[U-Boot-Users] environment not being used

[Shamile Khan]

Hi,

Just as a follow up, I conclude that U-boot treats flash reads exactly
as sdram reads i.e. 32-bit accesses. So its not just about the
environment variables. Most of the flash-based U-boot functionality
wouldn't work for us unless we modify all the commands that have access
to flash e.g md, imiinfo, bootm etc. A hardware fix (an 8-bit bus to our
byte-mode flash chip) seems like the right way to go.

Shamile

On Sat, 2004-01-31 at 12:12, Wolfgang Denk wrote:
> In message <1075423717.18221.233.camel at localhost.localdomain> you wrote:
> > 
> > To get around this, we have a small program which is stored in FPGA
> > bitstream and runs in FPGA on-chip memory (called BRAM). This program
> > copies u-boot binary image from flash to sdram and jumps to it. This
> > allows U-boot to run. However the problem is that the environment
> > variables saved in flash are not being used even though U-boot has been
> > configured with the CFG_ENV_IS_IN_FLASH option turned on. 
> > CFG_FLASH_BASE has been set to the flash base address of u-boot and when
> > I use saveenv the environment is saved at the proper offset
> > CFG_ENV_OFFSET. The only thing thats a bit different for my U-boot
> > configuration is that CFG_MONITOR_BASE is set to the sdram base address
> > where U-boot starts executing from instead of being set to
> > CFG_FLASH_BASE.
> 
> Normally U-Boot attempts to read the environment when  starting  from
> the same position in memory where it will save it to when you issue a
> "saveenv"  command.  You  will  have  to  modify U-Boot such that the
> initialization reads from the "fixed" copy in  RAM,  while  "saveenv"
> saves to the address in flash, performing the 16-bit-expansion needed
> for  your  setup. It seems obvious that a plain copy as usuall cannot
> work on your system.
> 
> Best regards,
> 
> Wolfgang Denk
> 
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