Add stubby.go to pkg/cmd/bkcust

In the hurried PR and commit, this file was also missed.

pkg/cmd/bkcust/stubby.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/project-machine/bootkit/pkg/stubby"
+	cli "github.com/urfave/cli/v2"
+)
+
+var sbatBuiltIn = `sbat,1,SBAT Version,sbat,1,https://github.com/rhboot/shim/blob/main/SBAT.md
+stubby.puzzleos,2,PuzzleOS,stubby,1,https://github.com/puzzleos/stubby
+linux.puzzleos,1,PuzzleOS,linux,1,NOURL`
+
+var stubbyCmd = cli.Command{
+	Name: "stubby",
+	Subcommands: []*cli.Command{
+		&cli.Command{
+			Name:      "smoosh",
+			ArgsUsage: "output-uki.efi stubby.efi vmlinuz initrd",
+			Action:    doStubbySmoosh,
+			Flags: []cli.Flag{
+				&cli.StringFlag{
+					Name:    "output",
+					Aliases: []string{"o"},
+					Usage:   "Put modified vars in <output>",
+					Value:   "",
+				},
+				&cli.StringFlag{
+					Name:  "cmdline",
+					Usage: "Embed the provided kernel command line",
+					Value: "",
+				},
+			},
+		},
+	},
+}
+
+func doStubbySmoosh(ctx *cli.Context) error {
+	var err error
+	args := ctx.Args().Slice()
+	if len(args) != 4 {
+		return fmt.Errorf("Got %d args, require 4", len(args))
+	}
+	output := args[0]
+	stubEfi := args[1]
+	kernel := args[2]
+	initrd := args[3]
+
+	sbat := sbatBuiltIn
+	if ctx.String("sbat") != "" {
+		content, err := os.ReadFile(ctx.String("sbat"))
+		if err != nil {
+			return err
+		}
+		sbat = string(content)
+	}
+
+	err = stubby.Smoosh(stubEfi, output, ctx.String("cmdline"), sbat, kernel, initrd)
+	if err != nil {
+		return err
+	}
+	fmt.Fprintf(os.Stderr, "Wrote to %s\n", output)
+
+	return nil
+}