add the initramfs package

The initramfs package contains a map[string][]byte.

It includes compressed kernel and initramfs for several kernel and
architecture combinations, as well as qemu command line.

It is created by go generate.

The package uses embed to incorporate those files. They are reasonably
small.

To see a possible usage, read vm_test.go

set up vm_test to direct all output to a pipe

Sadly, the original sin of os.Std{in,out,err} requires
an os.File, else we could use an in-memory pipe.

Use CombinedOutput in vm_test.

Signed-off-by: Ronald G Minnich <[email protected]>

Author: rminnich

go.mod

@@ -1,54 +1,70 @@
 module github.com/u-root/cpu
 
-go 1.23.0
+go 1.24
 
 toolchain go1.24.1
 
 require (
 	github.com/gliderlabs/ssh v0.3.5
 	github.com/kevinburke/ssh_config v1.2.0
 	github.com/u-root/u-root v0.11.1-0.20230913033713-004977728a9d
-	golang.org/x/crypto v0.36.0
-	golang.org/x/sys v0.31.0
+	golang.org/x/crypto v0.39.0
+	golang.org/x/sys v0.33.0
 )
 
 require (
+	github.com/apptainer/container-library-client v1.4.12
 	github.com/brutella/dnssd v1.2.9
 	github.com/creack/pty v1.1.18
 	github.com/go-git/go-billy/v5 v5.5.1-0.20240514075308-8f1b719cb6a2
+	github.com/google/go-containerregistry v0.20.6
 	github.com/google/uuid v1.6.0
 	github.com/hugelgupf/p9 v0.3.0
 	github.com/mdlayher/vsock v1.2.1
 	github.com/moby/sys/mountinfo v0.7.1
 	github.com/shirou/gopsutil v3.21.11+incompatible
 	github.com/willscott/go-nfs v0.0.0-20240424173852-04b947a7e58a
 	golang.org/x/exp v0.0.0-20230810033253-352e893a4cad
-	golang.org/x/term v0.30.0
+	golang.org/x/term v0.32.0
 )
 
 require (
 	github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be // indirect
+	github.com/apptainer/sif/v2 v2.21.1 // indirect
+	github.com/blang/semver/v4 v4.0.0 // indirect
+	github.com/containerd/stargz-snapshotter/estargz v0.16.3 // indirect
 	github.com/cyphar/filepath-securejoin v0.2.5 // indirect
+	github.com/docker/cli v28.2.2+incompatible // indirect
+	github.com/docker/distribution v2.8.3+incompatible // indirect
+	github.com/docker/docker-credential-helpers v0.9.3 // indirect
 	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/go-log/log v0.2.0 // indirect
 	github.com/go-ole/go-ole v1.2.6 // indirect
 	github.com/hashicorp/golang-lru/v2 v2.0.7 // indirect
-	github.com/klauspost/compress v1.16.7 // indirect
+	github.com/klauspost/compress v1.18.0 // indirect
 	github.com/klauspost/pgzip v1.2.6 // indirect
 	github.com/mdlayher/socket v0.4.1 // indirect
 	github.com/miekg/dns v1.1.55 // indirect
+	github.com/mitchellh/go-homedir v1.1.0 // indirect
+	github.com/opencontainers/go-digest v1.0.0 // indirect
+	github.com/opencontainers/image-spec v1.1.1 // indirect
 	github.com/pierrec/lz4/v4 v4.1.18 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
 	github.com/rasky/go-xdr v0.0.0-20170124162913-1a41d1a06c93 // indirect
+	github.com/sirupsen/logrus v1.9.3 // indirect
+	github.com/sylabs/json-resp v0.9.4 // indirect
 	github.com/tklauser/go-sysconf v0.3.11 // indirect
 	github.com/tklauser/numcpus v0.6.1 // indirect
 	github.com/u-root/uio v0.0.0-20230305220412-3e8cd9d6bf63 // indirect
 	github.com/ulikunitz/xz v0.5.11 // indirect
+	github.com/vbatts/tar-split v0.12.1 // indirect
 	github.com/vishvananda/netlink v1.2.1-beta.2 // indirect
 	github.com/vishvananda/netns v0.0.4 // indirect
 	github.com/willscott/go-nfs-client v0.0.0-20240104095149-b44639837b00 // indirect
 	github.com/yusufpapurcu/wmi v1.2.3 // indirect
-	golang.org/x/mod v0.12.0 // indirect
-	golang.org/x/net v0.38.0 // indirect
-	golang.org/x/sync v0.3.0 // indirect
-	golang.org/x/tools v0.12.0 // indirect
+	golang.org/x/mod v0.25.0 // indirect
+	golang.org/x/net v0.41.0 // indirect
+	golang.org/x/sync v0.15.0 // indirect
+	golang.org/x/tools v0.34.0 // indirect
 	google.golang.org/grpc v1.56.3 // indirect
 )

