[yocto] [meta-raspberry] No spi, i2c when booting with uboot (RPI 3)

[Ionel Badisor]

On 09/28/2016 01:02 PM, romil1 at gmx.de wrote:
> I noticed something strange in the boot messages:
> When bootings with u-boot i can see-> Machine model: Raspberry Pi 3 Model B
> Without u-boot it is-> Machine model: Raspberry Pi 3 Model B Rev 1.2
>
> Why is there a difference when Im using the same device-tree? Could this
> be the reason why spi and i2c is disabled?

quote from: 
https://www.raspberrypi.org/documentation/configuration/device-tree.md

 > The current implementation is not a pure Device Tree system - there
 > is still board support code that creates some platform devices - but 
 > the external interfaces (I2C, I2S, SPI), and the audio devices that
 > use them, must now be instantiated using a Device Tree Blob (DTB)
 > passed to the kernel by the loader (start.elf).

 From what I recall:
start.elf contains a default device tree blob. (dt-blob.bin)

Only a dt-blob.bin file will overwrite the device tree in second stage 
boot loader(start.elf)