[U-Boot-Users] [PATCH] fdt: add fdtcmd env var to allow post processing of device tree before boot

[Wolfgang Denk]

In message <A9365AF6-497C-403B-8580-2E8B9BCD20C3 at kernel.crashing.org> you wrote:
> 
> >> Added the 'fdtcmd' environment variable as a way to provide 'fdt'  
> >> commands
> >> that the user can supply to manipulate the device tree after  
> >> ft_board_setup()
> >> and before the tree is handled to the kernel.
> >
> > Where exactly is the needed, i. e. which spoecific situation  do  you
> > have  in  mind  where  this function cannot be implemented as part of
> > either a "preboot" or a standard "bootcmd" command sequence?
> 
> The situation is if we are fixing up or adding properties or nodes via  
> the ft_board_setup() how do I go about modifying that before the  
> device tree is handed to the kernel.
> 
> An example would be if we start adding the i2c node via code in u-boot  
> and after we have done that we want to add a frequency property at  
> runtime w/o changing the u-boot code.

So just run the needed commands before you run "bootm" as part of your
boot command sequence.

Best regards,

Wolfgang Denk

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