在查找资料过程中，发现自己搭建虚拟的arm环境的话，有一个比较好的软件就是qemu了，当然还有其他的，大家各投所好就好。
接下来说一下qemu环境搭建过程。
其实搭建很简单，作为小白，我还是捣鼓了两三天才真正的安装成功，正在尝试着怎么使用。
上篇已经讲了安装Ubuntu系统后root密码的设置，这里就要用到root密码进行软件安装了。
可以在命令行模式下先进行update，输入：sudo apt-get update
在保证电脑联网的情况下，Ubuntu会自动进行文件更新，这个操作并不会更新整个文件系统，
他只是同步le /etc/apt/sources.list 和 /etc/apt/sources.list.d 中列出的源的索引，这样才能获取到最新的软件包。
并且只有在更新了资源列表后才能使用apt-get install进行成功安装（我当时就是没有update就去安装程序，失败了好多次，各种欲哭无泪，
另：一定要保证自己的网络环境良好，更新的文件都不大但是我想你不会想看着电脑以100B的速度去下载6000K+的文件的555555）
在update完成之后就可以进行qemu的安装了，输入指令：sudo apt-get install qemu（如果失败并提示你需要尝试修复什么文件的话用sudo apt-get -f install qemu代替）
在连着输入两个表示同意的‘y’之后等着系统自己安装就好了。
安装完毕，输入qemu并联系按几下table，就会显示当前qemu支持的架构（还是内核？不是很清楚这个概念）
qemu安装到此结束。
========================================和上方震惊体标题后脑残的内容划清界限，下面搭建Vexpress的qemu环境==========================================================================
1. 安装qemu，参考上方脑残内容，安装完毕后查看qemu版本可出现如下内容表示安装成功
sly@ubuntu:~/develop$ qemu-arm --version qemu-arm version 2.11.1(Debian 1:2.11+dfsg-1ubuntu7.19) Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers
PS： 交叉编译工具链也需要安装 sudo apt-get install gcc-arm-linux-gnueabi
2. 编译Linux内核
sly@ubuntu:~/develop/linux-5.3.7$ make CROSS_COMPILE=arm-linux-gnueabi- ARCH=arm vexpress_defconfig
#
# configuration written to .config
#
修改Makfile如下两个变量值
ARCH ?= arm
CROSS_COMPILE ?= arm-linux-gnueabi-
编译：
sly@ubuntu:~/develop/linux-5.3.7$ make
sly@ubuntu:~/develop/linux-5.3.7$ make modules
sly@ubuntu:~/develop/linux-5.3.7$ make dtbs
生成的内核镱像位于arch/arm/boot/zImage， qemu启动时须要使用该镜像。
sly@ubuntu:~/develop/linux-5.3.7$ make scripts/kconfig/conf --syncconfig Kconfig CALL scripts/checksyscalls.sh CALL scripts/atomic/check-atomics.sh CHK include/generated/compile.h GZIP kernel/config_data.gz CC kernel/configs.o AR kernel/built-in.a GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a LD vmlinux.o MODPOST vmlinux.o MODINFO modules.builtin.modinfo- KSYM .tmp_kallsyms1.o KSYM .tmp_kallsyms2.o LD vmlinux SORTEX vmlinux SYSMAP System.map OBJCOPY arch/arm/boot/Image Kernel: arch/arm/boot/Image is ready GZIP arch/arm/boot/compressed/piggy_data AS arch/arm/boot/compressed/piggy.o LD arch/arm/boot/compressed/vmlinux OBJCOPY arch/arm/boot/zImage Kernel: arch/arm/boot/zImage is ready Building modules, stage 2. MODPOST 1 modules
3. 測试qemu和内核是否能执行成功
qemu已经安装好了。内核也编译成功了，到这里最好是測试一下，编译出来的内核是否OK，或者qemu对vexpress单板支持是否够友好。
执行命令：qemu-system-arm -M vexpress-a9 -m 512m -kernel /home/sly/develop/linux-5.3.7/arch/arm/boot/zImage -dtb linux-5.3.7/arch/arm/boot/dts/vexpress-v2p-ca9.dtb -nographic -append "console=ttyAMA0"
sly@ubuntu:~/develop$ qemu-system-arm -M vexpress-a9 -m 512m -kernel /home/sly/develop/linux-5.3.7/arch/arm/boot/zImage -dtb linux-5.3.7/arch/arm/boot/dts/vexpress-v2p-ca9.dtb -nographic -append "console=ttyAMA0"
pulseaudio: set_sink_input_volume() failed
pulseaudio: Reason: Invalid argument
pulseaudio: set_sink_input_mute() failed
pulseaudio: Reason: Invalid argument
