[U-Boot-Users] help in understand the address of standalone applications, ARM MCU

[U-Boot-Users] help in understand the address of standalone applications, ARM MCU

[J.P. Casainho]

Hello :-)

I would like to create a standalone application and I already read manual and 
also asked help here and got one good example however I can't get It working 
and I think the problem is in the address.

I am using an Olimex dev. board with a ARM9, AT91SAM9260 MCU. On my makefile I 
am linking with address 0xc100000, "LDFLAGS=-Bstatic -Ttext 0xc100000" -- is 
this address correct? How can I have sure of that? -- I got this value from 
makefile of "hello world" example.

When I do "tftp 0xc100000 flash_led.bin" the system hangs.. while If I try to 
do for example "tftp 0x1000 flash_led.bin" the code loads ok but after "go 
0x1000", the code does not work... It evens return while shouldn't because of 
an infinite loop on the code.

In the manual of the dev. board I have a memory map that says the 64MB RAM 
starts at 0x20000000 and ends on 0x23FFFFFF - If I do "tftp 0x20000000 
flash_LED.bin" system also hangs...

Can someone help me?

My flash_LED code is here: 
http://code.google.com/p/rockboxplayer/source/browse/trunk/flash_LED

And the help, example, I got before here in the mailing list: 
http://code.google.com/p/rockboxplayer/wiki/Flash_LED

I must say that with my dev. board comes an "hello world" example which is an 
empty function :-( -- but even I don't know to what address I should load it.

I did turn ON and OFF the LED on the dev. board using U-Boot shell, using the 
memory write and memory display commands ;-) -- I did write configure values 
to the PIO controller, enabling the PA6 pin as output and set and clear that 
pin to turn OFF and ON the green LED.

I am working on a Free/Open hardware digital audio player and recorder: 
http://www.rockbox.org/twiki/bin/view/Main/RockboxPlayer

Thanks in advance,

JPCasainho - http://www.Casainho.net

[U-Boot-Users] help in understand the address of standalone applications, ARM MCU

[Wolfgang Denk]

In message <200805111736.50691.casainho@gmail.com> you wrote:
> 
> I am using an Olimex dev. board with a ARM9, AT91SAM9260 MCU. On my makefile I 

Is this board supported in the public U-Boot git tree?

> am linking with address 0xc100000, "LDFLAGS=-Bstatic -Ttext 0xc100000" -- is 

What makes you think we would know the memory map of your board better
than you?

> this address correct? How can I have sure of that? -- I got this value from 
> makefile of "hello world" example.

As the first step you have to  understand  the  memory  map  of  your
system. We cannot know this.

> When I do "tftp 0xc100000 flash_led.bin" the system hangs.. while If I try to 

Then the address is obviously wrong - seems there is no RAM there.

> do for example "tftp 0x1000 flash_led.bin" the code loads ok but after "go 

Are you sur the code is really stored to this  address?  I  seriously
doubt  that.  0x1000  is  probably an address in flash memory on your
system, and you do not program the flash (normally)  when  running  a
"tftp" command.

> 0x1000", the code does not work... It evens return while shouldn't because of 
> an infinite loop on the code.

You are probably executing random code that happens to be at that
location in flash.

> In the manual of the dev. board I have a memory map that says the 64MB RAM 
> starts at 0x20000000 and ends on 0x23FFFFFF - If I do "tftp 0x20000000 

Ah, see! So what makes you think 0xc100000 could work?

> flash_LED.bin" system also hangs...

Probably because you are overwriting the exception vectors?

> I must say that with my dev. board comes an "hello world" example which is an 
> empty function :-( -- but even I don't know to what address I should load it.

Ask the company who provided that port of U-Boot and the example
program?

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
It is practically impossible to teach good programming style to  stu-
dents that have had prior exposure to BASIC: as potential programmers
they are mentally mutilated beyond hope of regeneration.   - Dijkstra

[U-Boot-Users] help in understand the address of standalone applications, ARM MCU

[J.P. Casainho]

Hello :-)

On Sunday 11 May 2008 19:31:05 you wrote:
> In message <200805111736.50691.casainho@gmail.com> you wrote:
> > I am using an Olimex dev. board with a ARM9, AT91SAM9260 MCU. On my
> > makefile I
>
> Is this board supported in the public U-Boot git tree?

No I think, It come with sources on CDROM, however this board looks like 
identical of the board/atmel/at91sam9260ek/.
http://git.denx.de/?p=u-boot.git;a=tree;f=board/atmel/at91sam9260ek;h=9872dae12d7fd41dfbdd82e5ea2ad900cc47c044;hb=f3612a7b199cab3942f60d9c1392eb39d58cc699

The board is the Olimex SAM9-L9260, manual: 
http://www.olimex.com/dev/pdf/ARM/ATMEL/SAM9-L9260.pdf


> > am linking with address 0xc100000, "LDFLAGS=-Bstatic -Ttext 0xc100000" --
> > is
>
> What makes you think we would know the memory map of your board better
> than you?

