diff --git a/bootstrapping Steps.org b/bootstrapping Steps.org
index 2b926b1..05b6446 100644
--- a/bootstrapping Steps.org
+++ b/bootstrapping Steps.org
@@ -37,7 +37,7 @@ gcc Linux\ Bootstrap/hex.c -o bin/hex
Then we can use it to make our bootstrap binary:
./bin/hex < stage0/stage0_monitor.hex0 > roms/stage0_monitor
-Which should have the sha256sum of 792e2be913921dd55a28f55dcf2e6b1523d34fdbccc27c38f77e74c99ef97a4b
+Which should have the sha256sum of c9d397b195c6ba2bb4b19428d8b21e7737a32e5275f3027270d8925aec878042
* Step 2 create a hex assembler
Now that we have a Hex monitor, we are now capable of either creating a text file (no ability to correct mistakes along the way) or any arbitrary hex program we want.
diff --git a/makefile b/makefile
index f612705..975c9d8 100644
--- a/makefile
+++ b/makefile
@@ -110,7 +110,7 @@ Generate-rom-test: ALL-ROMS
mkdir -p test
sha256sum roms/* | sort -k2 >| test/SHA256SUMS
-test_stage0_monitor_asm_match: stage0_monitor
+test_stage0_monitor_asm_match: asm stage0_monitor
mkdir -p test/stage0_test_scratch
sed 's/^[^#]*# //' stage0/stage0_monitor.hex0 > test/stage0_test_scratch/stage0_monitor.hex0.s
bin/asm test/stage0_test_scratch/stage0_monitor.hex0.s > test/stage0_test_scratch/stage0_monitor.hex0.hex0
diff --git a/stage0/stage0_monitor.hex0 b/stage0/stage0_monitor.hex0
index d9fdbe0..d680dc4 100644
--- a/stage0/stage0_monitor.hex0
+++ b/stage0/stage0_monitor.hex0
@@ -15,20 +15,35 @@
## along with stage0. If not, see .
# :start ; offset = 0
-E0002D2B0001 # LOADUI R11 1 ; Our toggle
-E0002D2D0600 # LOADUI R13 0x600 ; Where we are starting our Stack
- # ;; R14 will be storing our condition
-0D00002F # FALSE R15 ; Our holder
+
+0D00003C # TRUE R12 ; Our toggle, set to -1 (0xFFFFFFFF)
+
+# ;; Prepare often-used values that will be held in registers
+090001AC # ABS R10 R12 ; Set R10 to 1
+E0002D2B1100 # LOADUI R11 0x1100 ; R11 will hold 0x1100
+ #
+ # ;; R14 will be storing our condition
+ # ;;
+ # ;; R13 will be a stack pointer. It will be zero
+ # ;; on the start, and the stack grows up.
+ # ;; This means that when stack is used, the
+ # ;; first instructions of this program will be
+ # ;; overwritten. But because this is initialization
+ # ;; code, it is already not used at the time.
+ # ;; And the stack usage is fixed - there is only one CALL
+ # ;; instruction in this file
+ # ;;
+ # ;; R15 Is our holder. It is initialized to zero on start.
# ;; Prep TAPE_01
-E0002D201100 # LOADUI R0 0x1100
+0900040B # COPY R0 R11 ; 0x1100
42100001 # FOPEN_WRITE
# ;; Prep TAPE_02
-E0002D201101 # LOADUI R0 0x1101
+050210BA # OR R0 R11 R10 ; 0x1101
42100001 # FOPEN_WRITE
-# :loop ; offset = 24
+# :loop ; offset = 1e
0D000021 # FALSE R1 ; Read from tty
42100100 # FGETC ; Read a Char
E000A030000d # CMPSKIPI.NE R0 13 ; Replace all CR
@@ -36,44 +51,47 @@ E0002D20000a # LOADUI R0 10 ; WIth LF
42100200 # FPUTC ; Display the Char to User
# ;; Check for Ctrl-D
-
E000A0300004 # CMPSKIPI.NE R0 4
-3C000110 # JUMP @finish
+3C000108 # JUMP @finish
# ;; Check for EOF
-E0002CC0010a # JUMP.NP R0 @finish
+E0002CC00102 # JUMP.NP R0 @finish
# ;; Write out unprocessed byte
-E0002D211101 # LOADUI R1 0x1101 ; Write to TAPE_02
+050211BA # OR R1 R11 R10 ; Write to TAPE_02
