diff --git a/CHANGELOG b/CHANGELOG
index 34b8d20ebb..16b50e96f9 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -33,6 +33,24 @@ Changes since U-Boot 1.1.4:
 * Add support for Lite5200B board.
   Patch by  Patch by Jose Maria (Txema) Lopez, 16 Jan 2006
 
+* Updates to common PPC4xx onboard (DDR)SDRAM init code (405 and 440)
+
+  405 SDRAM: - The SDRAM parameters can now be defined in the board
+               config file and the 405 SDRAM controller values will
+               be calculated upon bootup (see PPChameleonEVB).
+               When those settings are not defined in the board
+               config file, the register setup will be as it is now,
+               so this implementation should not break any current
+               design using this code.
+
+               Thanks to Andrea Marson from DAVE for this patch.
+
+  440 DDR:   - Added function sdram_tr1_set to auto calculate the
+               TR1 value for the DDR.
+             - Added ECC support (see p3p440).
+
+  Patch by Stefan Roese, 17 Mar 2006
+
 * Apply SoC concept to arm926ejs CPUs, i.e. move the SoC specific
   timer and cpu_reset code from cpu/$(CPU) into the new
   cpu/$(CPU)/$(SOC) directories
diff --git a/cpu/ppc4xx/sdram.c b/cpu/ppc4xx/sdram.c
index e9548cdcf3..c5ab01738c 100644
--- a/cpu/ppc4xx/sdram.c
+++ b/cpu/ppc4xx/sdram.c
@@ -1,7 +1,10 @@
 /*
- * (C) Copyright 2005
+ * (C) Copyright 2005-2006
  * Stefan Roese, DENX Software Engineering, sr@denx.de.
  *
+ * (C) Copyright 2006
+ * DAVE Srl <www.dave-tech.it>
+ *
  * (C) Copyright 2002-2004
  * Stefan Roese, esd gmbh germany, stefan.roese@esd-electronics.com
  *
@@ -27,28 +30,19 @@
 #include <common.h>
 #include <ppc4xx.h>
 #include <asm/processor.h>
+#include "sdram.h"
 
 
 #ifdef CONFIG_SDRAM_BANK0
 
 
-#define mtsdram0(reg, data)  mtdcr(memcfga,reg);mtdcr(memcfgd,data)
-
-
-struct sdram_conf_s {
-	unsigned long size;
-	unsigned long reg;
-};
-
-typedef struct sdram_conf_s sdram_conf_t;
-
 #ifndef CFG_SDRAM_TABLE
 sdram_conf_t mb0cf[] = {
-	{(128 << 20), 0x000A4001},      /* (0-128MB) Address Mode 3, 13x10(4) */
-	{(64 << 20),  0x00084001},      /* (0-64MB) Address Mode 3, 13x9(4)   */
-	{(32 << 20),  0x00062001},      /* (0-32MB) Address Mode 2, 12x9(4)   */
-	{(16 << 20),  0x00046001},      /* (0-16MB) Address Mode 4, 12x8(4)   */
-	{(4 << 20),   0x00008001},      /* (0-4MB) Address Mode 5, 11x8(2)    */
+	{(128 << 20), 13, 0x000A4001},      /* (0-128MB) Address Mode 3, 13x10(4) */
+	{(64 << 20),  13, 0x00084001},      /* (0-64MB) Address Mode 3, 13x9(4)   */
+	{(32 << 20),  12, 0x00062001},      /* (0-32MB) Address Mode 2, 12x9(4)   */
+	{(16 << 20),  12, 0x00046001},      /* (0-16MB) Address Mode 4, 12x8(4)   */
+	{(4 << 20),   11, 0x00008001},      /* (0-4MB) Address Mode 5, 11x8(2)    */
 };
 #else
 sdram_conf_t mb0cf[] = CFG_SDRAM_TABLE;
@@ -59,31 +53,138 @@ sdram_conf_t mb0cf[] = CFG_SDRAM_TABLE;
 
