移植Linux 6.3.5系统到imx6ull开发板
目录
1.下载Linux源码包
2.解压源码包
3.清理工程
4.编译
4.1.选择imx6ull默认配置文件
4.2.编译
4.3.编译报错
4.4.编译通过
4.5.下载验证
5.Linux中添加自己的开发板
5.1.添加开发板默认配置文件
5.2.添加开发板对应的设备树文件
5.3.修改设备树目录下的Makefile文件
5.4.编译
本章主要是移植Linux 6.3.5版本到imx6ull 开发板
1.下载Linux源码包
下载链接：
linux-6.3.5.tar.gz：http://mirrors.163.com/kernel/
2.解压源码包
解压命令：
tar -zxvf linux-6.3.5.tar.gz
3.清理工程
在编译Linux之前，我们先对源码工程进行清理一下
make clean
4.编译
4.1.选择imx6ull默认配置文件
配置文件所在文件夹：arch/arm/configs ls查看配置文件有哪些，一眼看见imx系列有imx_v4_v5_defconfig和imx_v6_v7_defconfig两个默认的配置文件，但是我们选择哪个进行配置编译呢？
toto@toto:~/workspace/kernel/linux-6.3.5$ ls arch/arm/configs/
am200epdkit_defconfig exynos_defconfig milbeaut_m10v_defconfig omap2plus_defconfig socfpga_defconfig
aspeed_g4_defconfig footbridge_defconfig mmp2_defconfig orion5x_defconfig sp7021_defconfig
aspeed_g5_defconfig gemini_defconfig moxart_defconfig oxnas_v6_defconfig spear13xx_defconfig
assabet_defconfig h3600_defconfig mps2_defconfig pxa168_defconfig spear3xx_defconfig
at91_dt_defconfig hisi_defconfig multi_v4t_defconfig pxa3xx_defconfig spear6xx_defconfig
axm55xx_defconfig imxrt_defconfig multi_v5_defconfig pxa910_defconfig spitz_defconfig
bcm2835_defconfig imx_v4_v5_defconfig multi_v7_defconfig pxa_defconfig stm32_defconfig
clps711x_defconfig imx_v6_v7_defconfig mv78xx0_defconfig qcom_defconfig sunxi_defconfig
collie_defconfig integrator_defconfig mvebu_v5_defconfig realview_defconfig tegra_defconfig
davinci_all_defconfig ixp4xx_defconfig mvebu_v7_defconfig rpc_defconfig u8500_defconfig
dove_defconfig jornada720_defconfig mxs_defconfig s3c6400_defconfig versatile_defconfig
dram_0x00000000.config keystone_defconfig neponset_defconfig s5pv210_defconfig vexpress_defconfig
dram_0xc0000000.config lpae.config netwinder_defconfig sama5_defconfig vf610m4_defconfig
dram_0xd0000000.config lpc18xx_defconfig nhk8815_defconfig sama7_defconfig vt8500_v6_v7_defconfig
ep93xx_defconfig lpc32xx_defconfig omap1_defconfig shmobile_defconfig wpcm450_defconfig
网上查询了一下得知：imx_v4_v5_defconfig用于arm-v4，v5架构，而imx_v6_v7_defconfig用于arm-v6，v7架构的处理器 而imx6ull是arm-v7架构的，因此我们选择imx_v6_v7_defconfig进行配置编译。