Booting Linux on physical CPU 0x0
Linux version 5.3.7 (sly@ubuntu) (gcc version 7.4.0 (Ubuntu/Linaro 7.4.0-1ubuntu1~18.04.1)) #4 SMP Mon Dec 9 08:31:07 PST 2019
--省略甚多log----------
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.3.7 #4
Hardware name: ARM-Versatile Express
[<80110808>] (unwind_backtrace) from [<8010c680>] (show_stack+0x10/0x14)
[<8010c680>] (show_stack) from [<8074c7cc>] (dump_stack+0x88/0x9c)
[<8074c7cc>] (dump_stack) from [<80120e64>] (panic+0x110/0x310)
[<80120e64>] (panic) from [<80a01640>] (mount_block_root+0x1e8/0x2d4)
[<80a01640>] (mount_block_root) from [<80a01870>] (mount_root+0x144/0x160)
[<80a01870>] (mount_root) from [<80a019dc>] (prepare_namespace+0x150/0x198)
[<80a019dc>] (prepare_namespace) from [<80763874>] (kernel_init+0x8/0x114)
[<80763874>] (kernel_init) from [<801010e8>] (ret_from_fork+0x14/0x2c)
Exception stack(0x9e4a1fb0 to 0x9e4a1ff8)
1fa0: 00000000 00000000 00000000 00000000
1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) ]---
假设看到内核启动过程中的打印，说明前的搭建是成功的。
这里简介下qemu命令的參数：
-M vexpress-a9 模拟vexpress-a9单板，你能够使用-M ?參数来获取该qemu版本号支持的全部单板 -m 512M 单板执行物理内存512M -kernel /home/ivan/kernel_git/linux/arch/arm/boot/zImage 告诉qemu单板执行内核镜像路径 -nographic 不使用图形化界面，仅仅使用串口 -append "console=ttyAMA0" 内核启动參数。这里告诉内核vexpress单板执行。串口设备是哪个tty。从生成的.config文件CONFIG_CONSOLE宏找到
4. 利用busybox构建最小文件系统（下载地址：https://busybox.net/）
不加载文件系统穷的那个qemu会产生上面贴的log中的panic信息，下面先制作一个可用的最小文件系统。
a. 编译busybox
a1. 下载源文件后进行配置
sly@ubuntu:~/develop$ cd busybox-1.24.2/ sly@ubuntu:~/develop/busybox-1.24.2$ export ARCH=arm sly@ubuntu:~/develop/busybox-1.24.2$ export CROSS_COMPILE=arm-linux-gnueabi- sly@ubuntu:~/develop/busybox-1.24.2$ make menuconfig
a2.menuconfig配置成静态
Busybox Settings --->
Build Options --->
[*] Build BusyBox as a static binary (no shared libs)
a3. 开始编译, 编译完成后会在busybox目录下生成一个_install的目录，该目录是编译好的文件系统需要使用的一些命令集合。
sly@ubuntu:~/develop/busybox-1.24.2$ make defconfig
sly@ubuntu:~/develop/busybox-1.24.2$ make CROSS_COMPILE=arm-linux-gnueabi-
sly@ubuntu:~/develop/busybox-1.24.2$ make install CROSS_COMPILE=arm-linux-gnueabi-
生成的_install目录包含如下内容
sly@ubuntu:~/develop/busybox-1.24.2/_install$ ll total 20 drwxrwxr-x 5 sly sly 4096 Dec 9 08:14 ./ drwxr-xr-x 36 sly sly 4096 Dec 9 21:08 ../ drwxrwxr-x 2 sly sly 4096 Dec 9 08:14 bin/ lrwxrwxrwx 1 sly sly 11 Dec 9 08:14 linuxrc -> bin/busybox* drwxrwxr-x 2 sly sly 4096 Dec 9 08:14 sbin/ drwxrwxr-x 4 sly sly 4096 Oct 30 22:18 usr/
b. 制作根文件系统
b1. 新建一个根文件系统的文件夹
sly@ubuntu:~/develop$ mkdir rootfs
sly@ubuntu:~/develop$ cd rootfs/
b2. 拷贝install目录的命令集到文件夹中
sly@ubuntu:~/develop/rootfs$ cp -rf ../busybox-1.24.2/_install/* . sly@ubuntu:~/develop/rootfs$ ls bin dev lib linuxrc sbin usr
b3. 新建lib目录，从工具链中拷贝执行库到lib文件夹下
sly@ubuntu:~/develop/rootfs$ mkdir lib
sly@ubuntu:~/develop/rootfs$ cp -p /usr/arm-linux-gnueabi/lib/* ./lib
b4. 创建设备文件, 创建4个串口设备,和控制台
