text: #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <setjmp.h>
  #include <signal.h>
  #include <crypto.h>
  
  #include "arm_arch.h"
  
  unsigned int OPENSSL_armcap_P = 0;
  
  #if __ARM_MAX_ARCH__<7
  void OPENSSL_cpuid_setup(void)
  {
  }
  
  unsigned long OPENSSL_rdtsc(void)
  {
      return 0;
  }
  #else
  static sigset_t all_masked;
  
  static sigjmp_buf ill_jmp;
  static void ill_handler(int sig)
  {
      siglongjmp(ill_jmp, sig);
  }
  
  /*
   * Following subroutines could have been inlined, but it's not all
   * ARM compilers support inline assembler...
   */
  void _armv7_neon_probe(void);
  void _armv8_aes_probe(void);
  void _armv8_sha1_probe(void);
  void _armv8_sha256_probe(void);
  void _armv8_pmull_probe(void);
  unsigned long _armv7_tick(void);
  
  unsigned long OPENSSL_rdtsc(void)
  {
      if (OPENSSL_armcap_P & ARMV7_TICK)
          return _armv7_tick();
      else
          return 0;
  }
  
  /*
   * Use a weak reference to getauxval() so we can use it if it is available but
   * don't break the build if it is not.
   */
  # if defined(__GNUC__) && __GNUC__>=2
  void OPENSSL_cpuid_setup(void) __attribute__ ((constructor));
  extern unsigned long getauxval(unsigned long type) __attribute__ ((weak));
  # else
  static unsigned long (*getauxval) (unsigned long) = NULL;
  # endif
  
  /*
   * ARM puts the the feature bits for Crypto Extensions in AT_HWCAP2, whereas
   * AArch64 used AT_HWCAP.
   */
  # if defined(__arm__) || defined (__arm)
  #  define HWCAP                  16
                                    /* AT_HWCAP */
  #  define HWCAP_NEON             (1 << 12)
  
  #  define HWCAP_CE               26
                                    /* AT_HWCAP2 */
  #  define HWCAP_CE_AES           (1 << 0)
  #  define HWCAP_CE_PMULL         (1 << 1)
  #  define HWCAP_CE_SHA1          (1 << 2)
  #  define HWCAP_CE_SHA256        (1 << 3)
  # elif defined(__aarch64__)
  #  define HWCAP                  16
                                    /* AT_HWCAP */
  #  define HWCAP_NEON             (1 << 1)
  
  #  define HWCAP_CE               HWCAP
  #  define HWCAP_CE_AES           (1 << 3)
  #  define HWCAP_CE_PMULL         (1 << 4)
  #  define HWCAP_CE_SHA1          (1 << 5)
  #  define HWCAP_CE_SHA256        (1 << 6)
  # endif
  
  void OPENSSL_cpuid_setup(void)
  {
      char *e;
      struct sigaction ill_oact, ill_act;
      sigset_t oset;
      static int trigger = 0;
  
      if (trigger)
          return;
      trigger = 1;
  
      if ((e = getenv("OPENSSL_armcap"))) {
          OPENSSL_armcap_P = (unsigned int)strtoul(e, NULL, 0);
          return;
      }
  
      sigfillset(&all_masked);
      sigdelset(&all_masked, SIGILL);
      sigdelset(&all_masked, SIGTRAP);
      sigdelset(&all_masked, SIGFPE);
      sigdelset(&all_masked, SIGBUS);
      sigdelset(&all_masked, SIGSEGV);
  
      OPENSSL_armcap_P = 0;
  
      memset(&ill_act, 0, sizeof(ill_act));
      ill_act.sa_handler = ill_handler;
      ill_act.sa_mask = all_masked;
  
      sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
      sigaction(SIGILL, &ill_act, &ill_oact);
  
      if (getauxval != NULL) {
          if (getauxval(HWCAP) & HWCAP_NEON) {
              unsigned long hwcap = getauxval(HWCAP_CE);
  
              OPENSSL_armcap_P |= ARMV7_NEON;
  
              if (hwcap & HWCAP_CE_AES)
                  OPENSSL_armcap_P |= ARMV8_AES;
  
              if (hwcap & HWCAP_CE_PMULL)
                  OPENSSL_armcap_P |= ARMV8_PMULL;
  
              if (hwcap & HWCAP_CE_SHA1)
                  OPENSSL_armcap_P |= ARMV8_SHA1;
  
              if (hwcap & HWCAP_CE_SHA256)
                  OPENSSL_armcap_P |= ARMV8_SHA256;
          }
      } else if (sigsetjmp(ill_jmp, 1) == 0) {
          _armv7_neon_probe();
          OPENSSL_armcap_P |= ARMV7_NEON;
          if (sigsetjmp(ill_jmp, 1) == 0) {
              _armv8_pmull_probe();
              OPENSSL_armcap_P |= ARMV8_PMULL | ARMV8_AES;
          } else if (sigsetjmp(ill_jmp, 1) == 0) {
              _armv8_aes_probe();
              OPENSSL_armcap_P |= ARMV8_AES;
          }
          if (sigsetjmp(ill_jmp, 1) == 0) {
              _armv8_sha1_probe();
              OPENSSL_armcap_P |= ARMV8_SHA1;
          }
          if (sigsetjmp(ill_jmp, 1) == 0) {
              _armv8_sha256_probe();
              OPENSSL_armcap_P |= ARMV8_SHA256;
          }
      }
      if (sigsetjmp(ill_jmp, 1) == 0) {
          _armv7_tick();
          OPENSSL_armcap_P |= ARMV7_TICK;
      }
  
      sigaction(SIGILL, &ill_oact, NULL);
      sigprocmask(SIG_SETMASK, &oset, NULL);
  }
  #endif
  