feat(bios): BIOS interface accessible through SWI3

bbmkhash.c

@@ -25,7 +25,7 @@ int main(void) {
 ; Copyright (c) 2025 Gale Faraday\n\
 ; Licensed under MIT\n\
 \n\
-; This file generated by bbmkcmds.c\n\
+; This file generated by bbmkhash.c\n\
 \n\
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n\
 ;;\n\

docs/buzbee.typ

@@ -49,24 +49,29 @@ listed in alphabetical order. Below in @if-table is a list of available IFs.
 
 #figure(
   table(
-    columns: (1fr, auto),
+    columns: (auto, auto, 1fr),
     inset: 10pt,
     align: center,
     fill: (_, y) =>
       if calc.odd(y) { luma(250) }
       else { white },
     table.header(
-      [*Name* (pg. no.)], [*Description*]
+      [*Name* (pg. no.)], [*Command Token*], [*Description*]
     ),
     [`CALL` (#ref(<if-call>, form: "page"))],
+    [`$00`],
     [Call a resident routine in the MPU's address space.],
     [`HELP` (#ref(<if-help>, form: "page"))],
+    [`$01`],
     [Display a summary of known commands.],
     [`PEEK` (#ref(<if-peek>, form: "page"))],
+    [`$02`],
     [Dumps memory from the MPU's address space to the terminal.],
     [`POKE` (#ref(<if-poke>, form: "page"))],
+    [`$03`],
     [Overwrites memory in the MPU's address space.],
     [`SREC` (#ref(<if-srec>, form: "page"))],
+    [`$04`],
     [Switches into Motorola S-Record receive mode.],
   ),
   caption: [Table of IFs],
@@ -75,8 +80,7 @@ listed in alphabetical order. Below in @if-table is a list of available IFs.
 In the following pages these IFs are described in specific.
 
 IFs are tokenized from their textual form into a binary "bytecode" form. This
-bytecode is not reliably stable between versions, so it isn't described here in
-specific, but a general breakdown is provided.
+bytecode is described in @internals.
 
 First the text command name (eg. `CALL`) is hashed in some way into a token.
 Then conditional processing on the remainder of the line occurs. Values given in
@@ -147,12 +151,12 @@ BIOS routine.
   syntax: [`PEEK <BASE> [<HIGH>]`],
   params: (
     base: [
-      The address of the byte to dump or the base (lower bound) address of the
-      byte to start dumping from if `<HIGH>` is specified.
+      The address (two bytes) of the byte to dump or the base (lower bound)
+      address of the byte to start dumping from if `<HIGH>` is specified.
     ],
     high: [
       An optional operand given as the upper bound of the range to dump. Forms
-      a range together with `<BASE>`.
+      a range together with `<BASE>`. (two bytes)
     ],
   )
 )
@@ -160,8 +164,6 @@ BIOS routine.
 Peeking memory causes the MPU to read the requested bytes and dump them to the
 screen.
 
-#lorem(120)
-
 #pagebreak()
 
 === IF: `POKE` <if-poke>
@@ -170,12 +172,13 @@ screen.
   desc: "Writes values to the MPU's address space.",
   syntax: [`POKE <ADDR> <BYTES>`],
   params: (
-    addr: "The base (low) address to start writing bytes from.",
+    addr: "The base (low) address (two bytes) to start writing bytes from.",
     bytes: "The bytes to write into memory separated by whitespace.",
   )
 )
 
-#lorem(120)
+Poking memory causes the MPU to overwrite the bytes at `<ADDR>` with the bytes
+given in `<BYTES>`.
 
 #pagebreak()
 
@@ -187,7 +190,7 @@ screen.
   params: (),
 )
 
-#lorem(120)
+Motorola S-Record mode is currently a stub.
 
 #pagebreak()
 
@@ -273,7 +276,9 @@ Building the documentation can also be accomplished using `make docs`, provided
 = BUZBEE Internals and Modding <internals>
 
 BUZBEE's interpreter works by "compiling" textual user commands into bytecode
-for more simply passing parameters to IFs (see @if-top).
+for more simply passing parameters to IFs (see @if-top). The way that works is
+the implementation dependent, but each hash is one byte (1B) in size, and
+corresponds to an IF token, which is the index of the hash.
 
