(2006-08-06) rescue-bootcd

extra/syslinux-3.09/sample/c32entry.S

@@ -0,0 +1,67 @@
+#ident "$Id: c32entry.S,v 1.5 2005/01/03 08:23:16 hpa Exp $"
+# -----------------------------------------------------------------------
+#   
+#   Copyright 2003 H. Peter Anvin - All Rights Reserved
+#
+#   Permission is hereby granted, free of charge, to any person
+#   obtaining a copy of this software and associated documentation
+#   files (the "Software"), to deal in the Software without
+#   restriction, including without limitation the rights to use,
+#   copy, modify, merge, publish, distribute, sublicense, and/or
+#   sell copies of the Software, and to permit persons to whom
+#   the Software is furnished to do so, subject to the following
+#   conditions:
+#   
+#   The above copyright notice and this permission notice shall
+#   be included in all copies or substantial portions of the Software.
+#   
+#   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+#   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+#   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+#   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+#   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+#   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+#   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+#   OTHER DEALINGS IN THE SOFTWARE.
+#
+# -----------------------------------------------------------------------
+
+# COM32 start up code - must be linked first in the binary
+
+	
+		.section ".text","ax"
+		.globl _start
+_start:
+		# This first instruction acts as COM32 magic number
+		movl $0x21cd4cff,%eax
+
+		# Upwards string operations
+		cld
+
+		# Zero the .bss segment
+		xorl %eax,%eax
+		movl $__bss_start,%edi		# Symbol provided by linker
+		movl $_end+3,%ecx		# Symbol provided by linker
+		subl %edi,%ecx
+		shrl $2,%ecx
+		rep ; stosl
+
+		# Copy COM32 invocation parameters
+		leal 4(%esp),%esi		# Argument list
+		movl $__com32,%edi
+		movl $6,%ecx
+		movl %esp,-4(%edi)		# Save the initial stack ptr
+		cmpl (%esi),%ecx
+		jbe 1f
+		movl (%esi),%ecx
+1:		rep ; movsl
+
+		# Run program; we call this __start rather than main since we
+		# did not parse the command line or anything like that.
+		jmp __start
+
+		.section ".bss","aw"
+		.globl __entry_esp
+__entry_esp:	.space 4
+		.globl __com32
+__com32:	.space 4*6