feat(buzbee): implement buzbee input processing

src/buzbee.inc

@@ -8,10 +8,9 @@ BUZBEE IMPORT
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
-;; BUZBEE Structures
+;; BUZBEE Variables
 ;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-BBVARS STRUCT
-INPUT rmb $7F
-       ENDSTRUCT
+BBIN_BASE  EQU $0200
+BBIN_DEPTH EQU $7F

src/buzbee.s

@@ -2,7 +2,9 @@
 ; Copyright (c) 2025 Gale Faraday
 ; Licensed under MIT
 
+  INCLUDE "hardware.inc"
   INCLUDE "serial.inc"
+  INCLUDE "buzbee.inc"
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
@@ -15,8 +17,83 @@
   EXPORT BUZBEE
 
 BUZBEE
-  jsr INITBBVARS
+  bsr NEWLINE ; Setup the new input line and handle display.
+  bsr INPLOOP ; Fill input buffer.
+  cmpy #$0000 ; No data?
+  beq BUZBEE  ;  Try again...
+  ; TODO: Parse the input buffer
+  bra BUZBEE
 
+; Handle new lines; prints a new prompt and then clears the input buffer
+NEWLINE
+  PZSTR PROMPTLINE  ; Print prompt line
+CLRIN               ; Label to just clear input buffer without newline
+  clra              ; Init A and X
+  ldx #$0000
+NEXT@
+  sta BBIN_BASE,x   ; Clear input buffer
+  leax 1,x
+  cmpx #BBIN_DEPTH
+  blo NEXT@
+  ldy #$0000        ; Reset buffer fill pointer
+  rts
 
-INITBBVARS
+; Fills input buffer with characters from the serial console. Sets Y to the
+; 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'
+  beq INPLOOP
+  bitb #UARTF_LSR_DR   ; Is there a char in A?
+  beq NOCHAR@
+  cmpa #$1B            ; ESC?
+  beq HESC@            ;  Handle ESC
+  cmpa #$0D            ; CR?
+  beq EXIT@            ;  Then parse input buffer
+  cmpy #BBIN_DEPTH     ; Are we at the end of the input buffer?
+  beq FULLBUF@         ; Handle the buffer being full
+  sta BBIN_BASE,y      ; Add it to the input buffer
+  leay 1,y
+NOCHAR@
+  ; Check for error condition, work based on The Serial Port release 19
+  bitb #(UARTF_LSR_FIFO|UARTF_LSR_BI|UARTF_LSR_FE|UARTF_LSR_PE|UARTF_LSR_OE)
+  beq INPLOOP
+  bitb #UARTF_LSR_OE   ; Check for overrun error
+  beq NOOVER@
+  PZSTR EM_OVERRUN
+NOOVER@
+  bitb #UARTF_LSR_PE   ; Check for parity error
+  beq NOPARITY@
+  PZSTR EM_PARITY
+NOPARITY@
+  bitb #UARTF_LSR_FE   ; Check for framing error
+  beq NOFRAM@
+  PZSTR EM_FRAMING
+NOFRAM@
+  bitb #UARTF_LSR_FIFO ; Check for FIFO error
+  beq INPLOOP
+  PZSTR EM_FIFO
+  bra INPLOOP
+EXIT@
+  rts
+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.
+  rts
+FULLBUF@
+  lda #$07             ; ASCII BEL
+  jsr POUTCHAR
+  bra INPLOOP
 
+PROMPTLINE
+  fcb $0D,$0A,$25,$00 ; CR LF '%' NUL
+
+EM_OVERRUN
+  fcn "!!! Overrun Error !!!"
+EM_PARITY
+  fcn "!!! Parity Error !!!"
+EM_FRAMING
+  fcn "!!! Framing Error !!!"
+EM_FIFO
+  fcn "!!! FIFO Error !!!"