单独编译Tina Linux

在TinaSDK内，单独编译LinuxKernel 只需要在源码根目录下执行 mkernel命令即可开始针对于 kernel的编译操作，这里需要注意的是，mkernel 命令默认是没有生效的，您如果关闭了之前编译的终端/host系统，则需要重新执行 source build/envsetup.sh 命令来初始化 TinaSDK的编译环境。并且因为缓存问题，强烈建议你执行make clean 后执行，lunch 命令，输入 4 重新选择我们的 4. t113_100ask-tina 单板

ubuntu@ubuntu1804:~/tina-d1-h$ source build/envsetup.sh 
Setup env done! Please run lunch next.
ubuntu@ubuntu1804:~/tina-d1-h$ lunch 

You're building on Linux

Lunch menu... pick a combo:
     1. d1-h_nezha_min-tina
     2. d1-h_nezha-tina
     3. d1s_nezha-tina
     4. t113_100ask-tina

Which would you like? [Default t113_100ask]: 4
============================================
TINA_BUILD_TOP=/home/ubuntu/tina-d1-h
TINA_TARGET_ARCH=arm
TARGET_PRODUCT=t113_100ask
TARGET_PLATFORM=t113
TARGET_BOARD=t113-100ask
TARGET_PLAN=100ask
TARGET_BUILD_VARIANT=tina
TARGET_BUILD_TYPE=release
TARGET_KERNEL_VERSION=5.4
TARGET_UBOOT=u-boot-2018
TARGET_CHIP=sun8iw20p1
============================================
clean buildserver
[2]+  Killed                  $T/tools/build/buildserver --path $T 2> /dev/null 1>&2
[1] 49529
ubuntu@ubuntu1804:~/tina-d1-h$ 

单独编译kernel

前面介绍，在TinaSDK 环境内，单独编译 Linux kernel只需要 mkernel一个命令即可，如下图所示：

ubuntu@ubuntu1804:~/tina-d1-h$ mkernel
===This's tina environment.===
special target, skip mboot,marisc
make[1]: Entering directory '/home/ubuntu/tina-d1-h'
make[2]: Entering directory '/home/ubuntu/tina-d1-h/target/allwinner'
make[3]: Entering directory '/home/ubuntu/tina-d1-h/target/allwinner/t113-100ask'
/home/ubuntu/tina-d1-h/scripts/kconfig.pl  + /home/ubuntu/tina-d1-h/target/allwinner/generic/config-5.4 /home/ubuntu/tina-d1-h/device/config/chips/t113/configs/100ask/linux/config-5.4 > /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config.target
awk '/^(#[[:space:]]+)?CONFIG_KERNEL/{sub("CONFIG_KERNEL_","CONFIG_");print}' /home/ubuntu/tina-d1-h/.config >> /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config.target
echo "# CONFIG_KALLSYMS_EXTRA_PASS is not set" >> /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config.target
echo "# CONFIG_KALLSYMS_ALL is not set" >> /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config.target
echo "CONFIG_KALLSYMS_UNCOMPRESSED=y" >> /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config.target
/home/ubuntu/tina-d1-h/scripts/metadata.pl kconfig /home/ubuntu/tina-d1-h/tmp/.packageinfo /home/ubuntu/tina-d1-h/.config 5.4 > /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config.override
/home/ubuntu/tina-d1-h/scripts/kconfig.pl 'm+' '+' /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config.target /dev/null /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config.override > /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config.set
......
rm -f /home/ubuntu/tina-d1-h/out/t113-100ask/rootfs.img
rm -f /home/ubuntu/tina-d1-h/out/t113-100ask/usr.img
dd if=/home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/root.squashfs of=/home/ubuntu/tina-d1-h/out/t113-100ask/rootfs.img bs=128k conv=sync
282+1 records in
283+0 records out
37093376 bytes (37 MB, 35 MiB) copied, 0.0216129 s, 1.7 GB/s
( cd /home/ubuntu/tina-d1-h/out/t113-100ask ; find -maxdepth 1 -type f \! -name 'md5sums'  -printf "%P\n" | sort | xargs md5sum --binary > md5sums )
( cd /home/ubuntu/tina-d1-h/out/t113-100ask ; find -maxdepth 1 -type f \! -name 'md5sums'  -printf "%P\n" | sort | xargs openssl dgst -sha256 > sha256sums )
make[4]: Leaving directory '/home/ubuntu/tina-d1-h/target/allwinner/generic/image'
make[3]: Leaving directory '/home/ubuntu/tina-d1-h/target/allwinner/t113-100ask'
make[2]: Leaving directory '/home/ubuntu/tina-d1-h/target/allwinner'
make[1]: Leaving directory '/home/ubuntu/tina-d1-h'

