From: Michael Tremer <michael.tremer@ipfire.org>
Date: Sat, 25 Jan 2025 15:12:06 +0000 (+0000)
Subject: os: Implement some custom CPU model detection for ARM
X-Git-Tag: 0.9.30~381
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=03bb4ba5c2c3b6a0b33c7856addbafc5546bb612;p=pakfire.git

os: Implement some custom CPU model detection for ARM

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/pakfire/os.c b/src/pakfire/os.c
index bbc111b1..e80fe184 100644
--- a/src/pakfire/os.c
+++ b/src/pakfire/os.c
@@ -30,6 +30,88 @@
 
 // CPU Info
 
+#ifdef __aarch64__
+/*
+ * On aarch64, /proc/cpuinfo is very stripped down and does not give us a lot
+ * of information about the CPU. This function tries to add some extra stuff.
+ */
+static int pakfire_cpuinfo_aarch64(struct pakfire_cpuinfo* cpuinfo) {
+	const char* vendor = NULL;
+	const char* model = NULL;
+	uint64_t midr = 0;
+	int r;
+
+	// Skip this if we already have a CPU vendor and model
+	if (*cpuinfo->vendor || *cpuinfo->model)
+		return 0;
+
+	// Read MIDR EL1
+	asm volatile("mrs %0, MIDR_EL1" : "=r"(midr));
+
+	// Decode the register
+	uint8_t implementer = (midr >> 24) & 0x0ff;
+	//uint8_t variant     = (midr >> 20) & 0x00f;
+	uint16_t partnum    = (midr >>  4) & 0xfff;
+	//uint8_t revision    = (midr >>  0) & 0x00f;
+
+	// Find vendors
+	switch (implementer) {
+		// ARM
+		case 0x41:
+			vendor = "ARM";
+
+			// Find models
+			switch (partnum) {
+				// Neoverse-N1
+				case 0xd0c:
+					model = "Neoverse-N1";
+					break;
+
+				// Neoverse-V1
+				case 0xd40:
+					model = "Neoverse-V1";
+					break;
+
+				// Neoverse-N2
+				case 0xd49:
+					model = "Neoverse-N2";
+					break;
+
+				// Neoverse-V2
+				case 0xd4f:
+					model = "Neoverse-V2";
+					break;
+
+				// Neoverse-V3
+				case 0xd84:
+					model = "Neoverse-V3";
+					break;
+
+				// Neoverse-N3
+				case 0xd8e:
+					model = "Neoverse-N3";
+					break;
+			}
+	}
+
+	// Store vendor (if found)
+	if (vendor) {
+		r = pakfire_string_set(cpuinfo->vendor, vendor);
+		if (r < 0)
+			return r;
+	}
+
+	// Store the model (if found)
+	if (model) {
+		r = pakfire_string_set(cpuinfo->model, model);
+		if (r < 0)
+			return r;
+	}
+
+	return 0;
+}
+#endif /* __aarch64__ */
+
 static int pakfire_parse_cpuinfo(char* line, size_t length, void* data) {
 	struct pakfire_cpuinfo* cpuinfo = data;
 	int r;
@@ -71,6 +153,13 @@ int pakfire_cpuinfo(struct pakfire_cpuinfo* cpuinfo) {
 	if (r)
 		return r;
 
+	// Run architecture-specific stuff
+#ifdef __aarch64__
+	r = pakfire_cpuinfo_aarch64(cpuinfo);
+	if (r)
+		return r;
+#endif /* __aarch64__ */
+
 	// Fetch the number of processors
 	cpuinfo->count = sysconf(_SC_NPROCESSORS_CONF);