[U-Boot] How to download image to U-Boot

[Wolfgang Denk <wd@denx.de>]

Dear Grant Edwards,

In message <hdurn4$2bt$1@ger.gmane.org> you wrote:
> I've read through the U-Boot manual and FAQ, but I still
> haven't figured out how one downloads via the network an image
> to a board running U-Boot.  Previous projects have used
> RedBoot, and it provided a couple different mechanisms: 

There are many different ways in U-Boot - over serial line, over
Ethernet using TFTP or NFS, from a number of different storage devices
like MMC/SDCard, USB Mass Storage Devices, harddisks, ...

> Both of these methods would work through firewalls and WAN
> connections (even through satellite links), and could easily be
> automated in an "updater" utility that is then provided to
> customers to update images in flash.

You don't have much of authentication in such  an  envrionment  which
makes  it unacceptable even for mimimum security envrionments. If you
need such a szenario, then boot into a (minimal)  Linux  kernel,  and
run the update in a real OS.

> I can't seem to find out how one accomplishes the same task
> using U-Boot.  The only method I can figure out involve setting
> up a TFTP server (which is not going to be acceptible to
> customers), and then typing a series of commands while plugging

Why would this not be acceptable?

Alternatively, you can use NFS (but I guess you will argument that
setting up a NFS server is also not acceptable).

> into a serial console (also not going to be acceptible to
> customers).  The requirement is to update the image using just

Ah, also not acceptable.

Of course you can kill any system by  just  excluding  all  available
features  as  "not acceptable" - without giuving reasons for this, of
course. Note that this works fine for many, many others, so you might
want to ask yourself if your requirements are "acceptable".

> I found mention of netconsole, but I don't see how it's useful
> since you have to know a-priori the address of the machine from
> which you want to use it.  It would seem that you have to force

You don't have to.  You can use broadcasts.

> the customer to change the IP address of their machine (not
> acceptible).

Why am I not surprised that this is not acceptable, either?


Wolfgang Denk

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DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
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f u cn rd ths, itn tyg h myxbl cd.