On 1/11/06, hari krishna <kernel2006hari@xxxxxxxxxxxxxx> wrote:
hi kernel lovers,
my sysyem is red hat enterprise linux of linux version 2.6.9
i compiled the program given in oreilly device drivers 3rd edition .
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
MODULE_LICENCE("Dual BSD/GPL");
static int hello_init(void)
{
printk(KERN_ALERT "Hello, world\n");
return 0;
}
static void hello_exit(void)
{
printk(KERN_ALERT "Goodbye, cruel world\n");
}
module_init(hello_init);
module_exit(hello_exit);
but i got the below errors of
root@ihawk ddlinux]# gcc -c hello1.c
hello1.c:4: syntax error before string constant
hello1.c:4: warning: data definition has no type or storage class
hello1.c: In function `hello_init':
hello1.c:7: `KERN_ALERT' undeclared (first use in this function)
hello1.c:7: (Each undeclared identifier is reported only once
hello1.c:7: for each function it appears in.)
hello1.c:7: syntax error before string constant
hello1.c: In function `hello_exit':
hello1.c:13: `KERN_ALERT' undeclared (first use in this function)
hello1.c:13: syntax error before string constant
Remember you are doing kernel Module programming not compiling simple C program. Use following Makefile
****************************************************************************
obj-m := hello1.o
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)
all:
$(MAKE) -C $(KERNELDIR) M=$(PWD)
clean:
rm -rf *.o .*.cmd *.ko *.mod.c
**************************************************************************
For Loading modules use insmod and removing module use rmmod. To use this command you need to be root user.
regards,
Parag.