 #ifndef CONFIG_440
 
+#ifdef CFG_SDRAM_CASL
+static ulong ns2clks(ulong ns)
+{
+	ulong bus_period_x_10 = ONE_BILLION / (get_bus_freq(0) / 10);
+
+	return ((ns * 10) + bus_period_x_10) / bus_period_x_10;
+}
+#endif /* CFG_SDRAM_CASL */
+
+static ulong compute_sdtr1(ulong speed)
+{
+#ifdef CFG_SDRAM_CASL
+        ulong tmp;
+        ulong sdtr1 = 0;
+
+        /* CASL */
+        if (CFG_SDRAM_CASL < 2)
+                sdtr1 |= (1 << SDRAM0_TR_CASL);
+        else
+                if (CFG_SDRAM_CASL > 4)
+                        sdtr1 |= (3 << SDRAM0_TR_CASL);
+                else
+                        sdtr1 |= ((CFG_SDRAM_CASL-1) << SDRAM0_TR_CASL);
+
+        /* PTA */
+        tmp = ns2clks(CFG_SDRAM_PTA);
+        if ((tmp >= 2) && (tmp <= 4))
+                sdtr1 |= ((tmp-1) << SDRAM0_TR_PTA);
+        else
+                sdtr1 |= ((4-1) << SDRAM0_TR_PTA);
+
+        /* CTP */
+        tmp = ns2clks(CFG_SDRAM_CTP);
+        if ((tmp >= 2) && (tmp <= 4))
+                sdtr1 |= ((tmp-1) << SDRAM0_TR_CTP);
+        else
+                sdtr1 |= ((4-1) << SDRAM0_TR_CTP);
+
+        /* LDF */
+        tmp = ns2clks(CFG_SDRAM_LDF);
+        if ((tmp >= 2) && (tmp <= 4))
+                sdtr1 |= ((tmp-1) << SDRAM0_TR_LDF);
+        else
+                sdtr1 |= ((2-1) << SDRAM0_TR_LDF);
+
+        /* RFTA */
+        tmp = ns2clks(CFG_SDRAM_RFTA);
+        if ((tmp >= 4) && (tmp <= 10))
+                sdtr1 |= ((tmp-4) << SDRAM0_TR_RFTA);
+        else
+                sdtr1 |= ((10-4) << SDRAM0_TR_RFTA);
+
+        /* RCD */
+        tmp = ns2clks(CFG_SDRAM_RCD);
+        if ((tmp >= 2) && (tmp <= 4))
+                sdtr1 |= ((tmp-1) << SDRAM0_TR_RCD);
+        else
+                sdtr1 |= ((4-1) << SDRAM0_TR_RCD);
+
+        return sdtr1;
+#else /* CFG_SDRAM_CASL */
+        /*
+         * If no values are configured in the board config file
+         * use the default values, which seem to be ok for most
+         * boards.
+         *
+         * REMARK:
+         * For new board ports we strongly recommend to define the
+         * correct values for the used SDRAM chips in your board
+         * config file (see PPChameleonEVB.h)
+         */
+        if (speed > 100000000) {
+                /*
+                 * 133 MHz SDRAM
+                 */
+                return 0x01074015;
+        } else {
+                /*
+                 * default: 100 MHz SDRAM
+                 */
+                return 0x0086400d;
+        }
+#endif /* CFG_SDRAM_CASL */
+}
+
+/* refresh is expressed in ms */
+static ulong compute_rtr(ulong speed, ulong rows, ulong refresh)
+{
+#ifdef CFG_SDRAM_CASL
+        ulong tmp;
+
+        tmp = ((refresh*1000*1000) / (1 << rows)) * (speed / 1000);
+        tmp /= 1000000;
+
+        return ((tmp & 0x00003FF8) << 16);
+#else /* CFG_SDRAM_CASL */
+        if (speed > 100000000) {
+                /*
+                 * 133 MHz SDRAM
+                 */
+		return 0x07f00000;
+        } else {
+                /*
+                 * default: 100 MHz SDRAM
+                 */
+		return 0x05f00000;
+        }
+#endif /* CFG_SDRAM_CASL */
+}
+
 /*
  * Autodetect onboard SDRAM on 405 platforms
  */
 void sdram_init(void)
 {
+	ulong speed;
 	ulong sdtr1;
-	ulong rtr;
 	int i;
 