4.2.编译
修改Makefile文件，在如下地方添加如下两行
# Cross compiling and selecting different set of gcc/bin-utils
# ---------------------------------------------------------------------------
#
# When performing cross compilation for other architectures ARCH shall be set
# to the target architecture. (See arch/* for the possibilities).
# ARCH can be set during invocation of make:
# make ARCH=ia64
# Another way is to have ARCH set in the environment.
# The default ARCH is the host where make is executed.
# CROSS_COMPILE specify the prefix used for all executables used
# during compilation. Only gcc and related bin-utils executables
# are prefixed with $(CROSS_COMPILE).
# CROSS_COMPILE can be set on the command line
# make CROSS_COMPILE=ia64-linux-
# Alternatively CROSS_COMPILE can be set in the environment.
# Default value for CROSS_COMPILE is not to prefix executables
# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
ARCH ?= arm
CROSS_COMPILE ?= arm-linux-gnueabihf-
编译指令
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- distclean /*清理工程*/
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- imx_v6_v7_defconfig /*选择配置文件*/
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j8 /*提高编译速率,采用8线程编译*/
4.3.编译报错
经过1个小时的编译，结果报错了，如下；
LD [M] drivers/siox/siox-bus-gpio.ko
LD [M] net/bluetooth/bnep/bnep.ko
KSYMS .tmp_vmlinux.kallsyms2.S
AS .tmp_vmlinux.kallsyms2.S
LD vmlinux
NM System.map
SORTTAB vmlinux
OBJCOPY arch/arm/boot/Image
Kernel: arch/arm/boot/Image is ready
AS arch/arm/boot/compressed/head.o
LDS arch/arm/boot/compressed/vmlinux.lds
LZO arch/arm/boot/compressed/piggy_data
/bin/sh: 1: lzop: not found
CC arch/arm/boot/compressed/misc.o
arch/arm/boot/compressed/Makefile:162: recipe for target 'arch/arm/boot/compressed/piggy_data' failed
make[2]: *** [arch/arm/boot/compressed/piggy_data] Error 127
make[2]: *** 正在删除文件“arch/arm/boot/compressed/piggy_data”
make[2]: *** 正在等待未完成的任务....
arch/arm/boot/Makefile:58: recipe for target 'arch/arm/boot/compressed/vmlinux' failed
make[1]: *** [arch/arm/boot/compressed/vmlinux] Error 2
arch/arm/Makefile:301: recipe for target 'zImage' failed
make: *** [zImage] Error 2
原因：lzop库未找到 解决方法：手动安装lzop库
sudo apt-get install lzop
4.4.编译通过
toto@toto:~/workspace/kernel/linux-6.3.5$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j8
CALL scripts/checksyscalls.sh
Kernel: arch/arm/boot/Image is ready
CC arch/arm/boot/compressed/string.o
AS arch/arm/boot/compressed/hyp-stub.o
CC arch/arm/boot/compressed/decompress.o
LZO arch/arm/boot/compressed/piggy_data
CC arch/arm/boot/compressed/fdt_rw.o
CC arch/arm/boot/compressed/fdt_ro.o
CC arch/arm/boot/compressed/fdt_wip.o
CC arch/arm/boot/compressed/fdt.o
CC arch/arm/boot/compressed/fdt_check_mem_start.o
AS arch/arm/boot/compressed/lib1funcs.o
AS arch/arm/boot/compressed/ashldi3.o
AS arch/arm/boot/compressed/bswapsdi2.o
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
4.5.下载验证
将编译好的zImage和imx6ull-14x14-evk.dtb下载到开发板上 1.从网络启动 Linux 系统，设置u-boot下bootcmd和bootargs，
setenv bootargs 'console=ttymxc0,115200 root=/dev/mmcblk1p2 rootwait rw'
setenv bootcmd 'tftp 80800000 zImage; tftp 83000000 imx6ull-14x14-evk.dtb; bootz 80800000 - 83000000'
saveenv
重启开发板，串口打印信息如下；
[ 2.469400] platform regulatory.0: Falling back to sysfs fallback for: regulatory.db
[ 2.477276] ALSA device list:
[ 2.480344] No soundcards found.
[ 2.485955] /dev/root: Can't open blockdev
[ 2.490552] VFS: Cannot open root device "mmcblk1p2" or unknown-block(179,2): error -6
[ 2.498729] Please append a correct "root=" boot option; here are the available partitions:
[ 2.507139] 0100 65536 ram0
[ 2.507171] (driver?)
[ 2.513427] 0101 65536 ram1
[ 2.513457] (driver?)
[ 2.519697] 0102 65536 ram2
[ 2.519730] (driver?)
[ 2.525878] 0103 65536 ram3
[ 2.525904] (driver?)
[ 2.532141] 0104 65536 ram4
[ 2.532171] (driver?)
