[U-Boot] Veyron-speedy u-boot
Hi Simon,
I've tried porting u-boot to the veyron-speedy Chromebook, based upon the veyron-minnie patch.
I've attached a patch with my changes to this email.
However, when I boot, all I get is a black screen. So, I have some questions:
1. Does u-boot show output to the laptop's screen, or do I have to make a serial console? 2. If I have to make a serial console, where do I do this/what is the pin layout? 3. Do I just have to sign u-boot-dtb.img with vbutil_kernel before dd-ing it onto a USB, or do I have to do something else to make the right image?
Yours thankfully,
Riley Baird
Hi Riley,
On 15 February 2017 at 17:31, Riley Baird riley@openmailbox.org wrote:
Hi Simon,
I've tried porting u-boot to the veyron-speedy Chromebook, based upon the veyron-minnie patch.
I've attached a patch with my changes to this email.
However, when I boot, all I get is a black screen. So, I have some questions:
- Does u-boot show output to the laptop's screen, or do I have to make
a serial console?
It should show on both if all is well.
- If I have to make a serial console, where do I do this/what is the
pin layout?
You need a servo connector on the board - see here: https://www.chromium.org/chromium-os/servo
- Do I just have to sign u-boot-dtb.img with vbutil_kernel before
dd-ing it onto a USB, or do I have to do something else to make the right image?
I normally start up U-Boot from scratch, but it sounds like you are chain-loading it.
In that case I'm not sure what to do as I have not tried it. Your steps sound correct.
I've copied Tomeu who may know how to do this. If you figure it out it would be great to get a patch to README.rockchip.
Regards, Simon
Hi Riley,
On 16 February 2017 at 21:44, Simon Glass sjg@chromium.org wrote:
Hi Riley,
On 15 February 2017 at 17:31, Riley Baird riley@openmailbox.org wrote:
- Do I just have to sign u-boot-dtb.img with vbutil_kernel before
dd-ing it onto a USB, or do I have to do something else to make the right image?
I normally start up U-Boot from scratch, but it sounds like you are chain-loading it.
When chainloading, depthcharge will load and execute u-boot from a fixed address, and U-Boot needs to be told about it.
I chainloaded U-Boot on a nyan chromebook like this:
https://git.collabora.com/cgit/user/tomeu/u-boot.git/commit/?h=nyan-big&...
The important bit is changing u-boot's CONFIG_SYS_TEXT_BASE according to depthcharge's CONFIG_KERNEL_START.
https://chromium.googlesource.com/chromiumos/platform/depthcharge/+/master/b...
You may need to add some padding as shown in the .its file, but I don't remember now why CONFIG_SYS_TEXT_BASE cannot be adjusted instead (almost 2 years have passed already).
I think you can ignore the EAE commit in that branch because that code has been rewritten in u-boot since.
Good luck,
Tomeu
Hi Tomeu and Simon,
Thanks for giving me pointers on how the system works and how to get u-boot onto it. I'll try and get it working over the next couple of days.
I'm very glad that it's possible to chainload and the output comes out on the laptop screen, because I got a spreadsheet to work out how much it would cost to build a servo, and it was much more expensive than I thought! :)
Thanks again,
Riley
On 17 February 2017 at 10:18, Riley Baird riley@openmailbox.org wrote:
Hi Tomeu and Simon,
Thanks for giving me pointers on how the system works and how to get u-boot onto it. I'll try and get it working over the next couple of days.
I'm very glad that it's possible to chainload and the output comes out on the laptop screen, because I got a spreadsheet to work out how much it would cost to build a servo, and it was much more expensive than I thought! :)
Depending on what you plan to do with the machine, serial output can be very handy, specially if you want to run automated tests to validate whatever you end up doing with it.
Simon will know more about this, but I thought that the CPU UART lines are separate in the flex cable, so you may be able to find pads in the board that you can solder to.
Regards,
Tomeu
Thanks again,
Riley
Hi Tomeu,
On 17 February 2017 at 03:36, Tomeu Vizoso tomeu@tomeuvizoso.net wrote:
On 17 February 2017 at 10:18, Riley Baird riley@openmailbox.org wrote:
Hi Tomeu and Simon,
Thanks for giving me pointers on how the system works and how to get u-boot onto it. I'll try and get it working over the next couple of days.
I'm very glad that it's possible to chainload and the output comes out on the laptop screen, because I got a spreadsheet to work out how much it would cost to build a servo, and it was much more expensive than I thought! :)
Depending on what you plan to do with the machine, serial output can be very handy, specially if you want to run automated tests to validate whatever you end up doing with it.
Simon will know more about this, but I thought that the CPU UART lines are separate in the flex cable, so you may be able to find pads in the board that you can solder to.
Yes there are on separate lines (the servo connector) but it is a bit tricky to solder onto. You need a special connector which is cheap, but fine-pitched.
Regards,
Tomeu
Thanks again,
Riley
Regards, Simon
participants (3)
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Riley Baird -
Simon Glass -
Tomeu Vizoso