sly@ubuntu:~/develop/rootfs$ sudo mknod dev/tty1 c 4 1 sly@ubuntu:~/develop/rootfs$ sudo mknod dev/tty2 c 4 2 sly@ubuntu:~/develop/rootfs$ sudo mknod dev/tty3 c 4 3 sly@ubuntu:~/develop/rootfs$ sudo mknod dev/tty4 c 4 4 sly@ubuntu:~/develop/rootfs$sudo mknod -m 666 console c 5 1
b5. 制作SD根文件系统镜像, 生成虚拟sd卡并格式化为ext格式：
dd if=/dev/zero of=rootfs.ext3 bs=1M count=32
mkfs.ext3 rootfs.ext3
sly@ubuntu:~/develop$ dd if=/dev/zero of=rootfs.ext3 bs=1M count=32 32+0 records in 32+0 records out 33554432 bytes (34 MB, 32 MiB) copied, 0.0941612 s, 356 MB/s sly@ubuntu:~/develop$ mkfs.ext3 rootfs.ext3 mke2fs 1.44.1 (24-Mar-2018) Discarding device blocks: done Creating filesystem with 32768 1k blocks and 8192 inodes Filesystem UUID: fe2c8081-588f-4e0c-b0c7-09489d0fded5 Superblock backups stored on blocks: 8193, 24577 Allocating group tables: done Writing inode tables: done Creating journal (4096 blocks): done Writing superblocks and filesystem accounting information: done
sly@ubuntu:~/develop$ ls
busybox-1.24.2 linux-5.3.7 linux-5.3.7.tar rootfs rootfs.ext3 tmpfs
b6. 将虚拟sd卡挂载到/tmpfs，拷贝rootfs的所有文件到sd，卸载sd(块设备不能直接读写)
sudo mkdir tmpfs
sudo mount -t ext3 rootfs.ext3 tmpfs/ -o loop
sudo cp -r rootfs/* tmpfs/
sudo umount tmpfs
sly@ubuntu:~/develop$ sudo mount -t ext3 rootfs.ext3 tmpfs/ -o loop
sly@ubuntu:~/develop$ sudo cp -r rootfs/* tmpfs/
sly@ubuntu:~/develop$ ls tmpfs/
bin dev lib linuxrc lost+found sbin usr
sly@ubuntu:~/develop$ sudo umount tmpfs
sly@ubuntu:~/develop$ ls tmpfs/
sly@ubuntu:~/develop$
5. 启动内核，挂载rootfs
qemu-system-arm -M vexpress-a9 -m 512m -kernel /home/sly/develop/linux-5.3.7/arch/arm/boot/zImage -dtb linux-5.3.7/arch/arm/boot/dts/vexpress-v2p-ca9.dtb -nographic -append "root=/dev/mmcblk0 console=ttyAMA0" -sd rootfs.ext3
sly@ubuntu:~/develop$ qemu-system-arm -M vexpress-a9 -m 512m -kernel /home/sly/develop/linux-5.3.7/arch/arm/boot/zImage -dtb linux-5.3.7/arch/arm/boot/dts/vexpress-v2p-ca9.dtb -nographic -append "root=/dev/mmcblk0 console=ttyAMA0" -sd rootfs.ext3 WARNING: Image format was not specified for 'rootfs.ext3' and probing guessed raw. Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted. Specify the 'raw' format explicitly to remove the restrictions. pulseaudio: set_sink_input_volume() failed pulseaudio: Reason: Invalid argument pulseaudio: set_sink_input_mute() failed pulseaudio: Reason: Invalid argument Booting Linux on physical CPU 0x0 Linux version 5.3.7 (sly@ubuntu) (gcc version 7.4.0 (Ubuntu/Linaro 7.4.0-1ubuntu1~18.04.1)) #4 SMP Mon Dec 9 08:31:07 PST 2019=====================================================......