[U-Boot-Users] Excluding Env Variable section from the u-boot.bin

[U-Boot-Users] Excluding Env Variable section from the u-boot.bin

[Albert David]

Dears,
For my ppc405EP based custom board I would like to make few changes to
the u-boot memory map, so that every time I update the u-boot,
environment variables in the flash remain untouched.

Flash Memory used:S29GL128M(spansion 16MB Flash with 128 uniform
sectors of 128KB each)

Current mapping
U-Boot Start Flash Address 0xFFF60000 		- 2 sectors
U-Bot Env Variable Start Addr 0xFFFA000		- 1 sector
U-Bot Env Variable(Redundant)Start Addr 0xFFFC000	- 1 sector
U-Boot End sector				- 1 sector

Size of the binary output of u-boot(u-boot.bin) after build is 
128kb*5sectors=648Kbytes.

Current settings in the source tree:

U-boot-1.1.4/include/configs/my_board.h
#define CFG_FLASH_BASE		0xFFF60000
#define CFG_MONITOR_BASE	CFG_FLASH_BASE
#define CFG_MONITOR_LEN		(640 * 1024)

#define CFG_ENV_IS_IN_FLASH	1
#define CFG_ENV_ADDR		0xFFFA0000
#define CFG_ENV_SECT_SIZE	0x20000
#define CFG_ENV_ADDR_REDUND	0xFFFC0000
#define CFG_ENV_SIZE_REDUND	0x20000

U-boot-1.1.4/my_board/config.mk
TEXT_BASE = 0xFFF60000

U-boot-1.1.4/my_board/u-boot.lds
  ppcenv_assert = ASSERT(. < 0xFFFA0000, ".bss section too big,
overlaps .ppcenv section. Please update your confguration:
CFG_MONITOR_BASE, CFG_MONITOR_LEN and TEXT_BASE may need to be
modified.");
  . = 0xFFFA0000;
  .ppcenv :
  {
    common/environment.o(.ppcenv);
  }





Required mapping:
U-Bot Env Variable Start Addr 0xFFF8000		- 1 sector
U-Bot Env Variable(Redundant)Start Addr 0xFFFA000	- 1 sector
U-Boot Start Flash Address 0xFFFC0000 		- 2 sectors

Required Size of the binary output of u-boot(u-boot.bin) after build
is  128kb*2sectors=256Kbytes.

I have already tried to modify the above specified files to:

U-boot-1.1.4/include/configs/my_board.h
#define CFG_FLASH_BASE		0xFFFC0000
#define CFG_MONITOR_BASE	CFG_FLASH_BASE
#define CFG_MONITOR_LEN		(256 * 1024)

#define CFG_ENV_IS_IN_FLASH	1
#define CFG_ENV_ADDR		0xFFF80000
#define CFG_ENV_SECT_SIZE	0x20000
#define CFG_ENV_ADDR_REDUND	0xFFFA0000
#define CFG_ENV_SIZE_REDUND	0x20000

U-boot-1.1.4/my_board/config.mk
TEXT_BASE = 0xFFFC0000

U-boot-1.1.4/my_board/u-boot.lds
  ppcenv_assert = ASSERT(. < 0xFFF80000, ".bss section too big,
overlaps .ppcenv section. Please update your confguration:
CFG_MONITOR_BASE, CFG_MONITOR_LEN and TEXT_BASE may need to be
modified.");
  . = 0xFFF80000;
  .ppcenv :
  {
    common/environment.o(.ppcenv);
  }

But after doing "make all" I get the message
ppc_4xx-ld:.bss section too big, overlaps .ppcenv section. Please
update your confguration: CFG_MONITOR_BASE, CFG_MONITOR_LEN and
TEXT_BASE may need to be modified.

In a simple term, I wanted to build my u-boot by excluding environment
variable section of the memory..

Can any one help me?

Where am I going wrong??

Is there any other modification needs to be done other than the above
specified changes?

Thanks in advance for your support,
With best regards,
Albert.

