[U-Boot-Users] uploading OS over network instead of u-boot do wnloading it from a server.

[Brian S. Park <brian@corelis.com>]

Wonfgang,

 > U-boot supports the target-as-client method of downloading but does not
> > support the target-as-server method.  I've used both methods a number of
> > times over the years and both have their advantages and 
> disadvantages.  Your
>
>Can you please explain the advantages of the  boot  loader  providing
>server function?

The advantage I see is this.
1. You ship 1 less piece of software. Less number of application that needs 
to be installed/started is always better, IMHO, when it comes to support.
2. It makes the network configuration a bit simpler. If you do not have a 
dedicated TFTP server, you must use serial console to setup the  server IP 
before you can boot if you change the tftp server. Users only have to worry 
about 1 IP instead of 2 when setting up our product. Since large number of 
our users are not very network savvy, things like this make a difference 
when it comes to support.


>And if - for example during development -  interactive  operation  is
>required  or  wanted,  you  will have to type to _one_ interface only
>(U-Boot). Otherwise you have to switch between U-Boot  (start  server
>function),  host (run upload client), and back to U-Boot (start image
>or so).
>
>I'm sorry, but IMHO there is no advantage running  a  server  in  the
>boot loader.

I think this will be useful only when it is deployed to the field. I agree 
that during the development, it has little advantages.


>[There _is_  some  use  for  server-like  functions  in  U-Boot:  for
>example,  many  people  have  asked why U-Boot does not reply to ICMP
>messages (ping requests). There is no doubt that this would be a nice
>feature. On the other hand, think what it needs:  you  will  have  to
>always  enable  the  network interface(s), you will have to deal with
>situations like when MAC addresses and/or IP addresses are  not  set,
>and you will have to deal with incoming network packets at any time -
>this  would  make  the U-Boot design much more complicated. It _is_ a
>nice feature, but not worth the effort. IMHO.]

I have no idea how complicated it will be to implement server feature. 
Hopefully, it would be easier to do than ping since u-boot would listen to 
the incoming traffic only when commanded to do so.

Thanks.

Brian


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Brian S. Park  brian at corelis.com  (562) 926-6727 x143
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