5485 - promote SubX to top-level

25 files changed, 0 insertions, 910 deletions

diff --git a/subx/examples/Readme.md b/subx/examples/Readme.md
deleted file mode 100644
index d4bb1ff5..00000000
--- a/subx/examples/Readme.md
+++ /dev/null
@@ -1,6 +0,0 @@
-Small example programs, each with a simple pedagogical goal.
-
-They also help to validate SubX instruction semantics against native x86
-hardware. For example, loading a single byte to a register would for some time
-clear the rest of the register. This behavior was internally consistent with
-unit tests. It took running an example binary natively to catch the discrepancy.
diff --git a/subx/examples/ex1 b/subx/examples/ex1
deleted file mode 100755
index aeb62302..00000000
--- a/subx/examples/ex1
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex1.subx b/subx/examples/ex1.subx
deleted file mode 100644
index 0aca40f8..00000000
--- a/subx/examples/ex1.subx
+++ /dev/null
@@ -1,21 +0,0 @@
-# First program: same as https://www.muppetlabs.com/~breadbox/software/tiny/teensy.html
-# Just return 42.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex1.2.subx -o examples/ex1
-#   $ ./subx run examples/ex1
-# Expected result:
-#   $ echo $?
-#   42
-
-== code 0x09000000
-
-Entry:
-# syscall(exit, 42)
-bb/copy-to-EBX  2a/imm32  # 42 in hex
-b8/copy-to-EAX  1/imm32/exit
-cd/syscall  0x80/imm8
-
-== data 0x0a000000
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex10 b/subx/examples/ex10
deleted file mode 100755
index d8ad528e..00000000
--- a/subx/examples/ex10
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex10.subx b/subx/examples/ex10.subx
deleted file mode 100644
index 51cc0a8c..00000000
--- a/subx/examples/ex10.subx
+++ /dev/null
@@ -1,72 +0,0 @@
-# String comparison: return 1 iff the two args passed in at the commandline are equal.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex10.subx -o examples/ex10
-#   $ ./subx run examples/ex10 abc abd
-# Expected result:
-#   $ echo $?
-#   0  # false
-
-== code 0x09000000
-#   instruction                     effective address                                                   register    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
-
-Entry:  # return argv-equal(argv[1], argv[2])
-#       At the start of a SubX program:
-#         argc: *ESP
-#         argv[0]: *(ESP+4)
-#         argv[1]: *(ESP+8)
-#         ...
-    # . prolog
-    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
-    # argv-equal(argv[1], argv[2])
-    # . . push argv[2]
-    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
-    # . . push argv[1]
-    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
-    # . . call
-    e8/call argv-equal/disp32
-    # syscall(exit, EAX)
-    89/copy                         3/mod/direct    3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # copy EAX to EBX
-    b8/copy-to-EAX  1/imm32/exit
-    cd/syscall  0x80/imm8
-
-# compare two null-terminated ascii strings
-# reason for the name: the only place we should have null-terminated ascii strings is from commandline args
-argv-equal:  # (s1, s2) : null-terminated ascii strings -> EAX : boolean
-    # initialize s1 (ECX) and s2 (EDX)
-    8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none  .           1/r32/ECX   4/disp8         .                 # copy *(ESP+4) to ECX
-    8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none  .           2/r32/EDX   8/disp8         .                 # copy *(ESP+8) to EDX
-$argv-equal:loop:
-    # c1/EAX, c2/EBX = *s1, *s2
-    b8/copy-to-EAX  0/imm32
-    8a/copy-byte                    0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/AL    .               .                 # copy byte at *ECX to AL
-    bb/copy-to-EBX  0/imm32
-    8a/copy-byte                    0/mod/indirect  2/rm32/EDX    .           .             .           3/r32/BL    .               .                 # copy byte at *EDX to BL
-    # if (c1 == 0) break
-    3d/compare-EAX-and  0/imm32
-    74/jump-if-equal  $argv-equal:break/disp8
-    # if (c1 != c2) return false
-    39/compare                      3/mod/direct    0/rm32/EAX    .           .             .           3/r32/EBX   .               .                 # compare EAX and EBX
-    75/jump-if-not-equal  $argv-equal:false/disp8
-    # ++s1, ++s2
-    41/increment-ECX
-    42/increment-EDX
-    # end while
-    eb/jump  $argv-equal:loop/disp8
-$argv-equal:break:
-    # if (c2 == 0) return true
-    81          7/subop/compare     3/mod/direct    3/rm32/EBX    .           .             .           .           .               0/imm32           # compare EBX
-    75/jump-if-not-equal  $argv-equal:false/disp8
-$argv-equal:success:
-    b8/copy-to-EAX  1/imm32
-    c3/return
-    # return false
-$argv-equal:false:
-    b8/copy-to-EAX  0/imm32
-    c3/return
-
-== data 0x0a000000
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex11 b/subx/examples/ex11
deleted file mode 100755
index 0ffafb6f..00000000
--- a/subx/examples/ex11
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex11.subx b/subx/examples/ex11.subx
deleted file mode 100644
index ba75c1d3..00000000
--- a/subx/examples/ex11.subx
+++ /dev/null
@@ -1,357 +0,0 @@
-# Null-terminated vs length-prefixed ascii strings.