[ 2.538374] 0105 65536 ram5
[ 2.538403] (driver?)
[ 2.544549] 0106 65536 ram6
[ 2.544574] (driver?)
[ 2.550841] 0107 65536 ram7
[ 2.550872] (driver?)
[ 2.557018] 0108 65536 ram8
[ 2.557043] (driver?)
[ 2.563254] 0109 65536 ram9
[ 2.563283] (driver?)
[ 2.569508] 010a 65536 ram10
[ 2.569537] (driver?)
[ 2.575771] 010b 65536 ram11
[ 2.575797] (driver?)
[ 2.582113] 010c 65536 ram12
[ 2.582145] (driver?)
[ 2.588435] 010d 65536 ram13
[ 2.588464] (driver?)
[ 2.594697] 010e 65536 ram14
[ 2.594723] (driver?)
[ 2.601037] 010f 65536 ram15
[ 2.601065] (driver?)
[ 2.607313] b300 7634944 mmcblk1
[ 2.607339] driver: mmcblk
[ 2.614243] b308 4096 mmcblk1boot0
[ 2.614272] (driver?)
[ 2.621211] b310 4096 mmcblk1boot1
[ 2.621243] (driver?)
[ 2.628142] b318 15558144 mmcblk0
[ 2.628171] driver: mmcblk
[ 2.635045] b319 15556608 mmcblk0p1 ab37899a-01
[ 2.635076]
[ 2.641989] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,2)
[ 2.650483] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,2) ]---
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,2)
也就是提示内核崩溃，因为 VFS(虚拟文件系统)不能挂载根文件系统，因为根文件系统目录不存在。即使根文件系统目录存在，如果根文件系统目录里面是空的依旧会提示内核崩溃。这个就是根文件系统缺失导致的内核崩溃，但是内核是启动了的，只是根文件系统不存在而已。 本来开发板的eMMC默认是格式化分区好了，linux成功启动后就能成功挂载根文件系统，但是我们是为了学习的，eMMC的分区也应该知道怎么弄。因此在u-boot将eMMC分区擦除，后面自己手动来格式化分区eMMC。Linux系统启动后就会看到上面的信息“Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,2)”，提示内核崩溃。 跟文件系统的制作和加载将在下一篇文章进行详细介绍。
5.Linux中添加自己的开发板
下面我们来学习如何在Linux中添加自己的开发板信息。 在Linux中添加自己的开发板信息跟在u-boot中添加自己的开发板是一样的。
5.1.添加开发板默认配置文件
将 arch/arm/configs 目录下的 imx_v6_v7_mfg_defconfig 重新复制一份，命名为imx_toto_defconfig，命令如下：
cd arch/arm/configs
cp imx_v6_v7_defconfig imx_toto_defconfig
后面 imx_toto_defconfig 就是我们开发板的默认配置文件了，使用如下命令进行配置开发板对应的Linux内核：
make imx_toto_defconfig
5.2.添加开发板对应的设备树文件
添加适合 imx6ull 开发板的设备树文件，进入目录 arch/arm/boot/dts 中,可以看到Linux中有很多imx6ull版本的设备树文件
toto@toto:~/workspace/kernel/linux-6.3.5/arch/arm/boot/dts$ ls imx6ull
imx6ull-14x14-evk.dtb imx6ull-colibri-wifi.dtsi imx6ull-opos6ul.dtsi
imx6ull-14x14-evk.dts imx6ull-colibri-wifi-eval-v3.dtb imx6ull-phytec-phycore-som.dtsi
imx6ull-colibri-aster.dtb imx6ull-colibri-wifi-eval-v3.dts imx6ull-phytec-segin.dtsi
imx6ull-colibri-aster.dts imx6ull-colibri-wifi-iris.dtb imx6ull-phytec-segin-ff-rdk-emmc.dtb
imx6ull-colibri-aster.dtsi imx6ull-colibri-wifi-iris.dts imx6ull-phytec-segin-ff-rdk-emmc.dts
imx6ull-colibri.dtsi imx6ull-colibri-wifi-iris-v2.dtb imx6ull-phytec-segin-ff-rdk-nand.dtb