[U-Boot-Users] Excluding Env Variable section from the u-boot.bin

[Wolfgang Denk]

In message <61124de70601120327o12f9294die4bda6bbfdb464ac@mail.gmail.com> you wrote:
>
> For my ppc405EP based custom board I would like to make few changes to
> the u-boot memory map, so that every time I update the u-boot,
> environment variables in the flash remain untouched.
...
> U-boot-1.1.4/my_board/u-boot.lds
>   ppcenv_assert = ASSERT(. < 0xFFF80000, ".bss section too big,
> overlaps .ppcenv section. Please update your confguration:
> CFG_MONITOR_BASE, CFG_MONITOR_LEN and TEXT_BASE may need to be
> modified.");

Now isn't this a very precise error message? Which other hints do you need?

> Where am I going wrong??

Your whole approach seems  overkill  to  me.  Why  don;t  you  simply
include  a  "saveenv"  command  in your update script? As long as the
environment is not shifted (which  seems  unlikelyin  your  case)  no
other changes are needed.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"There is no statute of limitations on stupidity."
- Randomly produced by a computer program called Markov3.

[U-Boot-Users] Excluding Env Variable section from the u-boot.bin

[Albert David]

> Your whole approach seems  overkill  to  me.  Why  don;t  you  simply
> include  a  "saveenv"  command  in your update script? As long as the
> environment is not shifted (which  seems  unlikelyin  your  case)  no
> other changes are needed.
oh! i didnt know this! it's an easy way to retain env variables :)

btw,
when i update my u-boot in the field (for some unavoidable reason),
the update_uboot script erases all the u-boot flash sectors and over
writes the new u-boot.bin - what if somethings goes wrong with the
communication or power while copying u-boot.bin to flash?? i may loose
important settings of my product in the field! u-boot.bin  can always
be updated using the BDI tool! But i cannot recover the environment
variables.

i can make my update_uboot script in such a way that, before erasing
the u-boot sectors, it will copy the env section to some free  flash
sector(as a backup) , update the u-boot.bin and then call 'saveenv'. i
hope this is the better way to protect my environment variables.

please let me know if someone has better idea than this.
Best regards,
Albert.

[U-Boot-Users] Excluding Env Variable section from the u-boot.bin

[Tore Martin Hagen]

Albert David wrote:

>
>when i update my u-boot in the field (for some unavoidable reason),
>the update_uboot script erases all the u-boot flash sectors and over
>writes the new u-boot.bin - 
>
Hi, I think you should change your update_uboot script so that it only 
erases the sector with the bin. Are you updating u-boot from u-boot or 
from Linux (or some other OS)?

>what if somethings goes wrong with the
>communication or power while copying u-boot.bin to flash?? i may loose
>important settings of my product in the field! u-boot.bin  can always
>be updated using the BDI tool! But i cannot recover the environment
>variables.
>  
>
In this case you would need to read the environment variables first and 
keep them backed up during the u-boot update.

/Tore Martin Hagen

[U-Boot-Users] Excluding Env Variable section from the u-boot.bin

[Wolfgang Denk]

In message <61124de70601122029v6f84d9fbya8a6c22a9f59afa8@mail.gmail.com> you wrote:
>
> when i update my u-boot in the field (for some unavoidable reason),
> the update_uboot script erases all the u-boot flash sectors and over
> writes the new u-boot.bin - what if somethings goes wrong with the
> communication or power while copying u-boot.bin to flash?? i may loose

You shoudl always download theimage to ram *before* you start erasing
the flash, thus communication failures are not a problem.

If you have a power fail you are lost.

> important settings of my product in the field! u-boot.bin  can always
> be updated using the BDI tool! But i cannot recover the environment
> variables.

You can make it more reliable for normal operation by using redundant
environment setors.

> i can make my update_uboot script in such a way that, before erasing
> the u-boot sectors, it will copy the env section to some free  flash
> sector(as a backup) , update the u-boot.bin and then call 'saveenv'. i
> hope this is the better way to protect my environment variables.

Yes, you can additionally create a bacup copy for cases where you had
a power failure, but it is not as trivial as you  (1)  need  to  know
exactly  where your environment is located (ok, not so difficult) and
(2) in case of redundand sectors you will have to test which  one  is
the active and which one the obsoleted sector.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
[Braddock:] Mr. Churchill, you are drunk.
[Churchill:] And you madam, are ugly.  But I shall be sober tomorrow.