-#
-# By default we create strings with a 4-byte length prefix rather than a null suffix.
-# However we still need null-prefixed strings when interacting with the Linux
-# kernel in a few places. This layer implements a function for comparing
-# a null-terminated 'kernel string' with a length-prefixed 'SubX string'.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex11.subx -o examples/ex11
-#   $ ./subx run examples/ex11  # runs a series of tests
-#   ......  # all tests pass
-#
-# (We can't yet run the tests when given a "test" commandline argument,
-# because checking for it would require the function being tested! Breakage
-# would cause tests to not run, rather than to fail as we'd like.)
-
-== code 0x09000000
-#   instruction                     effective address                                                   register    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
-
-Entry:  # run all tests
-    e8/call  run-tests/disp32  # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'.
-    # syscall(exit, EAX)
-    89/copy                         3/mod/direct    3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # copy EAX to EBX
-    b8/copy-to-EAX  1/imm32/exit
-    cd/syscall  0x80/imm8
-
-# compare a null-terminated ascii string with a more idiomatic length-prefixed byte array
-# reason for the name: the only place we should have null-terminated ascii strings is from commandline args
-kernel-string-equal?:  # s : null-terminated ascii string, benchmark : length-prefixed ascii string -> EAX : boolean
-    # pseudocode:
-    #   n = benchmark->length
-    #   s1 = s
-    #   s2 = benchmark->data
-    #   i = 0
-    #   while i < n
-    #     c1 = *s1
-    #     c2 = *s2
-    #     if (c1 == 0) return false
-    #     if (c1 != c2) return false
-    #     ++s1, ++s2, ++i
-    #   return *s1 == 0
-    #
-    # registers:
-    #   i: ECX
-    #   n: EDX
-    #   s1: EDI
-    #   s2: ESI
-    #   c1: EAX
-    #   c2: EBX
-    #
-    # . prolog
-    55/push-EBP
-    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
-    # . save registers
-    51/push-ECX
-    52/push-EDX
-    53/push-EBX
-    56/push-ESI
-    57/push-EDI
-    # s1/EDI = s
-    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           7/r32/EDI   8/disp8         .                 # copy *(EBP+8) to EDI
-    # n/EDX = benchmark->length
-    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           2/r32/EDX   0xc/disp8       .                 # copy *(EBP+12) to EDX
-    8b/copy                         0/mod/indirect  2/rm32/EDX    .           .             .           2/r32/EDX   .               .                 # copy *EDX to EDX
-    # s2/ESI = benchmark->data
-    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   0xc/disp8       .                 # copy *(EBP+12) to ESI
-    81          0/subop/add         3/mod/direct    6/rm32/ESI    .           .             .           .           .               4/imm32           # add to ESI
-    # i/ECX = c1/EAX = c2/EBX = 0
-    b9/copy-to-ECX  0/imm32/exit
-    b8/copy-to-EAX  0/imm32
-    bb/copy-to-EBX  0/imm32
-$kernel-string-equal?:loop:
-    # if (i >= n) break
-    39/compare                      3/mod/direct    1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # compare ECX with EDX
-    7d/jump-if-greater-or-equal  $kernel-string-equal?:break/disp8
-    # c1 = *s1
-    8a/copy-byte                    0/mod/indirect  7/rm32/EDI    .           .             .           0/r32/AL    .               .                 # copy byte at *EDI to AL
-    # c2 = *s2
-    8a/copy-byte                    0/mod/indirect  6/rm32/ESI    .           .             .           3/r32/BL    .               .                 # copy byte at *ESI to BL
-    # if (c1 == 0) return false
-    3d/compare-EAX-and  0/imm32
-    74/jump-if-equal  $kernel-string-equal?:false/disp8
-    # if (c1 != c2) return false
-    39/compare                      3/mod/direct    0/rm32/EAX    .           .             .           3/r32/EBX   .               .                 # compare EAX and EBX
-    75/jump-if-not-equal  $kernel-string-equal?:false/disp8
-    # ++i
-    41/increment-ECX
-    # ++s1
-    47/increment-EDI
-    # ++s2
-    46/increment-ESI
-    eb/jump  $kernel-string-equal?:loop/disp8
-$kernel-string-equal?:break:
-    # return *s1 == 0
