//----------------------------------------------------------------
//	esp.s
//
//	This program shows how to display the initial contents of 
//	the processor's ESP register in hexadecimal format.
//
//	        assemble using:  $ as esp.s -o esp.o
//	        and link using:  $ ld esp.o eax2hex.o -o esp
//
//	programmer: ALLAN CRUSE
//	written on: 01 FEB 2006
//----------------------------------------------------------------

	.equ		sys_write, 4
	.equ		sys_exit,  1
	.equ		device_ID, 1

	.section	.data
msg:	.ascii		"\n\tESP="
buf: 	.ascii		"xxxxxxxx \n\n"
len:	.int		. - msg

	.section	.text
_start:
	# transfer contents of ESP to register EAX
	movl		%esp, %eax

	# use external subroutine to convert EAX into hex format
	movl		$buf, %edi
	call		eax2hex

	# write our message to the display device
	movl		$sys_write, %eax
	movl		$device_ID, %ebx
	movl		$msg, %ecx
	movl		len, %edx
	int		$0x80

	# terminate this program
	movl		$sys_exit, %eax
	movl		$0, %ebx
	int		$0x80

	.global		_start
	.end