Add support for nyan-big

[reey]

I would like to add support for the nyan-big chromebook (Acer Chromebook 13 CB5-311).
Should the nyan-big device be in a separate "acer" folder or is the nvidia folder fine?

The nyan-big device is similar to the norrin device.
u-boot does not include a norrin defconfig at the moment.
A nyan-big defconfig is already present, but it needs some changes to boot u-boot natively since the defconfig is made for a chainloading u-boot with coreboot..

The changes needed for the u-boot nyan-big_defconfig are:

CONFIG_SYS_TEXT_BASE=0x80110000 
CONFIG_ARMV7_LPAE=y
CONFIG_PHYS_64BIT=y

I've changed a few things in the bct.cfg file, but the board also boots with the original file which is used for norrin. The changes were made by looking at this file: https://github.com/coreboot/coreboot/blob/master/src/mainboard/google/nyan_big/bct/sdram-hynix-4GB-792.inc

A pull request for the tegra-uboot-flasher-scripts will follow after this is merged.

[swarren]

Unfortunately, we only add vendor-supplied support for non-NVIDIA boards, since some vendors have claimed copyright over their BCT files and requested we don't publish them. Where did you get these files from? If they're already published by their owner, then we can probably add them here. Perhaps the ChromeOS project publishes the data somewhere? Simon Glass might know (sjg@chromium.org).

We should add the files to an Acer directory, since it's an Acer board not NVIDIA. Or perhaps Google if they did the board design.

The copyright messages in all the files are NVIDIA 2014. That doesn't seem right for most of the files (excluding perhaps the trivial things like Makefiles which are likely identical to the same files in other boards).

IIRC, Nyan supports very many DRAM configurations and coreboot programs the DRAM, yet the BCT had DRAM timings in it. Is that right? Again, Simon Glass might be best to comment here.

[swarren]

Drop the README commits from the pull request.

The makefile mentions PM370_Hynix_2GB_H5TC4G63AFR_PBA_924MHz_01212014.bct. I'm not sure that PM370 is the right name for this board...

https://github.com/coreboot/coreboot/tree/master/src/mainboard/google/nyan_big/bct seems to contain BCTs for this platform. We may be able to accept changes derived from those files; I'll check. There are 6 different DRAM configs there; does this pull request support just one of those configs or ...?

[reey]

I basically just copied over the norrin config and changed it to nyan-big..
And I just kept the name of PM370_Hynix_2GB_H5TC4G63AFR_PBA_924MHz_01212014.bct since I'm not sure what would be the correct naming schema for it..

I kept the nvidia folder instead of google or acer because the nyan-big board in u-boot is also a subdirectory of nvidia..

I left the copyright statements untouched since I did not change that much..
If I should change that? If so, to what should I change it?

I wasn't sure how to add all of those bct files to this project so I just took one, that was working for me..
Maybe you could explain how to add all of those and how the tegra-uboot-flasher-scripts are going to choose the correct one?
Or do we need to the manually edit the Makefile depending on which config we want to use?