Re: u-boot & uImage on M5282LITE

On Feb 20, 2008, at 8:06 AM, alex wrote (offlist):

> I am also starting a project on this board and would love if you  
> gave a clear instruction list  of how  you built u-boot and put it  
> on the internal flash. I would like the board to boot automatically  
> to uclinux if i have the EXT_BOOT jumper open. Thanks  for any  
> help  you can provide.

Why certainly! I'm sending this to the list to document for others  
who may also be interested.

Limitation: I haven't worked out writeable access to internal flash;  
if you want to change the environment, you have to compile in the  
changes. I've been very careful not to write to the external flash,  
since I don't have any BDM tools running yet, and I don't want to  
destroy the load of dBUG that resides there. I've considered putting  
the environment in external flash, but haven't done so yet. Anyway,  
this is just a development board - when my real hardware shows up,  
I'll be putting more effort into it :)


Firstly, I started with u-boot 1.3.1

I don't know if the change to m68k_config.mk is strictly necessary,  
but I made it anyway, and it got caught up in the patch.

I made some changes to the include/configs/M5282EVB.h file, partly to  
change the environment, partly to change the flash configuration as a  
safety, and partly to change the load address.

The default load address is 0x10000. This is fine if you load a  
binary there and give uboot the command to "go" at that address.

I wanted to pass boot arguments to a linux kernel, however; A u-boot  
header is at the beginning of a uImage file; to make it so the kernel  
still loaded at 0x10000, I changed the load address to 0xFFC0. Then I  
could "bootp" to load an image, and "bootm" to boot it.

The kernel changes to read the boot arguments is another topic for  
another day :)
I had it working in 2.6.19; I've moved to 2.6.24-uc0, and have yet to  
apply the changes there.

Anyway.....

Apply the patches below to a stock u-boot 1.3.1.
Then, in the top level u-boot directory:
$ make M5282EVB_config
$ make

This will make the u-boot binary.

I could never get dBUG on the M5282LITE board to download over the  
network, so I use a serial transfer.
The s-record file for u-boot is based at the load address -  
0xF0000000. You can't download it directly to flash, however. First  
you have to download to ram, then copy it to flash. You can specify a  
negative offset to the dl command in dBUG:

dBUG> dl -efff0000

The offset of -0xEFFF0000 will load u-boot at 0x10000. Note that dBUG  
erroneously reports the offset as 0x10010000 when if finishes loading..

It will prompt you to start the download.
I use minicom; in minicom, ^A-S will prompt you for an upload. Select  
"ascii", then select the u-boot.srec file that you built in the u- 
boot directory.
After it transfers, minicom prompts you to hit a key to continue.
dBUG will tell you if it was successful.

Assuming it was, copy the image to flash.
dBUG> fl write F0000000 10000 20000

This copies 20000 bytes which is more than u-boot takes up, but it's  
a whole flash block; this way you don't have to be concerned with how  
much space u-boot actually occupies. The "fl write" command  
automatically erases the flash block first.

Then remove the EXT_BOOT jumper, reset the board, and it should come  
up in u-boot.
If you want to return to dBUG, just reinstall the jumper and reset  
the board.
Enjoy!

Here are my changes to u-boot. Note that you may want to edit the  
default environment in the M5282EVB.h file. I use dhcp, bootp, and an  
NFS root filesystem here. This is just what I did, YMMV. Not intended  
to be a distributed patch or anything.

--- u-boot-1.3.1/m68k_config.mk	2007-12-06 04:21:19.000000000 -0500
+++ u-boot/m68k_config.mk	2008-02-18 19:14:43.000000000 -0500
@@ -21,5 +21,5 @@
  # MA 02111-1307 USA
  #

-PLATFORM_CPPFLAGS += -DCONFIG_M68K -D__M68K__
+PLATFORM_CPPFLAGS += -DCONFIG_M68K -D__M68K__ -m528x
  PLATFORM_LDFLAGS  += -n
--- u-boot-1.3.1/include/configs/M5282EVB.h	2007-12-06  
04:21:19.000000000 -0500
+++ u-boot/include/configs/M5282EVB.h	2008-02-18 16:44:01.000000000  
-0500
@@ -48,8 +48,9 @@
  /* Configuration for environment
   * Environment is embedded in u-boot in the second sector of the flash
   */
-#define CFG_ENV_ADDR		0xffe04000
-#define CFG_ENV_SIZE		0x2000
+/*#define CFG_ENV_ADDR		0xffe04000*/
+#define CFG_ENV_ADDR		0xf0040000
+#define CFG_ENV_SIZE		0x4000
  #define CFG_ENV_IS_IN_FLASH	1

  /*
@@ -96,24 +97,19 @@
  #define CONFIG_BOOTDELAY	5
  #ifdef CONFIG_MCFFEC
  #	define CONFIG_ETHADDR	00:e0:0c:bc:e5:60
+#if 0
  #	define CONFIG_IPADDR	192.162.1.2
  #	define CONFIG_NETMASK	255.255.255.0
  #	define CONFIG_SERVERIP	192.162.1.1
  #	define CONFIG_GATEWAYIP	192.162.1.1
+#endif
  #	define CONFIG_OVERWRITE_ETHADDR_ONCE
  #endif				/* CONFIG_MCFFEC */

  #define CONFIG_HOSTNAME		M5272C3
  #define CONFIG_EXTRA_ENV_SETTINGS		\
  	"netdev=eth0\0"				\
-	"loadaddr=10000\0"			\
-	"u-boot=u-boot.bin\0"			\
-	"load=tftp ${loadaddr) ${u-boot}\0"	\
-	"upd=run load; run prog\0"		\
-	"prog=prot off ffe00000 ffe3ffff;"	\
-	"era ffe00000 ffe3ffff;"		\
-	"cp.b ${loadaddr} ffe00000 ${filesize};"\
-	"save\0"				\
+	"loadaddr=FFC0\0"			\
  	""

  #define CFG_PROMPT		"-> "
@@ -193,6 +189,8 @@
  #define CFG_FLASH_CFI
  #ifdef CFG_FLASH_CFI

+#define USE_EXTERNAL_FLASH
+#ifdef USE_EXTERNAL_FLASH
  #	define CFG_FLASH_CFI_DRIVER	1
  #	define CFG_FLASH_SIZE		0x1000000	/* Max size that the board might  
have */
  #	define CFG_FLASH_CFI_WIDTH	FLASH_CFI_16BIT
@@ -201,8 +199,19 @@
  #	define CFG_FLASH_PROTECTION	/* "Real" (hardware) sectors  
protection */
  #	define CFG_FLASH_CHECKSUM
  #	define CFG_FLASH_BANKS_LIST	{ CFG_FLASH_BASE }
+#else
+#	define CFG_FLASH_CFI_DRIVER	1
+#	define CFG_FLASH_SIZE		0x80000	/* Max size that the board might  
have */
+#	define CFG_FLASH_CFI_WIDTH	FLASH_CFI_32BIT
+#	define CFG_MAX_FLASH_BANKS	8	/* max number of memory banks */
+#	define CFG_MAX_FLASH_SECT	32	/* max number of sectors on one chip */
+#	define CFG_FLASH_PROTECTION	/* "Real" (hardware) sectors  
protection */
+#	define CFG_FLASH_CHECKSUM
+#	define CFG_FLASH_BANKS_LIST	{ CFG_INT_FLASH_BASE }
+#endif
  #endif

+
  / 
*-----------------------------------------------------------------------
   * Cache Configuration
   */



-
allon