[U-Boot-Users] Problems porting U-boot to custom board

[U-Boot-Users] Problems porting U-boot to custom board

[michael.firth at bt.com]

Apologies for the Newbie question, but I'm not really sure where else to
ask about this.

We've designed a board based around the Freescale MPC8343 processor, and
are trying to get U-boot running on it.

We have used an Embedded Planet evaluation board as the starting point
for our design. Unfortunately it seems that, although Embedded Planet
have ported U-Boot to their board, they haven't pushed the files to
support it upstream. Thus the only version of U-Boot I have that will
support this evaluation board is 1.1.4, which I know is ancient.

The system seems to be freezing very early on in the boot process (line
171 of the mpc83xx start.S file) while it seems to be doing some flash
remapping operations. What seems to be happening, using GDB and an
Abatron, is that it gets to this line, and then 'teleports' to a
function called 'hung()'.

The specific line that is giving the problem "lis r4,
(CFG_MONITOR_BASE)@h" looks to just be loading a register with a value,
but I don't really know PowerPC assembler.

I guess this leads me to four initial questions:
1) Is there any obvious gotcha that I'm likely to have fallen in to that
would cause this behaviour?
2) Given that this is an old version of U-boot, I'd like to move to a
more recent version. How difficult is it likely to be to port the board
support from u-boot-1.1.4 to the latest recommended version?
3) What is the latest recommended version? - I've seen references on
here to V1.2.0, but the latest available from the FTP area is 1.1.6.
4) If I do manage to port the Embedded Planet support in to the latest
U-Boot, would I be able to push that upstream, and, if I did so, would I
have to support that code?

Thanks in advance

Michael Firth

[U-Boot-Users] Problems porting U-boot to custom board

[Jerry Van Baren]

michael.firth at bt.com wrote:
> Apologies for the Newbie question, but I'm not really sure where else to
> ask about this.
> 
> We've designed a board based around the Freescale MPC8343 processor, and
> are trying to get U-boot running on it.
> 
> We have used an Embedded Planet evaluation board as the starting point
> for our design. Unfortunately it seems that, although Embedded Planet
> have ported U-Boot to their board, they haven't pushed the files to
> support it upstream. Thus the only version of U-Boot I have that will
> support this evaluation board is 1.1.4, which I know is ancient.
> 
> The system seems to be freezing very early on in the boot process (line
> 171 of the mpc83xx start.S file) while it seems to be doing some flash
> remapping operations. What seems to be happening, using GDB and an
> Abatron, is that it gets to this line, and then 'teleports' to a
> function called 'hung()'.
> 
> The specific line that is giving the problem "lis r4,
> (CFG_MONITOR_BASE)@h" looks to just be loading a register with a value,
> but I don't really know PowerPC assembler.

:-D  Methinks that will change.
<http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=blob;f=README;h=15428643edef7ea77710113f8908002b50328577;hb=HEAD#l3583>
or
<http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=blob;f=README;h=15428643edef7ea77710113f8908002b50328577;hb=HEAD#l3639>

> I guess this leads me to four initial questions:
> 1) Is there any obvious gotcha that I'm likely to have fallen in to that
> would cause this behaviour?

Are you running out of RAM rather than booting from flash or does your 
BDI2000 config file do RAM set up and memory map set up?   If so, that 
is most likely your problem.  The prior instruction:
  174         bl map_flash_by_law1
is mapping flash everywhere, so if you are running out of RAM or if your 
memory map isn't reset-virginal, you just mapped bogus flash instead of 
your program.  My mentor from way back had a term for this: "you just 
sh*t the nest."

> 2) Given that this is an old version of U-boot, I'd like to move to a
> more recent version. How difficult is it likely to be to port the board
> support from u-boot-1.1.4 to the latest recommended version?

Shouldn't be difficult, but level of difficult and level of expertise in 
the porting process are inversely proportional.

> 3) What is the latest recommended version? - I've seen references on
> here to V1.2.0, but the latest available from the FTP area is 1.1.6.

