Fix shell stream ownership and CPU frequency units

tools/build-riot-cpu-frequency-check.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+"""Build the frequency units and legacy ABI check against the prepared SDK."""
+import json
+from pathlib import Path
+import re
+import shlex
+import subprocess
+
+root = Path(__file__).resolve().parent.parent
+sdk = json.loads((root / 'build/config.json').read_text())['sdk']
+flags = {}
+resource = subprocess.check_output(['clang', '-print-resource-dir'], text=True).strip()
+for line in (root / 'build/darling-src/build/src/frameworks/CoreVideo/CMakeFiles/CoreVideo.dir/flags.make').read_text().splitlines():
+    if line.startswith('C_') and ' = ' in line:
+        key, value = line.split(' = ', 1)
+        flags[key] = [re.sub(r'/usr/lib/clang/\d+/include', resource + '/include', v) for v in shlex.split(value)]
+obj = root / 'build/riot-cpu-frequency-check.o'
+subprocess.run(['clang', *flags['C_DEFINES'], *flags['C_INCLUDES'], *flags['C_FLAGS'],
+                '-O2', '-c', str(root / 'tools/riot-cpu-frequency-check.c'), '-o', str(obj)], check=True)
+subprocess.run(['clang', '-target', 'x86_64-apple-macosx11.0', '-fuse-ld=lld', '-nostdlib',
+                '-isysroot', sdk, str(obj), '-lSystem', '-o', str(root / 'build/riot-cpu-frequency-check')], check=True)

tools/riot-cpu-frequency-check.c

@@ -0,0 +1,38 @@
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <sys/sysctl.h>
+
+int main(void) {
+    size_t length = 0;
+    if (sysctlbyname("hw.cpufrequency", NULL, &length, NULL, 0) || length != sizeof(uint64_t)) return 1;
+    const char *paths[] = {
+        "/Volumes/SystemRoot/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq",
+        "/Volumes/SystemRoot/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq",
+        "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq",
+        "/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq"
+    };
+    uint64_t expected = 0;
+    for (unsigned i=0; i<4; ++i) {
+        FILE* source = fopen(paths[i], "r");
+        unsigned long long khz = 0;
+        if (!source) continue;
+        int found = fscanf(source, "%llu", &khz); fclose(source);
+        if (found == 1 && khz > 0 && khz <= UINT64_MAX/1000) { expected = khz * 1000; break; }
+    }
+    uint64_t hz = 0;
+    length = sizeof(hz);
+    if (sysctlbyname("hw.cpufrequency", &hz, &length, NULL, 0)) {
+        if (errno != ENOENT || expected) return 2;
+        puts("CPU_FREQUENCY unavailable=1 invented_frequency=0 pass=1");
+        return 0;
+    }
+    if (length != 8 || hz < 1000000) return 3;
+    if (expected && hz != expected) return 4;
+    struct { uint32_t before, value, after; } legacy = {0x12345678,0,0x87654321};
+    int mib[] = {CTL_HW, HW_CPU_FREQ}; length = sizeof(legacy.value);
+    if (sysctl(mib, 2, &legacy.value, &length, NULL, 0) || length != 4 || legacy.value != (uint32_t)hz ||
+        legacy.before != 0x12345678 || legacy.after != 0x87654321) return 5;
+    printf("CPU_FREQUENCY hz=%llu width64=1 legacy_width32=1 pass=1\n", (unsigned long long)hz);
+    return 0;
+}