tests: arm64: Add comprehensive ARM architecture feature detection test

Nicolas Pitre · Nicolas Pitre · commit 924b9f42df91 · 2025-10-06T15:21:37.000-04:00
Add comprehensive test to validate ARM64 architectural feature detection
across ARMv8.1 through ARMv9-A implementations, providing runtime
verification of processor capabilities and security features.

Core architecture features tested:
- Exception Level (EL) support detection (EL0-EL3)
- SVE (Scalable Vector Extension) presence and capabilities
- Advanced SIMD (NEON) and Floating Point implementation levels
- Architecture version classification (ARMv8 vs ARMv9-A)

ARMv8.1-A+ features:
- LSE (Large System Extensions) atomic operations with level detection
- Pointer Authentication (PAC) with comprehensive variant analysis:
  * API/APA (Address), GPI/GPA (Generic) authentication
  * Enhanced PAC levels (1, 3, 4, 5) with FPACCOMBINE detection
  * QARMA3 algorithm support (GPA3/APA3)

ARMv8.5-A+ security and performance features:
- Branch Target Identification (BTI) for control flow integrity
- Memory Tagging Extensions (MTE) with level classification
- Random Number Generation (RNDR) hardware entropy
- Speculative Store Bypass Safe (SSBS) side-channel mitigation

ARMv8.7-A+ advanced features:
- WFxT (Wait with Timeout) enhanced synchronization
- RPRES (Reciprocal Precision) optimized math operations

ARMv8.8-A+ features:
- MOPS (Memory Copy/Set) optimized memory operations
- BC (Branch Consistency) advanced branch handling

Signed-off-by: Nicolas Pitre &lt;npitre@baylibre.com&gt;
diff --git a/include/zephyr/arch/arm64/cpu.h b/include/zephyr/arch/arm64/cpu.h
@@ -113,6 +113,12 @@
 #define ID_AA64PFR0_EL2_SHIFT	(8)
 #define ID_AA64PFR0_EL3_SHIFT	(12)
 #define ID_AA64PFR0_ELX_MASK	(0xf)
+#define ID_AA64PFR0_FP_SHIFT	(16)
+#define ID_AA64PFR0_FP_MASK	(0xf)
+#define ID_AA64PFR0_ADVSIMD_SHIFT	(20)
+#define ID_AA64PFR0_ADVSIMD_MASK	(0xf)
+#define ID_AA64PFR0_SVE_SHIFT	(32)
+#define ID_AA64PFR0_SVE_MASK	(0xf)
 #define ID_AA64PFR0_SEL2_SHIFT	(36)
 #define ID_AA64PFR0_SEL2_MASK	(0xf)
 
diff --git a/include/zephyr/arch/arm64/lib_helpers.h b/include/zephyr/arch/arm64/lib_helpers.h
@@ -69,7 +69,11 @@ MAKE_REG_HELPER(csselr_el1);
 MAKE_REG_HELPER(daif)
 MAKE_REG_HELPER(hcr_el2);
 MAKE_REG_HELPER(id_aa64pfr0_el1);
+MAKE_REG_HELPER(id_aa64pfr1_el1);
 MAKE_REG_HELPER(id_aa64mmfr0_el1);
+MAKE_REG_HELPER(id_aa64isar0_el1);
+MAKE_REG_HELPER(id_aa64isar1_el1);
+MAKE_REG_HELPER(id_aa64isar2_el1);
 MAKE_REG_HELPER(mpidr_el1);
 MAKE_REG_HELPER(par_el1);
 #if !defined(CONFIG_ARMV8_R)
@@ -199,6 +203,11 @@ static inline bool is_in_secure_state(void)
 	return !IS_ENABLED(CONFIG_ARMV8_A_NS);
 }
 
+static inline bool is_sve_implemented(void)
+{
+	return (((read_id_aa64pfr0_el1() >> ID_AA64PFR0_SVE_SHIFT) & ID_AA64PFR0_SVE_MASK) != 0U);
+}
+
 #endif /* !_ASMLANGUAGE */
 
