zliuva · July 8, 2011 14:56 · Jul 8, 2011
diff --git a/cpuid.s b/cpuid.s
@@ -0,0 +1,36 @@
+# cpuid.s
+# An x86_64 OS X port of the cpuid example found in Ch. 4 of Professional Assembly Language
+#
+# $ as -o cpuid.o cpuid.s
+# $ ld -o cpuid cpuid.o
+# $ ./cpuid 
+# GenuineIntel
+# $
+
+.data
+output:
+	.asciz "\0\0\0\0\0\0\0\0\0\0\0\0\n"
+len:
+	.long len - output
+
+.text
+.globl start
+
+start:
+	xor %rax, %rax
+	cpuid
+
+	leaq output(%rip), %rsi
+	movl %ebx, (%esi)
+	movl %edx, 4(%esi)
+	movl %ecx, 8(%esi)
+
+	movq len(%rip), %rdx
+	# leaq output(%rip), %rsi	# %rsi already contains address of output
+	movq $0x1, %rdi				# STDOUT
+	movq $0x02000004, %rax		# write
+	syscall
+
+	movq $0x0, %rdi
+	movq $0x02000001, %rax		# exit
+	syscall