macros: save, unsave, zero

davidad · Apr 30, 2014 · dfb0d13 · dfb0d13
1 parent a6f9a4a
commit dfb0d13
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diff --git a/macros.inc b/macros.inc
@@ -0,0 +1,11 @@
+macro save [reg] {
+  forward push qword reg
+  common macro unsave \{
+  reverse pop qword reg
+  common purge unsave
+  \}
+}
+
+macro zero [reg] {
+  forward xor reg, reg
+}
diff --git a/save_unsave_test.asm b/save_unsave_test.asm
@@ -0,0 +1,26 @@
+format ELF64
+include "syscalls.inc"
+include "macros.inc"
+public start
+
+start:
+	mov	edx,msg_size-1
+	lea	rsi,[msg]
+@@:
+
+	zero edi
+  save rdi
+    mov edi, 1
+    save rdi, rdx, rsi
+      zero di, edx, rsi
+    unsave
+    add rsi, rdi
+    mov	eax, SYSCALL_WRITE
+    syscall
+  unsave
+
+	mov	eax, SYSCALL_EXIT
+	syscall
+
+msg db '0123456789',0xA
+msg_size = $-msg