go.sum

@@ -0,0 +1,176 @@
+//go:build generate
+
+package main
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+
+	"github.com/google/go-containerregistry/pkg/crane"
+	"github.com/google/go-containerregistry/pkg/name"
+	"github.com/google/go-containerregistry/pkg/v1/mutate"
+	"github.com/u-root/u-root/pkg/cpio"
+	"github.com/u-root/u-root/pkg/tarutil"
+)
+
+type build struct {
+	os        string
+	arch      string
+	version   string
+	kernel    string
+	container string
+	env       []string
+	cmd       []string
+}
+
+var builds = []build{
+	{
+		os:        "linux",
+		arch:      "amd64",
+		version:   "v1",
+		kernel:    "bzImage",
+		container: "ghcr.io/hugelgupf/vmtest/kernel-amd64:main",
+		env:       []string{"GOARCH=amd64", "GOAMD64=v1"},
+		cmd:       []string{},
+	},
+	{
+		os:        "linux",
+		arch:      "arm64",
+		version:   "v1",
+		kernel:    "Image",
+		container: "ghcr.io/hugelgupf/vmtest/kernel-arm64:main",
+		env:       []string{"GOARCH=arm64"},
+		cmd:       []string{},
+	},
+	{
+		os:        "linux",
+		arch:      "arm",
+		kernel:    "zImage",
+		container: "ghcr.io/hugelgupf/vmtest/kernel-arm:main",
+		env:       []string{"GOARCH=arm", "GOARM=5"},
+		cmd:       []string{},
+	},
+	{
+		os:        "linux",
+		arch:      "riscv64",
+		kernel:    "Image",
+		container: "ghcr.io/hugelgupf/vmtest/kernel-riscv64:main",
+		env:       []string{"GOARCH=riscv64"},
+		cmd:       []string{},
+	},
+}
+
+func main() {
+	env := []string{"CGO_ENABLED=0"}
+	for _, b := range builds {
+		log.Printf("Build %v", b)
+		n := fmt.Sprintf("initramfs_%s_%s.cpio", b.os, b.arch)
+		cmd := []string{"-initcmd=/bbin/cpud", "-defaultsh=", "-o=" + n,
+			"../cmds/cpud",
+			"../../u-root/cmds/core/dhclient",
+		}
+		c := exec.Command("u-root", cmd...)
+		c.Stdout, c.Stderr = os.Stdout, os.Stderr
+		c.Env = append(os.Environ(), append(env, b.env...)...)
+		if err := c.Run(); err != nil {
+			log.Fatal(err)
+		}
+		f, err := os.ReadFile(n)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		var newcpio bytes.Buffer
+		rw := cpio.Newc.Writer(&newcpio)
+		recs := cpio.Newc.Reader(bytes.NewReader(f))
+		fixed := 0
+		cpio.ForEachRecord(recs, func(r cpio.Record) error {
+			switch r.Name {
+			case "bbin/bb":
+				fixed++
+				r.Name = "bbin/cibb"
+			case "bbin/init", "bbin/dhclient", "bbin/cpud":
+				fixed++
+				r.ReaderAt = bytes.NewReader([]byte("cibb"))
+				r.Info.FileSize = 4
+			}
+			if err := rw.WriteRecord(r); err != nil {
+				return fmt.Errorf("writing record %q failed: %w", r.Name, err)
+			}
+			return nil
+		})
+
+		if fixed < 2 {
+			log.Fatal("Did not fix any entries in %q", n)
+		}
+
+		// because we modify the cpio, and one of the tests makes sure the cpio matches compressed,
+		// write back the modified cpio.
+		if err := os.WriteFile(n, newcpio.Bytes(), 0644); err != nil {
+			log.Fatalf("writing back changed cpio %s:%v", n, err)
+		}
+
+		var out bytes.Buffer
+		gz := gzip.NewWriter(&out)
+		if _, err := gz.Write(newcpio.Bytes()); err != nil {
+			log.Fatal(err)
+		}
+		if err := gz.Close(); err != nil {
+			log.Fatal(err)
+		}
+		if err := os.WriteFile(n+".gz", out.Bytes(), 0644); err != nil {
+			log.Fatal(err)
+		}
+
+		if len(b.container) == 0 {
+			continue
+		}
+		ref, err := name.ParseReference(b.container)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		img, err := crane.Pull(ref.Name())
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		r := mutate.Extract(img)
+
+		opts := &tarutil.Opts{}
+		opts.Filters = []tarutil.Filter{tarutil.SafeFilter, func(h *tar.Header) bool {
+			return h.Name == b.kernel
+		},
+		}
+
+		if err := tarutil.ExtractDir(r, ".", opts); err != nil {
+			log.Fatal(err)
+		}
+
+		// tarutil does not let us extract a file with a name into a []byte.Unfortunate.
+		kname := fmt.Sprintf("kernel_%s_%s", b.os, b.arch)
+		if err := os.Rename(b.kernel, kname); err != nil {
+			log.Fatal(err)
+		}
+		if f, err = os.ReadFile(kname); err != nil {
+			log.Fatal(err)
+		}
+		var kout bytes.Buffer
+		gz = gzip.NewWriter(&kout)
+		if _, err := gz.Write(f); err != nil {
+			log.Fatal(err)
+		}
+		if err := gz.Close(); err != nil {
+			log.Fatal(err)
+		}
+		if err := os.WriteFile(kname+".gz", kout.Bytes(), 0644); err != nil {
+			log.Fatal(err)
+		}
+
+	}
+}