arm

问题 The linux system has arm64 having arm architecture armv8-a. How to know whether debian is running hard float or soft float? 回答1: In compliance with AAPCS64, GNU GCC for armv8 only provides the hard float aarch64 toolchain . This is unlike GCC for armv7-a, which provides arm-linux-gnueabi soft float toolchain and arm-linux-gnueabihf hard float toolchain. 来源： https://stackoverflow.com/questions/61114429/aarch64-linux-hard-float-or-soft-float

问题 I read document like this TrustZone Security Whitepaper. It describles that all resources like CPU, memory and others are divided by Secure World and Normal World . Programs in Normal World can not access resources in Secure World. You must call a special instrustion SMC to switch from Normal to Secure world (go through Monitor Mode). As I know, modern OS like Linux provides Kernel Mode and User Mode . User processes can not access resources located in kernel space, but invoke system calls. I

问题 I am constantly getting this warning while building my android studio code using terminal command gradle clean assembleRelease : Unable to strip library 'lib.so' due to missing strip tool for ABI 'ARMEABI'. Packaging it as is. Please help me on how to get this warning resolved. Note: I know this won't affect the behaviour of my app, but my APK is too bulky and this will surely help me reduce APK size. So I need this resolved. 回答1: The default installed NDK doesn't seem to have the tools

问题 I am trying to print a number that I have stored. I'm not sure if I am close or way off. Any help would be appreciated though. Here is my code: .data .balign 4 a: .word 4 .text .global main main: ldr r0, addr_of_a mov r1, #8 str r1, [r0] write: mov r0, #1 ldr r1, addr_of_a mov r2, #4 mov r7, #4 swi #0 bx lr addr_of_a: .word a It compiles and runs, but I don't see anything printed. From what I understand, I need the address of where to start printing in r1, how many bytes in r2, the file

问题 Under Ubuntu 64 bit I got llc --version LLVM (http://llvm.org/): LLVM version 3.1 Optimized build with assertions. Built Oct 15 2012 (18:15:59). Default target: x86_64-pc-linux-gnu Host CPU: btver1 Registered Targets: arm - ARM mips - Mips mips64 - Mips64 [experimental] mips64el - Mips64el [experimental] mipsel - Mipsel thumb - Thumb x86 - 32-bit X86: Pentium-Pro and above x86-64 - 64-bit X86: EM64T and AMD64 I can't do this clang -march=arm -x c++ /tmp/cpp.cpp error: unknown target CPU 'arm'

问题 Under Ubuntu 64 bit I got llc --version LLVM (http://llvm.org/): LLVM version 3.1 Optimized build with assertions. Built Oct 15 2012 (18:15:59). Default target: x86_64-pc-linux-gnu Host CPU: btver1 Registered Targets: arm - ARM mips - Mips mips64 - Mips64 [experimental] mips64el - Mips64el [experimental] mipsel - Mipsel thumb - Thumb x86 - 32-bit X86: Pentium-Pro and above x86-64 - 64-bit X86: EM64T and AMD64 I can't do this clang -march=arm -x c++ /tmp/cpp.cpp error: unknown target CPU 'arm'

问题 Command: I am trying to cross compile a simple C++ program using clang++. I'm using Linaro gcc tool-chain to obtain the library and other includes required. ${root}/bin/clang++ --target=arm-linux-gnueabihf --rtlib=compiler-rt --stdlib=libc++ -nostdinc++ -I${root}/include/c++/v1 -Wl,-L${root}/lib --sysroot ${sysroot} --gcc-toolchain=/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf -rpath ${root}/lib TestCodeX86toARM.cpp -o Test -v The value of root and sysroot is as

问题 I am very confused with Memory Map and Memory mapped I/O. Do general purpose registers for example in ARM Architecture r0, r1, and etc are generally memory mapped? Please help. 回答1: No, those registers are inside the actual CPU (or CPU core for multi-core CPUs). You can not access them through memory. A memory-mapped register is something which you access through an address or a pointer (in languages that has pointers). I/O devices often have memory-mapped registers, where you write to or

问题 I am very confused with Memory Map and Memory mapped I/O. Do general purpose registers for example in ARM Architecture r0, r1, and etc are generally memory mapped? Please help. 回答1: No, those registers are inside the actual CPU (or CPU core for multi-core CPUs). You can not access them through memory. A memory-mapped register is something which you access through an address or a pointer (in languages that has pointers). I/O devices often have memory-mapped registers, where you write to or

问题 I am very confused with Memory Map and Memory mapped I/O. Do general purpose registers for example in ARM Architecture r0, r1, and etc are generally memory mapped? Please help. 回答1: No, those registers are inside the actual CPU (or CPU core for multi-core CPUs). You can not access them through memory. A memory-mapped register is something which you access through an address or a pointer (in languages that has pointers). I/O devices often have memory-mapped registers, where you write to or