本节是关于生成设备节点。
学习资料来源于迅为的视频学习教程的整理
1.区分概念：
设备注册：platform_device，查看：/sys/devices/platform
驱动注册：platform_driver
生成设备节点：为了让应用程序可以调用，是"对上"的接口。
与设备注册无关，设备节点名称不需要与设备名称相同。查看：/dev/*
一般将设备节点的注册放在probe中，也可以放到init函数中。
杂项设备，或者说是对一部分字符设备的封装或者一部分不好分类的。
可以节省主设备号，驱动写起来相对简单（用封装好的杂项设备可以减少一步注册主设备号的过程）
Linux设备驱动一般分为：字符设备，块设备，网络设备。也可以按照子系统来分类，如：mm，led等
2.源代码位置
杂项设备初始化源代码：/drivers/char/misc.c，属于内核中强制编译的。
杂项设备注册头文件：include/linux/miscdevice.h，主要的结构体为miscdevice
1 struct miscdevice {
2 int minor; //设备号，一般系统分配随机取值
3 const char *name; //生成设备节点的名称，无限制
4 const struct file_operations *fops; //指向一个设备节点文件，对文件的操作
5 struct list_head list;
6 struct device *parent;
7 struct device *this_device;
8 const char *nodename;
9 mode_t mode;
10 };
11
12 extern int misc_register(struct miscdevice * misc); //生成设备节点的函数,一般在probe中被调用
13 extern int misc_deregister(struct miscdevice *misc);
设备节点本质是文件一个特殊文件，包括文件名，打开关闭等，文件结构体的头文件为include/linux/fs.h，结构体为file_operations
1 //相当重要的结构体
2 /*
3 * NOTE:
4 * all file operations except setlease can be called without
5 * the big kernel lock held in all filesystems.
6 */
7 struct file_operations {
8 struct module *owner; //必选参数，一般是THIS_MODULE
9 loff_t (*llseek) (struct file *, loff_t, int);
10 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
11 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
12 ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
13 ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
14 int (*readdir) (struct file *, void *, filldir_t);
15 unsigned int (*poll) (struct file *, struct poll_table_struct *);
16 /* remove by cym 20130408 support for MT660.ko */
17 #if 0
18 //#ifdef CONFIG_SMM6260_MODEM
19 #if 1// liang, Pixtree also need to use ioctl interface...
20 int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);
21 #endif
22 #endif
23 /* end remove */
24 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); //非必选，对GPIO操作，应用向底层驱动传值的
25 long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
26 int (*mmap) (struct file *, struct vm_area_struct *);
27 int (*open) (struct inode *, struct file *); //必选的参数，打开文件函数
28 int (*flush) (struct file *, fl_owner_t id);
29 int (*release) (struct inode *, struct file *); //必选的参数，关闭文件函数
30 int (*fsync) (struct file *, int datasync);
31 int (*aio_fsync) (struct kiocb *, int datasync);
32 int (*fasync) (int, struct file *, int);
33 int (*lock) (struct file *, int, struct file_lock *);
34 ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
35 unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
36 int (*check_flags)(int);
37 int (*flock) (struct file *, int, struct file_lock *);
38 ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
39 ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
40 int (*setlease)(struct file *, long, struct file_lock **);
41 long (*fallocate)(struct file *file, int mode, loff_t offset,
42 loff_t len);
43 /* add by cym 20130408 support for MT6260 and Pixtree */
44 #if defined(CONFIG_SMM6260_MODEM) || defined(CONFIG_USE_GPIO_AS_I2C)
45 int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long); //此处ioctl与上面的不一样
46 #endif
47 /* end add */
48 };
3. 驱动代码案例
在probe_linux_module基础上写devicenode_linux_module驱动，注意函数调用顺序，/dev下查看
devicenode_linux_module.c
1 #include <linux/init.h> 2 #include <linux/module.h> 3 #include <linux/platform_device.h> 4 //misc 5 #include <linux/miscdevice.h> 6 //注册设备节点的文件结构体 7 #include <linux/fs.h> 8 9 #define DRIVER_NAME "hello_ctl" 10 #define DEVICE_NAME "hello_ctl123" 11 12 static int hello_open(struct inode *inode, struct file *file){ 13 printk(KERN_EMERG "hello open "); //调用步骤4-1 14 return 0; 15 } 16 static int hello_release(struct inode *inode, struct file *file){ 17 printk(KERN_EMERG "hello release "); //调用步骤4-2 18 return 0; 19 } 20 static long hello_ioctl(struct file *file, unsigned int cmd, unsigned long arg){ 21 //打开之后操作的，所以参数里面不需要inode 22 printk(KERN_EMERG "hello ioctl "); //调用步骤4-3 23 printk("cmd is %d, arg is %d ", cmd, arg); 24 return 0; 25 } 26 //文件设备操作结构体 27 static struct file_operations hello_ops = { 28 .owner = THIS_MODULE, 29 // int (*open) (struct inode *, struct file *); 30 .open = hello_open, //调用步骤3-1 31 // int (*release) (struct inode *, struct file *) 32 .release = hello_release, //调用步骤3-2 33 // long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 34 .unlocked_ioctl = hello_ioctl, //调用步骤3-3 35 }; 36 //杂项设备结构体 37 static struct miscdevice hello_dev = { 38 .minor = MISC_DYNAMIC_MINOR, 39 .name = DEVICE_NAME, 40 .fops = &hello_ops, //调用步骤2 41 }; 42 43 44 static int hello_probe(struct platform_device *pdv){ 45 printk(KERN_EMERG "initialized "); 46 misc_register(&hello_dev); //一般在probe中调用.调用步骤1 47 return 0; 48 } 49 static int hello_remove(struct platform_device *pdv){ 50 printk(KERN_EMERG "remove "); 51 misc_deregister(&hello_dev); 52 return 0; 53 } 54 static void hello_shutdown(struct platform_device *pdv){ 55 ; 56 } 57 static int hello_suspend(struct platform_device *pdv, pm_message_t pmt){ 58 return 0; 59 } 60 static int hello_resume(struct platform_device *pdev){ 61 return 0; 62 } 63 64 struct platform_driver hello_driver = { 65 .probe = hello_probe, 66 .remove = hello_remove, 67 .shutdown = hello_shutdown, 68 .suspend = hello_suspend, 69 .resume = hello_resume, 70 .driver = { 71 .name = DRIVER_NAME, 72 .owner = THIS_MODULE, 73 } 74 }; 75 76 static int hello_init(void) 77 { 78 int DriverState; 79 printk(KERN_EMERG "hello world enter! "); 80 DriverState=platform_driver_register(&hello_driver); 81 printk(KERN_EMERG "DriverState is %d ", DriverState); 82 return 0; 83 } 84 85 static void hello_exit(void) 86 { 87 printk(KERN_EMERG "hello world exit! "); 88 platform_driver_unregister(&hello_driver); //unregister会查找release，如果找不到会报错 89 } 90 91 module_init(hello_init); 92 module_exit(hello_exit); 93 94 MODULE_LICENSE("Dual BSD/GPL"); 95 MODULE_AUTHOR("NANZH");
Makefile
1 obj-m += devicenode_linux_module.o 2 3 KDIR := /home/nan/iTOP4412/iTop4412_Kernel_3.0 4 5 PWD ?= $(shell pwd) 6 7 all: 8 make -C $(KDIR) M=$(PWD) modules 9 10 clean: 11 rm -rf *.o
测试结果：
1 # 板子上： 2 root@iTOP4412-ubuntu-desktop:# insmod devicenode_linux_module.ko 3 [ 112.202074] hello world enter! 4 [ 112.203980] initialized 5 [ 112.236250] DriverState is 0 6 查看生成的设备节点： 7 root@iTOP4412-ubuntu-desktop:# ls -l /dev/hello_ctl123 8 crw------- 1 root root 10, 46 Nov 22 05:55 /dev/hello_ctl123 9 root@iTOP4412-ubuntu-desktop:# rmmod devicenode_linux_module 10 [ 136.243713] hello world exit! 11 [ 136.246474] remove
以上
继编写简单的应用来调用设备节点：
根据上面生成的/dev/hello_ctl123节点来调用，基于应用层的，所以使用基本的C文件形式。
4. 函数头文件
# include <stdio.h> //printf
# include <sys/types.h> //基本系统数据类型，依据编译环境保持32位值还是64位值
# include <sys/stat.h> //系统调用头文件，如目录、管道、socket、字符、块的属性等
# include <fcntl.h> //定义了open函数
# include <unistd> //定义了close函数
# include <sys/ioctl.h> //定义了ioctl函数
编译器使用的是arm-2009q3，即arm-none-linux-gnueabi-gcc。编译使用的头文件在编译器的libc下，如：
/usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/usr/include/fcntl.h
5. 函数
open：返回文件描述符
ioctl：应用向驱动传值
close：关闭文件
编译方法：arm-none-linux-gnueabi-gcc -o invoke_hello123 invoke_hello123.c
6.详细的C文件：invoke_hello123.c
1 #include <stdio.h> 2 #include <sys/types.h> 3 #include <sys/stat.h> 4 #include <fcntl.h> 5 #include <unistd.h> 6 #include <sys/ioctl.h> 7 8 int main() 9 { 10 int fd; 11 char *hello_node = "/dev/hello_ctl123"; //设备节点的路径 12 13 fd = open(hello_node, O_RDWR|O_NDELAY); //只读，非阻塞方式 14 if (fd < 0) 15 perror("open"); 16 else{ 17 printf("App open %s success ",hello_node); 18 ioctl(fd, 1, 6); 19 } 20 21 close(fd); 22 return 0; 23 }
编译完成之后将编译产物invoke_hello123拷贝至开发板中运行，正确运行结果如下：
查看运行结果：
1 root@iTOP4412-ubuntu-desktop:~/tests/3# insmod devicenode_linux_module.ko
2 [ 1856.029716] hello world enter!
