Compare commits

..

11 Commits

5 changed files with 439 additions and 133 deletions

View File

@@ -12,7 +12,7 @@ insert_final_newline = true
indent_style = space indent_style = space
indent_size = 2 indent_size = 2
[*.md] [*.{md,typ}]
indent_style = space indent_style = space
indent_size = 2 indent_size = 2
max_line_length = 80 max_line_length = 80

View File

@@ -18,6 +18,10 @@ the CHIBI PC-09 hobby computer platform. It is the stock bootloader and
interface for the PC-09. This manual goes over the usage of BUZBEE, and some of interface for the PC-09. This manual goes over the usage of BUZBEE, and some of
the technical internals of how it works and how to hack on it. the technical internals of how it works and how to hack on it.
BUZBEE was created primarily to debug prototype versions of the CHIBI PC-09.
BUZBEE will grow alongside the CHIBI PC-09 project. It also functions as a
reference implementation of an OS using the CHIBI PC-09 BIOS.
The CHIBI PC-09 name and platform is copyright 2024-2025 Amber Zeller. The CHIBI The CHIBI PC-09 name and platform is copyright 2024-2025 Amber Zeller. The CHIBI
PC-09 BIOS is copyright 2024-2025 Gale Faraday and Amber Zeller. BUZBEE is PC-09 BIOS is copyright 2024-2025 Gale Faraday and Amber Zeller. BUZBEE is
copyright 2025 Gale Faraday. All CHIBI PC-09 components are licensed under the copyright 2025 Gale Faraday. All CHIBI PC-09 components are licensed under the
@@ -29,10 +33,11 @@ MIT license.
BUZBEE is at its core a chain loader or bootloader. This means that most of the BUZBEE is at its core a chain loader or bootloader. This means that most of the
functionality of the CHIBI starts with using BUZBEE. BUZBEE functions are broken functionality of the CHIBI starts with using BUZBEE. BUZBEE functions are broken
into two categories: _Internal Functions_ or "IFs," and _External Functions_ or into two categories: _Internal Functions_ or "IFs" defined in @if-top, and
"EFs." IFs are native routines mapped to textual commands entered at the BUZBEE _External Functions_ or "EFs" in @ef-top. IFs are native routines mapped to
prompt. EFs are native routines called through IFs. EFs can either be any user textual commands entered at the BUZBEE prompt. EFs are native routines called
supplied code, or one of a set of routines in the BIOS/BUZBEE ROM or "firmware". through IFs. EFs can either be any user supplied code, or one of a set of
routines in the BIOS/BUZBEE ROM or "firmware".
#pagebreak() #pagebreak()
@@ -44,21 +49,29 @@ listed in alphabetical order. Below in @if-table is a list of available IFs.
#figure( #figure(
table( table(
columns: (1fr, auto), columns: (auto, auto, 1fr),
inset: 10pt, inset: 10pt,
align: center, align: center,
fill: (_, y) =>
if calc.odd(y) { luma(250) }
else { white },
table.header( table.header(
[*Name* (pg. no.)], [*Description*] [*Name* (pg. no.)], [*Command Token*], [*Description*]
), ),
[`CALL` #ref(<if-call>, form: "page")], [`CALL` (#ref(<if-call>, form: "page"))],
[`$00`],
[Call a resident routine in the MPU's address space.], [Call a resident routine in the MPU's address space.],
[`HELP` #ref(<if-help>, form: "page")], [`HELP` (#ref(<if-help>, form: "page"))],
[`$01`],
[Display a summary of known commands.], [Display a summary of known commands.],
[`PEEK` #ref(<if-peek>, form: "page")], [`PEEK` (#ref(<if-peek>, form: "page"))],
[`$02`],
[Dumps memory from the MPU's address space to the terminal.], [Dumps memory from the MPU's address space to the terminal.],
[`POKE` #ref(<if-poke>, form: "page")], [`POKE` (#ref(<if-poke>, form: "page"))],
[`$03`],
[Overwrites memory in the MPU's address space.], [Overwrites memory in the MPU's address space.],
[`SREC` #ref(<if-srec>, form: "page")], [`SREC` (#ref(<if-srec>, form: "page"))],
[`$04`],
[Switches into Motorola S-Record receive mode.], [Switches into Motorola S-Record receive mode.],
), ),
caption: [Table of IFs], caption: [Table of IFs],
@@ -66,10 +79,18 @@ listed in alphabetical order. Below in @if-table is a list of available IFs.
In the following pages these IFs are described in specific. In the following pages these IFs are described in specific.
// TODO: Talk about how IFs are tokenized. IFs are tokenized from their textual form into a binary "bytecode" form. This
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
hex are encoded as their corresponding bytes directly. The token buffer
mechanics are described more in @internals. Subcommands are also hashed into
tokens.
#pagebreak() #pagebreak()
// Function for creating IF page headers
#let _ifpagehead( #let _ifpagehead(
desc: none, desc: none,
syntax: none, syntax: none,
