oasm: Add initial support for labels

A label is like a pin on a map with a number attached to it. OASM keeps track
of a number referred to as the psuedo instruction pointer (PIP). This value is
initially zero by default and is incremented every instruction. The purpose of
this value is to pin a location in the code and mark it to be at a specific address
so that further references to that label would be translated to the previous PIP value
at the time of encountering the label.

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 14 insertions, 13 deletions

diff --git a/etc/oemu/test-00.s b/etc/oemu/test-00.s
index b34c099..1fa7ff1 100644
--- a/etc/oemu/test-00.s
+++ b/etc/oemu/test-00.s
@@ -1,13 +1,14 @@
-mov x0, #1   ! ~ 0x00000000
-mov x1, #2   ! ~ 0x00000004
-mov x2, #3   ! ~ 0x00000008
-             ! X
-mov x2, #20  ! ~ 0x0000000C
-br x2        ! ~ 0x00000010  -----+
-!!!!!!!!!!!!!! X                  |
-!!!!!!!!!!!!!! X                  |
-             ! X                  |
-dec x0       ! ~ 0x00000014  <----+
-inc x1       ! ~ 0x00000018
-add x2, #3   ! ~ 0x0000001C
-hlt          ! ~ 0x00000020
+mov x0, #1       ! ~ 0x00000000
+mov x1, #2       ! ~ 0x00000004
+mov x2, #3       ! ~ 0x00000008
+                 ! X
+some_label:      ! X
+    mov x2, #20  ! ~ 0x0000000C
+    br x2        ! ~ 0x00000010  -----+
+    !!!!!!!!!!!!!! X                  |
+    !!!!!!!!!!!!!! X                  |
+                 ! X                  |
+    dec x0       ! ~ 0x00000014  <----+
+    inc x1       ! ~ 0x00000018
+    add x2, #3   ! ~ 0x0000001C
+    hlt          ! ~ 0x00000020