[U-Boot-Users] [Fwd: [PPCBoot-users] DHCP updating environment???]

Wolfgang Denk wd at denx.de
Tue Nov 5 13:57:09 CET 2002

In message <3DC7B80F.E41725BC at imc-berlin.de> you wrote:
> I asked this quetsion before. But on the PPCBoot mailing list.

I remember, and hoped somebody with a btter memory  than  mine  would
jump in.

> is there a reason why BootpCopyNetParams() in bootp.c does _not_ setenv the
> ipaddr?

IIRC this was  requested  by  one  /  some  users  with  nobody  else
complaining about this. [But this discussion may have happned about 2
years ago, so I may be wrong.]

> If I set autoload=n I want to use the dhcp command just to get the IP address
> from the server. But PPCBoot only sets the "bootfile" variable and nothing more!

No. With DHCP you cannot "just get the IP address"; you  will  always
get  what the DHCP server has to offer, and you default configuration
will most certainly ask for more than just the IP address.

> Wouldn't it make sense to set all the params we got from the DHCP server?

Maybe, maybe not. This depends on a lot of things.

For example: assume I manually set a parameter (maybe  ipaddr,  maybe
gatewayip); in this case I probably want to make sure that my pre-set
values   take   precedence   over   any  DHCP  supplied  (additional)
information. But then, I cannot simply implement some code which sets
the params gotten via DHCP if they are not present in the environment
- I think I remember there was an argument that in such  a  situation
you  would  not be able to get rid of a faulty setting suppllied once
by a misconfigured DHCP server.

> Well, at least the ones we're interessted in (see CONFIG_BOOTP_MASK).

I understand what you mean, but I would like to  hear  more  feedback
from others...

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
See us @ electronica 2002 in Munich, Nov 12-15, Hall A3, Booth A3.325 

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