[U-Boot-Users] auto-save environment if using default environment?

Aras Vaichas arasv at magtech.com.au
Wed Mar 26 00:49:04 CET 2008


Wolfgang Wegner wrote:
> On our board we have an FPGA, and for different applications a different
> FPGA file shall be loaded without updating the firmware. For this, the
> application has to set an U-Boot environment variable that specifies which
> FPGA file to load on next boot.
>   
We use an i2c EEPROM to hold board specific information. I read the
EEPROM from U-Boot and set up the MAC address and arch/mach number using
the misc_init_r(void) call method. This separates the U-boot environment
from the machine specific data. I also use the EEPROM to hold the SDRAM
settings so the first bootloader can configure the DRAM on multiple
boards without requiring multiple binaries.

I have a strange bootcmd. If U-Boot starts with a corrupted environment,
it runs the default bootcmd. The default bootcmd creates a bootcmd and
then runs saveenv so the next boot will run the new bootcmd..

eg. from my include/configs/board.h file

"bootcmd=setenv bootcmd '<complex bootcmd here>';saveenv;run bootcmd\0"

I then access the U-Boot environment area from Linux and do all the
"smart" stuff there. If I didn't do this, then Linux would access the
corrupted boot section!

Just my 0.02 euros worth.

Aras

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