From 82d3ddfc5c0bf2ba77c04d65630841f373cce709 Mon Sep 17 00:00:00 2001
From: s-ol <s-ol@users.noreply.github.com>
Date: Thu, 28 May 2020 17:34:15 +0200
Subject: Add ex.*

---
 README.md | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 66 insertions(+), 1 deletion(-)

(limited to 'README.md')

diff --git a/README.md b/README.md
index b3d718b..663f819 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,72 @@ back to front:
 - `survey.py`: replaces label references by their addresses
 - `format.py`: checks op-arguments and chops and orders arguments into ISA formats
 
-and now back to front with a little example:
+and now front to back with a little example:
+
+    $ ./format.py <ex.subv   >ex.format
+    $ ./survey.py <ex.format >ex.survey
+    $ ./pack.py   <ex.survey >ex.pack
+    $ ./elf.py    <ex.pack   >ex.elf
+    $ ./qemu.sh ex.elf
+
+`ex.subv`: hand-writable.
+
+    == code 0x80000000
+    # repeatedly print "Hi\\n"
+    main:
+      # load 0x10010000 (UART0) into t0
+      37/lui 5/rd/t0 0x10010/imm20
+      # store 0x48 (H) in UART0+0
+      13/opi 0/subop/add 6/rd/t1 0/rs/x0 48/imm12
+      23/store 2/subop/word 5/rs/t0 6/rs/t1 0/off12
+      # store 0x69 (i) in UART0+0
+      13/opi 0/subop/add 6/rd/t1 0/rs/x0 69/imm12
+      23/store 2/subop/word 5/rs/t0 6/rs/t1 0/off12
+      # store 0x0a (\n) in UART0+0
+      13/opi 0/subop/add 6/rd/t1 0/rs/x0 0a/imm12
+      23/store 2/subop/word 5/rs/t0 6/rs/t1 0/off12
+      # jump back up to the top
+      6f/jal 0/rd/x0 main/off21
+
+`ex.format`: arguments sliced and diced and put into the ISA order.
+
+    == code 0x80000000
+    main:
+    37/7 05/5 10010/20
+    13/7 06/5 00/3 00/5 48/12
+    23/7 00/5 02/3 05/5 06/5 00/7
+    13/7 06/5 00/3 00/5 69/12
+    23/7 00/5 02/3 05/5 06/5 00/7
+    13/7 06/5 00/3 00/5 0a/12
+    23/7 00/5 02/3 05/5 06/5 00/7
+    6f/7 00/5 main/8/off21>>12 main/1/off21>>11 main/10/off21>>1 main/1/off21>>20
+
+
+`ex.survey`: labels resolved, ready to be packed into hex format
+
+    == code 0x80000000
+    37/7 05/5 10010/20
+    13/7 06/5 00/3 00/5 48/12
+    23/7 00/5 02/3 05/5 06/5 00/7
+    13/7 06/5 00/3 00/5 69/12
+    23/7 00/5 02/3 05/5 06/5 00/7
+    13/7 06/5 00/3 00/5 0a/12
+    23/7 00/5 02/3 05/5 06/5 00/7
+    6f/7 00/5 ff/8 01/1 3f2/10 01/1
+
+`ex.pack`: fully packed, ready to run bare-metal
+
+    == code 0x80000000
+    b7 02 01 10
+    13 03 80 04
+    23 a0 62 00
+    13 03 90 06
+    23 a0 62 00
+    13 03 a0 00
+    23 a0 62 00
+    6f f0 5f fe
+
+`ex.elf`: binary file for use with `qemu` (see next section).
 
 Debugging
 ---------
-- 
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