@@ -99,7 +120,8 @@ In the following pages these IFs are described in specific.
), ),
) )
#lorem(120) Call takes an absolute pointer into the MPU's address space to call as if it
were a subroutine using `JSR`.
// TODO: For when CHIBI PC-09 Prototype #2 comes out or whenever we get banking // TODO: For when CHIBI PC-09 Prototype #2 comes out or whenever we get banking
// add it here "Special care must be taken to properly bank in the correct // add it here "Special care must be taken to properly bank in the correct
@@ -129,17 +151,18 @@ BIOS routine.
syntax: [`PEEK <BASE> [<HIGH>]`], syntax: [`PEEK <BASE> [<HIGH>]`],
params: ( params: (
base: [ base: [
The address of the byte to dump or the base (lower bound) address of the The address (two bytes) of the byte to dump or the base (lower bound)
byte to start dumping from if `<HIGH>` is specified. address of the byte to start dumping from if `<HIGH>` is specified.
], ],
high: [ high: [
An optional operand given as the upper bound of the range to dump. Forms 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)
], ],
) )
) )
#lorem(120) Peeking memory causes the MPU to read the requested bytes and dump them to the
screen.
#pagebreak() #pagebreak()
@@ -149,12 +172,13 @@ BIOS routine.
desc: "Writes values to the MPU's address space.", desc: "Writes values to the MPU's address space.",
syntax: [`POKE <ADDR> <BYTES>`], syntax: [`POKE <ADDR> <BYTES>`],
params: ( 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.", 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() #pagebreak()
@@ -166,32 +190,104 @@ BIOS routine.
params: (), params: (),
) )
#lorem(120) Motorola S-Record mode is currently a stub.
#pagebreak() #pagebreak()
== External Functions (EFs) <ef-top> == External Functions (EFs) <ef-top>
#lorem(120) External functions are any native user code that can be called with `CALL` (see
@if-call). This mechanism is usable to run any code or routine in memory as
though interactively using the MPU's `JSR` instruction.
=== EFs in ROM <ef-rom> === EFs in ROM <ef-rom>
#lorem(120) Some common EFs to call include the using call to reset the CHIBI PC-09 with
`CALL 8000`.
// TODO: Talk about memory test and BIOS interface
#pagebreak() #pagebreak()
= BUZBEE Reserved Memory Regions <res-mem> = BUZBEE Reserved Memory Regions <res-mem>
#lorem(120) BUZBEE uses memory in the 0200-02FF page. A table of the layout of this memory
is provided. The memory is laid out in a packed structure starting at 0200.
#table(
columns: (auto, 1fr, auto),
inset: 10pt,
align: center,
fill: (_, y) =>
if calc.odd(y) { luma(250) }
else { white },
table.header(
[*Internal Name*], [*Size (Bytes)*], [*Description*]
),
[`input`],
[128],
[Text input buffer],
[`cchinput`],
[2],
[Text input buffer character count],
[`tokens`],
[64],
[BUZBEE token buffer],
[`cbtokens`],
[2],
[Count of bytes in `tokens`],
[`scratch`],
[2],
[Internal scratch word used for some operations],
)
#pagebreak() #pagebreak()
= Building CHIBI PC-09 Firmware from Source <building> = Building CHIBI PC-09 Firmware from Source <building>
#lorem(120) Building the CHIBI PC-09 firmware from source requires LWTOOLS
#link("http://lwtools.ca"), a functioning C compiler (`cc`), and a POSIX Shell
implementation (`sh`). The firmware was developed using LWTOOLS version 4.24 on
Linux, though later versions may work as well. A GNU Make "makefile" is provided for
building on Linux. GNU binutils' `objcopy` is also used to build the compiled
Motorola S-Record into a raw binary. Development is tracked using Git.
Using the makefile is simple. It provides facilities for easy building, and
development.
To build an S-Record of the ROM run:
```sh
make generate && make boot.s19
```
To build a ROM image with `objcopy` run:
```sh
make generate && make
```
In order to rebuild, first the generated files and existing objects must be
cleaned. To do this a `make clean` pseudo-target is defined.
Building the documentation can also be accomplished using `make docs`, provided
`typst` is installed.
#pagebreak() #pagebreak()
= BUZBEE Internals and Modding <internals> = BUZBEE Internals and Modding <internals>
#lorem(120) BUZBEE's interpreter works by "compiling" textual user commands into bytecode
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.
+ BUZBEE sets up the prompt and input buffer with `NEWLINE`
+ BUZBEE enters an input processing loop that works with the CHIBI PC-09's
serial driver.
+ If no input is provided, restart.
+ BUZBEE makes a tokenizing pass over the input buffer.
+ BUZBEE attempts to execute the tokens, which may involve leaving the BUZBEE
loop, or in the event the IF returns, loops around and re-enters the BUZBEE
loop.

