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

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

[Edward Jubenville]

Using u-boot 1.1.4 with Linux kernel 2.4.25.

I'm trying to configure our device for flexibility in choosing static IP or
dynamic IP operation, based on which is most appropriate for the network
environment of the installation site.  I can get both to work fine with
u-boot, but I don't know how to pass the information on to the Linux kernel
as to which configuration was selected.  Presumably, the kernel shouldn't
start its DHCP client (dhclient) when static IP operation is selected.

Can someone recommend a strategy for u-boot to communicate the selection to
the kernel?  Is it done via the kernel command line, or by having the kernel
startup peek into u-boot's environment storage?

Thanks in advance,

Ed Jubenville

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

[Wolfgang Denk]

In message <GPECLCIGPLHEOMGPMCPAIEOMEKAA.edjubenville@adelphia.net> you wrote:
> 
> I'm trying to configure our device for flexibility in choosing static IP or
> dynamic IP operation, based on which is most appropriate for the network
> environment of the installation site.  I can get both to work fine with
> u-boot, but I don't know how to pass the information on to the Linux kernel
> as to which configuration was selected.  Presumably, the kernel shouldn't
> start its DHCP client (dhclient) when static IP operation is selected.

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.

> Can someone recommend a strategy for u-boot to communicate the selection to
> the kernel?  Is it done via the kernel command line, or by having the kernel
> startup peek into u-boot's environment storage?

Is there any chance that you did not even bother to read the manual?

Shame on you!

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,    CEO: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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give the wrong answers.

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

[Edward Jubenville]

> Wolfgang 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.

> 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.

Ed Jubenville

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

[Wolfgang Denk]

Dear Ed,

in message <GPECLCIGPLHEOMGPMCPACEOPEKAA.edjubenville@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
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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