On Mon, 4 Oct 2010 14:41:55 -0400 Michael Galime mgalime@datacomsystems.com wrote:
Hi.
I have a board which I am using Uboot on. Arm9, nand flash, etc.
Currently the board has the uboot image and the ENV in one partition, size 0x00200000.
I would like to make another partition for the ENV so that if I have to upgrade Uboot I don't lose my ENV.
What size does the partition have to be?
At a minimum, one block, so you can erase it independently of everything else.
You may want to use CONFIG_ENV_RANGE to assign multiple blocks in case one of the blocks is bad, or you may want to use the env.oob mechanism to dynamically choose a good block for the environment when each board's NAND is first programmed (but be aware that you'll have to run "nand env.oob" again whenever you reflash block zero).
And where in the Uboot code do I change the memory location and size for the env so I can rebuild Uboot and start using a new ENV partition?
Assuming you mean the location in NAND flash, and not in memory, look in your board config header file. You should find CONFIG_ENV_OFFSET, CONFIG_ENV_SIZE, etc.
-Scott