Hmmm... I am a novice :-) - my first time with 32 bits and U-Boot :-) - I 
tought that in some way memory map on U-Boot would be the same for every 
boards, dependant only on the MCU.


> > this address correct? How can I have sure of that? -- I got this value
> > from makefile of "hello world" example.
>
> As the first step you have to ?understand ?the ?memory ?map ?of ?your
> system. We cannot know this.

So them I assume the information on manual are what I am looking for. Is there 
any way to know that looking at sources of U-Boot?


> > When I do "tftp 0xc100000 flash_led.bin" the system hangs.. while If I
> > try to
>
> Then the address is obviously wrong - seems there is no RAM there.
>
> > do for example "tftp 0x1000 flash_led.bin" the code loads ok but after
> > "go
>
> Are you sur the code is really stored to this ?address? ?I ?seriously
> doubt ?that. ?0x1000 ?is ?probably an address in flash memory on your
> system, and you do not program the flash (normally) ?when ?running ?a
> "tftp" command.
>
> > 0x1000", the code does not work... It evens return while shouldn't
> > because of an infinite loop on the code.
>
> You are probably executing random code that happens to be at that
> location in flash.
>
> > In the manual of the dev. board I have a memory map that says the 64MB
> > RAM starts at 0x20000000 and ends on 0x23FFFFFF - If I do "tftp
> > 0x20000000
>
> Ah, see! So what makes you think 0xc100000 could work?
>
> > flash_LED.bin" system also hangs...
>
> Probably because you are overwriting the exception vectors?

Hmm... So I must know detailed memory map, and that depends on U-Boot usage, 
right? - the board manual just tells the principle and the end addresses of 
the SDRAM... - maybe the information I am looking for is in the sources of 
U-Boot...

> > I must say that with my dev. board comes an "hello world" example which
> > is an empty function :-( -- but even I don't know to what address I
> > should load it.
>
> Ask the company who provided that port of U-Boot and the example
> program?
>
> Best regards,
>
> Wolfgang Denk

Can you guide me? -- If I find the right address and use it on the -Ttext link 
time and on the tftp load and go command, my original program should work? is 
just that "simple" to have a externall application?

Thank you.

[U-Boot-Users] help in understand the address of standalone applications, ARM MCU

[Alessandro Rubini]

> Hmm... So I must know detailed memory map, and that depends on U-Boot usage, 
> right? - the board manual just tells the principle and the end addresses of 
> the SDRAM... - maybe the information I am looking for is in the sources of 
> U-Boot...

Most likely u-boot is running at 0x23f0.0000. Usually the initial
bytes are used for special purposes (I don't remember the details but
irq vectors might be located there), so anything in-between should
work. Try 0x2010.0000 (1M within the RAM area) or whatever.
In short: yes, it depends on the detailed memory map.

A good choice, if you don't want to know the details, is the address
where you load the kernel image (it's on the manual, or default boot
command). Note: not the flash address, but the load address in the
range 2000.0000-2400.0000; it usually is 32k in the ram, but whatever
it is, that is a safe address.  0 and 0xc000.0000 are definitely not good.

> If I find the right address and use it on the -Ttext link time and
> on the tftp load and go command, my original program should work?

Yes.

Hope this helps
/alessandro

[U-Boot-Users] help in understand the address of standalone applications, ARM MCU

[Wolfgang Denk]

In message <200805112051.43401.casainho@gmail.com> you wrote:
> 
> > Is this board supported in the public U-Boot git tree?
> 
> No I think, It come with sources on CDROM, however this board looks like 

Well, probably you should direct your questions to Olimex technical
support, then.

> Hmmm... I am a novice :-) - my first time with 32 bits and U-Boot :-) - I 
> tought that in some way memory map on U-Boot would be the same for every 
> boards, dependant only on the MCU.

No. The memory map is something that is board specific. Actyally you
define it when you port U-Boot to a specific board.

> So them I assume the information on manual are what I am looking for. Is there 
> any way to know that looking at sources of U-Boot?

Sure. Most of these definitions are in the board config file,
include/configs/<board>.h

> > > In the manual of the dev. board I have a memory map that says the 64MB
> > > RAM starts at 0x20000000 and ends on 0x23FFFFFF - If I do "tftp
> > > 0x20000000
...
> > Probably because you are overwriting the exception vectors?
> 
> Hmm... So I must know detailed memory map, and that depends on U-Boot usage, 

Not on usage, but on the configuration chosen by whoever ported U-Boot
to that board.

