From 404aeae4545d2426c089a5f8d5e82dae56f5212b Mon Sep 17 00:00:00 2001
From: Rutger Broekhoff
Date: Fri, 29 Dec 2023 21:31:53 +0100
Subject: Make Nix builds work

---
 vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go | 111 +++++++++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go

(limited to 'vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go')

diff --git a/vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go b/vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go
new file mode 100644
index 0000000..a968b80
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go
@@ -0,0 +1,111 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpu
+
+import (
+	"strings"
+	"syscall"
+)
+
+// HWCAP/HWCAP2 bits. These are exposed by Linux.
+const (
+	hwcap_FP       = 1 << 0
+	hwcap_ASIMD    = 1 << 1
+	hwcap_EVTSTRM  = 1 << 2
+	hwcap_AES      = 1 << 3
+	hwcap_PMULL    = 1 << 4
+	hwcap_SHA1     = 1 << 5
+	hwcap_SHA2     = 1 << 6
+	hwcap_CRC32    = 1 << 7
+	hwcap_ATOMICS  = 1 << 8
+	hwcap_FPHP     = 1 << 9
+	hwcap_ASIMDHP  = 1 << 10
+	hwcap_CPUID    = 1 << 11
+	hwcap_ASIMDRDM = 1 << 12
+	hwcap_JSCVT    = 1 << 13
+	hwcap_FCMA     = 1 << 14
+	hwcap_LRCPC    = 1 << 15
+	hwcap_DCPOP    = 1 << 16
+	hwcap_SHA3     = 1 << 17
+	hwcap_SM3      = 1 << 18
+	hwcap_SM4      = 1 << 19
+	hwcap_ASIMDDP  = 1 << 20
+	hwcap_SHA512   = 1 << 21
+	hwcap_SVE      = 1 << 22
+	hwcap_ASIMDFHM = 1 << 23
+)
+
+// linuxKernelCanEmulateCPUID reports whether we're running
+// on Linux 4.11+. Ideally we'd like to ask the question about
+// whether the current kernel contains
+// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=77c97b4ee21290f5f083173d957843b615abbff2
+// but the version number will have to do.
+func linuxKernelCanEmulateCPUID() bool {
+	var un syscall.Utsname
+	syscall.Uname(&un)
+	var sb strings.Builder
+	for _, b := range un.Release[:] {
+		if b == 0 {
+			break
+		}
+		sb.WriteByte(byte(b))
+	}
+	major, minor, _, ok := parseRelease(sb.String())
+	return ok && (major > 4 || major == 4 && minor >= 11)
+}
+
+func doinit() {
+	if err := readHWCAP(); err != nil {
+		// We failed to read /proc/self/auxv. This can happen if the binary has
+		// been given extra capabilities(7) with /bin/setcap.
+		//
+		// When this happens, we have two options. If the Linux kernel is new
+		// enough (4.11+), we can read the arm64 registers directly which'll
+		// trap into the kernel and then return back to userspace.
+		//
+		// But on older kernels, such as Linux 4.4.180 as used on many Synology
+		// devices, calling readARM64Registers (specifically getisar0) will
+		// cause a SIGILL and we'll die. So for older kernels, parse /proc/cpuinfo
+		// instead.
+		//
+		// See golang/go#57336.
+		if linuxKernelCanEmulateCPUID() {
+			readARM64Registers()
+		} else {
+			readLinuxProcCPUInfo()
+		}
+		return
+	}
+
+	// HWCAP feature bits
+	ARM64.HasFP = isSet(hwCap, hwcap_FP)
+	ARM64.HasASIMD = isSet(hwCap, hwcap_ASIMD)
+	ARM64.HasEVTSTRM = isSet(hwCap, hwcap_EVTSTRM)
+	ARM64.HasAES = isSet(hwCap, hwcap_AES)
+	ARM64.HasPMULL = isSet(hwCap, hwcap_PMULL)
+	ARM64.HasSHA1 = isSet(hwCap, hwcap_SHA1)
+	ARM64.HasSHA2 = isSet(hwCap, hwcap_SHA2)
+	ARM64.HasCRC32 = isSet(hwCap, hwcap_CRC32)
+	ARM64.HasATOMICS = isSet(hwCap, hwcap_ATOMICS)
+	ARM64.HasFPHP = isSet(hwCap, hwcap_FPHP)
+	ARM64.HasASIMDHP = isSet(hwCap, hwcap_ASIMDHP)
+	ARM64.HasCPUID = isSet(hwCap, hwcap_CPUID)
+	ARM64.HasASIMDRDM = isSet(hwCap, hwcap_ASIMDRDM)
+	ARM64.HasJSCVT = isSet(hwCap, hwcap_JSCVT)
+	ARM64.HasFCMA = isSet(hwCap, hwcap_FCMA)
+	ARM64.HasLRCPC = isSet(hwCap, hwcap_LRCPC)
+	ARM64.HasDCPOP = isSet(hwCap, hwcap_DCPOP)
+	ARM64.HasSHA3 = isSet(hwCap, hwcap_SHA3)
+	ARM64.HasSM3 = isSet(hwCap, hwcap_SM3)
+	ARM64.HasSM4 = isSet(hwCap, hwcap_SM4)
+	ARM64.HasASIMDDP = isSet(hwCap, hwcap_ASIMDDP)
+	ARM64.HasSHA512 = isSet(hwCap, hwcap_SHA512)
+	ARM64.HasSVE = isSet(hwCap, hwcap_SVE)
+	ARM64.HasASIMDFHM = isSet(hwCap, hwcap_ASIMDFHM)
+}
+
+func isSet(hwc uint, value uint) bool {
+	return hwc&value != 0
+}
-- 
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