Dec 28, 2017
Build your private LTE network for IIOT —
Abstract:
In some specfied conditions, the tele operator is considering share/reserve some spectrum resource to the IIOT(Industry IoT)applicance, like the NB-IoT/eMTC tech defined by 3GPP stardard.…
Nov 22, 2017
Build service with SOA in Openwrt —
In one of internal technical review meeting, the coder integrate the service into a existed substance/service, but considering of the scalability of this service, I strongly recommended the developer decouple this service from any substance and made them into a self-contained substance in order to provide the service to more clients in the future.…
Nov 2, 2017
Design a license system in embedded system —
License was widely used on many software/hardware area, such as Microsoft Windows Series, which use dedicated hardware to store their key and other information to verify the booting OS is legal or not.…
Oct 23, 2017
Fast logging system in embedded system —
Fast logging system in embedded system [TOC]
Introduction FLOG is a light-weight logging system which has features like, high throughput, non-blocking and lock-less write from different process, crash save in field.…
Aug 16, 2017
system test thoughts —
谈谈如何有效的测量系统负载和响应 嵌入式系统在系统测试过程中往往需要进行 Stability, Robustness, Accessbility, Responsibility 等等系统测试. 以来保证系统的功能完整性和健壮性.
嵌入式系统在设计在立项阶段会给出一个设计目标, 比如一款路由器，往往会给出以下类似的要求:
支持 802.11n/g/a/b 支持. 支持 2.4G, 5G 双频. 最大速率支持 (450Mbps). … 作为系统设计者,需要在设计阶段锚定这些目标进行技术选型.…
Jun 26, 2017
Some thoughts about memory issue —
最近一段时间在忙于内存问题的事情，算是有些成果输出吧。借机谈论一下自己的感想。
近来工程团队遇到几次比较严重的内存泄漏问题,有一些问题无疾而终.在接手工作后发现这些问题均是发生 在客户的现场,很难在实验室复现. 即使能够在长时间stability测试发现问题，因为现场发生比较遥远， 也是很难去定位问题. 针对此类问题,团队近期输出了几个内部产品, 较好的解决了其中的一些问题。
项目团队在 Devops team 的协助下已经有一套比较完备的测试工具, 单元测试，valgrind内存检查. 但是在集成测试阶段还是缺乏手段去快速定位内存问题。针对此类问题
工程团队重构了自定义的内存分配器，加入了头尾两部分的magic number, FREE() 内存后reset 内存单元内容. 在每次 ALLOC()/FREE() 强制检查合法性, 第一时间保留现场.…
Jun 5, 2017
Efficient data transfer through zero copy —
Zero-copy I/O practice in project Recently weeks, I was working on how to exploit the potentialities with the GMAC(1G Ethernet Media Access Controller) on the SoC in my desktop.…
Jun 4, 2017
don't use memset() init your struct —
Don’t use memset init your struct Even in some open source project, we always see memset filled in the code, here I had like give the reason why we should not use memset if possible.…