[U-Boot] changes to U-boot and GPL

[U-Boot] changes to U-boot and GPL

[Mangelschots, Jef]

We are getting confused when reading the GPL and interpreting how it applies to our situation.

We are adding features (not changing existing ones) to U-boot particular to our in-house developed system which we sell as a product to our customers.
These changes involve adding a menu command for common tasks particular to our product and adding
an in-house developed protocol for transferring files over a proprietary bus.
We do not see these changes as being useful to the general U-boot community. We do have some concerns about security
and opening our product (which is safety-critical) for malicious hacking by exposing the modifications.

This modified U-boot will be deployed on our products. It will not make sense to use on any other platforms.

Our question is:
Do we need to submit our changes to the U-boot maintainers for inclusion in the mainline distribution code ?

We understand the philosophy of GPL to give our customers the source code so they have the ability to inspect, modify and outsource
And customization without being dependent on us.

In that light we have no problem in either providing our customers with the full source code upon their request
OR simply load the full source code in the file system of the box it is shipped with.
So if a customer wants the code, they can load it of the box they bought from us.

Any suggestions ?
Thank you

________________________________
Any files attached to this e-mail will have been checked with virus detection software prior to transmission but you should carry out your own virus check before opening any attachment. Safetran Systems Corp does not accept liability for any damage or loss which may be caused by software viruses. The contents of this e-mail and any attachments are the property of Safetran Systems Corp and are intended for the confidential use by the named recipient only. They may be legally privileged and should not be communicated to, or relied upon, by any other person without written consent. If you are not the addressee, please notify us immediately at the following address: Safetran Systems Corporation, 2400 Nelson Miller Parkway, Louisville, Kentucky 40223. Safetran Systems Corp is a subsidiary of Invensys Plc. Registered office: Portland House, Bressenden Place, London, SW1E 5BF. UK Registered in England and Wales No. 1641421.

[U-Boot] changes to U-boot and GPL

[Mike Frysinger]

On Friday 28 May 2010 13:50:57 Mangelschots, Jef wrote:
> We are getting confused when reading the GPL and interpreting how it
> applies to our situation.

then you should hire a lawyer to interpret it for you.  legal advice cannot be 
obtained from mailing lists such as this.  the only thing you can get is 
random people's opinions.  so here is mine ;p.

> Do we need to submit our changes to the U-boot maintainers for inclusion in
> the mainline distribution code ?

this is never a requirement of the GPL for any project out there

> We understand the philosophy of GPL to give our customers the source code
> so they have the ability to inspect, modify and outsource And
> customization without being dependent on us.
> 
> In that light we have no problem in either providing our customers with the
> full source code upon their request OR simply load the full source code in
> the file system of the box it is shipped with. So if a customer wants the
> code, they can load it of the box they bought from us.

and those customers are free to take that source code and release it onto the 
internet.  so your original concerns seem kind of moot.
-mike
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[U-Boot] changes to U-boot and GPL

[Wolfgang Denk]

Dear "Mangelschots, Jef",

In message <226BC4AFA29FC24789DFD00DFF3084C250D369040B@SAFEMAIL.safetran.railad.com> you wrote:
> 
> We are getting confused when reading the GPL and interpreting how it
> applies to our situation.

You may want to read "A Practical Guide to GPL Compliance", see
http://www.softwarefreedom.org/resources/2008/compliance-guide.html

> We are adding features (not changing existing ones) to U-boot
> particular to our in-house developed system which we sell as a
> product to our customers.
> These changes involve adding a menu command for common tasks
> particular to our product and adding an in-house developed protocol
> for transferring files over a proprietary bus.
> We do not see these changes as being useful to the general U-boot
> community. We do have some concerns about security and opening our

What makes you think they would not be useful? Others might get
inspired by your menu system and adjust / extend it for their
purposes. U-Boot's origin is from a port to some board thatis of no
use to you - and still you benefit from a lot of code you can re-use.

> product (which is safety-critical) for malicious hacking by exposing
> the modifications.

Security by obscurity has never worked, and never will work.

Eventually a peer review from the experts in the community might even
help to improve the security of your system (and I mean the real one,
not the one you think you have).

But this is your decision, of course.

> This modified U-boot will be deployed on our products. It will not
> make sense to use on any other platforms.

This is your opinion. Other people my think differently.

> Our question is:
> Do we need to submit our changes to the U-boot maintainers for
> inclusion in the mainline distribution code ?

As Mike already pointed out: no.

> We understand the philosophy of GPL to give our customers the source
> code so they have the ability to inspect, modify and outsource And
> customization without being dependent on us.
> 
> In that light we have no problem in either providing our customers
> with the full source code upon their request OR simply load the full
> source code in the file system of the box it is shipped with. So if a
> customer wants the code, they can load it of the box they bought from
> us.

Out-of-tree ports have two distinct properties: 1) they are obsolete
from day 1 after their release (and often long before that), and 2)
they are a never ending maintenance effort. In our experience the
most efficient way to optimize product quality while minimizing
long-term maintenance efforts is to push all changes into mainline as
soon as possible.  You get free code reviews from the best experts in
the field, the community is maintaining your code for you, and there
is free help for you and your customers from the community.