========================================================================= ALSA device list: #0: ARM AC'97 Interface PL041 rev0 at 0x10004000, irq 24 input: ImExPS/2 Generic Explorer Mouse as /devices/platform/smb@4000000/smb@4000000:motherboard/smb@4000000:motherboard:iofpga@7,00000000/10007000.kmi/serio1/input/input2 Error: Driver 'vexpress-muxfpga' is already registered, aborting... drm-clcd-pl111 10020000.clcd: initializing Versatile Express PL111 drm-clcd-pl111 10020000.clcd: DVI muxed to daughterboard 1 (core tile) CLCD EXT4-fs (mmcblk0): mounting ext3 file system using the ext4 subsystem random: fast init done EXT4-fs (mmcblk0): mounted filesystem with ordered data mode. Opts: (null) VFS: Mounted root (ext3 filesystem) readonly on device 179:0. Freeing unused kernel memory: 1024K Run /sbin/init as init process random: crng init done can't run '/etc/init.d/rcS': No such file or directory Please press Enter to activate this console. / #
/ # ls
bin dev lib linuxrc lost+found sbin usr
6. 编写简单的模块进行加载
文件目录结构如下
sly@ubuntu:~/develop/module/first$ ls
first.c Makefile
编写源文件
#include <linux/module.h> #include <linux/kernel.h> int init_hello_module(void) { printk("init hello_moudle "); return 0; } void exit_hello_module(void) { printk("exit hello_module "); } module_init(init_hello_module); module_exit(exit_hello_module); MODULE_LICENSE("GPL");
makefile文件
KERN_DIR=../../linux-5.3.7 all: make -C $(KERN_DIR) M=`pwd` modules clean: make -C $(KERN_DIR) M=`pwd` modules clean rm -rf modules.order obj-m += first.o
执行编译，编译出ko文件
sly@ubuntu:~/develop/module/first$ make make -C ../../linux-5.3.7 M=`pwd` modules make[1]: Entering directory '/home/sly/develop/linux-5.3.7' CC [M] /home/sly/develop/module/first/first.o Building modules, stage 2. MODPOST 1 modules CC /home/sly/develop/module/first/first.mod.o LD [M] /home/sly/develop/module/first/first.ko make[1]: Leaving directory '/home/sly/develop/linux-5.3.7' sly@ubuntu:~/develop/module/first$ ls first.c first.ko first.mod first.mod.c first.mod.o first.o Makefile modules.order Module.symvers
rootfs根文件系统下面创建一个modules目录用来存放ko文件
拷贝rootfs的内容到rootfs.ext3虚拟SD中
mount -t ext3 rootfs.ext3 /mnt/ -o loop
cp -r rootfs/* /mnt
umount /mnt
启动开发板，加载KO
/ # ls bin lib lost+found sbin dev linuxrc modules usr / # cd te -/bin/sh: cd: can't cd to te / # cd modules/ /modules # ls first.ko /modules # insmod first.ko first: loading out-of-tree module taints kernel. init hello_moudle /modules # rmmod first.ko rmmod: can't change directory to '/lib/modules': No such file or directory /lib # lsmod lsmod: can't open '/proc/modules': No such file or directory
7. 继续完善文件系统
a. 创建etc及inittable文件，语句含义参考： https://blog.csdn.net/u014089899/article/details/80622607
sly@ubuntu:~/develop/rootfs$ mkdir etc sly@ubuntu:~/develop/rootfs$ cd etc/ sly@ubuntu:~/develop/rootfs/etc$ sudo vi inittab
inittab内容如下
::sysinit:/etc/init.d/rcS #::respawn:-/bin/sh #tty2::askfirst:-/bin/sh #::ctrlaltdel:/bin/umount -a -r console::askfirst:-/bin/sh ::ctrlaltdel:/sbin/reboot ::shutdown:/bin/umount -a -r
创建fstab，相应文件夹需要自行创建好 含义参考：https://blog.csdn.net/xyajia/article/details/79165655
