On Jul 7, 2016, at 6:36 AM, Gordo Cath <ds@y23.org> wrote:

Hi, I'd like to be able to set a register directly from my c code. I'm using the llvm compiler in a x86_64 build/run environment.

When I compile and link the following code I get no errors or warnings:

I used the thread_create_running function and during setup set the r11 register to 0xBEAD as a start state using x86_thread_state64_t .

///snippet---- at the very start of my thread I have the following tidbit of code: register uint64_t r11 asm("r11"); r11=0xfade; // some value -- don't care about the value, just want my value set. //end snippet

What, precisely, are you trying to do? As far as I know, that asm syntax is just wrong. I would expect to see something like this for x86_64: #include <stdio.h> #include <sys/types.h> int main() { int64_t r11; r11 = 0xc01ddeadbeef; /* init r11 */ asm ("movq %0, %%r11" :: "r"(r11) : "r11"); /* move r11 to %r11 */ r11 = 0; /* zero r11 */ asm ("movq %%r11, %0" : "=r"(r11) ::); /* move %r11 to r11 */ (void) printf("%llx\n", r11); /* verify %r11 */ return 0; } William Kucharski _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.... This email sent to site_archiver@lists.apple.com