See what's happening with all the out-of-tree ports - people come here
asking for help for really ancient versions, and we cannot help even
if we want because we don't know the code...

It's your choice.


Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: 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
Technology is dominated by those who manage what they do  not  under-
stand.

[U-Boot] loading S-record files

[Mangelschots, Jef]

We can load binary files by loading them in RAM (offset 0x3000000) first and then copying them to Flash with the cp.b command.

Now we are trying to load our executable (in S-record format) in Flash with the loads command (load S-record) using U-boot.

It is my understanding that S-record files specify the exact location of all data, so I assume that loads will write the content directly to Flash (without the need to load it in RAM first). Is this correct ?

I tried loading an S-record file of which the data is mapped to RAM and that seems to work,
But when the S-record file contains records that map a chunk to Flash, it gives the following error:

Unknown command 'S325F8045B0042414E434F4E464947555245445F5354CD' - try 'help'
=> S325F8045B20415445524154494F4E414C5F5354417E


FYI: 0xf8000000 is the start of our Flash.
Our U-boot is based on 2008.10 version.


Any files attached to this e-mail will have been checked with virus detection software prior to transmission but you should carry out your own virus check before opening any attachment. Safetran Systems Corp does not accept liability for any damage or loss which may be caused by software viruses. The contents of this e-mail and any attachments are the property of Safetran Systems Corp and are intended for the confidential use by the named recipient only. They may be legally privileged and should not be communicated to, or relied upon, by any other person without written consent. If you are not the addressee, please notify us immediately at the following address:  Safetran Systems Corporation, 2400 Nelson Miller Parkway, Louisville, Kentucky 40223. Safetran Systems Corp is a subsidiary of  Invensys Plc.  Registered office: Portland House, Bressenden Place, London, SW1E 5BF. UK Registered in England and Wales No. 1641421.

[U-Boot] which protocol do I use to send S-record files when using the loads command ?

[Peter Barada]

On Wed, 2010-08-18 at 10:11 -0700, Mangelschots, Jef wrote:

> What file transfer protocol do I use when sending an S-record file when I issue the loads command ?
> 
> I tried with both TerraTerm and Hyperterminal.
> 
> In Terraterm, when I use File | Send File ...,
> In HyperTerminal, I use the menu Transfer | Send Text File ...
> 
> In both these cases, it reads the first line correctly, but by the time it wants to process the following line, it ends up reading garbage. It looks like the terminal programs kept sending bytes while U-boot was processing the first S-record line (which is an S0 record).



Hmm, sounds like you don't use any flow-control on the serial port so
when u-boot goes away to do work it signals the other end(your host
running Terraterm/HyperTerminal) to stop transmitting until u-boot's
serial fifo has room in it.  If Terraterm/HyperTerminal don't have the
right flow-control setup then they'll keep tyring to stuff data into the
fifo (which gets dropped on the floor).


> I also tried sending a file with the protocols Xmodem, Ymodem, Kermit.
> Thy do not seem to work, or it is getting garbage (i.e. protocol specific headers, where it expects to see the actual S-record).
> 
> Our U-boot is based on 2008.10.
> 
> 
> Any files attached to this e-mail will have been checked with virus detection software prior to transmission but you should carry out your own virus check before opening any attachment. Safetran Systems Corp does not accept liability for any damage or loss which may be caused by software viruses. The contents of this e-mail and any attachments are the property of Safetran Systems Corp and are intended for the confidential use by the named recipient only. They may be legally privileged and should not be communicated to, or relied upon, by any other person without written consent. If you are not the addressee, please notify us immediately at the following address:  Safetran Systems Corporation, 2400 Nelson Miller Parkway, Louisville, Kentucky 40223. Safetran Systems Corp is a subsidiary of  Invensys Plc.  Registered office: Portland House, Bressenden Place, London, SW1E 5BF. UK Registered in England and Wales No. 1641421.
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot

[U-Boot] which protocol do I use to send S-record files when using the loads command ?

[Mangelschots, Jef]

What file transfer protocol do I use when sending an S-record file when I issue the loads command ?

I tried with both TerraTerm and Hyperterminal.

In Terraterm, when I use File | Send File ...,
In HyperTerminal, I use the menu Transfer | Send Text File ...

In both these cases, it reads the first line correctly, but by the time it wants to process the following line, it ends up reading garbage. It looks like the terminal programs kept sending bytes while U-boot was processing the first S-record line (which is an S0 record).

I also tried sending a file with the protocols Xmodem, Ymodem, Kermit.
Thy do not seem to work, or it is getting garbage (i.e. protocol specific headers, where it expects to see the actual S-record).

Our U-boot is based on 2008.10.


