NVidia BCT File aka Binary Configuration Table.

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Hi everyone,

I'm currently working with a Devboard NVidia Tegra 250 Harmony DevKit since about a year.

I've past my year to study Tegra's architecture and comportment on high level abstraction layers, using my GNU/Linux (Debian distrib) on it.

Now I'm working to understand this board a little more deeper, and now a day, I'm facing some problem with it.

Indeed, I'm currently trying to understand what it is this Binary Configuration Table binary.

About my research, it seems to be a Firmware like which is in charge of DDR Memory controller and Bootloader call.

So, my first question is: Am I on the right way with this definition?

Secondly, why did NVidia do this crappy thing??? I mean, there is no any other company working with ARM which choose to use this thing.

I also have a TI Omap based board, and there is no such thing on it.

Well, if anyone has informations/documentations/Links, I'll be happy to read them.

I've searched about this on Google, and for now, the only interesting things that I've found are coming from TrimSlice Wiki and xda-developers forums.

BCT is more commonly referred to as Boot Configuration Table.

It contains a large number of configuration options, among them location, size and load address of the boot loader.

Have a look at the bct_dump tool in the cbootimage repository.

Many thanks for this informations.

So, basically, I've download the L4T package, and just try to replace the default fastboot.bin with my cross-compiled u-boot for Tegra250.

Unfortunatly, it's not working at all :(

My problem is the following one:

Nvflash started
rcm version 0X20001
System Information:
chip name: t20
chip id: 0x20 major: 1 minor: 2
chip sku: 0x8
chip uid: 0x097c81c641816097
macrovision: disabled
hdcp: enabled
sbk burned: false
dk burned: false
boot device: nand
operating mode: 3
device config strap: 0
device config fuse: 0
sdram config strap: 0

sending file: static.bct
- 4080/4080 bytes sent
static.bct sent successfully
downloading bootloader -- load address: 0x108000 entry point: 0x108000
sending file: uboot.bin
| 173920/173920 bytes sent
uboot.bin sent successfully
waiting for bootloader to initialize

and then, I can wait for a looooonggg time for nothing, it seems that the uboot.bin doesn't do anything while the default fastboot.bin (900kb) correctly execute the next step on the script.

Is there any trick to do to be able to have a debug output?

Originally Posted by eppeP

BCT is more commonly referred to as Boot Configuration Table.

It contains a large number of configuration options, among them location, size and load address of the boot loader.

Have a look at the bct_dump tool in the cbootimage repository.

If that is the case, OMAP4 does have something similar, the Configuration Header. http://nishanthmenon.blogspot.com/20...-x-loader.html

Originally Posted by eppeP

BCT is more commonly referred to as Boot Configuration Table.

It contains a large number of configuration options, among them location, size and load address of the boot loader.

Have a look at the bct_dump tool in the cbootimage repository[/URL].

-MANY MANY MANY thanks for this URL, I was looking for this software for a long time.

I've been able to read and generate new BCT with it now
But, I'm still unable to boot on U-Boot :(

Originally Posted by Entropy512

If that is the case, OMAP4 does have something similar, the Configuration Header.

Yep, exactly, but basically, NVidia is less complicate in the load process but the way they handle the ROM boot and bootloader call is really crappy

I'm still investigating on my board, I really want to replace the fastboot with U-boot and push my whole system on NAND.

Originally Posted by DR I

-MANY MANY MANY thanks for this URL, I was looking for this software for a long time.

I've been able to read and generate new BCT with it now
But, I'm still unable to boot on U-Boot :(



Yep, exactly, but basically, NVidia is less complicate in the load process but the way they handle the ROM boot and bootloader call is really crappy

I'm still investigating on my board, I really want to replace the fastboot with U-boot and push my whole system on NAND.

Any progress on it yet ?

Sent from my HTC One X

Originally Posted by tids2k

Any progress on it yet ?

I've made some progress, but the way NV do not share at all this kind of informations is a little bit sad :(

I go forward step by step, I currently trying to build my own BCT based on the one provided by NVidia on it's L4T and CBootImage, but it seems to have some tricky things to know with the default BCT.

Mine is not compiling, CBootImage do not want to eat it
I'll gonna do some test tonight.

I let you inform of any evolve.

Originally Posted by DR I

I've made some progress, but the way NV do not share at all this kind of informations is a little bit sad :(

I go forward step by step, I currently trying to build my own BCT based on the one provided by NVidia on it's L4T and CBootImage, but it seems to have some tricky things to know with the default BCT.

Mine is not compiling, CBootImage do not want to eat it
I'll gonna do some test tonight.

I let you inform of any evolve.

thats good news, as far as with my understanding the tegra 3 follows the same chip architect and we would be able to debug with the same resources and might be able to induce a different BCT over the partial layer, thus giving access to an unsecured bootloader like UBOOT ?

Originally Posted by tids2k

thats good news, as far as with my understanding the tegra 3 follows the same chip architect and we would be able to debug with the same resources and might be able to induce a different BCT over the partial layer, thus giving access to an unsecured bootloader like UBOOT ?

Yes, indeed, I should now be able to do that, BUT, keep in mind that you have to sign your bootloader with csign before loading it on the Tegra DevKit.

This sounds completly crazy for me because the purpose of this board, as it's named, should be to DEVEL on it and then, you need to sign your bootloader?? C'mon NVidia, this is completly nuts, I don't really know if I'll continu to support and use their DevKit, I don't have time to waste with those kind of proprietary things.

If you're also working on that kind of board, we probably should help each other

Hi everyone,

I've been granted by NVidia to access their TRM so now I should be able to perform everything I want on the board.

So, I'll retry to install the u-boot during the week-end and see what's going on when I try to load it into the board.

So far, I've not been able to put anyone of my baremetal programs into the board and u-boot neither.

Sent from my Galaxy Nexus using XDA