-    8a/copy-byte                    0/mod/indirect  7/rm32/EDI    .           .             .           0/r32/AL    .               .                 # copy byte at *EDI to AL
-    3d/compare-EAX-and  0/imm32
-    75/jump-if-not-equal  $kernel-string-equal?:false/disp8
-$kernel-string-equal?:true:
-    b8/copy-to-EAX  1/imm32
-    eb/jump  $kernel-string-equal?:end/disp8
-$kernel-string-equal?:false:
-    b8/copy-to-EAX  0/imm32
-$kernel-string-equal?:end:
-    # . restore registers
-    5f/pop-to-EDI
-    5e/pop-to-ESI
-    5b/pop-to-EBX
-    5a/pop-to-EDX
-    59/pop-to-ECX
-    # . epilog
-    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
-    5d/pop-to-EBP
-    c3/return
-
-# - tests
-
-test-compare-null-kernel-string-with-empty-array:
-    # EAX = kernel-string-equal?(Null-kernel-string, "")
-    # . . push args
-    68/push  ""/imm32
-    68/push  Null-kernel-string/imm32
-    # . . call
-    e8/call  kernel-string-equal?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-    # check-ints-equal(EAX, 1, msg)
-    # . . push args
-    68/push  "F - test-compare-null-kernel-string-with-empty-array"/imm32
-    68/push  1/imm32/true
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-test-compare-null-kernel-string-with-non-empty-array:
-    # EAX = kernel-string-equal?(Null-kernel-string, "Abc")
-    # . . push args
-    68/push  "Abc"/imm32
-    68/push  Null-kernel-string/imm32
-    # . . call
-    e8/call  kernel-string-equal?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-    # check-ints-equal(EAX, 0, msg)
-    # . . push args
-    68/push  "F - test-compare-null-kernel-string-with-non-empty-array"/imm32
-    68/push  0/imm32/false
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-test-compare-kernel-string-with-equal-array:
-    # EAX = kernel-string-equal?(_test-Abc-kernel-string, "Abc")
-    # . . push args
-    68/push  "Abc"/imm32
-    68/push  _test-Abc-kernel-string/imm32
-    # . . call
-    e8/call  kernel-string-equal?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-    # check-ints-equal(EAX, 1, msg)
-    # . . push args
-    68/push  "F - test-compare-kernel-string-with-equal-array"/imm32
-    68/push  1/imm32/true
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-test-compare-kernel-string-with-inequal-array:
-    # EAX = kernel-string-equal?(_test-Abc-kernel-string, "Adc")
-    # . . push args
-    68/push  "Adc"/imm32
-    68/push  _test-Abc-kernel-string/imm32
-    # . . call
-    e8/call  kernel-string-equal?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-    # check-ints-equal(EAX, 0, msg)
-    # . . push args
-    68/push  "F - test-compare-kernel-string-with-equal-array"/imm32
-    68/push  0/imm32/false
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-test-compare-kernel-string-with-empty-array:
-    # EAX = kernel-string-equal?(_test-Abc-kernel-string, "")
-    # . . push args
-    68/push  ""/imm32
-    68/push  _test-Abc-kernel-string/imm32
-    # . . call
-    e8/call  kernel-string-equal?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-    # check-ints-equal(EAX, 0, msg)
-    # . . push args
-    68/push  "F - test-compare-kernel-string-with-equal-array"/imm32
-    68/push  0/imm32/false
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-test-compare-kernel-string-with-shorter-array:
-    # EAX = kernel-string-equal?(_test-Abc-kernel-string, "Ab")
-    # . . push args
-    68/push  "Ab"/imm32
-    68/push  _test-Abc-kernel-string/imm32
-    # . . call
-    e8/call  kernel-string-equal?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-    # check-ints-equal(EAX, 0, msg)
-    # . . push args
-    68/push  "F - test-compare-kernel-string-with-shorter-array"/imm32
-    68/push  0/imm32/false
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-test-compare-kernel-string-with-longer-array:
-    # EAX = kernel-string-equal?(_test-Abc-kernel-string, "Abcd")
-    # . . push args
-    68/push  "Abcd"/imm32
-    68/push  _test-Abc-kernel-string/imm32
-    # . . call
-    e8/call  kernel-string-equal?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-    # check-ints-equal(EAX, 0, msg)
-    # . . push args
-    68/push  "F - test-compare-kernel-string-with-longer-array"/imm32
-    68/push  0/imm32/false
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-# - helpers
-
-# print msg to stderr if a != b, otherwise print "."
