From 69f969bb7142a6543945b77797ff398eccf57fa5 Mon Sep 17 00:00:00 2001
From: Enrico Lumetti <enrico.lumetti@gmail.com>
Date: Wed, 5 May 2021 00:36:32 +0200
Subject: [PATCH] Add aarch64 execution infrastructure

---
 aarch64-hello.s      |  5 +++++
 runtime.s            |  5 +++++
 test-aarch64-run.scm | 11 +++++++++++
 test-util.scm        |  9 ++++++++-
 4 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 aarch64-hello.s
 create mode 100644 runtime.s
 create mode 100644 test-aarch64-run.scm

diff --git a/aarch64-hello.s b/aarch64-hello.s
new file mode 100644
index 0000000..2142ffb
--- /dev/null
+++ b/aarch64-hello.s
@@ -0,0 +1,5 @@
+.global _main
+
+_main:
+    mov x0, 42  // exit code
+    ret
diff --git a/runtime.s b/runtime.s
new file mode 100644
index 0000000..44f3fcf
--- /dev/null
+++ b/runtime.s
@@ -0,0 +1,5 @@
+.global main
+main:
+    bl _main
+	mov x8, 93 	// sys_exit() is at index 93 in kernel functions table
+	svc #0 		// generate kernel call sys_exit(123);
diff --git a/test-aarch64-run.scm b/test-aarch64-run.scm
new file mode 100644
index 0000000..40674b2
--- /dev/null
+++ b/test-aarch64-run.scm
@@ -0,0 +1,11 @@
+#lang racket
+
+(require "test-util.scm")
+
+(test-eq
+ (compile-arm-asm "aarch64-hello.s" "a.out")
+ #t)
+
+(test-eq
+ (run-arm-executable "a.out")
+ 42)
diff --git a/test-util.scm b/test-util.scm
index 7dc43d0..60388d2 100644
--- a/test-util.scm
+++ b/test-util.scm
@@ -1,7 +1,14 @@
 #lang racket
 
-(provide test-eq)
+(require racket/system)
+
+(provide test-eq compile-arm-asm run-arm-executable)
 
 (define (test-eq a b)
    (if (equal? a b) (displayln "PASS") (error (format "FAIL: ~a != ~a" a  b))))
 
+(define (compile-arm-asm filename outfilename)
+  (system (format "aarch64-linux-gnu-gcc -static ~a runtime.s -o ~a" filename outfilename)))
+
+(define (run-arm-executable filename)
+  (system/exit-code (format "qemu-aarch64 ./~a" filename)))