View File

@@ -5,16 +5,3 @@
; vim: ft=asm ; vim: ft=asm
BUZBEE IMPORT BUZBEE IMPORT
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; BUZBEE Variables
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
BBIN_BASE EQU $0200
BBIN_DEPTH EQU $7F
BBTOKENS_BASE EQU $0280
BBTOKENS_DEPTH EQU $3F
BBTOKENS_CCH EQU $02C0

View File

@@ -9,7 +9,29 @@
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; BUZBEE Machine Language Monitor for CHIBI PC-09 ;; BUZBEE Variables
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
BBIN_DEPTH EQU $80 ; Input buffer depth
BBTOKENS_DEPTH EQU $40 ; Token buffer depth
SECTION BBVARS,bss
tagbbvar STRUCT
input rmb BBIN_DEPTH ; Input buffer
cchinput rmd 1 ; Input buffer char count
tokens rmb BBTOKENS_DEPTH ; Token buffer
cbtokens rmd 1 ; Token buffer byte count
scratch rmd 1 ; Scratch word
ENDSTRUCT
ORG $0200
BBVAR tagbbvar
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; BUZBEE Main Loop
;; ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -18,13 +40,13 @@
EXPORT BUZBEE EXPORT BUZBEE
BUZBEE BUZBEE
bsr NEWLINE ; Setup the new input line and handle display. lbsr NEWLINE ; Setup the new input line and handle display.
bsr INPLOOP ; Fill input buffer. bsr INPLOOP ; Fill input buffer.
cmpy #$0000 ; No data? cmpy #0 ; No data?
beq BUZBEE ; Try again... beq BUZBEE ; Try again...
; TODO: Parse the input buffer into tokens lbsr TOKENIZE ; Try to tokenize the input buffer
; TODO: Execute the token buffer lbsr RUNIF ; Execute token buffer, handling any errors
bra BUZBEE bra BUZBEE ; Repeat
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
@@ -32,25 +54,11 @@ 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
; Fills input buffer with characters from the serial console. Sets Y to the ; Fills input buffer with characters from the serial console. Sets Y to the
; offset in the input buffer of the last char read. ; offset in the input buffer of the last char read.
INPLOOP INPLOOP
jsr PINCHAR ; Try to read a char jsr PINCHAR ; Try to read a char
cmpd #$0000 ; If no char keep waitin' cmpd #0 ; If no char keep waitin'
beq INPLOOP beq INPLOOP
bitb #UARTF_LSR_DR ; Is there a char in A? bitb #UARTF_LSR_DR ; Is there a char in A?
beq NOCHAR@ beq NOCHAR@
@@ -59,13 +67,14 @@ INPLOOP
cmpa #$08 ; BS? cmpa #$08 ; BS?
beq HBACKSPC@ ; Backup a char beq HBACKSPC@ ; Backup a char
cmpa #$0D ; CR? cmpa #$0D ; CR?
beq EXIT@ ; Then parse input buffer beq HCR@ ; Then terminate and parse input buffer
cmpy #BBIN_DEPTH ; Are we at the end of the input buffer? cmpy #BBIN_DEPTH ; Are we at the end of the input buffer?
beq FULLBUF@ ; Handle the buffer being full beq FULLBUF@ ; Handle the buffer being full
ECHO@ ECHO@
jsr POUTCHAR ; Echo char back, this includes BS chars jsr POUTCHAR ; Echo char back, this includes BS chars
sta BBIN_BASE,y ; Add it to the input buffer sta BBVAR.input,y ; Add it to the input buffer
leay 1,y leay 1,y
; Fall through
NOCHAR@ NOCHAR@
; Check for error condition, work based on The Serial Port release 19 ; 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) bitb #(UARTF_LSR_FIFO|UARTF_LSR_BI|UARTF_LSR_FE|UARTF_LSR_PE|UARTF_LSR_OE)
