uboot update needed.

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minkanjin
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uboot update needed.

Post by minkanjin » 04 Nov 2013, 09:42

Hi

It seems that linux kernels newer than 3.1 is incompatible with with the current uboot on the B3.
This discussion http://bugs.debian.org/658904 indicates that it's a problem with L2 cache that needs to be disabled by uboot and that a uboot version of at least 2011.12-3 is needed to solve the problem.

One user in the Arch Arm forums (http://archlinuxarm.org/forum/viewtopic ... 1&start=10) claims that installing the 3TB uboot image solves the problem. Unfortunately I have not been able to reproduce this, so either I didn't install the 3TB image correctly or I need an even newer uboot image.

Here is the uboot version information that I get from the serial console:
U-Boot 2010.06 (Jun 10 2011 - 09:06:51)
BUBBA|3
Did I install the 3TB uboot image incorrectly? If not, is there a newer uboot image that I can use?

johannes
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Re: uboot update needed.

Post by johannes » 04 Nov 2013, 16:53

Yes, you did install our 3 TB image correctly, but I cannot explain why it works for him but not for you. And no, sorry but we don't have a newer image available. I'd be happy to share our uboot config if you would want to build one yourself (port a new uboot to our board)?
/Johannes (Excito co-founder a long time ago, but now I'm just Johannes)

MouettE
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Re: uboot update needed.

Post by MouettE » 05 Nov 2013, 01:20

I'm very interested in that stuff too. However playinig with u-boot, which resides in flash, may probably be risquy no ? I mean what if we flash a broken version, it won't boot anymore, how do we re-flash a known working version without a working boot loader ?

And if we could have the config for the b2, it would be nice ;-) .

johannes
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Re: uboot update needed.

Post by johannes » 05 Nov 2013, 02:37

MouettE wrote:I'm very interested in that stuff too. However playinig with u-boot, which resides in flash, may probably be risquy no ? I mean what if we flash a broken version, it won't boot anymore, how do we re-flash a known working version without a working boot loader ?
Exactly, you have to know what you are doing here, there is no way to recover. The only (reasonable) way to re-flash is here in office, where we have the production equipment.

I'll dig out some stuff for you to have a look at, and you can decide for yourself.
/Johannes (Excito co-founder a long time ago, but now I'm just Johannes)

johannes
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Re: uboot update needed.

Post by johannes » 05 Nov 2013, 03:27

Quick thing to look at as a start:

Last winter we experimented with a uboot update but decided never to release it as an update (nor in production) due to the large risk (don't fix what isn't broken). However it did work well in our tests, so if you'd like to try this should work.

https://github.com/Excito/uboot-updated

However again; be careful. A bricked B3 is bricked.
/Johannes (Excito co-founder a long time ago, but now I'm just Johannes)

MouettE
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Re: uboot update needed.

Post by MouettE » 05 Nov 2013, 15:46

johannes wrote:Last winter we experimented with a uboot update but decided never to release it as an update (nor in production) due to the large risk (don't fix what isn't broken).
That is reasonable :wink:. And that's why hotheads like me make terrible sysadmins.

Is it so complicated to reflash the B3 board ? I don't have a large experience in this field, but I own a JTAG adapter which I never managed to use yet (all my attempts on other boards failed horribly).
johannes wrote:Last winter we experimented with a uboot update but decided never to release it as an update (nor in production) due to the large risk (don't fix what isn't broken). However it did work well in our tests, so if you'd like to try this should work.
I will try to compile it first. Then we'll see.

MouettE
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Re: uboot update needed.

Post by MouettE » 05 Nov 2013, 16:27

MouettE wrote:I will try to compile it first. Then we'll see.
Well I did clone the git tree and did directly on the device as stated in README.md

Code: Select all

make bubba3_config
make -j2
But I suppose I need a kwb image, so i added a

Code: Select all

make u-boot.kwb
In order to flash, I guess I sould place the compiled u-boot.kwb into an install folder on an empty key. Then reboot as indicated in the 3TB wiki page. Am I correct so far ?

MouettE
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Re: uboot update needed.

Post by MouettE » 05 Nov 2013, 16:31

I compiled on a wheezy system. Probably not the same compiler version as the one you used back in last winter. Probably not an issue but nevertheless, I don't know if I'll try it ....

johannes
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Re: uboot update needed.

Post by johannes » 06 Nov 2013, 02:39

MouettE wrote:In order to flash, I guess I sould place the compiled u-boot.kwb into an install folder on an empty key. Then reboot as indicated in the 3TB wiki page. Am I correct so far ?
Yes, should be right.
/Johannes (Excito co-founder a long time ago, but now I'm just Johannes)

johannes
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Re: uboot update needed.

Post by johannes » 06 Nov 2013, 02:52

MouettE wrote:Is it so complicated to reflash the B3 board ? I don't have a large experience in this field, but I own a JTAG adapter which I never managed to use yet (all my attempts on other boards failed horribly).
our production jig uses a process that works like this:

- connects a serial port to the b3 using test pins
- sends some special char early in the boot process, to invoke the hardware "loader"
- via serial, we transfer an intermediate loader software into the on-chip SRAM (which is very limited and cannot hold the full uboot). That SRAM is the only target that loader supports, since it cannot know what other memories the board may have.
- that intermediate loader then loads the full uboot (still from serial port in our case) and stores that on flash, done!

Note that this process works regardless of if you have a working uboot or not on the board, the internal hw "loader" can always be invoked.

You can of course use JTAG as well, but we didn't since this was simpler.
/Johannes (Excito co-founder a long time ago, but now I'm just Johannes)

MouettE
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Re: uboot update needed.

Post by MouettE » 06 Nov 2013, 11:23

That reminds me of this topic : Howto: Re-program Bubba (one) FLASH, a little bit simpler though.

So I would need a new TTL serial adapter and probably a piece of software to initiate and do the transfers. You think it would be possible to have these kind of infos ? I would perfectly understand if it wasn't possible.

johannes
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Re: uboot update needed.

Post by johannes » 07 Nov 2013, 05:19

Hi,

I didn't manage to dig out source code for our production test easilly, but you can start by looking here:

http://www.marvell.com/embedded-process ... Source.pdf

For instance chapter 24.2 is of interest.
/Johannes (Excito co-founder a long time ago, but now I'm just Johannes)

MouettE
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Re: uboot update needed.

Post by MouettE » 07 Nov 2013, 10:18

Thanks for the info !

From what I read (and saw in the generated kwb file), I could send these magic chars (0xBB 0x11 0x22 0x33 0x44 0x55 0x66 0x77), then directly the u-boot image via X-modem (that I think I can do it myself) ; the board should boot on this image, and with my serial console I should be able to stop u-boot from booting the OS and upload the same image from usb to the flash, from u-boot.

I just need to know where are the test pins on the board.

All this is quite exciting ;-)

johannes
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Re: uboot update needed.

Post by johannes » 07 Nov 2013, 15:37

Yeah, isn't this stuff the best? I fully agree. :)

http://wiki.excito.org/wiki/index.php/S ... cess_on_B3
/Johannes (Excito co-founder a long time ago, but now I'm just Johannes)

MouettE
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Re: uboot update needed.

Post by MouettE » 07 Nov 2013, 17:19

So it's the same as the serial console ? That's good news, it's already there so no hardware modifications. I will try all that in a few weeks when I have a little more time. Thanks for the pointers, I will keep you posted !

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