gdb: create some automated tests with pytest

gem5 baremetal: use m5exit m5op in exit() so as to not force users to
apply a patch for almost all examples

baremetal/add.c

@@ -0,0 +1,13 @@
+#include <common.h>
+
+void main(void) {
+	int i, j, k;
+	i = 1;
+    /* test-gdb-op1 */
+	j = 2;
+    /* test-gdb-op2 */
+	k = i + j;
+    /* test-gdb-result */
+	if (k != 3)
+		assert_fail();
+}

baremetal/add.py

@@ -0,0 +1,9 @@
+def test(self):
+    self.sendline('tbreak main')
+    self.sendline('continue')
+    self.continue_to('op1')
+    assert self.get_int('i') == 1
+    self.continue_to('op2')
+    assert self.get_int('j') == 2
+    self.continue_to('result')
+    assert self.get_int('k') == 3

baremetal/arch/aarch64/add.S

@@ -0,0 +1,12 @@
+.global main
+main:
+    /* 1 + 2 == 3 */
+    mov x0, #1
+    /* test-gdb-op1 */
+    add x1, x0, #2
+    /* test-gdb-result */
+    cmp x1, #3
+    beq 1f
+    bl assert_fail
+1:
+    ret

baremetal/arch/aarch64/add.py

@@ -0,0 +1,7 @@
+def test(self):
+    self.sendline('tbreak main')
+    self.sendline('continue')
+    self.continue_to('op1')
+    assert self.get_int('$x0') == 1
+    self.continue_to('result')
+    assert self.get_int('$x1') == 3

baremetal/arch/arm/add.S

@@ -0,0 +1,12 @@
+.global main
+main:
+    /* 1 + 2 == 3 */
+    mov r0, #1
+    /* test-gdb-op1 */
+    add r1, r0, #2
+    /* test-gdb-result */
+    cmp r1, #3
+    beq 1f
+    bl assert_fail
+1:
+    bx lr

baremetal/arch/arm/add.py

@@ -0,0 +1,7 @@
+def test(self):
+    self.sendline('tbreak main')
+    self.sendline('continue')
+    self.continue_to('op1')
+    assert self.get_int('$r0') == 1
+    self.continue_to('result')
+    assert self.get_int('$r1') == 3

baremetal/interactive/hello.c

@@ -2,5 +2,4 @@
 
 void main(void) {
 	puts("hello");
-	return;
 }

baremetal/lib/common.c

@@ -61,6 +61,13 @@ int _write(int file, char *ptr, int len) {
 
 /* Only 0 is supported for now, arm semihosting cannot handle other values. */
 void _exit(int status) {
+#if defined(GEM5)
+#if defined(__arm__)
+	__asm__ __volatile__ ("mov r0, #0; mov r1, #0; .inst 0xEE000110 | (0x21 << 16);");
+#elif defined(__aarch64__)
+	__asm__ __volatile__ ("mov x0, #0; .inst 0XFF000110 | (0x21 << 16);");
+#endif
+#else
 #if defined(__arm__)
     __asm__ __volatile__ ("mov r0, #0x18; ldr r1, =#0x20026; svc 0x00123456");
 #elif defined(__aarch64__)
@@ -76,6 +83,7 @@ void _exit(int status) {
 		"hlt 0xf000\n"
     );
 #endif
+#endif
 }
 
 void assert_fail() {

baremetal/return.c

@@ -1,3 +1 @@
-void main(void) {
-	return;
-}
+void main(void) {}