-	/*
-	 * Support for 100MHz and 133MHz SDRAM
-	 */
-	if (get_bus_freq(0) > 100000000) {
-		/*
-		 * 133 MHz SDRAM
-		 */
-		sdtr1 = 0x01074015;
-		rtr = 0x07f00000;
-	} else {
-		/*
-		 * default: 100 MHz SDRAM
-		 */
-		sdtr1 = 0x0086400d;
-		rtr = 0x05f00000;
-	}
+        /*
+         * Determine SDRAM speed
+         */
+        speed = get_bus_freq(0); /* parameter not used on ppc4xx */
+
+        /*
+         * sdtr1 (register SDRAM0_TR) must take into account timings listed
+         * in SDRAM chip datasheet. rtr (register SDRAM0_RTR) must take into
+         * account actual SDRAM size. So we can set up sdtr1 according to what
+         * is specified in board configuration file while rtr dependds on SDRAM
+         * size we are assuming before detection.
+         */
+        sdtr1 = compute_sdtr1(speed);
 
 	for (i=0; i<N_MB0CF; i++) {
 		/*
@@ -96,7 +197,7 @@ void sdram_init(void)
 		 */
 		mtsdram0(mem_mb0cf, mb0cf[i].reg);
 		mtsdram0(mem_sdtr1, sdtr1);
-		mtsdram0(mem_rtr, rtr);
+		mtsdram0(mem_rtr, compute_rtr(speed, mb0cf[i].rows, 64));
 
 		udelay(200);
 
@@ -120,6 +221,124 @@ void sdram_init(void)
 
 #else /* CONFIG_440 */
 
+#define NUM_TRIES 64
+#define NUM_READS 10
+
+static void sdram_tr1_set(int ram_address, int* tr1_value)
+{
+	int i;
+	int j, k;
+	volatile unsigned int* ram_pointer = (unsigned int *)ram_address;
+	int first_good = -1, last_bad = 0x1ff;
+
+	unsigned long test[NUM_TRIES] = {
+		0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF,
+		0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF,
+		0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000,
+		0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000,
+		0xAAAAAAAA, 0xAAAAAAAA, 0x55555555, 0x55555555,
+		0xAAAAAAAA, 0xAAAAAAAA, 0x55555555, 0x55555555,
+		0x55555555, 0x55555555, 0xAAAAAAAA, 0xAAAAAAAA,
+		0x55555555, 0x55555555, 0xAAAAAAAA, 0xAAAAAAAA,
+		0xA5A5A5A5, 0xA5A5A5A5, 0x5A5A5A5A, 0x5A5A5A5A,
+		0xA5A5A5A5, 0xA5A5A5A5, 0x5A5A5A5A, 0x5A5A5A5A,
+		0x5A5A5A5A, 0x5A5A5A5A, 0xA5A5A5A5, 0xA5A5A5A5,
+		0x5A5A5A5A, 0x5A5A5A5A, 0xA5A5A5A5, 0xA5A5A5A5,
+		0xAA55AA55, 0xAA55AA55, 0x55AA55AA, 0x55AA55AA,
+		0xAA55AA55, 0xAA55AA55, 0x55AA55AA, 0x55AA55AA,
+		0x55AA55AA, 0x55AA55AA, 0xAA55AA55, 0xAA55AA55,
+		0x55AA55AA, 0x55AA55AA, 0xAA55AA55, 0xAA55AA55 };
+
+	/* go through all possible SDRAM0_TR1[RDCT] values */
+	for (i=0; i<=0x1ff; i++) {
+		/* set the current value for TR1 */
+		mtsdram(mem_tr1, (0x80800800 | i));
+
+		/* write values */
+		for (j=0; j<NUM_TRIES; j++) {
+			ram_pointer[j] = test[j];
+
+			/* clear any cache at ram location */
+			__asm__("dcbf 0,%0": :"r" (&ram_pointer[j]));
+		}
+
+		/* read values back */
+		for (j=0; j<NUM_TRIES; j++) {
+			for (k=0; k<NUM_READS; k++) {
+				/* clear any cache at ram location */
+				__asm__("dcbf 0,%0": :"r" (&ram_pointer[j]));
+
+				if (ram_pointer[j] != test[j])
+					break;
+			}
+
+			/* read error */
+			if (k != NUM_READS)
+				break;
+		}
+
+		/* we have a SDRAM0_TR1[RDCT] that is part of the window */
+		if (j == NUM_TRIES) {
+			if (first_good == -1)
+				first_good = i;		/* found beginning of window */
+		} else { /* bad read */
+			/* if we have not had a good read then don't care */
+			if (first_good != -1) {
+				/* first failure after a good read */
+				last_bad = i-1;
+				break;
+			}
+		}
+	}
+
+	/* return the current value for TR1 */
+	*tr1_value = (first_good + last_bad) / 2;
+}
+
+
+#ifdef CONFIG_SDRAM_ECC
+static void ecc_init(ulong start, ulong size)
+{
+	ulong	current_addr;		/* current byte address */
+	ulong	end_addr;		/* end of memory region */
+	ulong	addr_inc;		/* address skip between writes */
+	ulong	cfg0_reg;		/* for restoring ECC state */
+
+	/*
+	 * TODO: Enable dcache before running this test (speedup)
+	 */
+
+	mfsdram(mem_cfg0, cfg0_reg);
+	mtsdram(mem_cfg0, (cfg0_reg & ~SDRAM_CFG0_MEMCHK) | SDRAM_CFG0_MEMCHK_GEN);
+
+	/*
+	 * look at geometry of SDRAM (data width) to determine whether we
+	 * can skip words when writing
+	 */
+	if ((cfg0_reg & SDRAM_CFG0_DRAMWDTH) == SDRAM_CFG0_DRAMWDTH_32)
+		addr_inc = 4;
+	else
+		addr_inc = 8;
+
+	current_addr = start;
+	end_addr = start + size;
+
+	while (current_addr < end_addr) {
+		*((ulong *)current_addr) = 0x00000000;
+		current_addr += addr_inc;
+	}
+
+	/*
+	 * TODO: Flush dcache and disable it again
+	 */
+
+	/*
+	 * Enable ecc checking and parity errors
+	 */
+	mtsdram(mem_cfg0, (cfg0_reg & ~SDRAM_CFG0_MEMCHK) | SDRAM_CFG0_MEMCHK_CHK);
+}
+#endif
+
 /*
  * Autodetect onboard DDR SDRAM on 440 platforms
  *
@@ -130,6 +349,7 @@ void sdram_init(void)
 long int initdram(int board_type)
 {
 	int i;
+	int tr1_bank1;
 