sly@ubuntu:~/develop/rootfs/etc$ sudo vi fstab # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # <file system> <mount point> <type> <options> <dump> <pass> # / was on /dev/sda1 during installation proc /proc proc defaults 0 0 tmpfs /tmp tmpfs defaults 0 0 sysfs /sys sysfs defaults 0 0 tmpfs /dev tmpfs defaults 0 0 var /dev tmpfs defaults 0 0 ramfs /dev ramfs defaults 0 0
创建init.d/rcS
sly@ubuntu:~/develop/rootfs/etc$ sudo mkdir init.d sly@ubuntu:~/develop/rootfs/etc$ cd init.d/ sly@ubuntu:~/develop/rootfs/etc/init.d$ sudo vi rcS #! /bin/sh PATH=/sbin:/bin:/usr/sbin:/usr/bin LD_LIBRARY_PATH=/lib export PATH LD_LIBRARY_PATH mount -a mkdir -p /dev/pts mount -t devpts devpts /dev/pts mdev -s mkdir -p /var/lock echo "----------------------------------------" echo " welcome debugging on A9 vexpress board" echo "----------------------------------------"
sly@ubuntu:~/develop/rootfs/etc/init.d$ sudo chmod 777 rcS
用最新的rootfs覆盖rootfs.ext3虚拟SD卡，启动开发板验证，效果如下：（出错部分不知道问什么挂在到mnt后在mnt中没有可执行权限，添加下可执行权限就行）
Error: Driver 'vexpress-muxfpga' is already registered, aborting... drm-clcd-pl111 10020000.clcd: initializing Versatile Express PL111 drm-clcd-pl111 10020000.clcd: DVI muxed to daughterboard 1 (core tile) CLCD input: AT Raw Set 2 keyboard as /devices/platform/smb@4000000/smb@4000000:motherboard/smb@4000000:motherboard:iofpga@7,00000000/10006000.kmi/serio0/input/input0 mmc0: new SD card at address 4567 Error: Driver 'vexpress-muxfpga' is already registered, aborting... drm-clcd-pl111 10020000.clcd: initializing Versatile Express PL111 drm-clcd-pl111 10020000.clcd: DVI muxed to daughterboard 1 (core tile) CLCD mmcblk0: mmc0:4567 QEMU! 32.0 MiB Error: Driver 'vexpress-muxfpga' is already registered, aborting... drm-clcd-pl111 10020000.clcd: initializing Versatile Express PL111 drm-clcd-pl111 10020000.clcd: DVI muxed to daughterboard 1 (core tile) CLCD Error: Driver 'vexpress-muxfpga' is already registered, aborting... drm-clcd-pl111 10020000.clcd: initializing Versatile Express PL111 drm-clcd-pl111 10020000.clcd: DVI muxed to daughterboard 1 (core tile) CLCD rtc-pl031 10017000.rtc: setting system clock to 2019-12-24T05:46:23 UTC (1577166383) ALSA device list: #0: ARM AC'97 Interface PL041 rev0 at 0x10004000, irq 24 input: ImExPS/2 Generic Explorer Mouse as /devices/platform/smb@4000000/smb@4000000:motherboard/smb@4000000:motherboard:iofpga@7,00000000/10007000.kmi/serio1/input/input2 Error: Driver 'vexpress-muxfpga' is already registered, aborting... drm-clcd-pl111 10020000.clcd: initializing Versatile Express PL111 drm-clcd-pl111 10020000.clcd: DVI muxed to daughterboard 1 (core tile) CLCD EXT4-fs (mmcblk0): mounting ext3 file system using the ext4 subsystem random: fast init done EXT4-fs (mmcblk0): mounted filesystem with ordered data mode. Opts: (null) VFS: Mounted root (ext3 filesystem) readonly on device 179:0. Freeing unused kernel memory: 1024K Run /sbin/init as init process random: crng init done can't run '/etc/init.d/rcS': Permission denied Please press Enter to activate this console.
