Hi,
I'm working on u-boot-usb and I think I get along quite well so far for the Atmel g45, thanks to this list. Slowly I do like the u-boot structure although it has a steep learning curve (I guess one week is considered steep by me). I've got the my Atmel Sam9G45 working for most parts (it boots well) and I hope to contribute some code soon (after usb is working well).
I do however have some questions about the u-boot startup behaviour.
What I want to create is the following :
1) u-boot starts and checks if it can start my application (either CRC check or whatever). This is the first thing u-boot should do. 2) if it can't boot it will listen on USB or ethernet for someone to upload a valid image or boot via NFS or whatever has been configured. 3) If it can boot, it will boot immediately (there may be a GPIO pin to override this behaviour) 4) once within the application (linux or whatever) I must be able to set a flag that lets u-boot wait for uploading a new image file when I soft-reset my device. This is needed for firmware upgrading of course. I still need to check if this flag is supported by the CPU or needs other support (eeprom perhaps). 5) After uploading an image the soft-reset is cleared and the whole sequence start over again, so it should boot the new image.
In short I want the application to be in control and only if there's no application installed or it's corrupt or when the application let's u-boot know, u-boot is in control. I know at step 2 there are some complications for testing purposes, so there must be a way to change the behavior (change the order of doing things). Maybe a kind of boot sequence added to u-boot would be fine. But the boot sequence only needs two items than. Either boot the image or stay in u-boot.
I know it's possible to do this but I wonder if it has been done before and if there any examples of it ?
Since I'm working on USB device support for my G45 and I want the above behaviour (or something very similar) I'm very much interested in any work that implements this or comes close to this. If it hasn't been done before I'm interested to work on this of course and contribute the work. In that case I'd be interested in anyone's opinion on this topic (I mean the way to implement it and stay consistent with the current u-boot code).
Best regards, Marcel
Hello everyone,
I want to do pci configuration in the function 'board_init_f'. How to do this?
Could I call the function "pci_init" in the function 'board_init_f' or add the function "pci_init" into the function array " init_sequence "?
In other words, what pre-conditions there are before calling pci_init? How to check the condition is ready?
Thanks!
Shuyou
Dear "sywang",
In message 20100927020635.0547228176@theia.denx.de you wrote:
I want to do pci configuration in the function 'board_init_f'. How to do this?
Why would you want to do that? Why cannot you wait until U-Boot has relocateditself to RAM so you have full access to all resources?
Could I call the function "pci_init" in the function 'board_init_f' or add the function "pci_init" into the function array " init_sequence "?
This might be difficult, as you still have a very limted runtime environment only, with just a minimal stack, without writable data, without valid BSS.
Best regards,
Wolfgang Denk
Wolfgang,
Thanks for your feedback.
Because the CPU-hang issue when pci_init still puzzle me, I want to check if the issue is caused by relocate_code, in spite of the very probability.
Do you have any suggestions about how to identify the root cause of PCI Init configuration hang?
Thanks! Shuyou
-----Original Message----- From: Wolfgang Denk [mailto:wd@denx.de] Sent: 2010年9月27日 15:27 To: sywang Cc: u-boot@lists.denx.de Subject: Re: [U-Boot] How to do pci_init in flash
Dear "sywang",
In message 20100927020635.0547228176@theia.denx.de you wrote:
I want to do pci configuration in the function 'board_init_f'. How to do this?
Why would you want to do that? Why cannot you wait until U-Boot has relocateditself to RAM so you have full access to all resources?
Could I call the function "pci_init" in the function 'board_init_f' or add the function "pci_init" into the function array " init_sequence "?
This might be difficult, as you still have a very limted runtime environment only, with just a minimal stack, without writable data, without valid BSS.
Best regards,
Wolfgang Denk
Dear Marcel,
In message 201009270011.32850.korgull@home.nl you wrote:
I do however have some questions about the u-boot startup behaviour.
Please read the manual; it should cover most of your questions.
What I want to create is the following :
- u-boot starts and checks if it can start my application (either CRC check
or whatever). This is the first thing u-boot should do. 2) if it can't boot it will listen on USB or ethernet for someone to upload a valid image or boot via NFS or whatever has been configured.
This is standard behaviour. See 7.4. Boot Arguments Unleashed etc., http://www.denx.de/wiki/view/DULG/LinuxBootArgs
- If it can boot, it will boot immediately (there may be a GPIO pin to
override this behaviour)
setenv bootdelay 0
- once within the application (linux or whatever) I must be able to set a flag
that lets u-boot wait for uploading a new image file when I soft-reset my device. This is needed for firmware upgrading of course. I still need to check if this flag is supported by the CPU or needs other support (eeprom perhaps).
see tools/env for tools to read and write the U-Boot environment settings from Linux. This can be used to change the boot command, boot delay etc.
