PROBLEM COMPILING

1-I use Slackware 11
2-I use RTAI patched kernel 2.4.33.3


root_at_darkstar:/usr/local/src/comedi# make



make  all-recursive
make[1]: Entering directory `/usr/local/src/comedi'
Making all in comedi
make[2]: Entering directory `/usr/local/src/comedi/comedi'
Making all in .
make[3]: Entering directory `/usr/local/src/comedi/comedi'
if gcc -DHAVE_CONFIG_H -I. -I. -I..    -I../include/ -DKBUILD_MODNAME=comedi
-DKBUILD_BASENAME=comedi_fops -D__KERNEL__
-I/usr/src/linux-2.4.33.3/include-Wall -Wstrict-prototypes
-Wno-trigraphs -O2 -fno-strict-aliasing
-fno-common -fomit-frame-pointer -pipe -mpreferred-stack-boundary=2
-march=i486 -fno-unit-at-a-time -DMODULE -DMODULE -D__MODULE_KERNEL_i686=1
-D__BOOT_KERNEL_ENTERPRISE=0 -D__BOOT_KERNEL_UP=1 -D__BOOT_KERNEL_SMP=0
-D__BOOT_KERNEL_BIGMEM=0 -D__BOOT_KERNEL_HUGEMEM=0 -I/usr/realtime/include
-g -O2 -MT comedi_ko-comedi_fops.o -MD -MP -MF
".deps/comedi_ko-comedi_fops.Tpo" -c -o comedi_ko-comedi_fops.o `test -f
'comedi_fops.c' || echo './'`comedi_fops.c; \
        then mv -f ".deps/comedi_ko-comedi_fops.Tpo"
".deps/comedi_ko-comedi_fops.Po"; else rm -f
".deps/comedi_ko-comedi_fops.Tpo"; exit 1; fi
comedi_fops.c:46:24: linux/cdev.h: No such file or directory
comedi_fops.c: In function `comedi_ioctl':
comedi_fops.c:89: warning: implicit declaration of function `iminor'
comedi_fops.c: In function `comedi_init':
comedi_fops.c:1743: warning: implicit declaration of function
`register_chrdev_region'
comedi_fops.c:1745: warning: implicit declaration of function `cdev_init'
comedi_fops.c:1746: error: invalid use of undefined type `struct cdev'
comedi_fops.c:1747: warning: implicit declaration of function
`kobject_set_name'
comedi_fops.c:1747: error: invalid use of undefined type `struct cdev'
comedi_fops.c:1748: warning: implicit declaration of function `cdev_add'
comedi_fops.c:1750: warning: implicit declaration of function
`unregister_chrdev_region'
comedi_fops.c:1758: warning: implicit declaration of function `cdev_del'
comedi_fops.c: At top level:
comedi_fops.c:1734: error: storage size of `comedi_cdev' isn't known
make[3]: *** [comedi_ko-comedi_fops.o] Error 1
make[3]: Leaving directory `/usr/local/src/comedi/comedi'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/usr/local/src/comedi/comedi'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/usr/local/src/comedi'
make: *** [all] Error 2

What's the matter?