 #endif /* ZEPHYR_INCLUDE_ARCH_ARM64_LIB_HELPERS_H_ */
diff --git a/tests/arch/arm64/arm64_isa_features/CMakeLists.txt b/tests/arch/arm64/arm64_isa_features/CMakeLists.txt
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(arm64_isa_features)
+
+target_sources(app PRIVATE src/main.c)
diff --git a/tests/arch/arm64/arm64_isa_features/prj.conf b/tests/arch/arm64/arm64_isa_features/prj.conf
@@ -0,0 +1,2 @@
+CONFIG_ZTEST=y
+CONFIG_OUTPUT_DISASSEMBLY=y
diff --git a/tests/arch/arm64/arm64_isa_features/src/main.c b/tests/arch/arm64/arm64_isa_features/src/main.c
@@ -0,0 +1,229 @@
+/*
+ * Copyright (c) 2025 BayLibre SAS
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/ztest.h>
+#include <zephyr/arch/arm64/lib_helpers.h>
+#include <stdint.h>
+
+ZTEST_SUITE(arm64_isa_features, NULL, NULL, NULL, NULL, NULL);
+
+ZTEST(arm64_isa_features, test_arm64_feature_detection)
+{
+	uint64_t pfr0 = read_id_aa64pfr0_el1();
+	uint64_t current_el = read_currentel();
+	uint64_t mmfr0 = read_id_aa64mmfr0_el1();
+
+	TC_PRINT("=== ARM64 ISA Feature Detection ===\n");
+	TC_PRINT("ID_AA64PFR0_EL1:  0x%016llx\n", pfr0);
+	TC_PRINT("ID_AA64MMFR0_EL1: 0x%016llx\n", mmfr0);
+
+	/* Check for ARMv9-A specific features */
+	TC_PRINT("\n=== Feature Analysis ===\n");
+
+	/* SVE support (Scalable Vector Extension) */
+	bool sve = is_sve_implemented();
+
+	TC_PRINT("SVE support: %s\n", sve ? "YES" : "NO");
+
+	/* Current Exception Level */
+	TC_PRINT("Current EL: EL%llu\n", GET_EL(current_el));
+
+	/* Check EL support */
+	TC_PRINT("EL0 AArch64: %s\n", is_el_implemented(0) ? "YES" : "NO");
+	TC_PRINT("EL1 AArch64: %s\n", is_el_implemented(1) ? "YES" : "NO");
+	TC_PRINT("EL2 AArch64: %s\n", is_el_implemented(2) ? "YES" : "NO");
+	TC_PRINT("EL3 AArch64: %s\n", is_el_implemented(3) ? "YES" : "NO");
+
+	/* Advanced SIMD (NEON) */
+	uint64_t advsimd = (pfr0 >> ID_AA64PFR0_ADVSIMD_SHIFT) & ID_AA64PFR0_ADVSIMD_MASK;
+
+	TC_PRINT("Advanced SIMD (NEON): %s (0x%llx)\n",
+		 (advsimd == 0) ? "YES" : (advsimd == 0xf) ? "NO" : "PARTIAL", advsimd);
+
+	/* Floating Point */
+	uint64_t fp = (pfr0 >> ID_AA64PFR0_FP_SHIFT) & ID_AA64PFR0_FP_MASK;
+
+	TC_PRINT("Floating Point: %s (0x%llx)\n",
+		 (fp == 0) ? "YES" : (fp == 0xf) ? "NO" : "PARTIAL", fp);
+
+	/* Check for additional ARMv8.5-A+ and ARMv9-A indicators */
+	uint64_t pfr1 = read_id_aa64pfr1_el1();
+	uint64_t isar0 = read_id_aa64isar0_el1();
+	uint64_t isar1 = read_id_aa64isar1_el1();
+	uint64_t isar2 = read_id_aa64isar2_el1();
+
+	TC_PRINT("\nID_AA64PFR1_EL1:  0x%016llx\n", pfr1);
+	TC_PRINT("ID_AA64ISAR0_EL1: 0x%016llx\n", isar0);
+	TC_PRINT("ID_AA64ISAR1_EL1: 0x%016llx\n", isar1);
+	TC_PRINT("ID_AA64ISAR2_EL1: 0x%016llx\n", isar2);
+
+	/* Check for ARMv8.1 LSE atomics */
+	uint64_t lse = (isar0 >> 20) & 0xf;
+
+	TC_PRINT("LSE Atomics: %s (0x%llx)\n", lse ? "YES" : "NO", lse);
+
+	/* Check for Pointer Authentication */
