[U-Boot-Users] help in understand the address of standalone applications, ARM MCU
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
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
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=9872da...
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.
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
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
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
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 :-) :-)
participants (4)
-
Alessandro Rubini -
J.P. Casainho -
Ulf Samuelsson -
Wolfgang Denk