-check-ints-equal:  # (a : int, b : int, msg : (address array byte)) -> boolean
-    # . prolog
-    55/push-EBP
-    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
-    # . save registers
-    51/push-ECX
-    53/push-EBX
-    # load args into EAX, EBX and ECX
-    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           0/r32/EAX   8/disp8         .                 # copy *(EBP+8) to EAX
-    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           3/r32/EBX   0xc/disp8       .                 # copy *(EBP+12) to EBX
-    # if (EAX == b/EBX) print('.') and return
-    39/compare                      3/mod/direct    0/rm32/EAX    .           .             .           3/r32/EBX   .               .                 # compare EAX and EBX
-    75/jump-if-unequal  $check-ints-equal:else/disp8
-    # . write-stderr('.')
-    # . . push args
-    68/push  "."/imm32
-    # . . call
-    e8/call  write-stderr/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-    # . return
-    eb/jump  $check-ints-equal:end/disp8
-    # otherwise print(msg)
-$check-ints-equal:else:
-    # copy msg into ECX
-    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           1/r32/ECX   0x10/disp8       .                # copy *(EBP+16) to ECX
-    # print(ECX)
-    # . . push args
-    51/push-ECX
-    # . . call
-    e8/call  write-stderr/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-    # print newline
-    # . . push args
-    68/push  Newline/imm32
-    # . . call
-    e8/call  write-stderr/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-$check-ints-equal:end:
-    # . restore registers
-    5b/pop-to-EBX
-    59/pop-to-ECX
-    # end
-    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
-    5d/pop-to-EBP
-    c3/return
-
-write-stderr:  # s : (address array byte) -> <void>
-    # . prolog
-    55/push-EBP
-    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
-    # . save registers
-    50/push-EAX
-    51/push-ECX
-    52/push-EDX
-    53/push-EBX
-    # syscall(write, 2/stderr, (data) s+4, (size) *s)
-    # . . fd = 2 (stderr)
-    bb/copy-to-EBX  2/imm32
-    # . . x = s+4
-    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           1/r32/ECX   8/disp8         .                 # copy *(EBP+8) to ECX
-    81          0/subop/add         3/mod/direct    1/rm32/ECX    .           .             .           .           .               4/imm32           # add to ECX
-    # . . size = *s
-    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           2/r32/EDX   8/disp8         .                 # copy *(EBP+8) to EDX
-    8b/copy                         0/mod/indirect  2/rm32/EDX    .           .             .           2/r32/EDX   .               .                 # copy *EDX to EDX
-    # . . syscall
-    b8/copy-to-EAX  4/imm32/write
-    cd/syscall  0x80/imm8
-    # . restore registers
-    5b/pop-to-EBX
-    5a/pop-to-EDX
-    59/pop-to-ECX
-    58/pop-to-EAX
-    # . end
-    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
-    5d/pop-to-EBP
-    c3/return
-
-== data 0x0a000000
-
-Newline:
-    # size
-    1/imm32
-    # data
-    0a/newline
-
-# for kernel-string-equal tests
-Null-kernel-string:
-    00/null
-
-_test-Abc-kernel-string:
-    41/A 62/b 63/c 00/null
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex12 b/subx/examples/ex12
deleted file mode 100755
index c13a86ed..00000000
--- a/subx/examples/ex12
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex12.subx b/subx/examples/ex12.subx
deleted file mode 100644
index 358da1d3..00000000
--- a/subx/examples/ex12.subx
+++ /dev/null
@@ -1,45 +0,0 @@
-# Example showing mmap syscall.
