#if defined(__aarch64__)
#include <stdint.h>

void exit(int8_t status){
  asm ( "mov x0, %0\n"        // Move the exit status into register x0
        "mov x8, #93\n"       // Syscall number for 'exit' is 93 in AArch64
        "svc #0\n"            // Make the syscall
        :                      // No output operands
        : "r" ((long)status)         // Input operand: status
        : "x0", "x8"           // Clobbered registers
  );
  for (;;);
}

intptr_t write(int32_t fd, const void* buf, intptr_t size){
  intptr_t n_written = 0;
  //register int32_t fd_w asm("w0") = fd;
  asm volatile( 
    // Assembly Instructions
    "mov x0, %1\n"  // Set x0 to value of fd
    "mov x1, %2\n"  // Set x1 to value of buf
    "mov x2, %3\n"  // Set x2 to value of size
    "mov x8, #64\n" // Syscall number for 'write' is 64 in AArch64
    "svc #0\n"      // Make syscall
    "mov %0, x0\n"  // Store return value in n_written
    // Output operands
    : "=r"(n_written)
    // Input operands
    : "r"((int64_t)fd), "r" (buf), "r"(size)
    // Clobbered registers
    : "x0", "x1", "x2", "x8"
  );
  return n_written;
}

#define CLONE_CHILD_SETTID   0x1000000
#define CLONE_CHILD_CLEARTID 0x200000
uint32_t fork(){
  long int rtn;
  long int flags = CLONE_CHILD_CLEARTID | CLONE_CHILD_SETTID;
  asm volatile (
    // Assembly Instructions
    "mov x8, #220\n"  // Syscall number for 'clone' is 220 in AArch64
    "mov x0, %1\n"    // clone flags
    "mov x1, #0\n"    // child stack pointer
    "mov x2, #0\n"    // parent_tidptr
    "mov x3, #0\n"    // tls
    "mov x4, #0\n"    // child_tidptr
    "svc #0\n"        // Make the syscall
    "mov %0, x0\n"    // save return value
    // Output operands
    : "=r" (rtn)
    // Input operand
    : "r" (flags)
    // Clobbered registers
    : "x0", "x1", "x2", "x3", "x4", "x8"
  );
  return (uint32_t)rtn;
}

#endif