3 [ 1856.040410] initialized
4 [ 1856.068655] DriverState is 0
5 root@iTOP4412-ubuntu-desktop:~/tests/3# ls /dev/hello_ctl123
6 /dev/hello_ctl123
7 root@iTOP4412-ubuntu-desktop:~/tests/3# ls -l /dev/hello_ctl123
8 crw------- 1 root root 10, 46 Nov 22 07:29 /dev/hello_ctl123
9 root@iTOP4412-ubuntu-desktop:~/tests/3# ./invoke_hello123
10 [ 1871.946816] hello open
11 [ 1871.948367] hello ioctl
12 App open /dev/hello_ctl123 success
13 [ 1871.960204] hello release
14 root@iTOP4412-ubuntu-desktop:~/tests/3# rmmod devicenode_linux_module
15 [ 1880.317030] hello world exit!
16 [ 1880.318624] remove
dmesg中含有hello_ioctl调用的打印信息，上面没有直接打印出来，在dmesg中有。
[ 65.291707] hello world enter!
[ 65.293621] initialized
[ 65.321764] DriverState is 0
[ 69.906179] hello open
[ 69.930525] hello ioctl
[ 69.932853] cmd is 1, arg is 6
[ 69.932905] hello release
在开发板上运行./invoke_hello123出错的log和解决如下：
# ERROR
root@iTOP4412-ubuntu-desktop:~/tests/3# ./invoke_hello123
-bash: ./invoke_hello123: No such file or directory
解决方法：https://blog.csdn.net/qq_22863619/article/details/80294232
iTOP4412-ubuntu-desktop:~/tests/3# readelf -a invoke_hello123 | grep Requesting
[Requesting program interpreter: /lib/ld-linux.so.3]
由此发现缺少的是库文件：/lib/ld-linux.so.3
遂到toolchain中查找：
nan@nanzh:~/iTOP4412/4-1$ find /usr/local/arm/arm-2009q3/ -iname "ld-linux.so.3"
/usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/lib/ld-linux.so.3
/usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/thumb2/lib/ld-linux.so.3
/usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/armv4t/lib/ld-linux.so.3
nan@nanzh:~/iTOP4412/4-1$ ls -l /usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/lib/ld-linux.so.3
lrwxrwxrwx 1 nan nan 12 10月 17 2009 /usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/lib/ld-linux.so.3 -> ld-2.10.1.so
于是将ld-2.10.1.so拷贝到开发板中并设置软连接
root@iTOP4412-ubuntu-desktop:# cp /mnt/ld-2.10.1.so /lib
root@iTOP4412-ubuntu-desktop:/lib# ln -s ld-2.10.1.so ld-linux.so.3
#ERROR 2
root@iTOP4412-ubuntu-desktop:~/tests/3# ./invoke_hello123
./invoke_hello123: error while loading shared libraries: libgcc_s.so.1: cannot open shared object file: No such file or directory
方法：
nan@nanzh:~/iTOP4412/4-1$ find /usr/local/arm/arm-2009q3/ -iname "libgcc_s.so.1"
/usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/lib/libgcc_s.so.1
/usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/thumb2/lib/libgcc_s.so.1
/usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/armv4t/lib/libgcc_s.so.1
nan@nanzh:~/iTOP4412/4-1$ ls -l /usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/lib/libgcc_s.so.1
-rw-r--r-- 1 nan nan 69371 10月 17 2009 /usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/lib/libgcc_s.so.1
拷贝到板子上继续
root@iTOP4412-ubuntu-desktop:~/tests/3# cp /mnt/libgcc_s.so.1 /lib/
root@iTOP4412-ubuntu-desktop:~/tests/3# ./invoke_hello123