-# Create a new segment using mmap, save the address, write to it.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex12.subx -o examples/ex12
-#   $ ./subx run examples/ex12
-# You shouldn't get a segmentation fault.
-
-== code 0x09000000
-#   instruction                     effective address                                                   register    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
-
-Entry:
-    # syscall(mmap, 0x1000)
-    bb/copy-to-EBX  Mmap-new-segment/imm32
-    b8/copy-to-EAX  0x5a/imm32/mmap
-    cd/syscall  0x80/imm8
-
-    # write to *EAX to check that we have access to the newly-allocated segment
-    c7          0/subop/copy        0/mod/direct    0/rm32/EAX    .           .             .           .           .               0x34/imm32        # copy to *EAX
-
-    # syscall(exit, EAX)
-    89/copy                         3/mod/direct    3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # copy EAX to EBX
-    b8/copy-to-EAX  1/imm32/exit
-    cd/syscall  0x80/imm8
-
-== data 0x0a000000
-
-# various constants used here were found in the Linux sources (search for file mman-common.h)
-Mmap-new-segment:  # type mmap_arg_struct
-    # addr
-    0/imm32
-    # len
-    0x100/imm32
-    # protection flags
-    3/imm32  # PROT_READ | PROT_WRITE
-    # sharing flags
-    0x22/imm32  # MAP_PRIVATE | MAP_ANONYMOUS
-    # fd
-    -1/imm32  # since MAP_ANONYMOUS is specified
-    # offset
-    0/imm32  # since MAP_ANONYMOUS is specified
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex2 b/subx/examples/ex2
deleted file mode 100755
index 55a87a3f..00000000
--- a/subx/examples/ex2
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex2.subx b/subx/examples/ex2.subx
deleted file mode 100644
index 025eb0fa..00000000
--- a/subx/examples/ex2.subx
+++ /dev/null
@@ -1,23 +0,0 @@
-# Add 1 and 1, and return the result in the exit code.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex2.subx -o examples/ex2
-#   $ ./subx run examples/ex2
-# Expected result:
-#   $ echo $?
-#   2
-
-== code 0x09000000
-
-Entry:
-# EBX = 1
-bb/copy-to-EBX  1/imm32
-# increment EBX
-43/increment-EBX
-# syscall(exit, EBX)
-b8/copy-to-EAX  1/imm32/exit
-cd/syscall  0x80/imm8
-
-== data 0x0a000000
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex3 b/subx/examples/ex3
deleted file mode 100755
index d85aba8e..00000000
--- a/subx/examples/ex3
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex3.subx b/subx/examples/ex3.subx
deleted file mode 100644
index 1d52e87f..00000000
--- a/subx/examples/ex3.subx
+++ /dev/null
@@ -1,39 +0,0 @@
-# Add the first 10 numbers, and return the result in the exit code.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex3.subx -o examples/ex3
-#   $ ./subx run examples/ex3
-# Expected result:
-#   $ echo $?
-#   55
-
-== code 0x09000000
-#   instruction                     effective address                                                   register    displacement    immediate
-# . op          subop               mod             rm32          base        index         scale       r32
-# . 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes
-
-Entry:
-    # result: EBX = 0
-    bb/copy-to-EBX  0/imm32
-    # counter: ECX = 1
-    b9/copy-to-ECX  1/imm32
-
-$loop:
-    # if (counter > 10) break
-    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0xa/imm32         # compare ECX
-    7f/jump-if-greater  $exit/disp8
-    # result += counter
-    01/add                          3/mod/direct    3/rm32/EBX    .           .             .           1/r32/ECX   .               .                 # add ECX to EBX
-    # ++counter
-    41/increment-ECX
-    # loop
-    eb/jump  $loop/disp8
-
-$exit:
-    # syscall(exit, EBX)
-    b8/copy-to-EAX  1/imm32/exit
-    cd/syscall  0x80/imm8
-
-== data 0x0a000000
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex4 b/subx/examples/ex4
deleted file mode 100755
index 66fb61e6..00000000
--- a/subx/examples/ex4
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex4.subx b/subx/examples/ex4.subx
deleted file mode 100644
index 31c1c10c..00000000
--- a/subx/examples/ex4.subx
+++ /dev/null
@@ -1,42 +0,0 @@
-# Read a character from stdin, save it to a global, write it to stdout.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex4.subx -o examples/ex4
-#   $ ./subx run examples/ex4
-
-== data 0x0a000000
