feng.c

#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/mmc/card.h>

#define DRIVER_AUTHOR "Pellaeon Lin <nfsmwlin@gmail.com>"
#define DRIVER_DESCRIPTION "Modify write protected partition number to nonexistent partition"
#define DRIVER_VERSION "1.0"

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL");

int __init init_feng(void)
{
        char wp_prevention_partno[256];
        mmc_blk_get_wp_prevention_partno(&wp_prevention_partno[0]);

        printk(KERN_INFO "feng: %s version %s\n", DRIVER_DESCRIPTION,
                DRIVER_VERSION);
        printk(KERN_INFO "feng: by %s\n", DRIVER_AUTHOR);

        printk("feng installed, old wp_prevention_partno=%s \n", wp_prevention_partno);
        mmc_blk_set_wp_prevention_partno(99);
        mmc_blk_get_wp_prevention_partno(&wp_prevention_partno[0]);
        printk("feng: NEW wp_prevention_partno=%s \n", wp_prevention_partno);

        return 0;
}

static void __exit exit_feng(void)
{
}

module_init(init_feng);
module_exit(exit_feng);

Makefile

obj-m +=feng.o

KERNELDIR ?= ~/android/kernel/k2u-jb-3.4.10-cl157896-1-built
PWD := $(shell pwd)
CROSS_COMPILE=/home/pellaeon/toolchains/arm-eabi-4.6/bin/arm-eabi-
ARCH=arm

default:
            $(MAKE) -C $(KERNELDIR) M=$(PWD) ARCH=arm CROSS_COMPILE=$(CROSS_COMPILE) modules

clean:
            $(MAKE) -C $(KERNELDIR) M=$(PWD) clean

wp_mod.c

#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/mmc/card.h>

#define DRIVER_AUTHOR "Pellaeon Lin <nfsmwlin@gmail.com>"
#define DRIVER_DESCRIPTION "Defeat system write protect"
#define DRIVER_VERSION "1.0"

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL");

int __init init_wp_mod(void)
{
        printk(KERN_INFO "wp_mod: %s version %s\n", DRIVER_DESCRIPTION,
                DRIVER_VERSION);
        printk(KERN_INFO "wp_mod: by %s\n", DRIVER_AUTHOR);

        set_mmc0_write_protection_type(0);

        printk("wp_mod installed, mmc0_write_prot_type=%d \n", get_mmc0_write_protection_type());

        return 0;
}

static void __exit exit_wp_mod(void)
{
}

module_init(init_wp_mod);
module_exit(exit_wp_mod);