fix arch match rule for armv8l

[yunyu950908]

Pull Request

Problem

I have tried to run n on my armv8l arch device, but could not get an appropriate result.

➜  ~ n lts
  Error: no version found for 'lts'

➜  ~ n lsr
Listing remote... Displaying 20 matches (use --all to see all).
➜  ~

After doing some research I saw some information about the relations among armv7l, armv8l, and arm64 from StackOverflow:

"arm64" represents the AArch64 state of the ARMv8-A architecture; there is no "armv8" target.

So, here is the problem in the script

n/bin/n

Lines 853 to 861 in a0cfc80

	case "${uname_m}" in
	x86_64) arch=x64 ;;
	i386 | i686) arch="x86" ;;
	aarch64) arch=arm64 ;;
	*)
	# e.g. armv6l, armv7l, arm64
	arch="${uname_m}"
	;;
	esac

Solution

Just declare armv8l use arm64 arch

aarch64 | armv8l) arch=arm64 ;;

And then it works

➜  n git:(master) ✗ ./bin/n lts

  installing : node-v12.16.1
       mkdir : /root/n/n/versions/node/12.16.1
       fetch : https://nodejs.org/dist/v12.16.1/node-v12.16.1-linux-arm64.tar.xz
####################################################################      95.7%

➜  n git:(master) ✗ ./bin/n lsr
Listing remote... Displaying 20 matches (use --all to see all).
13.10.1
13.10.0
13.9.0
13.8.0
13.7.0
13.6.0
13.5.0
13.4.0
13.3.0
13.2.0
13.1.0
13.0.1
13.0.0
12.16.1
12.16.0
12.15.0
12.14.1
12.14.0
12.13.1
12.13.0

ChangeLog

[shadowspawn]

I did some research but have not find a good explanation of what arm8l means. I did find two references that say arm8l does not guarantee 64 bit support, which makes it harder to test for arm64 support accurately for arm8l:

• Add arm8l support bannsec/revenge#3
• armv8l architecture: can't find armv8l-repodata in aarch64 repository  void-linux/xbps#43

I see there are two armv8 variations which do not include 64 bit support, but I am not sure if they would be identified with arm8l:

• https://en.wikipedia.org/wiki/ARM_architecture#ARMv8-R_and_ARMv8-M

Without making changes to n, I'll note there is support to override the architecture detection with --arch.

[shadowspawn]

What is the full uname string from your armv8l arch device?

uname -a

[yunyu950908]

Linux localhost 3.18.66-perf+ #1 SMP PREEMPT Fri Sep 14 21:27:03 CST 2018 armv8l GNU/Linux

PS: I noticed that the download link of tarball for armv8 on https://nodejs.org/en/download/ is this https://nodejs.org/dist/v12.16.1/node-v12.16.1-linux-arm64.tar.xz

[shadowspawn]

Thanks. I found a somewhat obscure command to tell whether OS is 32-bit or 64-bit: getconf LONG_BIT.

Given there is no build of node for armv8l, getting a false positive for the possibly rare case of 32-bit armv8, might just go with this PR without an extra test.

[shadowspawn]

Released in v6.4.0

Thank you for your contributions.