-
-# the global variable we save to
-X:
-    0/imm32  # space for read() to write to
-
-== code 0x09000000
-
-Entry:
-# syscall(read, stdin, X, 1)
-# . fd = 0 (stdin)
-bb/copy-to-EBX  0/imm32
-# . data = X (location to write result to)
-b9/copy-to-ECX  X/imm32
-# . size = 1 character
-ba/copy-to-EDX  1/imm32
-# . syscall
-b8/copy-to-EAX  3/imm32/read
-cd/syscall  0x80/imm8
-
-# syscall(write, stdout, X, 1)
-# . fd = 1 (stdout)
-bb/copy-to-EBX  1/imm32
-# . initialize X (location to read from)
-b9/copy-to-ECX  X/imm32
-# . size = 1 character
-ba/copy-to-EDX  1/imm32
-# . syscall
-b8/copy-to-EAX  4/imm32/write
-cd/syscall  0x80/imm8
-
-# syscall(exit, EBX)
-b8/copy-to-EAX  1/imm32/exit
-cd/syscall  0x80/imm8
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex5 b/subx/examples/ex5
deleted file mode 100755
index 37689c98..00000000
--- a/subx/examples/ex5
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex5.subx b/subx/examples/ex5.subx
deleted file mode 100644
index 6f5b1d90..00000000
--- a/subx/examples/ex5.subx
+++ /dev/null
@@ -1,45 +0,0 @@
-# Read a character from stdin, save it to a local on the stack, write it to stdout.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex5.subx -o examples/ex5
-#   $ ./subx run examples/ex5
-
-== code 0x09000000
-#   instruction                     effective address                                                   register    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
-
-Entry:
-
-    # allocate x on the stack
-    81          5/subop/subtract    3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # subtract from ESP
-
-    # syscall(read, stdin, x, 1)
-    # . fd = 0 (stdin)
-    bb/copy-to-EBX  0/imm32
-    # . data = x (location to write result to)
-    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none              1/r32/ECX   4/disp8         .                 # copy ESP+4 to ECX
-    # . size = 1 character
-    ba/copy-to-EDX  1/imm32
-    # . syscall
-    b8/copy-to-EAX  3/imm32/read
-    cd/syscall  0x80/imm8
-
-    # syscall(write, stdout, x, 1)
-    # . fd = 1 (stdout)
-    bb/copy-to-EBX  1/imm32
-    # . data = x (location to read from)
-    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none              1/r32/ECX   4/disp8         .                 # copy ESP+4 to ECX
-    # . size = 1 character
-    ba/copy-to-EDX  1/imm32
-    # . syscall
-    b8/copy-to-EAX  4/imm32/write
-    cd/syscall  0x80/imm8
-
-    # syscall(exit, EBX)
-    b8/copy-to-EAX  1/imm32/exit
-    cd/syscall  0x80/imm8
-
-== data 0x0a000000
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex6 b/subx/examples/ex6
deleted file mode 100755
index aa84591c..00000000
--- a/subx/examples/ex6
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex6.subx b/subx/examples/ex6.subx
deleted file mode 100644
index a90f11df..00000000
--- a/subx/examples/ex6.subx
+++ /dev/null
@@ -1,37 +0,0 @@
-# Print out a (global variable) string to stdout.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex6.subx -o examples/ex6
-#   $ ./subx run examples/ex6
-#   Hello, world!
-
-== code 0x09000000
-#   instruction                     effective address                                                   register    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
-
-Entry:
-    # syscall(write, stdout, X, Size)
-    # . fd = 1 (stdout)
-    bb/copy-to-EBX  1/imm32
-    # . initialize X (location to write result to)
-    b9/copy-to-ECX  X/imm32
-    # . initialize Size
-    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           2/r32/EDX   Size/disp32     .                 # copy *Size to EDX
-    # . syscall
-    b8/copy-to-EAX  4/imm32/write
-    cd/syscall  0x80/imm8
-
-    # syscall(exit, EBX)
-    b8/copy-to-EAX  1/imm32/exit
-    cd/syscall  0x80/imm8
-
-== data 0x0a000000
-
-Size:  # size of string
-    0x0e/imm32  # 14
-X:  # string to print
-    48 65 6c 6c 6f 2c 20 77 6f 72 6c 64 21 0a       00
-#   H  e  l  l  o  ,  ␣  w  o  r  l  d  !  newline  null
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex7 b/subx/examples/ex7
deleted file mode 100755
index 28c5bda9..00000000
--- a/subx/examples/ex7
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex7.subx b/subx/examples/ex7.subx
deleted file mode 100644
index d3b33f23..00000000
--- a/subx/examples/ex7.subx
+++ /dev/null
@@ -1,107 +0,0 @@
-# Example showing file syscalls.
