[U-Boot] Uboot - verified boot - CONFIG_OF_SEPARATE

[Thilo Cestonaro]

Hey!

When I build my Uboot with the CONFIG_OF_SEPARATE set to gain access to 
the compiled dtb, Uboot can't find my concatenated dtb during the boot.
After injecting the pulbic keys for the verified boot, I cat the 
u-boot.dtb behind the u-boot.bin. After that I mkimage the u-boot.img as 
usuall.

I found, that if I change the offset where the fdt_blob is searched for 
by +300, it finds the dtb correctly.
Like this:
-------------------
  #elif defined CONFIG_OF_SEPARATE
         /* FDT is at end of image */
-       gd->fdt_blob = (void *)(_end_ofs + _TEXT_BASE);
+       gd->fdt_blob = (void *)(_end_ofs + _TEXT_BASE + 300);
  #endif
-------------------

But I can't explain why this might be. The 300 isn't a random value! I 
calculated it via some debug output and it works reliably.
But like it is with these workarounds, I don't like them!
So I'm searching for an answer.

Any ideas, why the offset is not _end_ofs + _TEXT_BASE, like it should 
be?

Cheers,
Thilo