[U-Boot-Users] Excluding Env Variable section from the u-boot.bin

[Nuno João (Ext_NBS)]

	I have a configuration in 2 of "my" boards where the environment
	variable's area lays in a different sector from u-boot code,
	also so that it is possible to upgrade u-boot while keeping
	the environment:


In mpc8xx board I have:

/*
 * Environment in flash. It will be on the flash's 3rd 64KB block, fully
 * using it. U-boot will use the 1st two 64KB blocks, as specified by
 * CFG_MONITOR_LEN above.
 */
#define CFG_ENV_IS_IN_FLASH     1
#define CFG_ENV_OFFSET          0x20000 /*   Offset   of Environment Sector     */
#define CFG_ENV_SIZE            0x10000 /* Total Size of Environment Sector     */


In a mpc85xx board I have:

/*
 * Environment
 */
#define CFG_ENV_IS_IN_FLASH     1
#define CFG_ENV_SECT_SIZE       0x40000     /* 256K (one sector) for env */
/* env in its own flash sector, right before u-boot */
#define CFG_ENV_SIZE            CFG_ENV_SECT_SIZE
#define CFG_ENV_ADDR            0xffe00000


	I didn't need to change anything else. There are some preprocessor
	macros in the environment code that will handle most of the job.

	Cheers


-----Original Message-----
From: u-boot-users-admin@lists.sourceforge.net [mailto:u-boot-users-admin at lists.sourceforge.net] On Behalf Of Albert David
Sent: quinta-feira, 12 de Janeiro de 2006 11:27
To: u-boot-users at lists.sourceforge.net
Subject: [U-Boot-Users] Excluding Env Variable section from the u-boot.bin

Dears,
For my ppc405EP based custom board I would like to make few changes to
the u-boot memory map, so that every time I update the u-boot,
environment variables in the flash remain untouched.

(...)

[U-Boot-Users] Excluding Env Variable section from the u-boot.bin

[Wolfgang Denk]

In message <0248B0F35AF7B8418CA72E88AC00BF1F5BB51B@lisi053a.siemens.pt> you wrote:
> 
> 	I have a configuration in 2 of "my" boards where the environment
> 	variable's area lays in a different sector from u-boot code,
> 	also so that it is possible to upgrade u-boot while keeping
> 	the environment:

It is *always* possible to update the U-Boot image and keep  the  old
environment settings. Typically all you need for embedded environment
is a simple "saveenv" command.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
                  Nail here --X-- for new monitor.

[U-Boot-Users] Excluding Env Variable section from the u-boot.bin

[Nuno João (Ext_NBS)]

	As far as I understood / remember, you can have the
	environment and part of u-boot's code sharing the same
	sector, which makes it at least more difficult to upgrade
	the code using a BDI-like tool which usually works on
	a full-sector basis.
 

-----Original Message-----
From: wd@denx.de [mailto:wd at denx.de] 
Sent: quinta-feira, 12 de Janeiro de 2006 14:44
To: Nuno Jo?o (Ext_NBS)
Cc: u-boot-users at lists.sourceforge.net; Albert David
Subject: Re: [U-Boot-Users] Excluding Env Variable section from the u-boot.bin 
(...)

It is *always* possible to update the U-Boot image and keep  the  old
environment settings. Typically all you need for embedded environment
is a simple "saveenv" command.

[U-Boot-Users] Excluding Env Variable section from the u-boot.bin

[Wolfgang Denk]

In message <0248B0F35AF7B8418CA72E88AC00BF1F5BB51E@lisi053a.siemens.pt> you wrote:
> 
> 	As far as I understood / remember, you can have the
> 	environment and part of u-boot's code sharing the same

Yes.

> 	sector, which makes it at least more difficult to upgrade
> 	the code using a BDI-like tool which usually works on
> 	a full-sector basis.

If you use a BDI, you need a 3 command sequence: dump,  erase,  prog.
This  is  not  exactly  difficult. And if you have U-Boot running you
just can use "saveenv". This is trivial.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
I have a theory that it's impossible to prove anything, but  I  can't
prove it.