Suresh Bhaskaran wrote:
-----Original Message----- From: Jerry Van Baren [mailto:gerald.vanbaren@ge.com] Sent: Monday, October 06, 2008 10:07 AM To: Suresh Bhaskaran Cc: Andrejs Cainikovs; u-boot@lists.denx.de Subject: Re: [U-Boot] U-boot Saveenv question
Suresh Bhaskaran wrote:
- I verified flash contents using the md.w command in u-boot
- I've already verified correct flash r/w operation using the cp.w
command 3. Yes, the CONFIG_ENV_OVERWRITE flag is defined in my boardfile 4. Flinfo shows the correct flash configuration (sectors, etc) of the flash
I can see the new env variable (e.g. set serverip 10.0.0.1) at the end of the saveenv area in flash (after I do a saveenv). (the original entry is removed from the list in flash, and the new updated entry is added to the end of the list in flash).
Still, when I reboot u-boot, I don't get the new environment variable updated from flash.
What am I missing?
Thanks. Suresh
Please don't top post.
Are you using DHCP (BOOTP)? If you are, serverip is probably being sent
by your DHCP server and overriding the value you have set in your env.
I'm assuming you are *not* getting env CRC failure warnings on boot.
If neither of the above guesses solve the problem, please copy what is printed to the console on start up. Without more information, we're just guessing.
Best regards, gvb
Thanks for help:
I've got it working:
Final answer:
Sorry, workaround for you, this isn't the final answer.
- If *only* CONFIG_ENV_OVERWRITE is turned on in board file, then crc
is not written to flash [don't know if it's bug, or if I am setting incorrect flags]
This may work for you, but there is something else wrong for you. From the README file: If CONFIG_ENV_OVERWRITE is #defined in your config file, the write protection for vendor parameters is completely disabled. Anybody can change or delete these parameters. so CONFIG_ENV_OVERWRITE controls some logic WRT what can be changed in the env, but it doesn't directly affect flash writing.
- But if CFG_ENV_ADDR_REDUND is also set, then it sets CRC to flash,
and it works correctly.
s/CFG/CONFIG/ What version is your u-boot? They have been renamed CONFIG_* for several months now.
Again from the README: - CONFIG_ENV_ADDR_REDUND CONFIG_ENV_SIZE_REDUND
These settings describe a second storage area used to hold a redundant copy of the environment data, so that there is a valid backup copy in case there is a power failure during a "saveenv" operation. ...so this *does* directly affect flash writing. In particular, it causes "extra" flash writing.
My first suspicion is that you have a buffering/caching problem so that a non-redundant flash write doesn't actually go to completion (doesn't actually make it into the flash or the writes get reordered by the processor's bus interface unit). By setting the redundancy config option, your program does another flash write operation which forces the "hung" write out to flash.
I would check if your data cache is disabled or handled properly if enabled and I would check if you have the right "sync" magic to flush the flash write operations out the bus interface unit properly.
In any case, setup 2. works for me.
Thanks for all the help.
Suresh
Best regards, gvb