add validate layer

1 files changed, 50 insertions, 15 deletions

diff --git a/README.md b/README.md
index 55e5375..cd47df9 100644
--- a/README.md
+++ b/README.md
@@ -33,15 +33,17 @@ back to front:
 
 - `elf.py`: takes hex bytes and segment headers, outputs an ELF file
 - `pack.py`: packs bitfields (`3/3 1/1 f/4`) into hex bytes (`fb`)
+- `format.py`: bit-packs ops into ISA format
 - `survey.py`: replaces label references by their addresses
-- `format.py`: checks op-arguments and chops and orders arguments into ISA formats
+- `validate.py`: checks op-arguments and puts them into canonical order
 
 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
+    $ ./validate.py <ex.subv  >ex.valid
+    $ ./survey.py  <ex.valid  >ex.survey
+    $ ./format.py  <ex.survey >ex.format
+    $ ./pack.py    <ex.format >ex.pack
+    $ ./elf.py     <ex.pack   >ex.elf
     $ ./qemu.sh ex.elf
 
 `ex.subv`: hand-writable.
@@ -63,47 +65,80 @@ and now front to back with a little example:
       # 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.
+`ex.format`: mnemonics validated and discarded
 
     == code 0x80000000
     # repeatedly print "Hi\n"
     main:
     # load 0x10010000 (UART0) into t0
-    37/7 05/5 10010/20
+    37/u 05/rd 10010/imm20
     # store 0x48 (H) in UART0+0
-    13/7 06/5 00/3 00/5 48/12
-    23/7 00/5 02/3 05/5 06/5 00/7
+    13/i 0/subop 6/rd 0/rs 48/imm12
+    23/s 2/subop 5/rs2 6/rs1 0/off12
     # store 0x69 (i) in UART0+0
-    13/7 06/5 00/3 00/5 69/12
-    23/7 00/5 02/3 05/5 06/5 00/7
+    13/i 0/subop 6/rd 0/rs 69/imm12
+    23/s 2/subop 5/rs2 6/rs1 0/off12
     # store 0x0a (\n) in UART0+0
-    13/7 06/5 00/3 00/5 0a/12
-    23/7 00/5 02/3 05/5 06/5 00/7
+    13/i 0/subop 6/rd 0/rs 0a/imm12
+    23/s 2/subop 5/rs2 6/rs1 0/off12
+    # jump back up to the top
+    6f/j 0/4d main/off21
+
+`ex.survey`: references resolved and labels removed
+
+    == code 0x80000000
+    # repeatedly print "Hi\n"
+    # main:
+    # load 0x10010000 (UART0) into t0
+    37/u 05/rd 10010/imm20
+    # store 0x48 (H) in UART0+0
+    13/i 0/subop 6/rd 0/rs 48/imm12
+    23/s 2/subop 5/rs2 6/rs1 0/off12
+    # store 0x69 (i) in UART0+0
+    13/i 0/subop 6/rd 0/rs 69/imm12
+    23/s 2/subop 5/rs2 6/rs1 0/off12
+    # store 0x0a (\n) in UART0+0
+    13/i 0/subop 6/rd 0/rs 0a/imm12
+    23/s 2/subop 5/rs2 6/rs1 0/off12
     # jump back up to the top
-    6f/7 00/5 main/8/off21>>12 main/1/off21>>11 main/10/off21>>1 main/1/off21>>20
+    6f/j 0/4d fffe4/off21
 
-`ex.survey`: labels resolved, ready to be packed into hex format
+`ex.format`: arguments sliced and diced and put into the ISA order.
 
     == code 0x80000000
+    # repeatedly print "Hi\n"
+    # main:
+    # load 0x10010000 (UART0) into t0
     37/7 05/5 10010/20
+    # store 0x48 (H) in UART0+0
     13/7 06/5 00/3 00/5 48/12
     23/7 00/5 02/3 05/5 06/5 00/7
+    # store 0x69 (i) in UART0+0
     13/7 06/5 00/3 00/5 69/12
     23/7 00/5 02/3 05/5 06/5 00/7
+    # store 0x0a (\n) in UART0+0
     13/7 06/5 00/3 00/5 0a/12
     23/7 00/5 02/3 05/5 06/5 00/7
+    # jump back up to the top
     6f/7 00/5 ff/8 01/1 3f2/10 01/1
 
 `ex.pack`: fully packed, ready to run bare-metal
 
     == code 0x80000000
+    # repeatedly print "Hi\n"
+    # main:
+    # load 0x10010000 (UART0) into t0
     b7 02 01 10
+    # store 0x48 (H) in UART0+0
     13 03 80 04
     23 a0 62 00
+    # store 0x69 (i) in UART0+0
     13 03 90 06
     23 a0 62 00
+    # store 0x0a (\n) in UART0+0
     13 03 a0 00
     23 a0 62 00
+    # jump back up to the top
     6f f0 5f fe
 
 `ex.elf`: binary file for use with `qemu` (see next section).