After a little blinking debug i found, that the camera crashes after the next line:
copy_and_restart((void*)MEMISOSTART, (char*)blob_chdk_core, blob_chdk_core_size);
in the my_restart() function.
In my platform/sx20/sub/100f/makefile.inc:
MEMISOSTART=0xACB74
which is comes from sx10 branch.