1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
// Copyright 2020 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.
//go:build arm64
// +build arm64
package cpu
func osInit() {
// Retrieve info from system register ID_AA64ISAR0_EL1.
isar0 := getisar0()
// ID_AA64ISAR0_EL1
switch extractBits(isar0, 4, 7) {
case 1:
ARM64.HasAES = true
case 2:
ARM64.HasAES = true
ARM64.HasPMULL = true
}
switch extractBits(isar0, 8, 11) {
case 1:
ARM64.HasSHA1 = true
}
switch extractBits(isar0, 12, 15) {
case 1, 2:
ARM64.HasSHA2 = true
}
switch extractBits(isar0, 16, 19) {
case 1:
ARM64.HasCRC32 = true
}
switch extractBits(isar0, 20, 23) {
case 2:
ARM64.HasATOMICS = true
}
}
func extractBits(data uint64, start, end uint) uint {
return (uint)(data>>start) & ((1 << (end - start + 1)) - 1)
}
|
