USB support for U-Boot on Raspberry-Pi

Stephen Warren swarren at
Sat Jun 16 01:53:54 EDT 2012

On 06/15/2012 09:09 PM, Oleksandr Tymoshenko wrote:
> Hello,
> Last several weeks I've been working on porting U-Boot to Raspberry Pi
> (as it turned out in parallel with Stephen Warren)  and today I'm happy
> to announce that network support works stable enough.


I have tested this, and even booted a kernel with DT (the patch I posted
a little while back based on linux-next). A couple gotchas though:

CONFIG_OF_LIBFDT (for DT) or CONFIG_CMDLINE_TAG (for ATAGs) is needed to
make bootm work.

Much bigger: Oleksandr's U-Boot branch uses the other UART from what the
kernel usually uses (and that the binary bootloader sets up), so I
wasn't able to see any output from the kernel until I realized I needed
to hack U-Boot to put the UART pinmux back to its more usual setting; I
added the reverse of arch_cpu_init()'s pinmux changes to
cleanup_before_linux() for testing purposes.

But anyway, thanks for getting this working! I'll take a closer look at
your branch tomorrow, and try to integrate all the non-USB stuff (e.g.
config options, perhaps create a simple mbox driver) that are different
into my tree to keep them in sync, and perhaps post that as a follow-up
to the U-Boot patches I already posted.

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