/ # ls
bin etc linuxrc proc sys usr
dev lib modules sbin tmp var
进行insmod和rmmod操作，发现还需要创建几个文件夹，根据提示在lib下创建lib/modules和lib/modules/5.3.7，就此告一段落
/modules # ls first.ko hello /modules # cat hello hello /modules # vi hello /modules #
8.gdb远程调试内核
8.1.准备gdb
linux环境安装gcc后默认是不安装配到gdb的，我们调试的远端设备是arm的所以需要安装交叉编译的gdb，我们之前使用的交叉编译工具链是这个 arm-linux-gnueabi-gcc, 所以我们安装对应的gdb。这里下载的是目前较新的8.3版本
下载地址： http://ftp.gnu.org/gnu/gdb/
安装方法，建议在源码目录外新建一个文件夹进行编译，目录结构如下
sly@ubuntu:~/develop$ ls build_gdb busybox-1.24.2 gdb-8.3 linux-5.3.7 linux-5.3.7.tar module rootfs rootfs.ext3 start.sh stop.sh tmp
按照上面的交叉编译工具链进行安装对应的gdb
sly@ubuntu:~/develop/build_gdb$ ../gdb-8.3/configure --target=arm-linux-gnueabi sly@ubuntu:~/develop/build_gdb$ make sly@ubuntu:~/develop/build_gdb$ sudo make install
第一个坑：gdb需要环境上安装了textinfo，否则install的时候会失败，安装方法： sudo apt-get install texinfo
第二个坑：gdb运行remote调试时需要安装expat， 安装方法： sudo apt-get install expat
第三个坑：只安装expat不管用，需要安装dev的开发lib，安装方法： sudo apt-get install libexpat1-dev
第二和第三个坑填上后修改下第一步的configure的传入参数如下，带expat编译gdb，之后make再make install就可以了
sly@ubuntu:~/develop/build_gdb$ ../gdb-8.3/configure --target=arm-linux-gnueabi --with-expat
gdb默认安装路径： /usr/local/bin/arm-linux-gnueabi-gdb
安装完成后查看一下
sly@ubuntu:~/develop/build_gdb$ arm-linux-gnueabi-gdb -v GNU gdb (GDB) 8.3 Copyright (C) 2019 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
8.2 gdb连接qemu的虚拟环境
qemu的参数需要加上-s以便于gdb可以通过1234端口对内核进行连接，新的启动参数如下
qemu-system-arm -M vexpress-a9 -m 512m -kernel /home/sly/develop/linux-5.3.7/arch/arm/boot/zImage -dtb linux-5.3.7/arch/arm/boot/dts/vexpress-v2p-ca9.dtb -nographic -append "root=/dev/mmcblk0 console=ttyAMA0" -sd rootfs.ext3 -s
之后另起一个控制台，启动gdb进行连接
sly@ubuntu:~/develop/linux-5.3.7$ arm-linux-gnueabi-gdb vmlinux GNU gdb (GDB) 8.3 Copyright (C) 2019 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "--host=x86_64-pc-linux-gnu --target=arm-linux-gnueabi". Type "show configuration" for configuration details. For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>. Find the GDB manual and other documentation resources online at: <http://www.gnu.org/software/gdb/documentation/>. For help, type "help". Type "apropos word" to search for commands related to "word"... Reading symbols from vmlinux... (gdb) target remote localhost:1234 Remote debugging using localhost:1234 cpu_v7_do_idle () at arch/arm/mm/proc-v7.S:78 78 ret lr (gdb)
大功告成！！