@@ -83,66 +92,229 @@ NOPARITY@
PZSTR EM_FRAMING PZSTR EM_FRAMING
NOFRAM@ NOFRAM@
bitb #UARTF_LSR_FIFO ; Check for FIFO error bitb #UARTF_LSR_FIFO ; Check for FIFO error
beq INPLOOP beq INPLOOP ; Loop over
PZSTR EM_FIFO PZSTR EM_FIFO
bra INPLOOP bra INPLOOP ; Loop over
EXIT@ HCR@
sty BBVAR.cchinput ; Store buffer length
rts rts
HESC@ HESC@
lda #'^ ; Print a char that signifies that ESC was pressed lda #'^ ; Print a char that signifies that ESC was pressed
jsr POUTCHAR 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 rts
HBACKSPC@ HBACKSPC@
clrb ; Clear last char clrb ; Clear last char
leay -1,y leay -1,y
stb BBIN_BASE stb BBVAR.input
bra ECHO@ ; Echo the char in A bra ECHO@ ; Echo the char in A
FULLBUF@ FULLBUF@
lda #$07 ; ASCII BEL lda #$07 ; ASCII BEL
jsr POUTCHAR jsr POUTCHAR
bra INPLOOP lbra INPLOOP
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; Handle new lines; prints a new prompt and then clears the input buffer
;; NEWLINE
;; BUZBEE Command Hashing Routines PZSTR PROMPTLINE ; Print prompt line
;; CLRIN ; Label to just clear input buffer without newline
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; clra ; Init A and X
ldx #0
; Makes a hash of four chars in BBIN starting at offset X. NEXT@
; @param X: offset in BBIN to read the four chars from sta BBVAR.input,x ; Clear input buffer
; @return A: resulting hash leax 1,x
MKCMDSUM cmpx #BBIN_DEPTH
pshs b blo NEXT@
ldb #4 ; Loop over four chars ldy #0 ; Reset buffer fill pointer
clra ; Initialize accumulator
NEXTC@
suba BBIN_BASE,x ; Subtract current char from accumulator
leax 1,x ; Next char
decb ; Reduce count
cmpb #0 ; Are we at the end?
bne NEXTC@ ; No? loop
rts rts
; Maps a command hash to a command index, and executes it ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; @corrupts B ;;
; @param A: input hash ;; Hex Conversion and Printing Routines
; @return X: command data table index ;;
CALLFROMHASH ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
ldx #0 ; Counting up from zero
; Prints a byte in A
; @param A: byte to print
PBYTE
pshs b
tfr a,b ; Transfer lower nybble into B
andd #$F00F ; Mask and adjsut
asra
asra
asra
asra
anda #$0F
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 #$3A ; Hex? ':' '9'+1
blo SKIPB@
adcb #6 ; Hex offset
SKIPB@
tfr b,a ; Print char in B
jsr POUTCHAR
puls b ; Restore B
rts
; Converts a hexadecimal sequence into a byte value
; @param D: hex representation of a byte with A: MSD B: LSD
; @return A: returned byte value
; NOTE: Conversion logic credit to Wozniak. This code unrolled for speed.
HEX2BYT
eora #$B0 ; Map digits to 0-9
cmpa #9+1 ; Is it a decimal?
blo AISDEC@ ; Yes? skip hex adjust
adca #$88 ; Map 'A'-'F' to $FA-$FF
cmpa #$FA ; Hex char?
blo BADHEX@ ; No? Print error
AISDEC@
asla ; Shift MSD into upper nybble of A
asla
asla
asla
; Do B part
eorb #$B0 ; Map digits to 0-9
cmpa #9+1 ; Is it a decimal?
blo BISDEC@ ; Yes? skip hex adjust
adcb #$88 ; Map 'A'-'F' to $FA-$FF
andb #$0F ; Mask high nybble
cmpb #$0A ; Hex char?
blo BADHEX@ ; No? Print error
BISDEC@
stb BBVAR.scratch ; Store low nybble in scratch buffer
ora BBVAR.scratch ; Combine the nybbles