./invoke_hello123: error while loading shared libraries: libc.so.6: cannot open shared object file: No such file or directory
nan@nanzh:~/iTOP4412/4-1$ find /usr/local/arm/arm-2009q3/ -iname "libc.so.6"
/usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/lib/libc.so.6
/usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/thumb2/lib/libc.so.6
/usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/armv4t/lib/libc.so.6
nan@nanzh:~/iTOP4412/4-1$ ls -l /usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/lib/libc.so.6
lrwxrwxrwx 1 nan nan 14 10月 17 2009 /usr/local/arm/arm-2009q3/arm-none-linux-gnueabi/libc/lib/libc.so.6 -> libc-2.10.1.so
root@iTOP4412-ubuntu-desktop:~/tests/3# mount /dev/sdb3 /mnt
root@iTOP4412-ubuntu-desktop:~/tests/3# cp /mnt/libc-2.10.1.so /lib
root@iTOP4412-ubuntu-desktop:~/tests/3# cd /lib
root@iTOP4412-ubuntu-desktop:/lib# ln -s libc-2.10.1.so libc.so.6
以上总结，缺少库：/lib/ld-linux.so.3，libgcc_s.so.1，libc.so.6
使用readelf查看的具体内容如下。（ldd用于动态库）
root@iTOP4412-ubuntu-desktop:~/tests/3# readelf -a invoke_hello123 ELF Header: Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00 Class: ELF32 Data: 2's complement, little endian Version: 1 (current) OS/ABI: UNIX - System V ABI Version: 0 Type: EXEC (Executable file) Machine: ARM Version: 0x1 Entry point address: 0x8440 Start of program headers: 52 (bytes into file) Start of section headers: 2488 (bytes into file) Flags: 0x5000002, has entry point, Version5 EABI Size of this header: 52 (bytes) Size of program headers: 32 (bytes) Number of program headers: 8 Size of section headers: 40 (bytes) Number of section headers: 31 Section header string table index: 28 Section Headers: [Nr] Name Type Addr Off Size ES Flg Lk Inf Al [ 0] NULL 00000000 000000 000000 00 0 0 0 [ 1] .interp PROGBITS 00008134 000134 000013 00 A 0 0 1 [ 2] .note.ABI-tag NOTE 00008148 000148 000020 00 A 0 0 4 [ 3] .hash HASH 00008168 000168 000044 04 A 4 0 4 [ 4] .dynsym DYNSYM 000081ac 0001ac 0000c0 10 A 5 1 4 [ 5] .dynstr STRTAB 0000826c 00026c 0000b3 00 A 0 0 1 [ 6] .gnu.version VERSYM 00008320 000320 000018 02 A 4 0 2 [ 7] .gnu.version_r VERNEED 00008338 000338 000040 00 A 5 2 4 [ 8] .rel.dyn REL 00008378 000378 000008 08 A 4 0 4 [ 9] .rel.plt REL 00008380 000380 000040 08 A 4 11 4 [10] .init PROGBITS 000083c0 0003c0 00000c 00 AX 0 0 4 [11] .plt PROGBITS 000083cc 0003cc 000074 04 AX 0 0 4 [12] .text PROGBITS 00008440 000440 000204 00 AX 0 0 4 [13] .fini PROGBITS 00008644 000644 000008 00 AX 0 0 4 [14] .rodata PROGBITS 0000864c 00064c 000038 00 A 0 0 4 [15] .ARM.extab PROGBITS 00008684 000684 000018 00 A 0 0 4 [16] .ARM.exidx ARM_EXIDX 0000869c 00069c 000038 00 AL 12 0 4 [17] .eh_frame PROGBITS 000086d4 0006d4 000004 00 A 0 0 4 [18] .init_array INIT_ARRAY 000106d8 0006d8 000004 00 WA 0 0 4 [19] .fini_array FINI_ARRAY 000106dc 0006dc 000004 