arm | 易学教程

How clear and invalidate ARM v7 processor cache from User Mode on Linux 2.6.35

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问题 I tried clear and invalidate ARM v7 processor cache for instruction line, because instruction codes can change in execution. For reaching the effect, I tried 2 variants. Here they are: I used GCC __clear_cache() function but it didn't give a required result. Instruction codes in cache didn't change. I looked for a source codes for GCC and found the uclinux-eabi.h file where I found the next code for clearing cache: /* Clear the instruction cache from `beg' to `end'. This makes an inline

Windows Phone 7 and native C++/CLI

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问题 Microsoft recently released tools and documentation for its new Phone 7 platform, which to the dismay of those who have a big C++ codebase (like me) doesn't support native development anymore. Although I've found speculation about this decision being reversed, I doubt it. So I was thinking how viable would be to make this codebase available to Phone 7 by adapting it to compile under C++/CLI. Of course the user interface parts couldn't be ported, but I'm not sure about the rest. Anyone had a

How does native android code written for ARM run on x86?

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问题 Motorola just released an x86 based Android phone. I'm a little confused as to how native apps/libraries written for ARM(netflix for example) can run on this phone. I'd be grateful if someone could explain. 回答1: Yes, ARM native code runs on Intel x86 using an emulation feature named Houdini What this library does is reads ARM instructions on the fly and converts them to equivalent x86 instructions. This is the reason why many apps may work as is on x86 without actually having to build an

How to force IAR to use desired Cortex-M0+ instructions (optimization will be disabled for this func.)

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问题 I need to force IAR tp use certain Cortex-M0+ instruction in some part of my code while codding with C. Please do not offer pure asm functions or inline asm etc. I have managed to do this for 51 instruction but could not for ; ADR, BLX, RSBS, SBCS, SXTH instructions. Optimization is disabled for this function (#pragma optimization=none) I have tried many things by considering instruction behaviour. But IAR preferred to same function with different instructions. Did anyone else struggle with

How to force IAR to use desired Cortex-M0+ instructions (optimization will be disabled for this func.)

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Docker支持多架构

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Docker支持多架构注：要求19.03以上版本（以下的不支持，Ubuntu 18.04的docker默认版本为19.03）创建支持多架构的docker image （加buildx命令） export DOCKER_CLI_EXPERIMENTAL=enabled （作用是启用buildx） docker run --rm --privileged docker/binfmt:820fdd95a9972a5308930a2bdfb8573dd4447ad3 （注册ARM架构） cat /proc/sys/fs/binfmt_misc/qemu-aarch64 （确保enabled） docker buildx create --driver docker-container --use docker buildx inspect --bootstrap docker buildx ls （此时会多出来arm、arm64、ppc64le等） docker buildx build --platform linux/arm/v7,local --load -t ming:1.0 . 来源： 51CTO 作者： yangzhimingg 链接： https://blog.51cto.com/yangzhiming/2459368

NVIC_SystemReset() stuck in while loop (STM32F302VB)

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问题 I'm currently developing on a STM32F302VB and I need to perform a software reset. On all my previous projects (with STM32F427 and STM32F030C8), I've always used the NVIC_SystemReset() function successfully. But for some reason it won't work with this chip. The implementation is in CMSIS core_cm4.h and is as follows: __STATIC_INLINE void NVIC_SystemReset(void) { __DSB(); /* Ensure all outstanding memory accesses included buffered write are completed before reset */ SCB->AIRCR = ((0x5FA << SCB

Synchronous external abort on translation table walk

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问题 Can someone explain what would be the reason of this abort. I could not find an explanation in the manual. Basically I am getting this error in the IFSC code - Synchronous external abort on translation table walk. The IFSC are bits in the HSR register which is used with an ARMv7A using the virtualization extensions. 回答1: The IFSC is basically a virtualization version of the IFSR . IFSC code - Synchronous external abort on translation table walk. This means that the CPU had difficulty

How do I use ARM NEON intrinsics?

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问题 Basically I'm developing for an iPhone and I compile fine on the Mac, however I want to use NEON intrinsics to accelerate my vector math. I have experience with SSE and AVX, however I have no idea where to get the NEON header with the intrinsics from. I found only one on the net and it only worked for GCC, all the functions had some __builtin keywords behind them. I'm compiling on the xcode llvm 5.0 compiler. I know I can use ARM assembly, however I'd like to use the intrinsic functions

How do I use ARM NEON intrinsics?

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