- After uploading an image the soft-reset is cleared and the whole sequence
start over again, so it should boot the new image.
You can script all these things in U-Boot.
I know it's possible to do this but I wonder if it has been done before and if there any examples of it ?
There is all kinds of more or less complext stuff around. Read the manual. Read the default configurations set in other board config files. Read the code available in board/*/auto_update.c etc.
Best regards,
Wolfgang Denk
On Monday, September 27, 2010 09:25:36 am Wolfgang Denk wrote:
Dear Marcel,
In message 201009270011.32850.korgull@home.nl you wrote:
I do however have some questions about the u-boot startup behaviour.
Please read the manual; it should cover most of your questions.
Thanks for your kind reply. I do honestly have to say that I read a lot of u-boot code but actually only a parts of the manual.
What I want to create is the following :
- u-boot starts and checks if it can start my application (either CRC
check or whatever). This is the first thing u-boot should do. 2) if it can't boot it will listen on USB or ethernet for someone to upload a valid image or boot via NFS or whatever has been configured.
This is standard behaviour. See 7.4. Boot Arguments Unleashed etc., http://www.denx.de/wiki/view/DULG/LinuxBootArgs
I noticed that but had a different behavior in mind but was probably focused too much on USB instead of really looking at u-boot's behavior. Now that I read it again it does make a bit more sense and I think this will work out fine.
- If it can boot, it will boot immediately (there may be a GPIO pin to
override this behaviour)
setenv bootdelay 0
- once within the application (linux or whatever) I must be able to set
a flag that lets u-boot wait for uploading a new image file when I soft-reset my device. This is needed for firmware upgrading of course. I still need to check if this flag is supported by the CPU or needs other support (eeprom perhaps).
see tools/env for tools to read and write the U-Boot environment settings from Linux. This can be used to change the boot command, boot delay etc.
I used an AVR processor before and did this in the environment settings but currently that doesn't work for me yet. My env is in nor flash and I don't have a driver in linux yet to communicate with it. I'll look into this. Currently I write settings to eeprom but have no idea if it can be read from u-boot. I currently only use it for items that I need in Linux. I did see some drivers in u-boot for it, so I guess it should work as well and I'll have to try it or write a driver for my NOR flash.
- After uploading an image the soft-reset is cleared and the whole
sequence start over again, so it should boot the new image.
You can script all these things in U-Boot.
Great, that should solve it.
I know it's possible to do this but I wonder if it has been done before and if there any examples of it ?
There is all kinds of more or less complext stuff around. Read the manual. Read the default configurations set in other board config files. Read the code available in board/*/auto_update.c etc.
This does solve a lot of my questions. Thanks a lot for pointing me to that code and the other answers.
best regards, Marcel
Best regards,
Wolfgang Denk
Dear Marcel,
In message 201009292233.04020.korgull@home.nl you wrote:
see tools/env for tools to read and write the U-Boot environment settings from Linux. This can be used to change the boot command, boot delay etc.
I used an AVR processor before and did this in the environment settings but currently that doesn't work for me yet. My env is in nor flash and I don't have a driver in linux yet to communicate with it. I'll look into this.
Linux MTD drivers for NOR flash are really standard; they should work out of the box on all architectures.
Currently I write settings to eeprom but have no idea if it can be read from u-boot. I currently only use it for items that I need in Linux. I did see some
Yes, you can do this. Use the "eeprom read" (or raw "i2c" commands) to read the eemprom content into RAM; then you can use "env import" to import it into the environment.
Or you can combine "env export" with "eeprom write" for the opposite direction.
Best regards,
Wolfgang Denk
On Wednesday, September 29, 2010 10:51:06 pm Wolfgang Denk wrote:
Dear Marcel,
In message 201009292233.04020.korgull@home.nl you wrote:
see tools/env for tools to read and write the U-Boot environment settings from Linux. This can be used to change the boot command, boot delay etc.
I used an AVR processor before and did this in the environment settings but currently that doesn't work for me yet. My env is in nor flash and I don't have a driver in linux yet to communicate with it. I'll look into this.
Linux MTD drivers for NOR flash are really standard; they should work out of the box on all architectures.
ok. The vendor of my board must have overseen it and me too. I'll check it and try if I can make it work. This does have some advantage over using the eeprom although I guess I can still use the eeprom for some purpose. It's always good to have a choice.
Currently I write settings to eeprom but have no idea if it can be read from u-boot. I currently only use it for items that I need in Linux. I did see some
Yes, you can do this. Use the "eeprom read" (or raw "i2c" commands) to read the eemprom content into RAM; then you can use "env import" to import it into the environment.
Or you can combine "env export" with "eeprom write" for the opposite direction.
It looks like all I need is available or at least within reach. Thanks so much for your answers, it will save quite lot of time for me to move on in my project.
Best regards, Marcel
participants (3)
-
Marcel -
sywang -
Wolfgang Denk