Writing to TTBCR on ARM9 causes fault

I am trying to get L4 running on the freescale i.MX28 EVK.

During startup it stops with a fault at 
fiasco/src/kern/arm/bootstrap.cpp:236

   asm volatile("mcr p15, 0, %[ttbcr], c2, c0, 2" // TTBCR
                : : [ttbcr] "r" (Page::Ttbcr_bits));

Unlike ARM11, the ARM9 does not know about TTBCR. 
[http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0198e/I1014942.html]


So maybe this might be omitted on ARM9?


Martin