I can't build with linux emul compiled in...
% config TRUMP 
../../../../arch/i386/conf/files.i386:256: cannot open ../../../../compat/linux/arch/i386/files.linux_i386 for reading: No such file or directory
 
*** Stop.

even if I uncomment that line (looks like the linux files.i386 is
obsolete), though, the compile fails:

cc -x assembler-with-cpp -traditional-cpp -D_LOCORE -I. -I../../../../arch -I../../../.. -nostdinc -DKOLVIR -DPATTERN -DLOCKF_DEBUG -DDIAGNOSTIC -DAUDIO_DEBUG -DSYSVMSG -DSYSVSEM -DSYSVSHM -DCOMPAT_43 -DLINUX_GCC_SIGNATURE -DLKM -DHAS_VOPLEASE -DCDDA -DPCVT_CTRL_ALT_DEL -DCOLOR_KERNEL_FG="FG_GREEN" -DCOLOR_KERNEL_BG="BG_BLACK" -DIPFILTER_LOG -DMAXUSERS=32 -D_KERNEL  -Di386 -c ../../../../arch/i386/i386/locore.s
In file included from ../../../../arch/i386/i386/locore.s:99:
../../../../compat/linux/linux_syscall.h:43: compat/linux/arch/i386/linux_syscall.h: No such file or directory
*** Error code 1