (ecid3 >> 16) & 0xf;
+	if ((pvr == CONFIG_405EX_CHIP21_PVR_REV_C) &&
+			(pvr_28_31 != ecid3_12_15)) {
+		/* No reset required. */
+		return;
+	}
+
+	/* Step 3: */
+	if ((pvr == CONFIG_405EX_CHIP21_PVR_REV_D) &&
+			(ecid3_10_11 == CONFIG_405EX_CHIP21_ECID3_REV_D)) {
+		/* No reset required. */
+		return;
+	}
+
+	/* Reset required. */
+	__asm__ __volatile__ ("sync; isync");
+	mtspr(SPRN_DBCR0, 0x30000000);
+}
+#endif
+
 /*
  * Breath some life into the CPU...
  *
@@ -235,6 +295,10 @@ cpu_init_f (void)
 	u32 val;
 #endif
 
+#ifdef CONFIG_SYS_4xx_CHIP_21_ERRATA
+	chip_21_errata();
+#endif
+
 	reconfigure_pll(CONFIG_SYS_PLL_RECONFIG);
 
 #if (defined(CONFIG_405EP) || defined (CONFIG_405EX)) && \
diff --git a/arch/powerpc/include/asm/ppc405ex.h b/arch/powerpc/include/asm/ppc405ex.h
index 36d3149..8070385 100644
--- a/arch/powerpc/include/asm/ppc405ex.h
+++ b/arch/powerpc/include/asm/ppc405ex.h
@@ -43,6 +43,11 @@
 #define SDR0_PFC1		0x4101
 #define SDR0_MFR		0x4300	/* SDR0_MFR reg */
 
+#define SDR0_ECID0		0x0080
+#define SDR0_ECID1		0x0081
+#define SDR0_ECID2		0x0082
+#define SDR0_ECID3		0x0083
+
 #define SDR0_SDCS_SDD		(0x80000000 >> 31)
 
 #define SDR0_SRST_DMC		(0x80000000 >> 10)
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index f5bf4dd..68f9868 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -974,6 +974,37 @@
 #define PVR_5200B	0x80822014
 
 /*
+ * CHIP_21 Errata
+ */
+#ifdef CONFIG_SYS_4xx_CHIP_21_405EX_SECURITY
+#define CONFIG_SYS_4xx_CHIP_21_ERRATA
+#define CONFIG_405EX_CHIP21_PVR_REV_C	PVR_405EX1_RC
+#define CONFIG_405EX_CHIP21_PVR_REV_D	PVR_405EX1_RD
+#define CONFIG_405EX_CHIP21_ECID3_REV_D	0x0
+#endif
+
+#ifdef CONFIG_SYS_4xx_CHIP_21_405EX_NO_SECURITY
+#define CONFIG_SYS_4xx_CHIP_21_ERRATA
+#define CONFIG_405EX_CHIP21_PVR_REV_C	PVR_405EX2_RC
+#define CONFIG_405EX_CHIP21_PVR_REV_D	PVR_405EX2_RD
+#define CONFIG_405EX_CHIP21_ECID3_REV_D	0x1
+#endif
+
+#ifdef CONFIG_SYS_4xx_CHIP_21_405EXr_SECURITY
+#define CONFIG_SYS_4xx_CHIP_21_ERRATA
+#define CONFIG_405EX_CHIP21_PVR_REV_C	PVR_405EXR1_RC
+#define CONFIG_405EX_CHIP21_PVR_REV_D	PVR_405EXR1_RD
+#define CONFIG_405EX_CHIP21_ECID3_REV_D	0x2
+#endif
+
+#ifdef CONFIG_SYS_4xx_CHIP_21_405EXr_NO_SECURITY
+#define CONFIG_SYS_4xx_CHIP_21_ERRATA
+#define CONFIG_405EX_CHIP21_PVR_REV_C	PVR_405EXR2_RC
+#define CONFIG_405EX_CHIP21_PVR_REV_D	PVR_405EXR2_RD
+#define CONFIG_405EX_CHIP21_ECID3_REV_D	0x3
+#endif
+
+/*
  * System Version Register
  */
 
diff --git a/include/configs/kilauea.h b/include/configs/kilauea.h
index 031f8fb..2be1104 100644
--- a/include/configs/kilauea.h
+++ b/include/configs/kilauea.h
@@ -44,6 +44,12 @@
 #endif
 
 /*
+ * CHIP_21 errata - you must set this to match your CPU, else the board
+ * will not boot.
+ */
+#define CONFIG_SYS_4xx_CHIP_21_405EX_NO_SECURITY
+
+/*
  * Include common defines/options for all AMCC eval boards
  */
 #define CONFIG_HOSTNAME		kilauea
