From 590d5e9ef9f73e8eaac3093bac3ca1004aeb44d9 Mon Sep 17 00:00:00 2001
From: Imran Hameed <imhameed@microsoft.com>
Date: Thu, 24 Jun 2021 11:40:31 -0400
Subject: [PATCH] ??????????????

---
 src/mono/mono/mini/driver.c | 61 +++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/src/mono/mono/mini/driver.c b/src/mono/mono/mini/driver.c
index 4c694d5d0c558..92d8adc2015a3 100644
--- a/src/mono/mono/mini/driver.c
+++ b/src/mono/mono/mini/driver.c
@@ -11,6 +11,58 @@
  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
  */
 
+#if defined(__linux__)
+#include <sys/auxv.h>
+
+#define ARM64_HWCAPS(_) \
+	_(ARM64_HWCAP_FP, (1 << 0)) \
+	_(ARM64_HWCAP_ASIMD, (1 << 1)) \
+	_(ARM64_HWCAP_EVTSTRM, (1 << 2)) \
+	_(ARM64_HWCAP_AES, (1 << 3)) \
+	_(ARM64_HWCAP_PMULL, (1 << 4)) \
+	_(ARM64_HWCAP_SHA1, (1 << 5)) \
+	_(ARM64_HWCAP_SHA2, (1 << 6)) \
+	_(ARM64_HWCAP_CRC32, (1 << 7)) \
+	_(ARM64_HWCAP_ATOMICS, (1 << 8)) \
+	_(ARM64_HWCAP_FPHP, (1 << 9)) \
+	_(ARM64_HWCAP_ASIMDHP, (1 << 10)) \
+	_(ARM64_HWCAP_CPUID, (1 << 11)) \
+	_(ARM64_HWCAP_ASIMDRDM, (1 << 12)) \
+	_(ARM64_HWCAP_JSCVT, (1 << 13)) \
+	_(ARM64_HWCAP_FCMA, (1 << 14)) \
+	_(ARM64_HWCAP_LRCPC, (1 << 15)) \
+	_(ARM64_HWCAP_DCPOP, (1 << 16)) \
+	_(ARM64_HWCAP_SHA3, (1 << 17)) \
+	_(ARM64_HWCAP_SM3, (1 << 18)) \
+	_(ARM64_HWCAP_SM4, (1 << 19)) \
+	_(ARM64_HWCAP_ASIMDDP, (1 << 20)) \
+	_(ARM64_HWCAP_SHA512, (1 << 21)) \
+	_(ARM64_HWCAP_SVE, (1 << 22)) \
+	_(ARM64_HWCAP_ASIMDFHM, (1 << 23)) \
+	_(ARM64_HWCAP_DIT, (1 << 24)) \
+	_(ARM64_HWCAP_USCAT, (1 << 25)) \
+	_(ARM64_HWCAP_ILRCPC, (1 << 26)) \
+	_(ARM64_HWCAP_FLAGM, (1 << 27)) \
+	_(ARM64_HWCAP_SSBS, (1 << 28))
+
+struct uintstrpair {
+	unsigned int f;
+	const char *s;
+};
+
+enum {
+	#define expand_as_case(name, val) name = val,
+	ARM64_HWCAPS(expand_as_case)
+	#undef expand_as_case
+};
+
+static const struct uintstrpair arm64_hwcap_arr[] = {
+	#define expand_as_str(name, _) { name, #name },
+	ARM64_HWCAPS(expand_as_str)
+	#undef expand_as_str
+};
+#endif
+
 #include <config.h>
 #include <signal.h>
 #if HAVE_SCHED_SETAFFINITY
@@ -2063,6 +2115,15 @@ print_icall_table (void)
 int
 mono_main (int argc, char* argv[])
 {
+	#if defined(__linux__) && defined(__aarch64__)
+	{
+		unsigned long hwcap = getauxval(AT_HWCAP);
+		for (int i = 0; i < (sizeof (arm64_hwcap_arr) / sizeof (arm64_hwcap_arr [0])); ++i) {
+			struct uintstrpair p = arm64_hwcap_arr [i];
+			printf ("arm64 hwcap: %s available: %s\n", p.s, hwcap & p.f ? "yes" : "no");
+		}
+	}
+	#endif
 	MainThreadArgs main_args;
 	MonoAssembly *assembly;
 	MonoMethodDesc *desc;