-#
-# Create a file, open it for writing, write a character to it, close it, open
-# it for reading, read a character from it, close it, delete it, and return
-# the character read.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex7.subx -o examples/ex7
-#   $ ./subx run examples/ex7
-# Expected result:
-#   $ echo $?
-#   97
-
-== code 0x09000000
-#   instruction                     effective address                                                   register    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
-
-Entry:
-    # syscall(creat, Filename)
-    bb/copy-to-EBX  Filename/imm32
-    b9/copy-to-ECX  0x180/imm32/fixed-perms
-    b8/copy-to-EAX  8/imm32/creat
-    cd/syscall  0x80/imm8
-
-    # stream = syscall(open, Filename, O_WRONLY, 0)  # we can't use 'fd' because it looks like a hex byte
-    bb/copy-to-EBX  Filename/imm32
-    b9/copy-to-ECX  1/imm32/wronly
-    ba/copy-to-EDX  0x180/imm32/fixed-perms
-    b8/copy-to-EAX  5/imm32/open
-    cd/syscall  0x80/imm8
-    # save stream
-    bb/copy-to-EBX  Stream/imm32
-    89/copy                         0/mod/indirect  3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # copy EAX to *EBX
-
-    # syscall(write, Stream, "a", 1)
-    # . load stream
-    bb/copy-to-EBX  Stream/imm32
-    8b/copy                         0/mod/indirect  3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # copy *EBX to EBX
-    # .
-    b9/copy-to-ECX  A/imm32
-    ba/copy-to-EDX  1/imm32/size
-    b8/copy-to-EAX  4/imm32/write
-    cd/syscall  0x80/imm8
-
-    # syscall(close, Stream)
-    # . load stream
-    bb/copy-to-EBX  Stream/imm32
-    8b/copy                         0/mod/indirect  3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # copy *EBX to EBX
-    # .
-    b8/copy-to-EAX  6/imm32/close
-    cd/syscall  0x80/imm8
-
-    # stream = syscall(open, Filename, O_RDONLY, 0)
-    bb/copy-to-EBX  Filename/imm32
-    b9/copy-to-ECX  0/imm32/rdonly
-    ba/copy-to-EDX  0x180/imm32/fixed-perms
-    b8/copy-to-EAX  5/imm32/open
-    cd/syscall  0x80/imm8
-    # . save Stream
-    bb/copy-to-EBX  Stream/imm32
-    89/copy                         0/mod/indirect  3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # copy EAX to *EBX
-
-    # syscall(read, Stream, B, 1)
-    # . load stream
-    bb/copy-to-EBX  Stream/imm32
-    8b/copy                         0/mod/indirect  3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # copy *EBX to EBX
-    # .
-    b9/copy-to-ECX  B/imm32
-    ba/copy-to-EDX  1/imm32/size
-    b8/copy-to-EAX  3/imm32/read
-    cd/syscall  0x80/imm8
-
-    # syscall(close, Stream)
-    # . load stream
-    bb/copy-to-EBX  Stream/imm32
-    8b/copy                         0/mod/indirect  3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # copy *EBX to EBX
-    #
-    b8/copy-to-EAX  6/imm32/close
-    cd/syscall  0x80/imm8
-
-    # syscall(unlink, filename)
-    bb/copy-to-EBX  Filename/imm32
-    b8/copy-to-EAX  0xa/imm32/unlink
-    cd/syscall  0x80/imm8
-
-    # syscall(exit, b)
-    # . load b
-    bb/copy-to-EBX  B/imm32
-    8b/copy                         0/mod/indirect  3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # copy *EBX to EBX
-    #
-    b8/copy-to-EAX  1/imm32/exit
-    cd/syscall  0x80/imm8
-
-== data 0x0a000000
-
-Stream:
-    0/imm32
-A:
-    61/imm32/A
-B:
-    0/imm32
-Filename:
-    2e 66 6f 6f 00 00 00 00
-#   .  f  o  o  null
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex8 b/subx/examples/ex8
deleted file mode 100755
index 5be0e1e6..00000000
--- a/subx/examples/ex8
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex8.subx b/subx/examples/ex8.subx
deleted file mode 100644
index 9d7255e1..00000000
--- a/subx/examples/ex8.subx
+++ /dev/null
@@ -1,61 +0,0 @@
-# Example reading commandline arguments: compute length of first arg.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex8.subx -o examples/ex8
-#   $ ./subx run examples/ex8 abc de fghi
-# Expected result:
-#   $ echo $?