+	uint64_t pauth_api = (isar1 >> 4) & 0xf;
+	uint64_t pauth_apa = (isar1 >> 8) & 0xf;
+	uint64_t pauth_gpi = (isar1 >> 28) & 0xf;
+	uint64_t pauth_gpa = (isar1 >> 24) & 0xf;
+
+	TC_PRINT("Pointer Auth (API - Address ImplDef): %s (0x%llx)\n",
+		 pauth_api ? "YES" : "NO", pauth_api);
+	TC_PRINT("Pointer Auth (APA - Address Arch): %s (0x%llx)\n",
+		 pauth_apa ? "YES" : "NO", pauth_apa);
+	TC_PRINT("Pointer Auth (GPI - Instr ImplDef): %s (0x%llx)\n",
+		 pauth_gpi ? "YES" : "NO", pauth_gpi);
+	TC_PRINT("Pointer Auth (GPA - Instr Arch): %s (0x%llx)\n",
+		 pauth_gpa ? "YES" : "NO", pauth_gpa);
+
+	/* Decode APA level */
+	if (pauth_apa == 0x5) {
+		TC_PRINT("  APA Level 5: Enhanced PAC with FPACCOMBINE\n");
+	} else if (pauth_apa == 0x4) {
+		TC_PRINT("  APA Level 4: Enhanced PAC with FPAC\n");
+	} else if (pauth_apa == 0x3) {
+		TC_PRINT("  APA Level 3: Enhanced PAC2\n");
+	} else if (pauth_apa == 0x1) {
+		TC_PRINT("  APA Level 1: Basic PAC\n");
+	}
+
+	/* Check for Branch Target Identification (ARMv8.5-A) */
+	uint64_t bti = (pfr1 >> 0) & 0xf;
+
+	TC_PRINT("Branch Target Identification (BTI): %s (0x%llx)\n", bti ? "YES" : "NO", bti);
+
+	/* Check for Memory Tagging Extensions (ARMv8.5-A) */
+	uint64_t mte = (pfr1 >> 8) & 0xf;
+
+	TC_PRINT("Memory Tagging Extension (MTE): %s (0x%llx)\n", mte ? "YES" : "NO", mte);
+	if (mte == 0x2) {
+		TC_PRINT("  MTE Level 2: Full MTE\n");
+	} else if (mte == 0x1) {
+		TC_PRINT("  MTE Level 1: EL0-only\n");
+	}
+
+	/* Check for Random Number Generation (ARMv8.5-A) */
+	uint64_t rndr = (pfr1 >> 16) & 0xf;
+
+	TC_PRINT("Random Number Generation (RNDR): %s (0x%llx)\n", rndr ? "YES" : "NO", rndr);
+
+	/* Check for Speculative Store Bypass Safe (ARMv8.5-A) */
+	uint64_t ssbs = (pfr1 >> 12) & 0xf;
+
+	TC_PRINT("Speculative Store Bypass Safe (SSBS): %s (0x%llx)\n", ssbs ? "YES" : "NO", ssbs);
+
+	/* Check for additional ISAR2 features */
+	/* WFxT - Wait For Event/Interrupt with Timeout (ARMv8.7-A) */
+	uint64_t wfxt = (isar2 >> 0) & 0xf;
+
+	TC_PRINT("WFxT (Wait with Timeout): %s (0x%llx)\n", wfxt ? "YES" : "NO", wfxt);
+
+	/* RPRES - Reciprocal Estimate and Reciprocal Square Root Estimate */
+	uint64_t rpres = (isar2 >> 4) & 0xf;
+
+	TC_PRINT("RPRES (Reciprocal Precision): %s (0x%llx)\n", rpres ? "YES" : "NO", rpres);
+
+	/* GPA3 - Generic Pointer Authentication using QARMA3 */
+	uint64_t gpa3 = (isar2 >> 8) & 0xf;
+
+	TC_PRINT("Pointer Auth (GPA3 - QARMA3): %s (0x%llx)\n", gpa3 ? "YES" : "NO", gpa3);
+
+	/* APA3 - Address Pointer Authentication using QARMA3 */
+	uint64_t apa3 = (isar2 >> 12) & 0xf;
+
+	TC_PRINT("Pointer Auth (APA3 - QARMA3): %s (0x%llx)\n", apa3 ? "YES" : "NO", apa3);
+
+	/* MOPS - Memory Copy and Memory Set instructions (ARMv8.8-A) */
+	uint64_t mops = (isar2 >> 16) & 0xf;
+
+	TC_PRINT("MOPS (Memory Copy/Set): %s (0x%llx)\n", mops ? "YES" : "NO", mops);
+
+	/* BC - BC (Branch Consistency) model */