 BUZBEE's source, and the surrounding BIOS source is well commented, but a
 general summary of the control flow is provided here.

linkscript

@@ -1,9 +1,17 @@
+; BIOS
 section RESET load 8000
 section SERIAL
+
+; BIOS Interface and Utilities
+section BIOSINT load 8800
 section MEMTEST
 
+; BUZBEE Monitor
 section BUZBEE
 section BBHASHES
 
+; Static Data
 section VECTORS high 100000
 section VERSION high
+
+entry 8000

src/buzbee.s

@@ -42,11 +42,12 @@ BBVAR tagbbvar
 BUZBEE
   lbsr NEWLINE       ; Setup the new input line and handle display.
   bsr INPLOOP        ; Fill input buffer.
-  cmpy #$0000  ; No data?
+  cmpy #0            ; No data?
   beq BUZBEE         ;  Try again...
-  ; TODO: Parse the input buffer into tokens
-  lbsr RUNIF
-  bra BUZBEE
+  lbsr MKINSENSITIVE ; Make the input buffer case insensitive
+  lbsr TOKENIZE      ; Try to tokenize the input buffer
+  lbsr RUNIF         ; Execute token buffer, handling any errors
+  bra BUZBEE         ; Repeat
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
@@ -58,7 +59,7 @@ BUZBEE
 ; offset in the input buffer of the last char read.
 INPLOOP
   jsr PINCHAR          ; Try to read a char
-  cmpd #$0000          ; If no char keep waitin'
+  cmpd #0              ; If no char keep waitin'
   beq INPLOOP
   bitb #UARTF_LSR_DR   ; Is there a char in A?
   beq NOCHAR@
@@ -101,7 +102,7 @@ HCR@
 HESC@
   lda #'^              ; Print a char that signifies that ESC was pressed
   jsr POUTCHAR
-  ldy #$0000           ; On return we cmpy #$0000 and if eq then newline.
+  ldy #0               ; On return we cmpy #0 and if eq then newline
   rts
 HBACKSPC@
   clrb                 ; Clear last char
@@ -118,13 +119,28 @@ NEWLINE
   PZSTR PROMPTLINE  ; Print prompt line
 CLRIN               ; Label to just clear input buffer without newline
   clra              ; Init A and X
-  ldx #$0000
+  ldx #0
 NEXT@
   sta BBVAR.input,x ; Clear input buffer
   leax 1,x
   cmpx #BBIN_DEPTH
   blo NEXT@
-  ldy #$0000        ; Reset buffer fill pointer
+  ldy #0            ; Reset buffer fill pointer
+  rts
+
+; Makes the input buffer case insensitive
+MKINSENSITIVE
+NEXTC@
+  lda BBVAR.input,x
+  cmpa #'z            ; Is the char outside the lowercase range?
+  bhi NOTLCASE@       ;  Yes? Skip offset part
+  cmpa #'a            ; Again on the other side of the range
+  blo NOTLCASE@
+  anda #$DF           ; -32
+NOTLCASE@
+  leax 1,x            ; Ready next char
+  cmpx BBVAR.cchinput ; Are we at the end?
+  bne NEXTC@          ;  No? Loop
   rts
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -143,24 +159,22 @@ PBYTE
   asra
   asra
   asra
-  bsr NYB2HEX ; Print A
-  jsr POUTCHAR
-  tfr b,a      ; Print B next
-  bsr NYB2HEX ; Print B
-  jsr POUTCHAR
-  puls b
-  rts
-
-; Converts a nybble into a valid hex digit
-; @param A: nybble to convert to a char
-; @return A: resulting char
-NYB2HEX
   anda #$0F
-  ora #'0     ; Add "0"
-  cmpa #$3A   ; ":" "9"+1
-  blo SKIP@
-  adca #6     ; Add offset to "A" in ascii
-SKIP@
+  ora #'0      ; Add '0' to offset to digits
+  cmpa #$3A    ; Hex? ':' '9'+1
+  blo SKIPA@
+  adca #6      ; Hex offset
+SKIPA@
+  jsr POUTCHAR ; Print char in A
+  andb #$0F
+  orb #'0      ; Add '0' to offset to digits
+  cmpb #$3A    ; Hex? ':' '9'+1
+  blo SKIPB@
+  adcb #6      ; Hex offset
+SKIPB@
+  tfr b,a      ; Print char in B
+  jsr POUTCHAR
+  puls b       ; Restore B
   rts
 
