megaed-sv: input latency test

[megadrive.git] / megaed-sv / asmtools.s

diff --git a/megaed-sv/asmtools.s b/megaed-sv/asmtools.s
new file mode 100644 (file)
index 0000000..db93940
--- /dev/null
+++ b/megaed-sv/asmtools.s
@@ -0,0 +1,52 @@
+# Assemble with gas
+#   --register-prefix-optional --bitwise-or
+
+.macro ldarg  arg, stacksz, reg
+    move.l (4 + \arg * 4 + \stacksz)(%sp), \reg
+.endm
+
+
+.globl read_joy_responses /* u8 *rbuf */
+read_joy_responses:
+    ldarg       0, 0, a1
+    movem.l     d2-d7, -(sp)
+    movea.l     #0xa10003, a0
+    move.b      #0x40, (6,a0)
+    move.b      #0x40, (a0)
+
+.macro one_test val
+    move.l      #100/12-1, d0
+0:
+    dbra        d0, 0b
+    move.b      \val, d0
+    move.b      d0, (a0)
+    move.b      (a0), d0
+    move.b      (a0), d1
+    move.b      (a0), d2
+    move.b      (a0), d3
+    move.b      (a0), d4
+    move.b      (a0), d5
+    move.b      (a0), d6
+    move.b      (a0), d7
+    move.b      d0, (a1)+
+    move.b      d1, (a1)+
+    move.b      d2, (a1)+
+    move.b      d3, (a1)+
+    move.b      d4, (a1)+
+    move.b      d5, (a1)+
+    move.b      d6, (a1)+
+    move.b      d7, (a1)+
+.endm
+
+       move.w          #0x2700, sr
+    one_test    #0x00
+    one_test    #0x40
+    one_test    #0x00
+    one_test    #0x40
+    one_test    #0x00
+       move.w          #0x2000, sr
+    movem.l     (sp)+, d2-d7
+    rts
+
+
+# vim:filetype=asmM68k:ts=4:sw=4:expandtab