前言
此篇为调试记录，基于两个大的方向来归纳这篇文章要提的内容：
1.ninja编译命令提高调试效率
2.高通的源码在R上引入了QSSI(Qualcomm Single System Image),从字面上来看，就是要将system独立出来解耦，为厂商升级最新的android版本铺路.
细节描述
针对编译
未对ninja编译做分析，旨在让参与模块的小伙伴们能有方式提高调试效率，调试android R版本的都知道编译调试带来的痛苦.
./prebuilts/build-tools/linux-x86/bin/ninja -f out/combined-bengal.ninja -j32 aboot
如上面调试aboot模块，在全编译之后，可以后期用上述命令单编译，当然还可以是bootimage vendorimage等等.
另外需要注意的一点是android Q之后，Google启用了动态分区，system 、vendor、product等分区的大小是动态可变的，而且存在分区表中的分区是super,
这里不重点介绍动态分区，但是开启了动态分区的版本 ，如果是需要调试验证问题，比如在vendor中做了修改，那在编译完之后，就需要重新打包super image，
重新打包super的命令看了之后补上(Todo).
补充：看了一眼build.sh脚本里的用法，高通已经做了几个版本的迭代了
vendor\qcom\opensource\core-utils\build\build.sh
# Version 0:
# Supports just the basic make commands (passes on all args like -j32 to the make command).
# Version 1:
# Supports dist command as well - needed for target-files/ota generation.
# Usage: ./build.sh dist -j32
# This triggers make dist for qssi and target lunch, generates target-files, merges them
# and triggers ota generation.
# Version 2:
# Supports custom copy paths for dynamic patition images when compiled with dist.
# option : --dp_images_path=<custom-copy-path>
# Version 3:
# Supports segmenting the build into qssi only, target only and merge only steps and
# enabling users to call specific steps or full build by giving no separate steps.
# options: --qssi_only, --target_only, --merge_only
# Usage: ./build.sh dist -j32 --qssi_only (for only qssi build) or ./build.sh dist -j32 (for full build)
# Note: qssi_only and target_only options can be given together but merge_only should not be combined with
# any other options.
# Version 4:
# Supports lunch qssi variant to build qssi only images.
# enables users to build standalone qssi images independent of any targets
# option(s): --qssi_only
# Usage: ./build.sh dist -j32 --qssi_only or ./build.sh dist -j32. Either way the outcome will be the same
# Note: --target_only and --merge_only options will throw an error with lunch qssi variantversion0,version1 ------基本支持full编译
version2 ------动态分区Image拷贝客制化
version3 ------支持模块化编译，如：
./build.sh --qssi_only 仅编译qssi
./build.sh --target_only 仅编译oem target product
./build.sh --merge_only merge上述两部分的镜像内容，之前提到的合并super image的情形，还有包括打包最终的merge ota、merge target-file都可以用此命令完成.
version4 ------ 只lunch qssi可独立编译出qssi only image
命令暂时没有一个个去验证，调试阶段时间紧，主要是自己试到的和道听途说的总结
编译system
build.sh dist qssi_only -j8
build.sh dist merge_only -j8
编译vendor.img
build.sh vendorimage dist target_only -j8
build.sh dist merge_only -j8
build.sh dist merge_only -j8会生成super.imgQSSI的做法
按我目前的粗浅理解，systemimage的编译独立于其他模块，
所以编译脚本的执行贯彻的也是如此，第一阶段的TARGET_PRODUCT就是qssi.
source build/envsetup.sh
lunch qssi-userdebug等待编译完成，执行第二阶段其他image的编译，TARGET_PRODUCT即为oem project.
整体编译时间至少是在4小时以上，所以凡是涉及到需要全编译的调试，就得折腾的鸡飞狗跳，但谁叫我们吃的就是这碗饭呢，乐观面对，毕竟这才是生活的本质.