 ; Converts a hexadecimal sequence into a byte value
@@ -203,19 +217,77 @@ BADHEX@
 ;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
+; Attempts to parse the input buffer into tokens depending on the command
+TOKENIZE
+  ldd BBVAR.cchinput   ; Do we have input to work with?
+  cmpd #4              ; Do we have even enough space for a string command
+  blo TOKFAIL@         ;  No? GTFO
+  ldy #0               ; Initialize Y; used to track current position in BBVAR.input
+  ldx #0               ; Initialize X; used to track position in BBVAR.tokens
+  bsr SKIPTONEXTC      ; Get the next non-whitespace char
+  bsr MKCMDSUM         ; Hash the first four non-whitespace chars
+  bsr HASH2TOKEN       ; Try to turn that hash into a proper token
+  bcs TOKFAIL@
+  bra STTOK@           ; Store token
+NEXTHEX@               ; Next hex token
+  bsr SKIPTONEXTC      ; Skip to next whitespace
+  ldd BBVAR.input,y    ; Get hex value (two digits)
+  bsr HEX2BYT          ; Convert hex value to byte value
+STTOK@
+  sta BBVAR.tokens,x   ; Store curent token
+  leax 1,x             ; Advance to next token
+  cmpx #BBTOKENS_DEPTH ; Is this next token in bounds?
+  beq FULLBUF@         ;  No? handle a full buffer
+  bra NEXTHEX@         ; Try to turn the next character into a hex value
+FULLBUF@
+  PZSTR EM_FULLTOKBUF  ; Print an error message
+  clrd                 ; Say we wrote no tokens
+  std BBVAR.cbtokens
+  rts
+TOKFAIL@
+  PZSTR EM_TOKFAIL     ; Print tokenization fail
+  clrd                 ; Say we wrote no tokens
+  std BBVAR.cbtokens
+  rts
+
+; Converts a runtime command hash into a portable token. Command tokens are
+; indexes into BBCHT, which is generated at compile-time
+; @param A: runtime hash
+; @return A: output token
+; @return CC.C: set if error state, cleared otherwise
+HASH2TOKEN
+  pshs x           ; Preserve & init X; other routines in this group use it
+  ldx #0
+NEXTHASH@
+  cmpa BBCHT,x     ; Is this hash our hash?
+  beq THISHASH@    ;  Yes? turn it into a token
+  leax 1,x         ; Begin considering next hash
+  cmpx BBCHTC      ; Is the next hash even in the table?
+  blo NEXTHASH@    ;  Yes? try this next hash, No? fall through
+  PZSTR EM_BADHASH CALL; Print an error message to the user
+  puls x
+  orcc #1          ; Set CC.C to indicate error
+  rts
+THISHASH@
+  puls x
+  andcc #$FE       ; Clear CC.C to indicate success
+  rts
+
 ; Makes a hash of four chars in BBIN starting at offset X
-; @param X: offset in BBIN to read the four chars from
+; @param Y: offset in BBIN to read the four chars from
 ; @return A: resulting hash
+; @return Y: offset after hash processing
 MKCMDSUM
   pshs b
   ldb #4             ; Loop over four chars
   clra               ; Initialize accumulator
 NEXTC@
-  suba BBVAR.input,x ; Subtract current char from accumulator
-  leax 1,x           ; Next char
+  suba BBVAR.input,y ; Subtract current char from accumulator
+  leax 1,y           ; Next char
   decb               ; Reduce count
   cmpb #0            ; Are we at the end?
   bne NEXTC@         ;  No? loop
+  puls b
   rts
 
