[U-Boot] RFC, am335x_evm.h patch for u-boot on SD and rest on eMMC on BBB

[Robert P. J. Day]

  i'm still interested on thoughts on this proposed patch:

On Wed, 4 Sep 2013, Robert P. J. Day wrote:

>
>  soldiering on with my configuring and building u-boot for my BBB, i
> have a proposal for include/configs/am335x_evm.h:
>
> #define CONFIG_BOOTCOMMAND \
>         "run findfdt; " \
>         "run mmcboot;" \
>         "setenv mmcdev 1; " \
>         "setenv bootpart 1:2; " \
>         "setenv mmcroot /dev/mmcblk1p2 ro; " \    <-- add this line
>         "run mmcboot;" \
>         "run nandboot;"

  to recap, the idea is that if the first "run mmcboot" fails and both
"mmcdev" and "bootpart" are reassigned to refer to mmc device 1, it
only makes sense to adjust "mmcroot" to refer to the same device from
which to get the root filesystem. naturally, that can be done from
within uEnv.txt, but it seems to make sense that that should be the
default.

  to be a bit more verbose, i'm setting up a classroom exercise where
students will have a fully installed and bootable BBB, but they'll get
an exercise to download, configure and install u-boot (MLO and
u-boot.img) on an SD card where that's *all* that will be on the SD
card, so the BBB will run u-boot off of the SD card, but will
automatically switch to eMMC for the kernel image and root filesystem
when it tries to boot.

  thoughts?

rday

-- 

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Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
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