X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Fstart.S;h=68c604cc276b33a6701dab250d16784de3d45bd0;hb=41f912229e43e5436dd9040809afe33d228b0a95;hp=351b5e1532a95eb286d1c05c82509034cade63f2;hpb=750d21936d284127e265d050ccbce76fca1ece1a;p=pintos-anon

diff --git a/src/threads/start.S b/src/threads/start.S
index 351b5e1..68c604c 100644
--- a/src/threads/start.S
+++ b/src/threads/start.S
@@ -1,9 +1,19 @@
-# This module gets linked first, so that the kernel entry point
-# is the very beginning of its binary image.  All we need to do is
-# jump to the real entry point.
+#### The loader needs to have some way to know the kernel's entry
+#### point, that is, the address to which it should jump to start the
+#### kernel.  We handle this by writing the linker script kernel.lds.S
+#### so that this module appears at the very beginning of the kernel
+#### image, and then using that as the entry point.
 
-	.globl start
+.section .start
+	
+.globl start
+.func start
+	# Terminate the backtrace that debug_backtrace() would output.
+	movl $0, %ebp
+
+	# Call main.
 start:	call main
 
-	# If main returns, spin.
+	# main() should not return, but if it does, spin.
 1:	jmp 1b
+.endfunc