00 WA 0 0 4 [20] .jcr PROGBITS 000106e0 0006e0 000004 00 WA 0 0 4 [21] .dynamic DYNAMIC 000106e4 0006e4 0000f0 08 WA 5 0 4 [22] .got PROGBITS 000107d4 0007d4 000030 04 WA 0 0 4 [23] .data PROGBITS 00010804 000804 000008 00 WA 0 0 4 [24] .bss NOBITS 0001080c 00080c 000004 00 WA 0 0 1 [25] .ARM.attributes ARM_ATTRIBUTES 00000000 00080c 000029 00 0 0 1 [26] .comment PROGBITS 00000000 000835 00002a 00 0 0 1 [27] .debug_frame PROGBITS 00000000 000860 00004c 00 0 0 4 [28] .shstrtab STRTAB 00000000 0008ac 00010b 00 0 0 1 [29] .symtab SYMTAB 00000000 000e90 0006f0 10 30 81 4 [30] .strtab STRTAB 00000000 001580 0002d9 00 0 0 1 Key to Flags: W (write), A (alloc), X (execute), M (merge), S (strings) I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown) O (extra OS processing required) o (OS specific), p (processor specific) There are no section groups in this file. Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align EXIDX 0x00069c 0x0000869c 0x0000869c 0x00038 0x00038 R 0x4 PHDR 0x000034 0x00008034 0x00008034 0x00100 0x00100 R E 0x4 INTERP 0x000134 0x00008134 0x00008134 0x00013 0x00013 R 0x1 [Requesting program interpreter: /lib/ld-linux.so.3] LOAD 0x000000 0x00008000 0x00008000 0x006d8 0x006d8 R E 0x8000 LOAD 0x0006d8 0x000106d8 0x000106d8 0x00134 0x00138 RW 0x8000 DYNAMIC 0x0006e4 0x000106e4 0x000106e4 0x000f0 0x000f0 RW 0x4 NOTE 0x000148 0x00008148 0x00008148 0x00020 0x00020 R 0x4 GNU_STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RW 0x4 Section to Segment mapping: Segment Sections... 00 .ARM.exidx 01 02 .interp 03 .interp .note.ABI-tag .hash .dynsym .dynstr .gnu.version .gnu.version_r .rel.dyn .rel.plt .init .plt .text .fini .rodata .ARM.extab .ARM.exidx .eh_frame 04 .init_array .fini_array .jcr .dynamic .got .data .bss 05 .dynamic 06 .note.ABI-tag 07 Dynamic section at offset 0x6e4 contains 25 entries: Tag Type Name/Value 0x00000001 (NEEDED) Shared library: [libgcc_s.so.1] 0x00000001 (NEEDED) Shared library: [libc.so.6] 0x0000000c (INIT) 0x83c0 0x0000000d (FINI) 0x8644 0x00000019 (INIT_ARRAY) 0x106d8 0x0000001b (INIT_ARRAYSZ) 4 (bytes) 0x0000001a (FINI_ARRAY) 0x106dc 0x0000001c (FINI_ARRAYSZ) 4 (bytes) 0x00000004 (HASH) 0x8168 0x00000005 (STRTAB) 0x826c 0x00000006 (SYMTAB) 0x81ac 0x0000000a (STRSZ) 179 (bytes) 0x0000000b (SYMENT) 16 (bytes) 0x00000015 (DEBUG) 0x0 0x00000003 (PLTGOT) 0x107d4 0x00000002 (PLTRELSZ) 64 (bytes) 0x00000014 (PLTREL) REL 0x00000017 (JMPREL) 0x8380 0x00000011 (REL) 0x8378 0x00000012 (RELSZ) 8 (bytes) 0x00000013 (RELENT) 8 (bytes) 0x6ffffffe (VERNEED) 0x8338 0x6fffffff (VERNEEDNUM) 2 0x6ffffff0 (VERSYM) 0x8320 0x00000000 (NULL) 0x0 Relocation section '.rel.dyn' at offset 0x378 contains 1 entries: Offset Info Type Sym.Value Sym. Name 00010800 00000515 R_ARM_GLOB_DAT 00000000 __gmon_start__ Relocation section '.rel.plt' at offset 0x380 