 	for (i=0; i<N_MB0CF; i++) {
 		/*
@@ -163,6 +383,16 @@ long int initdram(int board_type)
 		udelay(10000);
 
 		if (get_ram_size(0, mb0cf[i].size) == mb0cf[i].size) {
+			/*
+			 * Optimize TR1 to current hardware environment
+			 */
+			sdram_tr1_set(0x00000000, &tr1_bank1);
+			mtsdram(mem_tr1, (tr1_bank1 | 0x80800800));
+
+#ifdef CONFIG_SDRAM_ECC
+			ecc_init(0, mb0cf[i].size);
+#endif
+
 			/*
 			 * OK, size detected -> all done
 			 */
diff --git a/cpu/ppc4xx/sdram.h b/cpu/ppc4xx/sdram.h
new file mode 100644
index 0000000000..62b5442f3b
--- /dev/null
+++ b/cpu/ppc4xx/sdram.h
@@ -0,0 +1,78 @@
+/*
+ * (C) Copyright 2006
+ * Stefan Roese, DENX Software Engineering, sr@denx.de.
+ *
+ * (C) Copyright 2006
+ * DAVE Srl <www.dave-tech.it>
+ *
+ * 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 _SDRAM_H_
+#define _SDRAM_H_
+
+#include <config.h>
+
+#define mtsdram0(reg, data)  mtdcr(memcfga,reg);mtdcr(memcfgd,data)
+
+#define ONE_BILLION	1000000000
+
+struct sdram_conf_s {
+	unsigned long size;
+	int rows;
+	unsigned long reg;
+};
+
+typedef struct sdram_conf_s sdram_conf_t;
+
+/* Bitfields offsets */
+#define SDRAM0_TR_CASL		(31 - 8)
+#define SDRAM0_TR_PTA		(31 - 13)
+#define SDRAM0_TR_CTP		(31 - 15)
+#define SDRAM0_TR_LDF		(31 - 17)
+#define SDRAM0_TR_RFTA		(31 - 29)
+#define SDRAM0_TR_RCD		(31 - 31)
+
+#ifdef CFG_SDRAM_CL
+/* SDRAM timings [ns] according to AMCC/IBM names (see SDRAM_faq.doc) */
+#define CFG_SDRAM_CASL		CFG_SDRAM_CL
+#define CFG_SDRAM_PTA		CFG_SDRAM_tRP
+#define CFG_SDRAM_CTP		(CFG_SDRAM_tRC - CFG_SDRAM_tRCD - CFG_SDRAM_tRP)
+#define CFG_SDRAM_LDF		0
+#ifdef CFG_SDRAM_tRFC
+#define CFG_SDRAM_RFTA		CFG_SDRAM_tRFC
+#else
+#define CFG_SDRAM_RFTA		CFG_SDRAM_tRC
+#endif
+#define CFG_SDRAM_RCD		CFG_SDRAM_tRCD
+#endif /* #ifdef CFG_SDRAM_CL */
+
+/*
+ * Some defines for the 440 DDR controller
+ */
+#define SDRAM_CFG0_DC_EN	0x80000000	/* SDRAM Controller Enable	*/
+#define SDRAM_CFG0_MEMCHK	0x30000000	/* Memory data error checking mask*/
+#define SDRAM_CFG0_MEMCHK_NON	0x00000000	/* No ECC generation		*/
+#define SDRAM_CFG0_MEMCHK_GEN	0x20000000	/* ECC generation		*/
+#define SDRAM_CFG0_MEMCHK_CHK	0x30000000	/* ECC generation and checking	*/
+#define SDRAM_CFG0_DRAMWDTH	0x02000000	/* DRAM width mask		*/
+#define SDRAM_CFG0_DRAMWDTH_32	0x00000000	/* 32 bits			*/
+#define SDRAM_CFG0_DRAMWDTH_64	0x02000000	/* 64 bits			*/
+
+#endif
diff --git a/include/configs/PPChameleonEVB.h b/include/configs/PPChameleonEVB.h
index e1155e2e43..16e2cc6d64 100644
--- a/include/configs/PPChameleonEVB.h
+++ b/include/configs/PPChameleonEVB.h
@@ -139,8 +139,18 @@
 #define CFG_I2C_RTC_ADDR	0x68
 #define CFG_M41T11_BASE_YEAR	1900
 
