Regroup asm blocks

src/main.rs

@@ -17,6 +17,7 @@ unsafe extern "C" fn _enter() -> ! {
         // load hartid into t0; if t0 =/= 0, then jump to busy loop
         "csrr t0, mhartid",
         "bnez t0, 3f",
+        
         // before we use the `la` pseudo-instruction for the first time,
         // we need to set `gp` (look up linker relaxation)
         ".option push", // pushes the current option stack
@@ -42,12 +43,13 @@ unsafe extern "C" fn _enter() -> ! {
     "2:",
         // BSS is clear!
         "j 4f",
-        // busy loop if hartid =/= 0
-    "3:",
-        "wfi",
-        "j 3b",
-    "4:",
     
+    // busy loop if hartid =/= 0
+    "3:",
+        "wfi", // wait for interrupt (or nop)
+        "j 3b",
+    
+    "4:",
         // "tail-call" to {start} (call without saving a return address)
         "tail {start}",
         start = sym start, // {start} refers to the function [start] below