contains 8 entries: Offset Info Type Sym.Value Sym. Name 000107e0 00000116 R_ARM_JUMP_SLOT 000083e0 open 000107e4 00000216 R_ARM_JUMP_SLOT 000083ec abort 000107e8 00000316 R_ARM_JUMP_SLOT 000083f8 __libc_start_main 000107ec 00000516 R_ARM_JUMP_SLOT 00000000 __gmon_start__ 000107f0 00000716 R_ARM_JUMP_SLOT 00008410 perror 000107f4 00000816 R_ARM_JUMP_SLOT 0000841c ioctl 000107f8 00000916 R_ARM_JUMP_SLOT 00008428 printf 000107fc 00000a16 R_ARM_JUMP_SLOT 00008434 close Unwind table index '.ARM.exidx' at offset 0x69c contains 7 entries: 0x8440 <_start>: 0x1 [cantunwind] 0x84a0 <__do_global_dtors_aux>: 0x80b0b0b0 Compact model 0 0xb0 finish 0xb0 finish 0xb0 finish 0x84bc <frame_dummy>: @0x8684 Compact model 1 0xb1 0x08 pop {r3} 0x84 0x00 pop {r14} 0xb0 finish 0xb0 finish 0x84ec <main>: @0x8690 Compact model 1 0x9b vsp = r11 0x40 vsp = vsp - 4 0x84 0x80 pop {r11, r14} 0xb0 finish 0xb0 finish 0x8574 <__libc_csu_fini>: 0x80b0b0b0 Compact model 0 0xb0 finish 0xb0 finish 0xb0 finish 0x8578 <__libc_csu_init>: 0x80aeb0b0 Compact model 0 0xae pop {r4, r5, r6, r7, r8, r9, r10r14} 0xb0 finish 0xb0 finish 0x8644 <_fini>: 0x1 [cantunwind] Symbol table '.dynsym' contains 12 entries: Num: Value Size Type Bind Vis Ndx Name 0: 00000000 0 NOTYPE LOCAL DEFAULT UND 1: 000083e0 0 FUNC GLOBAL DEFAULT UND open@GLIBC_2.4 (2) 2: 000083ec 0 FUNC GLOBAL DEFAULT UND abort@GLIBC_2.4 (2) 3: 000083f8 0 FUNC GLOBAL DEFAULT UND __libc_start_main@GLIBC_2.4 (2) 4: 00000000 0 FUNC GLOBAL DEFAULT UND __aeabi_unwind_cpp_pr0@GCC_3.5 (3) 5: 00000000 0 NOTYPE WEAK DEFAULT UND __gmon_start__ 6: 00000000 0 NOTYPE WEAK DEFAULT UND _Jv_RegisterClasses 7: 00008410 0 FUNC GLOBAL DEFAULT UND perror@GLIBC_2.4 (2) 8: 0000841c 0 FUNC GLOBAL DEFAULT UND ioctl@GLIBC_2.4 (2) 9: 00008428 0 FUNC GLOBAL DEFAULT UND printf@GLIBC_2.4 (2) 10: 00008434 0 FUNC GLOBAL DEFAULT UND close@GLIBC_2.4 (2) 11: 00000000 0 FUNC GLOBAL DEFAULT UND __aeabi_unwind_cpp_pr1@GCC_3.5 (3) Symbol table '.symtab' contains 111 entries: Num: Value Size Type Bind Vis Ndx Name 0: 00000000 0 NOTYPE LOCAL DEFAULT UND 1: 00008134 0 SECTION LOCAL DEFAULT 1 2: 00008148 0 SECTION LOCAL DEFAULT 2 3: 00008168 0 SECTION LOCAL DEFAULT 3 4: 000081ac 0 SECTION LOCAL DEFAULT 4 5: 0000826c 0 SECTION LOCAL DEFAULT 5 6: 00008320 0 SECTION LOCAL DEFAULT 6 7: 00008338 0 SECTION LOCAL DEFAULT 7 8: 00008378 0 SECTION LOCAL DEFAULT 8 9: 00008380 0 SECTION LOCAL DEFAULT 9 10: 000083c0 0 SECTION LOCAL DEFAULT 10 11: 000083cc 0 SECTION LOCAL DEFAULT 11 12: 00008440 0 SECTION LOCAL DEFAULT 12 13: 00008644 0 SECTION LOCAL DEFAULT 13 14: 0000864c 0 SECTION LOCAL DEFAULT 14 15: 00008684 0 SECTION LOCAL DEFAULT 15 16: 0000869c 0 SECTION LOCAL DEFAULT 16 17: 000086d4 0 SECTION LOCAL DEFAULT 17 18: 000106d8 0 SECTION LOCAL DEFAULT 18 19: 000106dc 0 SECTION LOCAL DEFAULT 19 20: 000106e0 0 