imx6ull-colibri-emmc-aster.dtb imx6ull-colibri-wifi-iris-v2.dts imx6ull-phytec-segin-ff-rdk-nand.dts
imx6ull-colibri-emmc-aster.dts imx6ull-dhcom-drc02.dtb imx6ull-phytec-segin-lc-rdk-nand.dtb
我们这里使用 imx6ull-14x14-evk.dts。拷贝 imx6ull-14x14-evk.dts，然后将其重命名为 imx6ull-toto.dts，命令如下：
cd arch/arm/boot/dts
cp imx6ull-14x14-evk.dts imx6ull-toto.dts
.dts 是设备树源码文件，编译 Linux 的时候会将其编译为.dtb 文件
5.3.修改设备树目录下的Makefile文件
打开 arch/arm/boot/dts/Makefile 文件，找 到 “ dtb-$(CONFIG_SOC_IMX6UL) ”配置项，在此配置项中加入“imx6ull-toto.dtb” ，如下所示：
dtb-$(CONFIG_SOC_IMX6UL) += \
imx6ul-14x14-evk.dtb \
imx6ul-ccimx6ulsbcexpress.dtb \
imx6ul-ccimx6ulsbcpro.dtb \
imx6ul-geam.dtb \
imx6ul-isiot-emmc.dtb \
imx6ul-isiot-nand.dtb \
imx6ul-kontron-bl.dtb \
imx6ul-kontron-bl-43.dtb \
imx6ul-liteboard.dtb \
imx6ul-tqma6ul1-mba6ulx.dtb \
imx6ul-tqma6ul2-mba6ulx.dtb \
imx6ul-tqma6ul2l-mba6ulx.dtb \
imx6ul-opos6uldev.dtb \
imx6ul-pico-dwarf.dtb \
imx6ul-pico-hobbit.dtb \
imx6ul-pico-pi.dtb \
imx6ul-phytec-segin-ff-rdk-emmc.dtb \
imx6ul-phytec-segin-ff-rdk-nand.dtb \
imx6ul-prti6g.dtb \
imx6ul-tx6ul-0010.dtb \
imx6ul-tx6ul-0011.dtb \
imx6ul-tx6ul-mainboard.dtb \
imx6ull-14x14-evk.dtb \
imx6ull-toto.dtb \
25行是我们添加的“imx6ull_toto.dtb”，这样编译 Linux 的时候就可以从 imx6ull-toto.dts 编译出 imx6ull-toto.dtb 文件了。
5.4.编译
现在Linux内核已经添加了imx6ull开发板，接下来就是编译测试。为了方便后续的编译，我们先进行编译脚本的创建，脚本内容如下：
vi build.sh
#!/bin/sh
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- distclean
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- imx_toto_defconfig
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- all -j8
给编译脚本文件添加可执行权限：
chmod 777 build.sh
编译
./build.sh
下载验证
Starting kernel ...
[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Linux version 6.3.5-g43eca22d987f-dirty (toto@toto) (arm-linux-gnueabihf-gcc (Linaro GCC 7.5-2019.12) 7.5.0, GNU ld (Linaro_Binutils-2019.12) 2.28.2.20170706) #1 SMP Sat Jun 10 23:45:23 CST 2023
[ 0.000000] CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=10c5387d
[ 0.000000] CPU: div instructions available: patching division code
[ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[ 0.000000] OF: fdt: Machine model: Freescale i.MX6 UltraLiteLite 14x14 EVK Board
[ 0.000000] Memory policy: Data cache writealloc
Linux 内核启动成功，说明我们已经在Linux 内核源码中添加了imx6ull开发板。 至此Linux系统已经移植到imx6ull开发板，但是网络是否正常工作现在还不能知道，需要制作跟文件系统后，Linux启动后成功挂载跟文件系统后才能知道，下一篇将介绍跟文件系统的制作与eMMC的分区。
今天的内容到此就完了，感谢大家的收看，如有不正之处，欢迎批评指正，下期再见！