+/*
+ * SDRAM configuration (please see cpu/ppc/sdram.[ch])
+ */
 #define CONFIG_SDRAM_BANK0	1	/* init onboard SDRAM bank 0	*/
 
+/* SDRAM timings used in datasheet */
+#define CFG_SDRAM_CL            2
+#define CFG_SDRAM_tRP           20
+#define CFG_SDRAM_tRC           65
+#define CFG_SDRAM_tRCD          20
+#undef  CFG_SDRAM_tRFC
+
 /*
  * Miscellaneous configurable options
  */
diff --git a/include/configs/p3p440.h b/include/configs/p3p440.h
index 831d018e2d..0662544aed 100644
--- a/include/configs/p3p440.h
+++ b/include/configs/p3p440.h
@@ -1,5 +1,5 @@
 /*
- * (C) Copyright 2005
+ * (C) Copyright 2005-2006
  * Stefan Roese, DENX Software Engineering, sr@denx.de.
  *
  * (C) Copyright 2002 Scott McNutt <smcnutt@artesyncp.com>
@@ -71,9 +71,10 @@
  * DDR SDRAM
  *----------------------------------------------------------------------*/
 #define CONFIG_SDRAM_BANK0	1	/* init onboard DDR SDRAM bank 0*/
-#define CFG_SDRAM_TABLE	{	\
-		{(256 << 20), 0x000C4001}, /* 256MB mode 3, 13x10(4) */	\
-		{(64 << 20),  0x00082001}} /* 64MB mode 2, 12x9(4)   */
+#define CONFIG_SDRAM_ECC		/* enable ECC support		*/
+#define CFG_SDRAM_TABLE	{ \
+		{(256 << 20), 13, 0x000C4001}, /* 256MB mode 3, 13x10(4)*/ \
+		{(64 << 20),  12, 0x00082001}} /* 64MB mode 2, 12x9(4)	*/
 
 /*-----------------------------------------------------------------------
  * Serial Port
@@ -275,6 +276,9 @@
 #define CFG_FLASH_ERASE_TOUT	120000	/* Timeout for Flash Erase (in ms)	*/
 #define CFG_FLASH_WRITE_TOUT	500	/* Timeout for Flash Write (in ms)	*/
 
+#define CFG_FLASH_USE_BUFFER_WRITE 1	/* use buffered writes (20x faster)	*/
+#define CFG_FLASH_PROTECTION	1	/* hardware flash protection		*/
+
 #define CFG_FLASH_EMPTY_INFO		/* print 'E' for empty sector on flinfo */
 #define CFG_FLASH_QUIET_TEST	1	/* don't warn upon unknown flash	*/