rts
BADHEX@
PZSTR EM_BADHEX ; Print an error message
clrd ; Prevent RUNIF from executing
std BBVAR.cbtokens
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; BUZBEE Tokenizing Routines
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; 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@ NEXTHASH@
cmpa BBCHT,x ; Is this hash our hash? cmpa BBCHT,x ; Is this hash our hash?
beq CALCPTR@ ; Yes? skip to next step to put ptr in x beq THISHASH@ ; Yes? turn it into a token
leax 1,x ; Begin considering next hash leax 1,x ; Begin considering next hash
cmpx BBCHTC ; Is this the last byte? cmpx BBCHTC ; Is the next hash even in the table?
blo NEXTHASH@ ; No? try next hash, Yes? fall through blo NEXTHASH@ ; Yes? try this next hash, No? fall through
PZSTR EM_BADCMD ; Print an error message PZSTR EM_BADHASH CALL; Print an error message to the user
lbra IFHELP ; Proceed to call "HELP" puls x
CALCPTR@ orcc #1 ; Set CC.C to indicate error
tfr x,d ; Swap into d to do a cheap multiply rts
asld ; Cheaply << to get *2, pointer size THISHASH@
tfr d,x ; Restore x from d and jump to function at index puls x
jmp [BBCMDPTRTBL,x] andcc #$FE ; Clear CC.C to indicate success
rts
; Makes a hash of four chars in BBIN starting at offset X
; @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,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
; @param Y: current index in text buffer
; @return Y: resulting index in text buffer
SKIPTONEXTC
lda BBVAR.input,y ; Get our char?
cmpa #$20 ; SPACE or control char?
bhi EXIT@ ; Yes? End
leay 1,y ; Iterate next char
bra SKIPTONEXTC
EXIT@
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; BUZBEE IF Handling Functions
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Executes a command based on the initial token
; @corrupts B
; @return X: command data table index
RUNIF
clrd ; Do we have any tokens?
cmpd BBVAR.cbtokens
beq NOTOK@
ldx #0 ; Counting up from zero
lda BBVAR.tokens ; Load token
tfr a,b ; Get the index in D
asld ; Cheaply << to get *2, pointer size
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
IFPTRTBL
fdb IFCALL
fdb IFHELP
fdb IFPEEK
fdb IFPOKE
fdb IFSREC
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
@@ -150,21 +322,74 @@ CALCPTR@
;; ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Call a pointer
IFCALL
ldd BBVAR.cbtokens ; Only jump if three tokens given
cmpd #3
lbne INVALIDARG
jsr [BBVAR.tokens+1] ; Make our jump (doesn't implicitly return)
rts
; Print out a help message ; Print out a help message
IFHELP IFHELP
PZSTR HELP_MSG PZSTR HELP_MSG
rts rts
; Placeholder function labels to make assembler happy before git commit ; Peek memory
IFCALL
IFPEEK IFPEEK
ldd BBVAR.cbtokens ; One 16-bit token given, single peek
cmpd #3
lblo INVALIDARG ; Not enough args given
bhi SELTYPE@ ; Select forward or backward peek
SINGLE@
lda [BBVAR.tokens+1] ; Get byte
lbsr PBYTE ; Print peek byte
rts
SELTYPE@
ldd BBVAR.cbtokens ; Have enough tokens?
cmpd #5
lbne INVALIDARG ; No? bounce out
ldd BBVAR.tokens+1 ; Are we forwards (BASE < HIGH)?
cmpd BBVAR.tokens+3
beq SINGLE@ ; Gracefully handle BASE == HIGH
