Support for linux armv7

[leejack1000]

I want to build this project to linux armv7 device
cmd: env GOOS=linux GOARCH=arm GOARM=7 go build
got errors:
.../github.com/go-piv/piv-go@v1.10.0/piv/piv.go:103:7: undefined: scContext
.../github.com/go-piv/piv-go@v1.10.0/piv/piv.go:104:7: undefined: scHandle
.../github.com/go-piv/piv-go@v1.10.0/piv/piv.go:105:7: undefined: scTx
.../github.com/go-piv/piv-go@v1.10.0/piv/key.go:521:19: undefined: scTx
.../github.com/go-piv/piv-go@v1.10.0/piv/key.go:614:29: undefined: scTx
.../github.com/go-piv/piv-go@v1.10.0/piv/key.go:668:24: undefined: scTx
.../github.com/go-piv/piv-go@v1.10.0/piv/key.go:773:59: undefined: scTx
.../github.com/go-piv/piv-go@v1.10.0/piv/key.go:929:22: undefined: scTx
.../github.com/go-piv/piv-go@v1.10.0/piv/key.go:1085:22: undefined: scTx
.../github.com/go-piv/piv-go@v1.10.0/piv/key.go:1130:24: undefined: scTx
.../github.com/go-piv/piv-go@v1.10.0/piv/key.go:1130:24: too many errors

[ericchiang]

You'd have to add a build tag to one of the pcsc_*.go files, and potentially fix some of the cgo declarations https://github.com/go-piv/piv-go/tree/master/piv

I don't have an arm7 device to test, so I haven't added the tags. Feel free to send a PR!

[circa10a]

If anyone else comes across this issue, here is how I was able to build for linux arm in CI on debian 11. First need to install the required packages (this is on an x86 host):

apt-get update && apt-get install -y gcc gcc-aarch64-linux-gnu pkg-config pcscd pcsc-tools libpcsclite-dev
# For linux arm64 builds, we need the arm64 libs for the aarch64 gcc compiler
dpkg --add-architecture arm64 && apt-get update && apt-get install -y --no-install-recommends libpcsclite-dev:arm64

Then my goreleaser file (.goreleaser.yml) which required CGO_ENABLED=1 and CC=aarch64-linux-gnu-gcc at build time.

project_name: project
release:
  disable: true
builds:
  - binary: "{{.ProjectName}}"
    env:
      - CGO_ENABLED=1
    goos:
      - linux
    goarch:
      - amd64
      - arm64
    ldflags:
      - -X main.Version={{.Version}}
    flags:
      - -a
    overrides:
      - goos: linux
        goarch: arm64
        env:
          - CC=aarch64-linux-gnu-gcc
          - CGO_ENABLED=1
archives:
  - name_template: "{{.ProjectName}}_{{.Version}}_{{.Os}}_{{.Arch}}"
    format: tar.gz
snapshot:
  name_template: "{{ .Tag }}-next"

[leejack1000]

Good, thanks