Hi Peter, I've spent a fun few hours, where booting under the modeldebugger works fine, but the isim_system fails uncompressing the kernel. I assumed I'd broken something in boot_wrapper and hyp mode, but reverting that gave the same thing. I finally hacked up something to do md4 on 64k blocks of the compressed image, and indeed it's different. Unfortunately, *where* it's different changes with each build. I can't make tonight's Linaro Toolchain call, but any ideas would be appreciated. If not, I'll try doing sums in the bootwrapper and see if I can figure it out... Thanks, Rusty.