 ; Skips "whitespace" to the next semantic char
@@ -245,24 +317,16 @@ RUNIF
   beq NOTOK@
   ldx #0           ; Counting up from zero
   lda BBVAR.tokens ; Load token
-NEXTHASH@
-  cmpa BBCHT,x     ; Is this hash our hash?
-  beq CALCPTR@     ;  Yes? skip to next step to put ptr in x
-  leax 1,x         ; Begin considering next hash
-  cmpx BBCHTC      ; Is this the last byte?
-  blo NEXTHASH@    ;  No? try next hash, Yes? fall through
-  PZSTR EM_BADHASH ; Print an error message
-  lbra IFHELP      ; Proceed to call "HELP"
-CALCPTR@
-  tfr x,d          ; Swap into d to do a cheap multiply
+  tfr a,d          ; Get the index in D
+  clra
   asld             ; Cheaply << to get *2, pointer size
-  tfr d,x          ; Restore x from d and jump to function at index
-  jmp [BBCMDPTRTBL,x]
+  tfr d,x          ; Move to X so we can use indexed mode with the offset
+  jmp [IFPTRTBL,x] ; Select IF
 NOTOK@
   rts
 
 ; IF pointer table
-BBCMDPTRTBL
+IFPTRTBL
   fdb IFCALL
   fdb IFHELP
   fdb IFPEEK
@@ -388,5 +452,8 @@ EM_TOKFAIL
   fcc "!!! Tokenization Failure !!!"
   fcb $0D,$0A,$00
 EM_BADHEX
-  fcc "!!! Maleformed Hex Value !!!"
+  fcc "!!! Malformed Hex Value !!!"
+  fcb $0D,$0A,$00
+EM_FULLTOKBUF
+  fcc "!!! Token Buffer Overrun !!!"
   fcb $0D,$0A,$00

src/memtest.s

@@ -1,44 +0,0 @@
-; CHIBI PC-09 Prototype #1 Boot ROM -- Memory Testing Routines
-; Copyright (c) 2024-2025 Amber Zeller, Gale Faraday
-; Licensed under MIT
-
-  INCLUDE "hardware.inc"
-  INCLUDE "serial.inc"
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;
-;; Memory Testing Routines
-;;
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-  SECTION MEMTEST
-
-  EXPORT RAMTEST
-
-; RAM testing routine. Ported to 6809 from 6800, based on source for ROBIT-2 for
-; MIKBUG.
-RAMTEST
-  ldx #STACK_TOP+1     ; bottom of testable SRAM, $0200
-AGAIN@                 ; Store 1 in memory
-  lda #1               ; Set [X] to 1
-  sta 0,x
-  cmpa 0,x             ; If failed print out an error indicator
-  bne ERR@
-NEXT@                  ; Loop point for next address
-  asla                 ; Shift A and [X] left
-  asl 0,x
-  cmpa 0,x             ; Compare A and [X]
-  bne ERR@
-  cmpa #$80            ; Only test up to $80
-  bne NEXT@            ; Loop if not $80
-  cmpx #$60FF          ; Compare X to end of RAM
-  beq PASS@            ; Finish if we're at the end
-  leax 1,x             ; Increment X
-  bra AGAIN@
-ERR@                   ; Write out error indicator
-  ldb #'X
-  jsr POUTCHAR
-PASS@                  ; Pass test
-  ldb #'P
-  jsr POUTCHAR
-  rts

src/reset.s

@@ -4,7 +4,6 @@
 
   INCLUDE "buzbee.inc"
   INCLUDE "hardware.inc"
-  INCLUDE "memtest.inc"
   INCLUDE "serial.inc"
   INCLUDE "version.inc"
 
@@ -24,7 +23,7 @@ RESET
 CLRSTACK
   ; Initialize the system stack
   clra               ; Init A & X to zero out the stack
-  ldx #$0000
+  ldx #0
 NEXT@
   sta STACK_BOTTOM,x ; Write a zero and progress to the next byte
   leax 1,x
@@ -36,18 +35,12 @@ BOOTSCR
   lda #13      ; 9600 baud
   ldb #%11     ; 8N1
   jsr INITUART ; Initialize serial console
-  ldx #VERMSG  ; Print version information
-  jsr POUTZSTR
-
-; Progress to POST
-POST
-  jsr RAMTEST
+  PZSTR VERMSG ; Print version information
 
