cmd/earlyinit: handle args from cmdline

These are set by the bootloader.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/earlyinit/main.go

@@ -4,6 +4,7 @@ import (
 	"log"
 	"os"
 	"runtime"
+	"strings"
 	. "syscall"
 )
 
@@ -12,6 +13,22 @@ func main() {
 	log.SetFlags(0)
 	log.SetPrefix("earlyinit: ")
 
+	var (
+		option map[string]string
+		flags  []string
+	)
+	if len(os.Args) > 1 {
+		option = make(map[string]string)
+		for _, s := range os.Args[1:] {
+			key, value, ok := strings.Cut(s, "=")
+			if !ok {
+				flags = append(flags, s)
+				continue
+			}
+			option[key] = value
+		}
+	}
+
 	if err := Mount(
 		"devtmpfs",
 		"/dev/",