init: fall back to busybox's shell

Run busybox's shell if AOSP's shell fails to run. This makes
debug shell more reliable.

diff --git a/initrd/init b/initrd/init
index fd2da25..e8899a7 100755 (executable)
--- a/initrd/init
+++ b/initrd/init
@@ -135,6 +135,7 @@ debug_shell()
        if [ -x system/bin/sh ]; then
                echo Running MirBSD Korn Shell...
                USER="($1)" system/bin/sh -l 2>&1
+               [ $? -ne 0 ] && /bin/sh 2>&1
        else
                echo Running busybox ash...
                sh 2>&1