#### make completed successfully (25 seconds) ####

如果你得 kernel没有修改，整个编译过程非常快，TinaSDK系统默认会检查配置文件，看是否有改动，如果有改动，则会编译改动位置，如果无改动，就会直接跳过进行后续的头处理打包处理。

Kconfig 配置方法

如果你需要修改内核配置项，可以在TinaSDK源码目录下执行 make kernel_menuconfig命令来进入到内核的菜单选项界面。

对于menuconfig是一种图形化配置工具，这里以 kernel menuconfig 作为例子，讲解如何使用 Kconfig 基础配置方法。

首先我们进入 kernel menuconfig

make kernel_menuconfig

ubuntu@ubuntu1804:~/tina-d1-h$ make kernel_menuconfig
===This's tina environment.===
special target, skip mboot,marisc
export MAKEFLAGS= ;make V=ss -C target/allwinner menuconfig
make[1]: Entering directory '/home/ubuntu/tina-d1-h/target/allwinner'
make[2]: Entering directory '/home/ubuntu/tina-d1-h/target/allwinner/t113-100ask'
rm -f /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config.prev
rm -f /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.configured
/home/ubuntu/tina-d1-h/scripts/kconfig.pl  + /home/ubuntu/tina-d1-h/target/allwinner/generic/config-5.4 /home/ubuntu/tina-d1-h/device/config/chips/t113/configs/100ask/linux/config-5.4 > /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61/.config
export MAKEFLAGS= ;make -C /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61 -C /home/ubuntu/tina-d1-h/out/t113-100ask/compile_dir/target/linux-t113-100ask/linux-5.4.61 HOSTCFLAGS="-O2 -I/home/ubuntu/tina-d1-h/out/host/include -I/home/ubuntu/tina-d1-h/out/host/usr/include  -Wall -Wmissing-prototypes -Wstrict-prototypes" CROSS_COMPILE="arm-openwrt-linux-muslgnueabi-" ARCH="arm" KBUILD_HAVE_NLS=no KBUILD_BUILD_USER="" KBUILD_BUILD_HOST="" CONFIG_SHELL="bash" V=''  CC="arm-openwrt-linux-muslgnueabi-gcc" menuconfig
make[3]: Entering directory '/home/ubuntu/tina-d1-h/lichee/linux-5.4'
--define-variable argument does not have a value for the variable
--define-variable argument does not have a value for the variable
scripts/kconfig/mconf  Kconfig
configuration written to .config

*** End of the configuration.
*** Execute 'make' to start the build or try 'make help'.

make[3]: Leaving directory '/home/ubuntu/tina-d1-h/lichee/linux-5.4'
make[2]: Leaving directory '/home/ubuntu/tina-d1-h/target/allwinner/t113-100ask'
make[1]: Leaving directory '/home/ubuntu/tina-d1-h/target/allwinner'

#### make completed successfully (6 seconds) ####

这里就是 kernel menuconfig 的主目录。其具体的操作方法如下图所示。

我们再进入较为常用的 Device Driver ，看一下各个符号的含义。

其中，可以使用 空格键 选中各个选项，这里以 Multimedia support 选项为例：

也可以使用 Y M N 键来修改选项：

遇到被其他依赖选择的选项，可以查看 Help 页面检查被什么选项所依赖。

进入 Help 页面后，便可以查看这个选项的依赖情况。需要注意的是，有些选项是作为底层依赖无法随意取消，例如这里示例的 Hardware Monitoring support 选项。

Kconfig 所创建的界面还有一个功能，就是搜索功能，方便快速的找到目标选项。这里以搜索 LCD 屏幕 icn6202 驱动为例。

在 Kconfig 的界面中按 / 键，进入搜索页面。

Kconfig修改配置示例

调整 kernel打印等级默认为7

默认不知道 kernel的printk打印等级配置在哪里，通过搜索得到路径，上面那个 Enable support for printk 并不是我们要找到的调整系统默认打印等级的配置项。继续往下，找到了一个 Delay each boot printk message by N milliseconds 通过查看这个也不是，这个配置和是用来调整因为系统信息显示过快而调整每个 printk的打印间隔时间的。

还有一个 Early printk 看着类似，但是也不是，不过我们可以大概知道是在 Kernel hacking这个类目内，