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Android, Chinese New Year, blockchain, Cache miss Week5 (02/02) 這個月雖然有年假但比平常更忙！ 結論: 放假不一定放鬆, 想專心做事 :-) 網路文章 Processor Pipeline Gallery of Processor Cache Effects Using Streamline to Guide Cache Optimization 參考這篇分析Kodi17.6影片播放時的L1/L2 cache access情況, 播放2160p影片時L1/L2 data ratios不高分別在0.046/0.18, 使用Kodi18更少分別為0.041/0.16. 另外Kodi18在記憶體使用上比17.6減少3.6%, cache miss 減少47~55%. Cache Refill Ratios算法 L1 data ratio: $CacheDataRefill/$CacheDataAccess L2 data ratio: $CacheL2DataRefill/$CacheL2DataAccess 網路資源 Blockchain Demo 大略的介紹blockchain, 簡單明瞭.

Android, Algorithms Week1 (01/05) 讀書心得 Algorithms on Graphs - Week5 給出座標上n個點: 找出最短路徑(the shortest path) 分群(Clustering) 為Minimun Spanning Tree相關問題, 可以使用Kruskal’s MST Algorithm 及Disjoint-set 來解. for all u ∈ V : MakeSet(v ) X ← empty set // a set with solution edges sort the edges E by weight for all {u, v } ∈ E in non-decreasing weight order: if Find(u) != Find(v): add {u, v } to X Union(u, v ) return X Week2 (01/12) 網路文章 Android编译系统中的Android....

SEAndroid, Algorithms, Numpy Android N -> O 被自己的石頭砸到腳 對於晶片廠來說Android決解了軟體開發的問題, 也加速了ODM/OEM的開發時程. 沒錯…但對於手機/電視之外的應用..存在些問題. 另外差異化及客制帶來些不定時炸彈. Sepolicy for Android Treble 使用numpy array修改pixel values. 網路資源 Machine Learning 101 - Jason Mayes New year’s resolutions IELTS overall 6.5 Data Structures and Algorithms Specialization Master of Computer Science in Data Science

A Note about sepolicy in Android Oreo. First thing first SELinux documents: SELinux for Android 8.0 What is SELinux? What is SEAndroid? SELinux Policy Concepts and Overview Android sepolicy files Policy path: /system/sepolicy BOARD_SEPOLICY_DIR (device/$VENDOR/$DEVICE/sepolicy/, device/$VENDOR/$DEVICE/common/sepolicy/) Policy Macros: system/sepolicy/public/te_macros system/sepolicy/public/global_macros system/sepolicy/public/ioctl_macros system/sepolicy/public/neverallow_macros system/sepolicy/private/mls_macros system/sepolicy/reqd_mask/mls_macros Security Context: file_contexts, labeling files infilesystem. property_contexts, labeling android system/vendor properties genfs_contexts, Pre-file labeling for /proc files, generic filesystem security contexts. seapp_contexts, used by zygote and installd via libselinux, mapping app UID andseinfofor /data/data directory hwservice_contexts, for hwservice manager to check vndservice_contestx, for vndservice manager to check service_contexts, for service manager to check Type Enforcement *....

SELinux, Arm Tech Symposia 2017 Taiwan, golang, IoT Week44 (11/03) 網路資源 Firmware Updates over Low-Power Wide Area Networks Enabling firmware updates over LPWAN ARMmbed/lorawan-fota-demo 滿有趣的問題, IoT建置會預期device要能長達10年的壽命, 但10年間的變化是很大的. Week45 (11/10) 網路文章 Android SELinux Treble Android O 為了加速產品開發, 在framework上有重大的改變, 使用了Treble. Vender, ODM, OEM有各自需要維護的partitions. Week46 (11/17) 網路文章 Neural fuzzing: applying DNN to software security testing 好奇其它的nural networks的應用, 常看到CNN. 網路資源 hacdias/filemanager 感覺不錯用的web filemanager, 目前很有活力, 送了一個PR不到1天就被merge了. 讀書心得 因為把玩hacdias/filemanager看了一下A Tour of Go在語法上還不太能適應, 不過還滿容易上手的, Method跟Interface的用法還要再研究一下, Concurrency也要花一點時間了解, 必竟concurrency是最大的賣點吧!...

A Note for SELinux and SEAndroid policy configuration. SEAndroid Security-Enhanced Linux in Android SELinux for Android 8 - Treble mode SEAndroid安全機制中的文件安全上下文關聯分析 - file_context SEAndroid安全機制中的進程安全上下文關聯分析 - process Android 8 Treble mode: Kernel early mount PRODUCT_FULL_TREBLE, PRODUCT_FULL_TREBLE_OVERRIDE, BOARD_SEPOLICY_DIRS Android 4.3 ~ 6 TE macro define: external/sepolicy/te_macros Android 8 TE macro define: system/sepolicy/te_macros ##################################### # domain_trans(olddomain, type, newdomain) # Allow a transition from olddomain to newdomain # upon executing a file labeled with type....

Some metrics for ARM Mali performance analysis in DS-5 Streamline or MGD. DS-5 Streamline Mali-470 (Utgard) GPU Bandwidth = (Words read, master + Words written, master) * Bus Width Overdraw = Fragments Passed Z/stencil count * Number of Cores / Resolution * FPS GPU Bandwidth = (38342943+38661456) * (128/8) = 1232070384 bytes/s = 1174.99 MB/s Overdraw = (79194586+79152584+79112550+79117609)/(1920x1080) = 152.67 Mali-T820 (Midgard) Job Slots JS0: fragment shading. JS1: vertex, geometry, compute, and tiling....