Clean up & comment task_init

kernel/cpu/i386/tasking_helpers.asm

@@ -50,24 +50,24 @@ switch_to_thread_asm:
 
 global task_init
 
+; Switch to usermode, given a usermode stack and EIP to switch to
+
 task_init:
-  pop ecx
-  pop ebx
-  cli
-  mov ax, 0x23
+  pop ecx ; ecx = user ESP
+  pop ebx ; ebx = user EIP
+  mov ax, 0x23 ; Load data segment selectors with the usermode data segment
   mov ds, ax
   mov es, ax
   mov fs, ax
   mov gs, ax
-  mov eax, ecx
-  push 0x23
-  push eax
-  pushf
-  pop eax
-  or eax, 0x200
-  push eax
-  push 0x1B
-  push ebx
+  push 0x23 ; Push SS
+  push ecx ; push user ESP
+  pushf ; push flags
+  pop eax ; pop flags into eax
+  or eax, 0x200 ; enable interrupts when iret runs 
+  push eax ; push modified flags
+  push 0x1B ; push CS
+  push ebx ; push user EIP
   iret
 
 global wait_for_unblocked_thread_asm