SECTION LOCAL DEFAULT 20 21: 000106e4 0 SECTION LOCAL DEFAULT 21 22: 000107d4 0 SECTION LOCAL DEFAULT 22 23: 00010804 0 SECTION LOCAL DEFAULT 23 24: 0001080c 0 SECTION LOCAL DEFAULT 24 25: 00000000 0 SECTION LOCAL DEFAULT 25 26: 00000000 0 SECTION LOCAL DEFAULT 26 27: 00000000 0 SECTION LOCAL DEFAULT 27 28: 0000847c 0 NOTYPE LOCAL DEFAULT 12 $a 29: 0000847c 0 FUNC LOCAL DEFAULT 12 call_gmon_start 30: 00008498 0 NOTYPE LOCAL DEFAULT 12 $d 31: 000083c0 0 NOTYPE LOCAL DEFAULT 10 $a 32: 00008644 0 NOTYPE LOCAL DEFAULT 13 $a 33: 00008148 0 NOTYPE LOCAL DEFAULT 2 $d 34: 00008440 0 NOTYPE LOCAL DEFAULT 12 $a 35: 0000869c 0 NOTYPE LOCAL DEFAULT 16 $d 36: 00008470 0 NOTYPE LOCAL DEFAULT 12 $d 37: 00000000 0 FILE LOCAL DEFAULT ABS init.c 38: 0000864c 0 NOTYPE LOCAL DEFAULT 14 $d 39: 000083c8 0 NOTYPE LOCAL DEFAULT 10 $a 40: 00008648 0 NOTYPE LOCAL DEFAULT 13 $a 41: 00000000 0 FILE LOCAL DEFAULT ABS crtstuff.c 42: 000106e0 0 OBJECT LOCAL DEFAULT 20 __JCR_LIST__ 43: 00010808 0 NOTYPE LOCAL DEFAULT 23 $d 44: 000084a0 0 NOTYPE LOCAL DEFAULT 12 $a 45: 000084a0 0 FUNC LOCAL DEFAULT 12 __do_global_dtors_aux 46: 000084b8 0 NOTYPE LOCAL DEFAULT 12 $d 47: 0001080c 1 OBJECT LOCAL DEFAULT 24 completed.6082 48: 000086a4 0 NOTYPE LOCAL DEFAULT 16 $d 49: 000106dc 0 NOTYPE LOCAL DEFAULT 19 $d 50: 000106dc 0 OBJECT LOCAL DEFAULT 19 __do_global_dtors_aux_fin 51: 000084bc 0 NOTYPE LOCAL DEFAULT 12 $a 52: 000084bc 0 FUNC LOCAL DEFAULT 12 frame_dummy 53: 000084e4 0 NOTYPE LOCAL DEFAULT 12 $d 54: 00008684 0 NOTYPE LOCAL DEFAULT 15 $d 55: 000106d8 0 NOTYPE LOCAL DEFAULT 18 $d 56: 000106d8 0 OBJECT LOCAL DEFAULT 18 __frame_dummy_init_array_ 57: 0001080c 0 NOTYPE LOCAL DEFAULT 24 $d 58: 00000000 0 FILE LOCAL DEFAULT ABS invoke_hello123.c 59: 00008650 0 NOTYPE LOCAL DEFAULT 14 $d 60: 000084ec 0 NOTYPE LOCAL DEFAULT 12 $a 61: 00008564 0 NOTYPE LOCAL DEFAULT 12 $d 62: 00008690 0 NOTYPE LOCAL DEFAULT 15 $d 63: 000086b4 0 NOTYPE LOCAL DEFAULT 16 $d 64: 00000000 0 FILE LOCAL DEFAULT ABS elf-init.c 65: 00008574 0 NOTYPE LOCAL DEFAULT 12 $a 66: 000086bc 0 NOTYPE LOCAL DEFAULT 16 $d 67: 00008638 0 NOTYPE LOCAL DEFAULT 12 $d 68: 00000010 0 NOTYPE LOCAL DEFAULT 27 $d 69: 00000000 0 FILE LOCAL DEFAULT ABS crtstuff.c 70: 000086d4 0 NOTYPE LOCAL DEFAULT 17 $d 71: 000086d4 0 OBJECT LOCAL DEFAULT 17 __FRAME_END__ 72: 000106e0 0 NOTYPE LOCAL DEFAULT 20 $d 73: 000106e0 0 OBJECT LOCAL DEFAULT 20 __JCR_END__ 74: 000107d4 0 OBJECT LOCAL HIDDEN 22 _GLOBAL_OFFSET_TABLE_ 75: 000106dc 0 NOTYPE LOCAL HIDDEN 18 __init_array_end 76: 000106d8 0 NOTYPE LOCAL HIDDEN 18 __init_array_start 77: 000106e4 0 OBJECT LOCAL HIDDEN 21 _DYNAMIC 78: 000083cc 0 NOTYPE LOCAL DEFAULT 11 $a 79: 000083dc 0 NOTYPE LOCAL DEFAULT 11 $d 80: 000083e0 0 NOTYPE LOCAL DEFAULT 11 $a 81: 00010804 0 NOTYPE WEAK DEFAULT 23 data_start 82: 000083e0 0 FUNC GLOBAL DEFAULT