42100200 # FPUTC ; Print the Char
# ;; Convert byte to nybble
-E0002D0D003e # CALLI R13 @hex ; Convert it
+E0002D0D003a # CALLI R13 @hex ; Convert it
# ;; Get another byte if nonhex
-E0002CC0ffc2 # JUMP.NP R0 @loop ; Don't use nonhex chars
+E0002CC0ffc4 # JUMP.NP R0 @loop ; Don't use nonhex chars
# ;; Deal with the case of second nybble
-E0002C9B000e # JUMP.Z R11 @second_nybble ; Jump if toggled
+E0002C9C000e # JUMP.Z R12 @second_nybble ; Jump if toggled
# ;; Process first byte of pair
E100B0F0000f # ANDI R15 R0 0x0F ; Store First nibble
-0D00002B # FALSE R11 ; Flip the toggle
-3C00ffae # JUMP @loop
+0D00002C # FALSE R12 ; Flip the toggle
+3C00ffb0 # JUMP @loop
# ;; Combined second nybble in pair with first
-# :second_nybble ; offset = 76
+
+# :second_nybble ; offset = 6e
E0002D5F0004 # SL0I R15 4 ; Shift our first nibble
E100B000000f # ANDI R0 R0 0x0F ; Mask out top
0500000F # ADD R0 R0 R15 ; Combine nibbles
# ;; Writeout and prepare for next cycle
-E0002D1B0001 # LOADI R11 1 ; Flip the toggle
-E0002D211100 # LOADUI R1 0x1100 ; Write the combined byte
-42100200 # FPUTC ; To TAPE_01
-3C00ff8a # JUMP @loop ; Try to get more bytes
+0D00003C # TRUE R12 ; Flip the toggle
+
+# ; Write the combined byte
+0900041B # COPY R1 R11 ; To TAPE_01
+42100200 # FPUTC
+3C00ff90 # JUMP @loop ; Try to get more bytes
+
+# :hex ; offset = 8e
-# :hex ; offset = 9a
# ;; Deal with line comments starting with #
E1001FE00023 # CMPUI R14 R0 35
E0002C5E007e # JUMP.E R14 @ascii_comment
@@ -107,39 +125,39 @@ E1001FE00066 # CMPUI R14 R0 102
E0002C7E000e # JUMP.LE R14 @ascii_low
# ;; Ignore the rest
-3C00001e # JUMP @ascii_other
+3C00001e # JUMP @ascii_other
-# :ascii_num ; offset = FD
+# :ascii_num ; offset = f2
E10011000030 # SUBUI R0 R0 48
0D01001D # RET R13
-# :ascii_low ; offset = 108
+# :ascii_low ; offset = fc
E10011000057 # SUBUI R0 R0 87
0D01001D # RET R13
-# :ascii_high ; offset = 112
+# :ascii_high ; offset = 106
E10011000037 # SUBUI R0 R0 55
0D01001D # RET R13
-# :ascii_other ; offset = 11c
+# :ascii_other ; offset = 110
0D000030 # TRUE R0
0D01001D # RET R13
-# :ascii_comment ; offset = 124
+# :ascii_comment ; offset = 118
0D000021 # FALSE R1 ; Read from tty
42100100 # FGETC ; Read another char
E000A030000d # CMPSKIPI.NE R0 13 ; Replace all CR
E0002D20000a # LOADUI R0 10 ; WIth LF
42100200 # FPUTC ; Let the user see it
E1001FE0000a # CMPUI R14 R0 10 ; Stop at the end of line
-E0002D211101 # LOADUI R1 0x1101 ; Write to TAPE_02
+050211BA # OR R1 R11 R10 ; Write to TAPE_02
42100200 # FPUTC ; The char we just read
-E0002C6Effd2 # JUMP.NE R14 @ascii_comment ; Otherwise keep looping
-3C00ffc6 # JUMP @ascii_other
+E0002C6Effd4 # JUMP.NE R14 @ascii_comment ; Otherwise keep looping
+3C00ffc8 # JUMP @ascii_other
-# :finish ; offset = 156
-E0002D201100 # LOADUI R0 0x1100 ; Close TAPE_01
+# :finish ; offset = 148
+0900040B # COPY R0 R11 ; Close TAPE_01
42100002 # FCLOSE
-E0002D201101 # LOADUI R0 0x1101 ; Close TAPE_02
+050210BA # OR R0 R11 R10 ; Close TAPE_02
42100002 # FCLOSE
FFFFFFFF # HALT
diff --git a/stage0/stage0_monitor.s b/stage0/stage0_monitor.s
index 746f6ca..f69bb09 100644
--- a/stage0/stage0_monitor.s
+++ b/stage0/stage0_monitor.s
@@ -15,17 +15,31 @@
; along with stage0. If not, see .
