[U-Boot-Users] Statically assigned IP addresses

[Kerl, John]

All:

Thanks for the reply.

No, not a cheap hub/switch (as evidenced by the fact that all is
well when running in Linux).  The problem is my naive
understanding of U-boot:  In our firmware, Ethernet is enabled
at start-up, and we always answer pings.  (And you do not need
interrupts to do that -- our firmware runs polled and handles
pings just fine.)  I am in the habit of thinking that if a node
doesn't answer a ping, it is inoperable.  Also, we run a TFTP
server on the board, with a client on the PC.  This way, the PC
can do a TFTP put to download files, or TFTP get to retrieve
them.  Whereas U-boot runs a TFTP client on the board, and can
only download.

It is simply the case that U-boot was designed differently:

*	Pings are not answered.

*	Ethernet is brought up only when one runs tftpboot
	et al.

*	There appears to be no way to use TFTP to copy data
	from the board to the PC.

These are U-boot design decisions; my error was in expecting
something else.

Thanks for all the prompt and helpful replies!


-----Original Message-----
From: Wolfgang Denk [mailto:wd at denx.de]
Sent: Tuesday, January 13, 2004 1:02 PM
To: Kerl, John
Cc: u-boot-users at lists.sourceforge.net
Subject: Re: [U-Boot-Users] Statically assigned IP addresses 


Dear John,

in message <C7FFFEA58B43D311920D0004ACE5333F10E4F4FF at amer25.avnet.com> you
wrote:
> 
> 1.	On my Chameleon 405EP board, it appears the Ethernet
> 	interface is off by default.  While the board is

No, it is not off. It get's enabled when used.

> 	running Linux, the Ethernet interface is *not*
> 	brought up by default -- rather, I must type
> 	'ifconfig eth0 up'.  This seems strange, but I can

Did you enable IP autoconfiguration in the kernel, and did  you  pass
appropriate "ip=" comand line arguments to Linux?

> 	live with it.  While the board is running U-boot,
> 	on the other hand, there does not appear to be a
> 	'bring up Ethernet' command.  I have MAC address and

Ethernet get's enabled when used.

> 	IP address set in environment variables, so what else
> 	do I need to do to get the board to answer a ping???

U-Boot can be configured to send ping  ICMP  messages  and  show  the
reply, but it does not answer incoming ICMP requests.

> 2.	Probably the same as the first question -- assigning
> 	a static IP address.  In our lab, we do not use DHCP;
> 	addresses are statically assigned.  Is setenv ipaddr
> 	{n.n.n.n} sufficient?  If not, what else do I need
> 	to do?

For  U-Boot  this  is  sufficient.  For  Linux  you  must  pass  this
information to the Linux kernel using an "ip=" command line argument.


Ummm... what exactly is unclear in the description in
http://www.denx.de/twiki/bin/view/DULG/LinuxBootArgs
that you need to ask all these questions?

> 3.	Is this standard U-boot behavior, or is it peculiar
> 	to the Chameleon board?  On the boards we manufacture
> 	(and in our firmware), Ethernet comes up by default.

This is standard U-Boot behaviour.

I don't understand what you mean by "comes up".  U-Boot  imnitializes
the network interface(s) only when you try to use them.

Best regards,

Wolfgang Denk

-- 
See us @ Embedded World, Nuremberg, Feb 17 - 19,  Hall 12.0 Booth 440
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
Any sufficiently advanced technology is indistinguishable from magic.
                                                   - Arthur C. Clarke