[U-Boot-Users] U-Boot & FTP

[U-Boot-Users] U-Boot & FTP

[D Palmer]

Are there any patches/modifications that enable U-boot to boot a kernel
via FTP. ?

Thanks in advance
Thank you, 

Donald Palmer
Senior Software Engineer
General Micro Systems, Inc
8358 Maple Place
Rancho Cucamonga, Ca  91730
(909)980-4863 x119
dpalmer at gms4sbc.com

[U-Boot-Users] U-Boot & FTP

[Jerry Van Baren]

D Palmer wrote:
> Are there any patches/modifications that enable U-boot to boot a kernel
> via FTP. ?
> 
> Thanks in advance
> Thank you, 
> 
> Donald Palmer

No.  This has been asked before and Wolfgang has discouraged people from 
going that down that path (apparently successfully).

FTP requires TCP (TFTP requires UDP).  UDP is simple and easy to 
implement within u-boot's constraints.  TCP is a _lot_ of work to 
implement in a non-tasking environment like u-boot.

gvb

[U-Boot-Users] U-Boot & FTP

[Wolfgang Denk]

In message <E89EC5FBB92CAB4C9BB301E636B0D858075C14@mailserver4.mail4.local> you wrote:
> Are there any patches/modifications that enable U-boot to boot a kernel
> via FTP. ?

No, and there will be none.

FTP requires TCP/IP, which is too  much  overhead  just  for  a  boot
loader. If you need FTP, then boot an OS which runs the download.

On the othe rhand, U-Boot offers TFTP and  NFS  for  download,  so  I
wonder why you think that FTP would make your life easier.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Computers are not intelligent.  They only think they are.

[U-Boot-Users] U-Boot & FTP

[Tolunay Orkun]

Wolfgang Denk wrote:
> In message <E89EC5FBB92CAB4C9BB301E636B0D858075C14@mailserver4.mail4.local> you wrote:
> 
>>Are there any patches/modifications that enable U-boot to boot a kernel
>>via FTP. ?
> 
> 
> No, and there will be none.
> 
> FTP requires TCP/IP, which is too  much  overhead  just  for  a  boot
> loader. If you need FTP, then boot an OS which runs the download.
> 
> On the othe rhand, U-Boot offers TFTP and  NFS  for  download,  so  I
> wonder why you think that FTP would make your life easier.
> 
> Best regards,
> 
> Wolfgang Denk
> 

I can think of one case where FTP would be desirable. If the host is 
behind a stateful firewall and TFTP Server is on the other side, the 
client might not be able to access the TFTP server properly. Because per 
TFTP RFC the server uses a dynamic port as source port for response 
packets which is detected as unsolicited by stateful firewalls and 
dropped. Unlike FTP this dynamic port number is not negotiated so 
stateful firewall cannot implement an ALG (unless ignoring the source 
port numbers completely which reduces the effectiveness of the firewall 
and is not desirable).

Such a problem did surface while updating firmware of a VOIP phone using 
TFTP (not u-boot related but could have been).

Now, typically the TFTP server and the U-Boot host is not seperated by a 
firewall but it could be in some situations. I personally do not need it 
but I can see it may be needed by some. A very basic lightweight and 
tight TCP support could be developped for FTP support. There are some 
TCP implementations for really limited resource hosts.

[U-Boot-Users] U-Boot & FTP

[Wolfgang Denk]

Dear Tolunay,

in message <41DB36C9.3080807@orkun.us> you wrote:
> 
> I can think of one case where FTP would be desirable. If the host is 
> behind a stateful firewall and TFTP Server is on the other side, the 

I'm not sure if it is a good idea to attempt to  run  TFTP  across  a
firewall. If you need a firewall, you don't want to have TFTP traffic
running through it.

> client might not be able to access the TFTP server properly. Because per 

How about using NFS?

> but I can see it may be needed by some. A very basic lightweight and 
> tight TCP support could be developped for FTP support. There are some 
> TCP implementations for really limited resource hosts.

I didn't say it is impossible. It's just unlikely to be added.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Alliance: In international politics, the union  of  two  thieves  who
have  their hands so deeply inserted in each other's pocket that they
cannot separately plunder a third.                   - Ambrose Bierce

[U-Boot-Users] U-Boot & FTP

[Jerry Van Baren]

Wolfgang Denk wrote:
> Dear Tolunay,
> 
> in message <41DB36C9.3080807@orkun.us> you wrote:
> 
>>I can think of one case where FTP would be desirable. If the host is 
>>behind a stateful firewall and TFTP Server is on the other side, the 
> 
> 
> I'm not sure if it is a good idea to attempt to  run  TFTP  across  a
> firewall. If you need a firewall, you don't want to have TFTP traffic
> running through it.
> 
> 
>>client might not be able to access the TFTP server properly. Because per 
> 
> 
> How about using NFS?
> 
> 
>>but I can see it may be needed by some. A very basic lightweight and 
>>tight TCP support could be developped for FTP support. There are some 
>>TCP implementations for really limited resource hosts.
> 
> 
> I didn't say it is impossible. It's just unlikely to be added.
> 
> Best regards,
> 
> Wolfgang Denk

Wolfgang has higher standards than most of us ;-) and thus has not had 
the "pleasure" of working with Windows.  With Windows XP SP2 
firewalling, TFTP loading using a Windows box as the server breaks by 
default because the firewalling blocks the u-boot TFTP inbound requests.

