From dc6132dc06dfb3f52d337e164a00d6502c1f6f2c Mon Sep 17 00:00:00 2001
From: Aaron Janse <aaron@ajanse.me>
Date: Mon, 17 Aug 2020 03:24:56 -0700
Subject: [PATCH] elaborate error message for initfs chdir failure

---
 src/lib.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index b816c13..0c78f18 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -170,7 +170,12 @@ pub extern fn userspace_init() {
     let path = b"initfs:/bin/init";
     let env = unsafe { INIT_ENV };
 
-    assert_eq!(syscall::chdir(b"initfs:"), Ok(0));
+    if let Err(err) = syscall::chdir(b"initfs:") {
+        info!("Failed to enter initfs ({}).", err);
+        info!("Perhaps the kernel was compiled with an incorrect INITFS_FOLDER \
+               environment variable value?");
+        panic!("Unexpected error while trying to enter initfs:.");
+    }
 
     assert_eq!(syscall::open(b"debug:", syscall::flag::O_RDONLY).map(FileHandle::into), Ok(0));
     assert_eq!(syscall::open(b"debug:", syscall::flag::O_WRONLY).map(FileHandle::into), Ok(1));