When compiling ide as a module on 2.5.39, encountered the following error
gcc -Wp,-MD,./.ide.o.d -D__KERNEL__ -I/v6/src/2539/linux-2.5.39/include
-Wall -Wstrict-prototypes -Wno-trigraphs -O2 -fomit-frame-pointer
-fno-strict-aliasing -fno-common -pipe -mpreferred-stack-boundary=2
-march=i586 -I/v6/src/2539/linux-2.5.39/arch/i386/mach-generic -nostdinc
-iwithprefix include -DMODULE -include
/v6/src/2539/linux-2.5.39/include/linux/modversions.h
-DKBUILD_BASENAME=ide -DEXPORT_SYMTAB -c -o ide.o ide.c
ide.c:3578: redefinition of `init_module'
ide.c:3556: `init_module' previously defined here
ide.c: In function `cleanup_module':
ide.c:3601: warning: implicit declaration of function `bus_unregister'
{standard input}: Assembler messages:
{standard input}:8863: Error: symbol `init_module' is already defined
make[2]: *** [ide.o] Error 1
make[2]: Leaving directory `/v6/src/2539/linux-2.5.39/drivers/ide'
make[1]: *** [ide] Error 2
make[1]: Leaving directory `/v6/src/2539/linux-2.5.39/drivers'
make: *** [drivers] Error 2
Jeff