// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package sysinfo

import (
	"bufio"
	"bytes"
	"io"
	"os"
	"strings"
)

func readLinuxProcCPUInfo(buf []byte) error {
	f, err := os.Open("/proc/cpuinfo")
	if err != nil {
		return err
	}
	defer f.Close()

	_, err = io.ReadFull(f, buf)
	if err != nil && err != io.ErrUnexpectedEOF {
		return err

// license that can be found in the LICENSE file.

//go:build linux && arm64

package cpu

import (
	"errors"
	"io"
	"os"
	"strings"
)

func readLinuxProcCPUInfo() error {
	f, err := os.Open("/proc/cpuinfo")
	if err != nil {
		return err
	}
	defer f.Close()

	var buf [1 << 10]byte // enough for first CPU
	n, err := io.ReadFull(f, buf[:])

		// 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)