Our customer requested, and I plan to implement Real Soon Now, that the 
u-boot TFTP source port be configurable: my plan is to make an 
environment variable:
* If set, use that port as the u-boot source port
* If not set, use the current method of using a pseudo random port

Our customer will modify their TFTP server so that it blindly starts the 
TFTP transfer using the pre-configured target IP address and UDP port. 
This will have the effect of "punching through" the XP firewall, 
allowing the remainder of the TFTP transfer to proceed normally.

This is ugly and requires a preconfigured, known system (but can be 
aided by some extra knowledge like a DHCP configuration request just 
occurred therefore a TFTP load is going to happen Real Soon Now) BUT it 
does allow our customer to provide a system that _their_ customer 
doesn't need to know how to modify firewall rules.

...and that is how the Dumbing Down of the World occurs :-(.

I will provide a patch when I get it working and I will understand 100% 
if Wolfgang rejects it.  Perhaps we can use the SourceForge "upload 
patch" feature to store patches that a few people find useful but are 
not of general use and are rejected by Wolfgang.

gvb

[U-Boot-Users] U-Boot & FTP

[Marius Groeger]

On Wed, 5 Jan 2005, Jerry Van Baren wrote:

> Wolfgang Denk wrote:
>> Dear Tolunay,
>> 
>> in message <41DB36C9.3080807@orkun.us> you wrote:
>> 
>>> I can think of one case where FTP would be desirable. If the host is 
>>> behind a stateful firewall and TFTP Server is on the other side, the
>>
>> I'm not sure if it is a good idea to attempt to  run  TFTP  across  a
>> firewall. If you need a firewall, you don't want to have TFTP traffic
>> running through it.
...
> Wolfgang has higher standards than most of us ;-) and thus has not had the 
> "pleasure" of working with Windows.  With Windows XP SP2 firewalling, TFTP 
> loading using a Windows box as the server breaks by default because the 
> firewalling blocks the u-boot TFTP inbound requests.

Which is why the OP wanted to have support _FTP_, and not TFTP.

And I still fail to see why a suitable patch for this, complying to 
all patch submission rules (most notably the one about not increasing 
the footprint when the feature is turned off), would be rejected. 
Granted, it's probably a lot of work, but if the guy is willing to do 
it...

Regards,
Marius

-- 
Marius Groeger <mgroeger@sysgo.com>
SYSGO AG                      Embedded and Real-Time Software
Voice: +49 6136 9948 0                  FAX: +49 6136 9948 10
www.sysgo.com | www.elinos.com | www.osek.de | www.imerva.com

[U-Boot-Users] U-Boot & FTP

[Jerry Van Baren]

Marius Groeger wrote:
> On Wed, 5 Jan 2005, Jerry Van Baren wrote:
> 
>> Wolfgang Denk wrote:
>>
>>> Dear Tolunay,
>>>
>>> in message <41DB36C9.3080807@orkun.us> you wrote:
>>>
>>>> I can think of one case where FTP would be desirable. If the host is 
>>>> behind a stateful firewall and TFTP Server is on the other side, the
>>>
>>>
>>> I'm not sure if it is a good idea to attempt to  run  TFTP  across  a
>>> firewall. If you need a firewall, you don't want to have TFTP traffic
>>> running through it.
> 
> ...
> 
>> Wolfgang has higher standards than most of us ;-) and thus has not had 
>> the "pleasure" of working with Windows.  With Windows XP SP2 
>> firewalling, TFTP loading using a Windows box as the server breaks by 
>> default because the firewalling blocks the u-boot TFTP inbound requests.
> 
> 
> Which is why the OP wanted to have support _FTP_, and not TFTP.
> 
> And I still fail to see why a suitable patch for this, complying to all 
> patch submission rules (most notably the one about not increasing the 
> footprint when the feature is turned off), would be rejected. Granted, 
> it's probably a lot of work, but if the guy is willing to do it...
> 
> Regards,
> Marius

I didn't say it would be rejected.  Wolfgang said there would never be 
such a patch: I don't know if he meant it would be rejected or if he was 
predicting the future based on what has happened in the past (I suspect 
the latter).

The beauty of Open Source is that the OP is free to make a FTP patch. 
If he goes forward, bully for him.  If Wolfgang subsequently rejects his 
patch, NBD, it met the OP's need.  Furthermore, if it meets more 
peoples' needs, they are free to add it to their builds with or without 
Wolfgang's endorsement.

At this point there really isn't much point discussing hypothetical 
patches by OPs and hypothetical rejections by Wolfgang.

gvb

[U-Boot-Users] U-Boot & FTP

[Wolfgang Denk]

In message <41DBF1AA.1020803@smiths-aerospace.com> you wrote:
>
> Our customer requested, and I plan to implement Real Soon Now, that the 
> u-boot TFTP source port be configurable: my plan is to make an 

Urghhh...

> I will provide a patch when I get it working and I will understand 100% 
> if Wolfgang rejects it.  Perhaps we can use the SourceForge "upload 
> patch" feature to store patches that a few people find useful but are 
> not of general use and are rejected by Wolfgang.

Why should I reject it if it's useful to you and doesn't hurt
others...

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Always try to do things in chronological order; it's  less  confusing
that way.