flash partition fs overview


flash partition fs overviewNandFlashnand flash对于NandFlash的认识尝试不做更多理解,只需要了解非易失存储、擦除寿命有限、通常是10K级别,同时写操作需要基于Page来。没有办法按照内存的存储基本单位字节来操作,由多个Page组成一个Block 每个 Page保留 一些字节用以 做ECC ( error correcting code )校验。通常按照如下分布。32 pages of 512+16 bytes each for a block size (effective) of 16 KB 64 pages of 2,048+64 ...

hi3798cv200 android 编译


hi3798cv200 android compilesdk 百度云下载 密码:w11f开发环境搭建和初次编译参考Android 解决方案 开发指南.pdf- >开发环境配置烧写工具HiTool-STB-3.1.35.zip 会在成功编译镜像后自动拷贝到out文件夹。$ sudo find / -name HiTool-STB* /home/jay/hi3798cv200/HiSTBAndroidV600R002C00SPC030/out/target/product/Hi3798CV200/HiTool-STB-3.1.35.zip提示:部分windows应用工具直接打包到了sd...

a64 sdk pack tool


pack tool编译打包相关脚本文件。vim -p build.sh buildroot/scripts/mkcommon.sh buildroot/scripts/mkcmd.sh tools/pack/pack boot0拷贝tools/pack/chips/sun50iw1p1/bin/boot0_sdcard_sun50iw1p1.bin到out/boot0_sdcard.fex#tools/pack/pack line 132 boot_file_list=( chips/${PACK_CHIP}/bin/boot0_sdcard_${PACK_CHIP}.bin:out/...

android boot image


android boot image全志 a64 linux sdk采用了android 的boot image,这里顺着该sdk系统理解android的引导镜像。如下linux-3.10/scripts/build.sh 代码片段显示,在完成内核编译后,改脚本直接将kernel的二进制可执行文件和cpio的gzip压缩包rootfs.cpio.gz 一起合并进入boot.img。#linux-3.10/scripts/build.sh line.27 export MKBOOTIMG=${LICHEE_TOOLS_DIR}/pack/pctools/linux/android/mkbo...

ramfs


ramfsWhat is ramfs?Ramfs is a very simple FileSystem that exports Linux's disk cacheing mechanisms (the page cache and dentry cache) as a dynamically resizable ram-based filesystem.ramfs 是一个基于linux缓存机制(page cache and dentry cache)的简易文件系统,基于ram,大小可动态调整。Normally all files are cached in memory by Li...

arm级vp9 编解码cpu概况


vp9 decoder cpu summary这里系统了解全志和海思的解码能力。allwinner h6https://pan.baidu.com/s/1aA-jRLSWtjaUq6BhXxq8mw em4jhttp://linux-sunxi.org/H6从Allwinner_H6_V200_User_Manual_V1.1_decrypted->Chapter 2 Overview->2.2.6. Video Engine ->2.2.6.1. Video Decoder 从User Manual 来看,能够达到4k@30fps的帧率,但是实际测试在6fps。a...

v4l2 driver framework code review


v4l2 drvier framework code review术语解释术语解释vfevideo front end driverccicamera control interfacecsicamera serial interface启动流程$dmesg -T |egrep -i 'vfe|ov5640|v4l|csi|cci'如上启动顺序csi、cci、mipi 等外设初始化;vfe控制 v4l2 启动;vfe在初始化 v4l2-device启动的时候已经同sub-device ov5640 通信,但是此时ov5640 启动还没有加载,这部分需要详细走读下代码;sub-devic...

linux gpio libc


gpio对linux c app里面的一个gpio操作云里雾里半天,是时候好好理理了。https://www.kernel.org/doc/Documentation/gpio/sysfs.txthttps://www.kernel.org/doc/Documentation/gpio/gpio-legacy.txt主要是这gpio number是如何同pin number 一一对应的。256 root@mxj-zbcs-310:#tree /sys/class/gpio . |-- export |-- gpio120 -> ../../devices/soc.0/1c20800...

Overview of the V4L2 driver framework


Overview of the V4L2 driver frameworkThis text documents the various structures provided by the V4L2 framework and their relationships.IntroductionThe V4L2 drivers tend to be very complex due to the complexity of the hardware: most devices have multiple ICs, export multiple device nodes in /dev, ...

使用VS2017 开发Linux C应用


使用VS2017 开发Linux C应用Visual C++ for Linux Development依赖环境sudo apt-get install zip openssh-server g++ gdb gdbserver配置sshd 支持root账户登录vi /etc/ssh/sshd_config permitRootLogin yes重定向uname,默认不支持aarch64echo "echo ARM" > /bin/uname #暂时不支持arrch64,需要重定向unameinclude在工程添加了路径添加了.h 文件,尽管在include 时...