Buy yourself a copy of git (that is a joke) and use it to get the head 
of the development tree.
   <http://www.denx.de/cgi-bin/gitweb.cgi>
As a bonus that cannot be overstated, it also gives you source control 
over your local changes.
<http://www.kernel.org/pub/software/scm/git/>
<http://git.or.cz/>
<http://www.kernel.org/pub/software/scm/git/docs/everyday.html>
<http://www.kernel.org/pub/software/scm/git/docs/tutorial.html>

> 4) If I do manage to port the Embedded Planet support in to the latest
> U-Boot, would I be able to push that upstream, and, if I did so, would I
> have to support that code?

Yes and no, but it would be appreciated.  ;-)

> Thanks in advance
> 
> Michael Firth

Good luck,
gvb

P.S. I'm loving gitweb, can paste mysterious urls for the poor reader to 
click into. :-D  Slow news day here at work. ;-)

[U-Boot-Users] Problems porting U-boot to custom board

[Wolfgang Denk]

In message <9B595346504D314DA4936056A3E156EB869481@E03MVX3-UKDY.domain1.systemhost.net> you wrote:
>
> 3) What is the latest recommended version? - I've seen references on
> here to V1.2.0, but the latest available from the FTP area is 1.1.6.

The recommended version is top of tree in git repository.

And you are wrong, of course U-Boot 1.2.0 is  available  on  the  FTP
server: ftp://ftp.denx.de/pub/u-boot/u-boot-1.2.0.tar.bz2

Where did you look? At the old SourceForge site? Didn't it say in
black letters:

	NOTE: current source code is available from DENX git
	repository and FTP server; see
	http://www.denx.de/en/Software/GIT

?

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH, HRB 165235 Munich, CEO: Wolfgang Denk
Office:  Kirchenstr. 5,       D-82194 Groebenzell,            Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
He is truly wise who gains wisdom from another's mishap.

[U-Boot-Users] Problems porting U-boot to custom board

[michael.firth at bt.com]

> -----Original Message-----
> From: wd at denx.de [mailto:wd at denx.de] 
> Sent: 25 March 2007 21:33
> To: Firth,MJC,Michael,XGH35 R
> Cc: u-boot-users at lists.sourceforge.net
> Subject: Re: [U-Boot-Users] Problems porting U-boot to custom board 
> 
> 
> In message 
> <9B595346504D314DA4936056A3E156EB869481@E03MVX3-UKDY.domain1.s
> ystemhost.net> you wrote:
> >
> > 3) What is the latest recommended version? - I've seen 
> references on 
> > here to V1.2.0, but the latest available from the FTP area is 1.1.6.
> 
> The recommended version is top of tree in git repository.
> 
> And you are wrong, of course U-Boot 1.2.0 is  available  on  the  FTP
> server: ftp://ftp.denx.de/pub/u-boot/u-boot-1.2.0.tar.bz2
> 
> Where did you look? At the old SourceForge site? Didn't it 
> say in black letters:
> 
> 	NOTE: current source code is available from DENX git
> 	repository and FTP server; see
> 	http://www.denx.de/en/Software/GIT
> 
> ?

Apologies for that, I did think I'd checked the FTP site, but obviously
I hadn't as the file is on there.

I would suggest that the note on the SourceForge site doesn't make it
that clear that SourceForge has been discontinued - I think for a lot of
projects the 'current source code' is in a CVS/GIT repository, but for
many projects that 'current source code' isn't considered stable. It
seems for U-boot that the top of the GIT tree is considered stable,
which makes the situation slightly different. Prepending the note with
"This SourceForge area is no longer being updated - " would clarify
things a lot.