+	uint64_t bc = (isar2 >> 20) & 0xf;
+
+	TC_PRINT("BC (Branch Consistency): %s (0x%llx)\n", bc ? "YES" : "NO", bc);
+
+	TC_PRINT("\n=== Architecture Assessment ===\n");
+	if (sve) {
+		TC_PRINT("Architecture: ARMv9-A (SVE detected)\n");
+		if (bti || mte || rndr) {
+			TC_PRINT("ARMv8.5-A+ features: ");
+			if (bti) {
+				TC_PRINT("BTI ");
+			}
+			if (mte) {
+				TC_PRINT("MTE ");
+			}
+			if (rndr) {
+				TC_PRINT("RNDR ");
+			}
+			if (ssbs) {
+				TC_PRINT("SSBS ");
+			}
+			TC_PRINT("\n");
+		}
+		if (wfxt || mops || gpa3 || apa3) {
+			TC_PRINT("ARMv8.7-A+ features: ");
+			if (wfxt) {
+				TC_PRINT("WFxT ");
+			}
+			if (mops) {
+				TC_PRINT("MOPS ");
+			}
+			if (gpa3) {
+				TC_PRINT("GPA3 ");
+			}
+			if (apa3) {
+				TC_PRINT("APA3 ");
+			}
+			TC_PRINT("\n");
+		}
+	} else if (bti || mte || rndr || ssbs) {
+		TC_PRINT("Architecture: ARMv8.5-A+ (BTI/MTE/RNDR detected)\n");
+	} else if (lse >= 2 && (pauth_api || pauth_apa)) {
+		TC_PRINT("Architecture: ARMv8.1+ with enhanced features (LSE Level 2+ and PAC)\n");
+	} else if (lse || pauth_api || pauth_apa) {
+		TC_PRINT("Architecture: ARMv8.1+ with ARMv9-A features (LSE/PAC)\n");
+	} else {
+		TC_PRINT("Architecture: ARMv8-A (no ARMv8.1+ features detected)\n");
+	}
+
+	/* Decode LSE level */
+	if (lse >= 2) {
+		TC_PRINT("LSE Level 2: Atomics with enhanced ordering\n");
+	} else if (lse == 1) {
+		TC_PRINT("LSE Level 1: Basic atomic instructions\n");
+	}
+
+	/* Basic validation that we can read system registers */
+	zassert_not_equal(pfr0, 0, "ID_AA64PFR0_EL1 should not be zero");
+	zassert_not_equal(current_el, 0, "CurrentEL should not be zero");
+
+	/* We should be running in EL1 */
+	zassert_equal(GET_EL(current_el), 1, "Should be running in EL1");
+
+	/* ARMv9-A configuration validation */
+	if (IS_ENABLED(CONFIG_ARMV9_A)) {
+		/* ARMv9-A mandates SVE support */
+		zassert_true(sve, "CONFIG_ARMV9_A enabled but no SVE detected");
+
+		/* ARMv9-A should have enhanced security features */
+		zassert_true(pauth_api || pauth_apa,
+			     "CONFIG_ARMV9_A enabled but no Pointer Authentication detected");
+
+		/* If PAC is present, validate it's enhanced (Level 3+) */
+		if (pauth_apa) {
+			zassert_true(pauth_apa >= 3,
+				     "CONFIG_ARMV9_A enabled but PAC level too low (0x%llx) - "
+				     "expected enhanced PAC (Level 3+)", pauth_apa);
+		}
+
+		/* ARMv9-A platforms should support modern atomic operations */
+		zassert_true(lse >= 1,
+			     "CONFIG_ARMV9_A enabled but no LSE atomics detected");
+	}
+}
diff --git a/tests/arch/arm64/arm64_isa_features/testcase.yaml b/tests/arch/arm64/arm64_isa_features/testcase.yaml
@@ -0,0 +1,8 @@
+common:
+  arch_allow: arm64
+  tags: arm64
+
+tests:
+  arch.arm64.isa_features:
+    integration_platforms:
+      - fvp_base_revc_2xaem/v9a

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+CONFIG_ZTEST=y`
	`2`	`+CONFIG_OUTPUT_DISASSEMBLY=y`