Any files attached to this e-mail will have been checked with virus detection software prior to transmission but you should carry out your own virus check before opening any attachment. Safetran Systems Corp does not accept liability for any damage or loss which may be caused by software viruses. The contents of this e-mail and any attachments are the property of Safetran Systems Corp and are intended for the confidential use by the named recipient only. They may be legally privileged and should not be communicated to, or relied upon, by any other person without written consent. If you are not the addressee, please notify us immediately at the following address:  Safetran Systems Corporation, 2400 Nelson Miller Parkway, Louisville, Kentucky 40223. Safetran Systems Corp is a subsidiary of  Invensys Plc.  Registered office: Portland House, Bressenden Place, London, SW1E 5BF. UK Registered in England and Wales No. 1641421.

[U-Boot] which protocol do I use to send S-record files when using the loads command ?

[Wolfgang Denk]

Dear "Mangelschots, Jef",

In message <226BC4AFA29FC24789DFD00DFF3084C2524247EDD2@SAFEMAIL.safetran.railad.com> you wrote:
> What file transfer protocol do I use when sending an S-record file when I issue the loads command ?

There is no protoco. You just send line by line...

> I tried with both TerraTerm and Hyperterminal.

Why did you not follow the description in the Manual?


> In both these cases, it reads the first line correctly, but by the time it wants to process the following line, it ends up reading garbage. It looks like the terminal programs kept sending bytes while U-boot was processing the first S-record line (which
>  is an S0 record).

Yes. With other terminal emulation programs you may have to twiddle
with inter-character and especially inter-line timings.

> I also tried sending a file with the protocols Xmodem, Ymodem, Kermit.

loads is not supposed to support xmodem or ymodem or kermit (binary)
protocols.

For ymoden, please use the loady command.

For kermit binary protocol, please use the loadb command
(recommended: most stable and often fastest of the serial protocols).

> Any files attached to this e-mail will have been checked with virus detection software prior to transmission but you should carry out your own virus check before opening any attachment. Safetran Systems Corp does not accept liability for any damage or l

Omit this crap when posting to a public mailing list. If you cannot
switch that off, then use a different, neutral mail account for
posting to mailing lists.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: 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
The word "fit", as I understand it, means "appropriate to a purpose",
and I would say the body of the Dean is supremely appropriate to  the
purpose of sitting around all day and eating big heavy meals.
                                 - Terry Pratchett, _Moving Pictures_

[U-Boot] which protocol do I use to send S-record files when using the loads command ?

[Wolfgang Denk]

Dear Peter Barada,

In message <1282151376.23742.30.camel@thunk> you wrote:
> 
> Hmm, sounds like you don't use any flow-control on the serial port so
> when u-boot goes away to do work it signals the other end(your host
> running Terraterm/HyperTerminal) to stop transmitting until u-boot's
> serial fifo has room in it.  If Terraterm/HyperTerminal don't have the
> right flow-control setup then they'll keep tyring to stuff data into the
> fifo (which gets dropped on the floor).

Such wild speculations that are not based on personal experience or
knowledge are not really helpful.


U-Boot does not implement any kind of flow control on the serial port.

For S-Record download, there is some basic synchronization based on
the echo of the input that it sends back (assuming CONFIG_LOADS_ECHO
is set in the board configuration), but this requires a terminal
emulation that understands how to handle that.  This is why the manual
recommends "cu" and "kermit".



Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: 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
But the only way of discovering the limits  of  the  possible  is  to
venture a little way past them into the impossible.
                         - _Profiles of the Future_ (1962; rev. 1973)
                  ``Hazards of Prophecy: The Failure of Imagination''

[U-Boot] which protocol do I use to send S-record files when using the loads command ?

[Wolfgang Denk]

Dear Jef,

In message <226BC4AFA29FC24789DFD00DFF3084C2524247EE08@SAFEMAIL.safetran.railad.com> you wrote:
> > Why did you not follow the description in the Manual?
> 
> Did you mean:
> http://www.denx.de/wiki/view/DULG/SystemSetup

Yes.

> I can't get Kermit for Windows to work with U-boot.

Why not? Kermit works basicly everywhere. I've been using in since CPM
times on virtually every platform I worked on (admitted, this does not
include Windows).

> TerraTerm and HyperTerminal work great for everything (binary transfers with loadb)
> but just not for loads.

I have no idea if they allow configuration of inter-character and/or
inter-line delays; if they do, you can try to tweak these.

> cu is not an option for us. Our customers use Windows.

INstall an OS then. Install Linux. If needed under coLinux, or in a
virtual machine.

> In Terraterm, there is an option to set a delay for every character.
> The least I seem to be able to do is 1ms/char, which makes it really slow, but it runs (it is running now, but it takes forever).

Actually you need the delay mostly after the newline character, when
U-Boot is programming the tranferred data to flash.

> Has anyone ever successfully been able to use these tools for loads, that you know ?

Sorry, I never use windows, and most people in my envrionment don't
use it either.

> -----Original Message-----
> From: Wolfgang Denk [mailto:wd at denx.de]
> Sent: Wednesday, August 18, 2010 10:32 AM
> To: Mangelschots, Jef
> Cc: u-boot at lists.denx.de

No need for a full-quote here. Please don't.


...
> Any files attached to this e-mail will have been checked with virus detecti>
...

And *please* STOP attaching these stupid trailers.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: 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
Always try to do things in chronological order; it's  less  confusing
that way.