[U-Boot-Users] How to configure for flexible static/dynamic IP operation.

Wolfgang Denk wd at denx.de
Sat May 12 21:35:45 CEST 2007

Dear Ed,

in message <GPECLCIGPLHEOMGPMCPACEOPEKAA.edjubenville at roadrunner.com> you wrote:
> > Why should it be important to the Linux kernel how U-Boot got it's IP
> > configuration? You just poss the information with your bootargs,  and
> > the kernel uses it, that's all.
> Because if u-boot leases an IP from a DHCP server, isn't it the kernel's
> responsibility to maintain that lease?  Our devices are not usually turned
> off and on for extremely long periods of time (months).  I am assuming the
> device could be up far longer than the lease time, so doesn't the kernel
> have the responsibility to renew the lease?  At least, that's my
> understanding of how DHCP works.

I see. Yes, this is true,  if  you  want  to  handle  this  strictly.
However,  I  think that even when you use the Linux kernel's IP auto-
configuration feature (CONFIG_IP_PNP_DHCP) the kernel will not  renew
any leases. At least I am not aware of this.

I may be wrong here, but my understanding is that you have to  handle
this  from  user  space. So normally you would just pass to Linux the
information that you did a DHCP setup in U-Boot  (like  by  adding  a
string  "ip_pnp"  to the bootargs settings), which you then can check
in user space to set up the necessary stuff to renew the leases.

> > Is there any chance that you did not even bother to read the manual?
> Nope.  No chance.  Read it.  Didn't find the info.  Maybe it's there, but I
> didn't find it.

You are right. I misunderstood your question at first reading. I did
not understand what you were really after.

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,    CEO: Wolfgang Denk & Detlev Zundel
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