fix unknow bug: change busybox from docker, maintain the PATH env vars

kernel/src/shell.rs

@@ -9,11 +9,17 @@ use alloc::vec::Vec;
 
 #[cfg(not(feature = "run_cmdline"))]
 pub fn run_user_shell() {
-    #[cfg(target_arch = "x86_64")]
-        let init_shell="/bin/busybox";
-
-    #[cfg(not(target_arch = "x86_64"))]
-        let init_shell="/busybox";
+/// the busybox of alpine linux can not transfer env vars into child process
+/// Now we use busybox from
+/// https://raw.githubusercontent.com/docker-library/busybox/82bc0333a9ae148fbb4246bcbff1487b3fc0c510/musl/busybox.tar.xz -O busybox.tar.xz
+/// This one can transfer env vars!
+/// Why???
+
+//    #[cfg(target_arch = "x86_64")]
+//        let init_shell="/bin/busybox"; // from alpine linux
+//
+//    #[cfg(not(target_arch = "x86_64"))]
+        let init_shell="/busybox"; //from docker-library
 
     #[cfg(target_arch = "x86_64")]
         let init_envs=vec!["PATH=/usr/sbin:/usr/bin:/sbin:/bin:/usr/x86_64-alpine-linux-musl/bin".into()];