Regarding the "make install" for the zaptel drivers under linux-2.4.27:
[root@baramx01 zaptel]# make
cc -I. -O4 -g -Wall -DBUILDING_TONEZONE -DSTANDALONE_ZAPATA -c -o gendigits.o gendigits.c
cc -o gendigits gendigits.o -lm
./gendigits
gcc -I/usr/src/linux-2.4/include -O6 -DMODULE -D__KERNEL__ -DEXPORT_SYMTAB -I/usr/src/linux/drivers/net -Wall -I. -Wstrict-prototypes -fomit-frame-pointer -I/usr/src/linux/drivers/net/wan -I /usr/src/linux/include -I/usr/src/linux/include/net -DMODVERSIONS -include /usr/src/linux-2.4/include/linux/modversions.h -DSTANDALONE_ZAPATA -c zaptel.c
In file included from /usr/src/linux-2.4/include/linux/kernel.h:15,
from zaptel.c:42:
/usr/include/asm/byteorder.h:6:2: warning: #warning using private kernel header; include <endian.h> instead!
In file included from /usr/src/linux-2.4/include/linux/bitops.h:69,
from /usr/include/asm/system.h:7,
from /usr/src/linux-2.4/include/linux/spinlock.h:6,
from /usr/src/linux-2.4/include/linux/module.h:12,
from zaptel.c:44:
/usr/include/asm/bitops.h:327:2: warning: #warning This includefile is not available on all architectures.
/usr/include/asm/bitops.h:328:2: warning: #warning Using kernel headers in userspace: atomicity not guaranteed
In file included from /usr/src/linux-2.4/include/linux/spinlock.h:6,
from /usr/src/linux-2.4/include/linux/module.h:12,
from zaptel.c:44:
/usr/include/asm/system.h: In function `__cmpxchg':
/usr/include/asm/system.h:126: error: `LOCK_PREFIX' undeclared (first use in this function)
/usr/include/asm/system.h:126: error: (Each undeclared identifier is reported only once
/usr/include/asm/system.h:126: error: for each function it appears in.)
/usr/include/asm/system.h:126: error: syntax error before string constant
... Many explosions afterward...