Thanks

Michael

[U-Boot-Users] Problems porting U-boot to custom board

[michael.firth at bt.com]

> -----Original Message-----
> From: Jerry Van Baren [mailto:gerald.vanbaren at smiths-aerospace.com] 
> Sent: 23 March 2007 17:49
> To: Firth,MJC,Michael,XGH35 R
> Cc: u-boot-users at lists.sourceforge.net
> Subject: Re: [U-Boot-Users] Problems porting U-boot to custom board
> 
> 
> 
> :-D  Methinks that will change. 
> <http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=blob;f=R
> EADME;h=15428643edef7ea77710113f8908002b50328577;hb=HEAD#l3583>
> or 
> <http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=blob;f=R
> EADME;h=15428643edef7ea77710113f8908002b50328577;hb=HEAD#l3639>
> 

I was slightly concerned that the README file doesn't seem to be
completely up to date - for example, under the 'directory hierarchy'
section there is no reference to the 'mpc834x' family. 

I have read most of it as a general guide now, but, at 52 pages of plain
text, it can be slow going. Are there any plans to split the Readme in
to sections?

Also, what is the difference between the two links you posted?

> > I guess this leads me to four initial questions:
> > 1) Is there any obvious gotcha that I'm likely to have fallen in to 
> > that would cause this behaviour?
> 
> Are you running out of RAM rather than booting from flash or 
> does your 
> BDI2000 config file do RAM set up and memory map set up?   If 
> so, that 
> is most likely your problem.  The prior instruction:
>   174         bl map_flash_by_law1
> is mapping flash everywhere, so if you are running out of RAM 
> or if your 
> memory map isn't reset-virginal, you just mapped bogus flash 
> instead of 
> your program.  My mentor from way back had a term for this: "you just 
> sh*t the nest."

I was running out of Flash, but, you were right, the BDI2000 config file
was doing some processor configuration. I didn't expect that to cause
too many problems, as I would have thought that U-Boot would undo what
it had done, but I have moved to a simpler BDI2000 config file which
doesn't do any pre-configuration, and the problem has now changed.

What I'm now seeing is that as soon as U-Boot enables the Machine Check
Exception (function 'cpu_init_f' in cpu_init.c) the processor reboots. I
guess my challenge now is to understand what conditions can cause the
machine check, and work out which one it is, and why.

> 
> > 2) Given that this is an old version of U-boot, I'd like to 
> move to a 
> > more recent version. How difficult is it likely to be to port the 
> > board support from u-boot-1.1.4 to the latest recommended version?
> 
> Shouldn't be difficult, but level of difficult and level of 
> expertise in 
> the porting process are inversely proportional.
> 

I'll probably give that a go, once I get to the end of the pain of
getting our board running and migrating that to the latest U-Boot,
migrating the Embedded Planet board over should be fairly easy by
comparison.

> > 3) What is the latest recommended version? - I've seen 
> references on 
> > here to V1.2.0, but the latest available from the FTP area is 1.1.6.
> 
> Buy yourself a copy of git (that is a joke) and use it to get 
> the head 
> of the development tree.
>    <http://www.denx.de/cgi-bin/gitweb.cgi>
> As a bonus that cannot be overstated, it also gives you 
> source control 
> over your local changes. <http://www.kernel.org/pub/software/scm/git/>
> <http://git.or.cz/> 
> <http://www.kernel.org/pub/software/scm/git/docs/everyday.html>
> <http://www.kernel.org/pub/software/scm/git/docs/tutorial.html>
> 

I guess a question that follows on from that is, if I use the head of
the development tree, how do I keep it current, so that I don't wind up
running some unsupportable interim version between V1.2.0 and V1.2.1 -
is that a job that getting to grips with GIT will help with?

> > 4) If I do manage to port the Embedded Planet support in to 
> the latest 
> > U-Boot, would I be able to push that upstream, and, if I 
> did so, would 
> > I have to support that code?
> 
> Yes and no, but it would be appreciated.  ;-)
> 
> > Thanks in advance
> > 
> > Michael Firth
> 
> Good luck,
> gvb
> 
> P.S. I'm loving gitweb, can paste mysterious urls for the 
> poor reader to 
> click into. :-D  Slow news day here at work. ;-)
> 
Indeed! I'm happy to have mysterious URLs when they contain useful
information.

Thanks for your help so far

Michael