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authorKartik Agaram <vc@akkartik.com>2018-09-01 09:39:36 -0700
committerKartik Agaram <vc@akkartik.com>2018-09-01 09:39:36 -0700
commitea7f869856a614d14de31c680c8dd290de1cc113 (patch)
tree6cbbf70db886032a807bcc9e64d27412fbbe9cc3 /subx/examples/ex2.subx
parenta413105a5dc4741ccd1c364cc82609d2aa25f6c5 (diff)
downloadmu-ea7f869856a614d14de31c680c8dd290de1cc113.tar.gz
4529 - move examples to a sub-directory
Diffstat (limited to 'subx/examples/ex2.subx')
-rw-r--r--subx/examples/ex2.subx20
1 files changed, 20 insertions, 0 deletions
diff --git a/subx/examples/ex2.subx b/subx/examples/ex2.subx
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+## add 1 and 1, and return the result in the exit code
+#
+# To run:
+#   $ subx translate ex2.subx ex2
+#   $ subx run ex2
+# Expected result:
+#   $ echo $?
+#   2
+
+== 0x08048054  # code segment, after leaving room for ELF header
+# instruction                     effective address                                                   operand     displacement    immediate
+# op          subop               mod             rm32          base        index         scale       r32
+# 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes
+  bb/copy                                                                                                                         1/imm32           # copy 1 to EBX
+  81          0/subop/add         3/mod/direct    3/rm32/EBX                                                                      1/imm32           # add 1 to EBX
+  # exit(EBX)
+  b8/copy                                                                                                                         1/imm32           # copy 1 to EAX
+  cd/syscall                                                                                                                      0x80/imm8         # int 80h
+
+# vim:ft=subx