arm64

I am curious about the feasibility of running old ARM32-Linux programs on AARCH64-Linux machines and I conducted some experiments: write a program "Hello, World!" and compile it statically with arm-none-linux-gnueabi-gcc and aarch64-linux-gnu-gcc. statically build and create a ramdisk using busybox and aarch64 compiler. put the 2 "Hello, World!" programs (in ARM32 and AARCH64) to the ramdisk. build a simple AARCH64-Linux kernel with vexpress_defconfig and aarch64 compiler. run the kernel and ramdisk using qemu-system-aarch64. (All binary files including busybox in the ramdisk are statically

Currently I'm developing some research-related programs and I need to find the pte of some specific addresses. My development environment is Juno r1 board (CPUs are A53 and A57 ) and it's running arm64 Linux kernel. I use some typical page table walk codes like this: int find_physical_pte(void *addr) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *ptep; unsigned long long address; address = (unsigned long long)addr; pgd = pgd_offset(current->mm, address); printk(KERN_INFO "\npgd is: %p\n", (void *)pgd); printk(KERN_INFO "pgd value: %llx\n", *pgd); if (pgd_none(*pgd) || pgd_bad(*pgd)) return -1;

On iOS, there are two similar functions, OSAtomicAdd32 and OSAtomicAdd32Barrier . I'm wondering when you would need the Barrier variant. Disassembled, they are: _OSAtomicAdd32: ldxr w8, [x1] add w8, w8, w0 stxr w9, w8, [x1] cbnz w9, _OSAtomicAdd32 mov x0, x8 ret lr _OSAtomicAdd32Barrier: ldaxr w8, [x1] add w8, w8, w0 stlxr w9, w8, [x1] cbnz w9, _OSAtomicAdd32Barrier mov x0, x8 ret lr In which scenarios would you need the Load-Acquire / Store-Release semantics of the latter? Can LDXR / STXR instructions be reordered? If they can, is it possible for an atomic update to be "lost" in the absence

I am trying to build my Xcode project, but I recieve the error displayed below. Please help me to solve this error, thank you in advance. duplicate symbol __non_lazy_classes in: /Applications/Xcode.app/Contents/Developer/Toolchains/OSX10.10.xctoolchain/usr/lib/arc/libarclite_iphoneos.a(arclite.o) /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/arc/libarclite_iphoneos.a(arclite.o) duplicate symbol _OBJC_METACLASS_$___ARCLite__ in: /Applications/Xcode.app/Contents/Developer/Toolchains/OSX10.10.xctoolchain/usr/lib/arc/libarclite_iphoneos.a(arclite.o)

I am trying to call a method that returns a double using NSInvocation . But I found that it does not working in 64 bit iOS apps. It works on on OS X, in the simulator -- both 32-bit and 64 bit -- iPad 2, and iPad Air with a 32-bit build. Only the 64-bit build on an iPad Air device has this problem. This is the code to demo the problem: NSMethodSignature *signature = [NSString instanceMethodSignatureForSelector:@selector(doubleValue)]; for (int i = 0; i < 10; i++) { NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:signature]; NSString *str = [NSString stringWithFormat:@"%d