:start
- LOADUI R11 1 ; Our toggle
- LOADUI R13 0x600 ; Where we are starting our Stack
- ;; R14 will be storing our condition
- FALSE R15 ; Our holder
+ TRUE R12 ; Our toggle, set to -1 (0xFFFFFFFF)
+
+ ;; Prepare often-used values that will be held in registers
+ ABS R10 R12 ; Set R10 to 1
+ LOADUI R11 0x1100 ; R11 will hold 0x1100
+
+ ;; R14 will be storing our condition
+ ;;
+ ;; R13 will be a stack pointer. It will be zero
+ ;; on the start, and the stack grows up.
+ ;; This means that when stack is used, the
+ ;; first instructions of this program will be
+ ;; overwritten. But because this is initialization
+ ;; code, it is already not used at the time.
+ ;; And the stack usage is fixed - there is only one CALL
+ ;; instruction in this file
+ ;;
+ ;; R15 Is our holder. It is initialized to zero on start.
;; Prep TAPE_01
- LOADUI R0 0x1100
+ COPY R0 R11 ; 0x1100
FOPEN_WRITE
;; Prep TAPE_02
- LOADUI R0 0x1101
+ OR R0 R11 R10 ; 0x1101
FOPEN_WRITE
:loop
@@ -45,7 +59,7 @@
JUMP.NP R0 @finish
;; Write out unprocessed byte
- LOADUI R1 0x1101 ; Write to TAPE_02
+ OR R1 R11 R10 ; Write to TAPE_02
FPUTC ; Print the Char
;; Convert byte to nybble
@@ -55,11 +69,11 @@
JUMP.NP R0 @loop ; Don't use nonhex chars
;; Deal with the case of second nybble
- JUMP.Z R11 @second_nybble ; Jump if toggled
+ JUMP.Z R12 @second_nybble ; Jump if toggled
;; Process first byte of pair
ANDI R15 R0 0x0F ; Store First nibble
- FALSE R11 ; Flip the toggle
+ FALSE R12 ; Flip the toggle
JUMP @loop
;; Combined second nybble in pair with first
@@ -69,9 +83,10 @@
ADD R0 R0 R15 ; Combine nibbles
;; Writeout and prepare for next cycle
- LOADI R11 1 ; Flip the toggle
- LOADUI R1 0x1100 ; Write the combined byte
- FPUTC ; To TAPE_01
+ TRUE R12 ; Flip the toggle
+ ; Write the combined byte
+ COPY R1 R11 ; To TAPE_01
+ FPUTC
JUMP @loop ; Try to get more bytes
:hex
@@ -121,14 +136,14 @@
LOADUI R0 10 ; WIth LF
FPUTC ; Let the user see it
CMPUI R14 R0 10 ; Stop at the end of line
- LOADUI R1 0x1101 ; Write to TAPE_02
+ OR R1 R11 R10 ; Write to TAPE_02
FPUTC ; The char we just read
JUMP.NE R14 @ascii_comment ; Otherwise keep looping
JUMP @ascii_other
:finish
- LOADUI R0 0x1100 ; Close TAPE_01
+ COPY R0 R11 ; Close TAPE_01
FCLOSE
- LOADUI R0 0x1101 ; Close TAPE_02
+ OR R0 R11 R10 ; Close TAPE_02
FCLOSE
HALT
diff --git a/test/SHA256SUMS b/test/SHA256SUMS
index 5741dbd..8de36b8 100644
--- a/test/SHA256SUMS
+++ b/test/SHA256SUMS
@@ -5,7 +5,7 @@ f4bbf9e9c4828170d0c153ac265382dc705643f95efd2a029243326d426be5a4 roms/forth
2b80849180d5fb3757bcca2471b6337808e5b5ca80b18d93fa82ddef0435b84b roms/lisp
3020b194ead31ae19ba66fc35ed95465514373f6005896350d1608c9efabbdca roms/M0
059d38e34275029f2de5f600f08fe01bd13cd173f7da58e3fbec7114074beff2 roms/SET
-792e2be913921dd55a28f55dcf2e6b1523d34fdbccc27c38f77e74c99ef97a4b roms/stage0_monitor
+c9d397b195c6ba2bb4b19428d8b21e7737a32e5275f3027270d8925aec878042 roms/stage0_monitor
13b45134a88c1c6db349cb40f82269cee9edfce71ac644dc0e137bad053bf5ce roms/stage1_assembler-0
156f555fce5b02f52445652b1ed0b443295706cdfbe23c5a021bd4efc77179bb roms/stage1_assembler-1
2c02c50958f489a660a4915d2a9e207a0c61f411d42628bdaf4dcf6bf7149a9d roms/stage1_assembler-2