UND open@@GLIBC_2.4 83: 000083ec 0 FUNC GLOBAL DEFAULT UND abort@@GLIBC_2.4 84: 00008574 4 FUNC GLOBAL DEFAULT 12 __libc_csu_fini 85: 00008440 0 FUNC GLOBAL DEFAULT 12 _start 86: 000083f8 0 FUNC GLOBAL DEFAULT UND __libc_start_main@@GLIBC_ 87: 00000000 0 FUNC GLOBAL DEFAULT UND __aeabi_unwind_cpp_pr0@@G 88: 00000000 0 NOTYPE WEAK DEFAULT UND __gmon_start__ 89: 00000000 0 NOTYPE WEAK DEFAULT UND _Jv_RegisterClasses 90: 00008644 0 FUNC GLOBAL DEFAULT 13 _fini 91: 00008410 0 FUNC GLOBAL DEFAULT UND perror@@GLIBC_2.4 92: 0000864c 4 OBJECT GLOBAL DEFAULT 14 _IO_stdin_used 93: 00010804 0 NOTYPE GLOBAL DEFAULT 23 __data_start 94: 0001080c 0 NOTYPE GLOBAL DEFAULT ABS __bss_start__ 95: 0000841c 0 FUNC GLOBAL DEFAULT UND ioctl@@GLIBC_2.4 96: 000086d4 0 NOTYPE GLOBAL DEFAULT ABS __exidx_end 97: 00010808 0 OBJECT GLOBAL HIDDEN 23 __dso_handle 98: 00010810 0 NOTYPE GLOBAL DEFAULT ABS __end__ 99: 00008578 204 FUNC GLOBAL DEFAULT 12 __libc_csu_init 100: 00010810 0 NOTYPE GLOBAL DEFAULT ABS __bss_end__ 101: 00008428 0 FUNC GLOBAL DEFAULT UND printf@@GLIBC_2.4 102: 00008434 0 FUNC GLOBAL DEFAULT UND close@@GLIBC_2.4 103: 0001080c 0 NOTYPE GLOBAL DEFAULT ABS __bss_start 104: 00010810 0 NOTYPE GLOBAL DEFAULT ABS _bss_end__ 105: 00010810 0 NOTYPE GLOBAL DEFAULT ABS _end 106: 0001080c 0 NOTYPE GLOBAL DEFAULT ABS _edata 107: 0000869c 0 NOTYPE GLOBAL DEFAULT ABS __exidx_start 108: 00000000 0 FUNC GLOBAL DEFAULT UND __aeabi_unwind_cpp_pr1@@G 109: 000084ec 136 FUNC GLOBAL DEFAULT 12 main 110: 000083c0 0 FUNC GLOBAL DEFAULT 10 _init Histogram for bucket list length (total of 3 buckets): Length Number % of total Coverage 0 0 ( 0.0%) 1 0 ( 0.0%) 0.0% 2 1 ( 33.3%) 18.2% 3 0 ( 0.0%) 18.2% 4 1 ( 33.3%) 54.5% 5 1 ( 33.3%) 100.0% Version symbols section '.gnu.version' contains 12 entries: Addr: 0000000000008320 Offset: 0x000320 Link: 4 (.dynsym) 000: 0 (*local*) 2 (GLIBC_2.4) 2 (GLIBC_2.4) 2 (GLIBC_2.4) 004: 3 (GCC_3.5) 0 (*local*) 0 (*local*) 2 (GLIBC_2.4) 008: 2 (GLIBC_2.4) 2 (GLIBC_2.4) 2 (GLIBC_2.4) 3 (GCC_3.5) Version needs section '.gnu.version_r' contains 2 entries: Addr: 0x0000000000008338 Offset: 0x000338 Link: 5 (.dynstr) 000000: Version: 1 File: libgcc_s.so.1 Cnt: 1 0x0010: Name: GCC_3.5 Flags: none Version: 3 0x0020: Version: 1 File: libc.so.6 Cnt: 1 0x0030: Name: GLIBC_2.4 Flags: none Version: 2 Notes at offset 0x00000148 with length 0x00000020: Owner Data size Description GNU 0x00000010 NT_GNU_ABI_TAG (ABI version tag) OS: Linux, ABI: 2.6.16 Attribute Section: aeabi File Attributes Tag_CPU_name: "5TE" Tag_CPU_arch: v5TE Tag_ARM_ISA_use: Yes Tag_THUMB_ISA_use: Thumb-1 Tag_ABI_PCS_wchar_t: 4 Tag_ABI_FP_denormal: Needed Tag_ABI_FP_exceptions: Needed Tag_ABI_FP_number_model: IEEE 754 Tag_ABI_align_needed: 8-byte Tag_ABI_align_preserved: 8-byte, except leaf SP Tag_ABI_enum_size: int
至此设备节点的注册和调用