-#   3  # length of 'abc'
-#
-# At the start of a SubX program:
-#   argc: *ESP
-#   argv[0]: *(ESP+4)
-#   argv[1]: *(ESP+8)
-#   ...
-# Locals start from ESP-4 downwards.
-
-== code 0x09000000
-#   instruction                     effective address                                                   register    displacement    immediate
-# . op          subop               mod             rm32          base        index         scale       r32
-# . 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes
-
-Entry:
-    # . prolog
-    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
-    # EAX = ascii-length(argv[1])
-    # . . push args
-    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
-    # . . call
-    e8/call  ascii-length/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-
-    # exit(EAX)
-    89/copy                         3/mod/direct    3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # copy EAX to EBX
-    b8/copy-to-EAX  1/imm32/exit
-    cd/syscall  0x80/imm8
-
-ascii-length:  # s : (address array byte) -> n/EAX
-    # EDX = s
-    8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none  .           2/r32/EDX   4/disp8         .                 # copy *(ESP+4) to EDX
-    # var result/EAX = 0
-    b8/copy-to-EAX  0/imm32
-$ascii-length:loop:
-    # var c/ECX = *s
-    8a/copy-byte                    0/mod/*         2/rm32/EDX    .           .             .           1/r32/CL    .               .                 # copy byte at *EDX to CL
-    # if (c == '\0') break
-    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0/imm32           # compare ECX
-    74/jump-if-equal  $ascii-length:end/disp8
-    # ++s
-    42/increment-EDX
-    # ++result
-    40/increment-EAX
-    # loop
-    eb/jump  $ascii-length:loop/disp8
-$ascii-length:end:
-    # return EAX
-    c3/return
-
-== data 0x0a000000
-
-# . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex9 b/subx/examples/ex9
deleted file mode 100755
index fce7629c..00000000
--- a/subx/examples/ex9
+++ /dev/null
Binary files differdiff --git a/subx/examples/ex9.subx b/subx/examples/ex9.subx
deleted file mode 100644
index e3318b05..00000000
--- a/subx/examples/ex9.subx
+++ /dev/null
@@ -1,55 +0,0 @@
-# Example showing arg order on the stack.
-#
-# Show difference between ascii codes of first letter of first arg and first
-# letter of second arg.
-#
-# To run (from the subx directory):
-#   $ ./subx translate examples/ex9.subx -o examples/ex9
-#   $ ./subx run examples/ex9 z x
-# Expected result:
-#   $ echo $?
-#   2
-#
-# At the start of a SubX program:
-#   argc: *ESP
-#   argv[0]: *(ESP+4)
-#   argv[1]: *(ESP+8)
-#   ...
-# Locals start from ESP-4 downwards.
-
-== code 0x09000000
-#   instruction                     effective address                                                   register    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
-
-Entry:
-    # . prolog
-    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
-    # ascii-difference(argv[1], argv[2])
-    # . . push argv[2]
-    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
-    # . . push argv[1]
-    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
-    # . . call
-    e8/call  ascii-difference/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-    # syscall(exit, EAX)
-    89/copy                         3/mod/direct    3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # copy EAX to EBX
-    b8/copy-to-EAX  1/imm32/exit
-    cd/syscall  0x80/imm8
-
-ascii-difference:  # (s1, s2) : null-terminated ascii strings
-    # a = first letter of s1 (ECX)
-    8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none              0/r32/EAX   4/disp8         .                 # copy *(ESP+4) to EAX
-    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # copy *EAX to EAX
-    # b = first letter of s2 (EDX)
-    8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none              1/r32/ECX   8/disp8                           # copy *(ESP+8) to ECX
-    8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           1/r32/ECX   .               .                 # copy *ECX to ECX
-    # a-b
-    29/subtract                     3/mod/direct    0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # subtract ECX from EAX
-    c3/return
-
-== data 0x0a000000
-
-# . . vim:nowrap:textwidth=0