[meta-xilinx] U-Boot and I2C

[Arno Steffens]

I want to issue an I2C-command before booting the kernel.
Does the u-boot for ZYNQ supports I2C? I didn't found it activated in any ZYNQ board, so I am wondering why!?
Any hints how to activate? 
My first experiments to enable it failed with a reboot:
Zynq> i2c probe
Valid chip addresses:Error, wrong i2c adapter 0 max 0 possible
Error, wrong i2c adapter 0 max 0 possible
undefined instruction
pc : [<00000004>]          lr : [<1ef3b2d8>]
reloc pc : [<e50ca004>]    lr : [<040052d8>]
sp : 1db25d78  ip : 00000030     fp : 1ef3b16c
r10: 00000002  r9 : 1db25ee8     r8 : 1ef8a617
r7 : 00000000  r6 : ffffffff     r5 : 00000000  r4 : 00000000
r3 : 00000002  r2 : 0000080a     r1 : 00000000  r0 : 1ef9ba30
Flags: nZCv  IRQs off  FIQs off  Mode SVC_32
Resetting CPU ...

What is expected for the parameters for (I guess it is this command ?):
i2c nm chip address[.0, .1, .2] - write to I2C device (constant address)