Try using some offset - say 256 kB or so; that should be sufficient in
any case - i. e. try 0x20040000 as download address.

> Can you guide me? -- If I find the right address and use it on the -Ttext link 
> time and on the tftp load and go command, my original program should work? is 
> just that "simple" to have a externall application?

I really think you should ask the vendor who provides the code.  Only
when they get a sufficient load of support calls they will learn that
it's better to push their changes back upstream.

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 flow chart is a most thoroughly oversold piece of  program  docu-
mentation.              -- Frederick Brooks, "The Mythical Man Month"

[U-Boot-Users] help in understand the address of standaloneapplications, ARM MCU

[Ulf Samuelsson]

> In message <200805111736.50691.casainho@gmail.com> you wrote:
>> 
>> I am using an Olimex dev. board with a ARM9, AT91SAM9260 MCU. On my makefile I 
> 
> Is this board supported in the public U-Boot git tree?
> 
>> am linking with address 0xc100000, "LDFLAGS=-Bstatic -Ttext 0xc100000" -- is 
> 
> What makes you think we would know the memory map of your board better
> than you?
> 
>> this address correct? How can I have sure of that? -- I got this value from 
>> makefile of "hello world" example.

By looking at the datasheet of the part in questions!

The AT91SAM9260 has fixed decoding of chip selects.
If you want to put your code in SDRAM, you need to put
is somewhere from [0x20000000 .. 0x20000000 + SDRAM_SIZE ]
U-Boot is typically located at  [0x20000000 + SDRAM_SIZE - 0x100000]

> 
> As the first step you have to  understand  the  memory  map  of  your
> system. We cannot know this.
> 
>> When I do "tftp 0xc100000 flash_led.bin" the system hangs.. while If I try to 
> 
> Then the address is obviously wrong - seems there is no RAM there.
> 
>> do for example "tftp 0x1000 flash_led.bin" the code loads ok but after "go 
> 
> Are you sur the code is really stored to this  address?  I  seriously
> doubt  that.  0x1000  is  probably an address in flash memory on your
> system, and you do not program the flash (normally)  when  running  a
> "tftp" command.
> 

0x1000 looks like internal SRAM. This is VERY limited in size.

>> 0x1000", the code does not work... It evens return while shouldn't because of 
>> an infinite loop on the code.
> 
> You are probably executing random code that happens to be at that
> location in flash.
> 
>> In the manual of the dev. board I have a memory map that says the 64MB RAM 
>> starts at 0x20000000 and ends on 0x23FFFFFF - If I do "tftp 0x20000000 
> 
> Ah, see! So what makes you think 0xc100000 could work?
> 
>> flash_LED.bin" system also hangs...
> 
> Probably because you are overwriting the exception vectors?
> 
>> I must say that with my dev. board comes an "hello world" example which is an 
>> empty function :-( -- but even I don't know to what address I should load it.
> 
> Ask the company who provided that port of U-Boot and the example
> program?
> 


Best Regards
Ulf Samuelsson

[U-Boot-Users] help in understand the address of standaloneapplications, ARM MCU

[J.P. Casainho]

I would like to "thank you" everyone who did answered to my questions.

I got now a simple code to work, my first stand alone application :-) - I did 
used that values suggested by Wolfgang Den and Alessandro Rubini, both values 
work :-)

I did read the include/configs/sam9l9260.h but I couldn't understand where is 
the information of the first address on SDRAM that I can use for a standalone 
application. I am not worried for now about that.

I tried a more complex code that uses a periodic interval timer to do a delay 
on flash LED code however this code does not work, It comes back to U-Boot 
shell with return value of 1. What can I be doing wrong?

So, to resume and maybe in hope to help someone like me:

My standalone application that is working:
http://code.google.com/p/rockboxplayer/source/browse/flash_led-0.c

My make file:
http://code.google.com/p/rockboxplayer/source/browse/Makefile?r=11

And I just needed to do on U-Boot shell:
"tftp 0x20040000 flash_LED.bin" and after "go 0x20040000" :-) :-)

Thank you all :-) :-)

[U-Boot-Users] help in understand the address of standaloneapplications, ARM MCU

[J.P. Casainho]

"I tried a more complex code that uses a periodic interval timer to do a delay 
on flash LED code however this code does not work, It comes back to U-Boot 
shell with return value of 1. What can I be doing wrong?" -- to answer my own 
questions, the page 
http://www.denx.de/wiki/view/DULG/MyStandaloneProgramDoesNotWork did help 
because I was not going to the right entry point :-)

Thank you all :-) :-)