arm

ARM Neon: Store n-th position(s) of non-zero byte(s) in a 8-byte vector lane

由 让人想犯罪 __ 提交于 2020-01-05 04:27:15
问题 I want to convert a Neon 64-bit vector lane to get the n-th position(s) of non-zero (aka. 0xFF) 8-bit value(s), and then fill the rest of the vector with zeros. Here are some examples: 0 1 2 3 4 5 6 7 d0: 00 FF 00 FF 00 00 00 FF d1: 1 3 7 0 0 0 0 0 d0: 00 FF FF FF 00 00 FF 00 d1: 1 2 3 6 0 0 0 0 d0: FF FF FF FF FF FF FF FF d1: 0 1 2 3 4 5 6 7 d0: FF 00 00 00 00 00 00 00 d1: 0 0 0 0 0 0 0 0 d0: 00 00 00 00 00 00 00 00 d1: 0 0 0 0 0 0 0 0 I have the feeling that it's probably one or two bit

C++/QT/ARM Processors Cross-compiling/Programming [closed]

由 删除回忆录丶 提交于 2020-01-04 18:08:01
问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 6 years ago . dear all {C++|QT|ARM Processors} developers Hello Recently, I'm involved in a QT/ARM Processor software development project. The general components of the project is: Processor: Mini440 FriendlyARM (400 MHz Samsung S3C2440 ARM926T), www.friendlyarm.net www.arm9.net OS: Linux

linux 设备树格式详解

由 余生颓废 提交于 2020-01-04 17:20:08
1. Linux设备树的起源 在Linux 2.6中，arch/arm/plat-xxx和arch/arm/mach-xxx中充斥着大量的垃圾代码，相当多数的代码只是在描述板级细节，而这些板级细节对于内核来讲，不过是垃圾，如板上的platform设备、resource、i2c_board_info、spi_board_info以及各种硬件platform_data。常见的s3c2410、s3c6410等板级目录，代码量在数万行。 Linus Torvalds对于此种情况大发雷霆，在2011年的ARM Linux邮件列表宣称this whole ARM thing is a f*cking pain in the ass” 所以Linux开发社区就开始整改，设备树最早用于PowerPC等其他体系架构，ARM架构开发社区就开始采用设备树来描述设备的信息 2. Linux设备树的常见概念 DT : Device Tree FDT : Flattened DeviceTree OF : Open Firmware DTS : Device Tree Source DTSI : Device Tree Source Include DTB : Device Tree Blob DTC : Device Tree Compiler 2.1快速编译设备树---DTC (device tree

Linux的交叉编译 及configure配置

由 强颜欢笑 提交于 2020-01-04 09:50:22
这两天需要把一个CDVS的工程代码从Linux 平台上移植到ARM平台上，花了两天才搞定，之前很早申请的博客，到现在还没有技术文章会，以后决定凡是花两三天才搞定的东西都会把解决过程发到这里，很多东西靠百度什么的不太好使，必要的时候确实Google更好用。想想也是，在百度上搜，很多都是迄今为止中国程序员碰到过的问题，在Google上搜就是全世界程序员碰到过的问题。废话不多说了，切入正题。 由于原工程已经在PC-Linux上跑通，所以只需要修改configure的配置参数即可。这里我通过linux下的build.sh来对configure传入脚本。 下面试build.sh的脚本内容： 1 #!/bin/sh 2 # build the CDVS Test Model 3 # with full optimizations and multithreading: 4 CFLAGS="-march=armv7-a -O2 -DNDEBUG -fopenmp -pipe" 5 export PATH=$PATH:/usr/local/arm/arm-hik_v7a-linux-uclibcgnueabi/bin 6 # run configure with optimization flags and prepending "tm-" to all binaries (e.g. tm

Why error in cross compiling Arm Linux GCC?

由 ￡可爱￡侵袭症＋ 提交于 2020-01-04 05:55:06
问题 I'm trying to use AppWeb, and i wrote a very simple program to embed AppWeb into my application, it's using a function in AppWeb library. #include <appweb/appweb.h> int main(int argc, char** argv) { return maRunWebServer("appweb.conf"); } I dont know when I compile with gcc (or cc), it compiled successful. But, when I cross compile to Arm architecture, is have been getting error. This is my Makefile: CC = gcc LIBS = lib FLAG = -lappweb -lmpr TEST_TARGET = embed-appweb OBJS = embed-appweb all:

Including foreign shared library when running a binary with qemu

由 瘦欲@ 提交于 2020-01-04 03:55:06
问题 I have a foreign ARM binary I need to run with Qemu. It relies on an ncurses shared library, libncurses.so.5 . I've tried running qemu-arm -L /usr/arm-linux-gnueabihf/ ./program Which complains that it can't find libncurses.so.5 . I have the correct ncurses shared lib and added it to /usr/arm-linux-gnueabihf/lib/ . The filename is libncurses.so.5 and I have it symlinked to libncurses.so as well but running the program still fails. program: error while loading shared libraries: libncurses.so.5

timer_create() : -1 EAGAIN (Resource temporarily unavailable)

由 那年仲夏 提交于 2020-01-04 02:38:37
问题 I'm having trouble to create timer under my embedded Linux running ARM. I'm using a home made C++ library to manage timer. I didn't code it myself, I don't know deeply the implementation despite I have access to the source code... It works for a while and then I got the error "EAGAIN". Using strace I noticed that when it doesn't work the timer ID is quiet high! timer_create(CLOCK_MONOTONIC, {0, SIGRT_3, SIGEV_SIGNAL, {...}}, 0xbed50af4) = -1 EAGAIN (Resource temporarily unavailable) See the

Does using global variables increase or decrease performance, in C code compiled for ARM7?

由 爱⌒轻易说出口 提交于 2020-01-03 21:07:09
问题 Does using lots of global variables in C code decrease or increase performance, when compiled for an ARM7 embedded platform? The code base consists of multiple C source code files which refer each other's global variables using the extern keyword. Different functions from different source code files refer to different global variables. Some of the variables are arrays. The compiler I'm using is IAR's EW ARM kickstart edition (32kb). 回答1: This will always decrease performance and increase

program exits without error when linking boost library

由 二次信任 提交于 2020-01-03 19:08:14
问题 I have a problem with linking boost library into my cross-compiled c++ program. The code I write is cross-compiled with CodeSourcery under Ubuntu 12.04 for an arm-target (Pandaboard, also Ubuntu 12.04). Compiling simple test-programs without library works fine, even OpenCV with static libraries works fine. But here is the problem when linking boost 1.52.0 libraries: When crosscompiled WITH linking boost libraries (-lboost_thread -lboost_system) the program compiles without errors, but when

Segment Fault caused by using new or malloc on embedded device [closed]

由 僤鯓⒐⒋嵵緔 提交于 2020-01-03 19:04:00
问题 This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center. Closed 6 years ago . I am trying to build my application with C++ instead of C for my MIPS based embedded device . First, I had a link problem that you can see here. This
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