set root variable for uImage?

[Sascha Hauer]

Hi Adam,

On Wed, Jul 03, 2013 at 05:21:37PM +0200, Adam Furmanczuk wrote:
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> Hi,
> 
> I restate this question from my previous thread "how to flash and set
> root variable". Thanks very much to Sascha and Alexander for
> introducing into barebox building and flashing.
> 
> I have a basic scenario. Want to boot uImage and then hand over to the
> root partition. With u-Boot this was very easy:
> 
> setenv bootargs "console=tty0 console=ttymxc0,115200n8
> root=/dev/mmcblk0p3 rootfstype=ext4 rootwait ro"
> 
> With barebox however, when I boot the uImage, it complains about not
> setting correct "root=".:
> 
> [ 1.718527] VFS: Cannot open root device "(null)" or
> unknown-block(0,0): error -6
> [ 1.726226] Please append a correct "root=" boot option; here are the
> available partitions:
> 
> Now what i do in Barbox is the following;
> 
> (hint enter to go into console)
> barebox at myhost:/ mkdir /media2
> barebox at myhost:/ mount /dev/disk0.1 fat /media2
> barebox at myhost:/ bootm /media2/uImage root=/dev/mmcblk0p3 rootfstype=ext4

the bootm command evaluates the 'bootargs' environment variable, so
before executing bootm do a:

export bootargs="root=/dev/mmcblk0p3 rootfstype=ext4"

(sidenote: This is not documented with 'help bootm', shame on us. Try
the 'magicvar' command instead which lists all variables with special
meanings)

Sascha

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