 ; Hand off control to the BUZBEE monitor and print notification of leaving the
 ; firmware
 ENTERMON
-  ldx #TXTRUN
-  jsr POUTZSTR
+  PZSTR TXTRUN
   jmp BUZBEE
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -57,4 +50,5 @@ ENTERMON
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 TXTRUN
-  fcn "<3RUN<3"
+  fcc "<3RUN<3"
+  fcb $0D,$0A,$00

src/utils.inc

@@ -1,7 +1,8 @@
-; CHIBI PC-09 Prototype #1 -- Memory Testing Routines Header
+; CHIBI PC-09 Prototype #1 -- BIOS Utilities Header
 ; Copyright (c) 2025 Amber Zeller, Gale Faraday
 ; Licensed under MIT
 
 ; vim: ft=asm
 
-RAMTEST IMPORT
+ROBIT IMPORT
+PRINTVER IMPORT

src/utils.s

@@ -0,0 +1,99 @@
+; CHIBI PC-09 Prototype #1 Boot ROM -- BIOS Utilities
+; Copyright (c) 2024-2025 Amber Zeller, Gale Faraday
+; Licensed under MIT
+
+  INCLUDE "hardware.inc"
+  INCLUDE "serial.inc"
+  INCLUDE "version.inc"
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;
+;; CHIBI/O Stable BIOS Interface
+;;
+;; Called through SWI3
+;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+  SECTION BIOSINT
+
+  EXPORT CHIBIO
+
+; CHIBI/O Entrypoint -- Stable, but defined by linkerscript $8800
+; @param A: Function ID
+CHIBIO
+  tfr a,d              ; 8-to-16 tfr, fill both a and b
+  clra                 ; Clear MSB
+  asld                 ; Convert to word offset
+  tfr d,x              ; Put in X for indexing mode
+  jmp [CHIBIOPTRTBL,x] ; Jump!
+
+; Jump table TODO: Document function IDs and pointers
+CHIBIOPTRTBL
+  fdb IOPRINTVER ; Print the firmware version string
+  fdb $0000      ; TODO: Interactive BIOS setup utilitiy call
+  fdb ROBIT      ; Access the ROBIT memory test
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;
+;; CHIBI/O Function Implementations
+;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+; Prints the firmware's version information
+IOPRINTVER
+  PZSTR VERMSG
+  rti
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;
+;; Memory Testing Routines
+;;
+;; This family of BIOS routines does not return, upon completion the CHIBI must
+;; be reset.
+;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+  SECTION MEMTEST
+
+  EXPORT ROBIT
+
+; RAM testing routine. Ported to 6809 from 6800, based on source for ROBIT-2 for
+; MIKBUG.
+ROBIT
+  ldx #STACK_TOP+1     ; bottom of testable SRAM, $0200
+AGAIN@                 ; Store 1 in memory
+  lda #1               ; Set [X] to 1
+  sta 0,x
+  cmpa 0,x             ; If failed print out an error indicator
+  bne ERR@
+NEXT@                  ; Loop point for next address
+  asla                 ; Shift A and [X] left
+  asl 0,x
+  cmpa 0,x             ; Compare A and [X]
+  bne ERR@
+  cmpa #$80            ; Only test up to $80
+  bne NEXT@            ; Loop if not $80
+  cmpx #$60FF          ; Compare X to end of RAM
+  beq PASS@            ; Finish if we're at the end
+  leax 1,x             ; Increment X
+  bra AGAIN@
+ERR@                   ; Write out error indicator
+  ldb #'X
+  jsr POUTCHAR
+PASS@                  ; Pass test
+  ldb #'P
+  jsr POUTCHAR
+  bra HALT
+
+; Prints a message about completing a memory test prompting the user to reset
+; then puts the MPU in a loop where it only responds to interrupts, effectively
+; halting the CHIBI
+HALT
+  PZSTR MSG_FINISH
+LOOP@
+  sync
+  bra LOOP@
+
+MSG_FINISH
+  fcc "Memory test finished! Please reset"
+  fcb $0D,$0A,$00

src/vecs.s

@@ -3,6 +3,7 @@
 ; Licensed under MIT
 
   INCLUDE "reset.inc"
+  INCLUDE "utils.inc"
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
@@ -14,7 +15,7 @@
 
 VECTORS
   fdb $0000  ; Exception
-  fdb $0000 ; SWI3
+  fdb CHIBIO ; SWI3
   fdb $0000  ; SWI2
   fdb $0000  ; FIRQ
   fdb $0000  ; IRQ