[meta-xilinx] u-boot environment limit

[Arno Steffens]

If I increase the uboot environment (by patching zynq-common.h) it happens that uboot stops working.
With a few lines changing/adding it seems to boot normal. 
With more lines is stops after "DRAM:  ECC disabled 496 MiB"

Now I played with the patch and get once this (see below):
This looks a bit like overwriting memory.

So is there a fix limit for the environment? It seems to be one huge string, right?
How can I extend this? Is this a bug?

#define CONFIG_ENV_SIZE			0x10000 -> this seems to me big enough.

U-Boot 2016.07-dirty (Feb 14 2017 - 12:59:07 +0100)

Model: Zynq MicroZED Board
Board: Xilinx Zynq
DRAM:  ECC disabled 496 MiB
Error binding driver 'gpio_zynq': -12
Error binding driver 'serial_zynq': -12
Error binding driver 'zynq_qspi': -12
Error binding driver 'zynq_gem': -12
Error binding driver 'arasan_sdhci': -12
Error binding driver 'generic_simple_bus': -12
Some drivers failed to bind
Error binding driver 'generic_simple_bus': -12
Some drivers failed to bind
initcall sequence 1ef99b98 failed at call 0400ea34 (err=-12)
### ERROR ### Please RESET the board ###

Best regards

Arno