bhi INVALIDARG ; Malformed if BASE > HIGH
ldx BBVAR.tokens+1 ; Get BASE
NEXT@
lda ,x+ ; Get the next byte
lbsr PBYTE ; Print our byte
cmpx BBVAR.tokens+3 ; Are we at <HIGH> yet?
bne NEXT@ ; No? loop
rts
; Poke bytes into memory
; NOTE: Blocks could also use 6309 TFM instruction
IFPOKE IFPOKE
ldx BBVAR.cbtokens ; Make sure we have enough tokens
cmpx #4
lblo INVALIDARG
leax -3,x ; Get count of bytes to write into X
ldy #0 ; Setup Y for indexing
NEXTB@
lda BBVAR.tokens+3,y ; Get source byte to copy
sta [BBVAR.tokens+1,y] ; Copy byte
leay +1,y ; Increment memory indexer
leax -1,x ; Decement byte count
cmpx #0 ; Are we at our last byte?
bhi NEXTB@ ; No? loop
rts
; Placeholder function labels to make assembler happy before git commit
IFSREC IFSREC
rts rts
; Invalid argument IF tail
INVALIDARG
PZSTR EM_BADARG
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; BUZBEE Strings and Tables ;; BUZBEE Strings and Fixed Data
;; ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -175,8 +400,6 @@ HELP_MSG
fcb $0D,$0A fcb $0D,$0A
fcc "CALL <PTR> - Call the pointer given in <PTR> as a subroutine." fcc "CALL <PTR> - Call the pointer given in <PTR> as a subroutine."
fcb $0D,$0A fcb $0D,$0A
fcc "EXEC <PTR> - Start program at <PTR>."
fcb $0D,$0A
fcc "HELP [CMD] - Display help, command optional." fcc "HELP [CMD] - Display help, command optional."
fcb $0D,$0A fcb $0D,$0A
fcc "PEEK <BASE> [<HIGH>] - Read memory at <BASE> to <HIGH>." fcc "PEEK <BASE> [<HIGH>] - Read memory at <BASE> to <HIGH>."
@@ -184,30 +407,36 @@ HELP_MSG
fcc "POKE <ADDR> <BYTES> - Overwrite memory with <BYTES> starting at <BASE>." fcc "POKE <ADDR> <BYTES> - Overwrite memory with <BYTES> starting at <BASE>."
fcb $0D,$0A fcb $0D,$0A
fcc "SREC - Enter Motorola S-Record entry mode." fcc "SREC - Enter Motorola S-Record entry mode."
fcb $0D,$0A
fcb $00 fcb $00
BBCMDPTRTBL
fdb IFCALL
fdb IFHELP
fdb IFPEEK
fdb IFPOKE
fdb IFSREC
PROMPTLINE PROMPTLINE
fcb $0D,$0A,$25,$00 ; CR LF '%' NUL fcb $0D,$0A,$25,$00 ; CR LF '%' NUL
EM_OVERRUN EM_OVERRUN
fcc "!!! Overrun Error !!!" fcc "!!! UART Overrun Error !!!"
fcb $0D,$0A,$00 fcb $0D,$0A,$00
EM_PARITY EM_PARITY
fcc "!!! Parity Error !!!" fcc "!!! UART Parity Error !!!"
fcb $0D,$0A,$00 fcb $0D,$0A,$00
EM_FRAMING EM_FRAMING
fcc "!!! Framing Error !!!" fcc "!!! UART Framing Error !!!"
fcb $0D,$0A,$00 fcb $0D,$0A,$00
EM_FIFO EM_FIFO
fcc "!!! FIFO Error !!!" fcc "!!! UART FIFO Error !!!"
fcb $0D,$0A,$00 fcb $0D,$0A,$00
EM_BADCMD EM_BADHASH
fcc "!!! Bad Command Hash !!!" fcc "!!! Bad Command Hash !!!"
fcb $0D,$0A,$00 fcb $0D,$0A,$00
EM_BADARG
fcc "!!! Malformed Arguments !!!"
fcb $0D,$0A,$00
EM_TOKFAIL
fcc "!!! Tokenization Failure !!!"
fcb $0D,$0A,$00
EM_BADHEX
fcc "!!! Malformed Hex Value !!!"
fcb $0D,$0A,$00
EM_FULLTOKBUF
fcc "!!! Token Buffer Overrun !!!"
fcb $0D,$0A,$00

View File

@@ -24,7 +24,7 @@ RESET
CLRSTACK CLRSTACK
; Initialize the system stack ; Initialize the system stack
clra ; Init A & X to zero out the stack clra ; Init A & X to zero out the stack
ldx #$0000 ldx #0
NEXT@ NEXT@
sta STACK_BOTTOM,x ; Write a zero and progress to the next byte sta STACK_BOTTOM,x ; Write a zero and progress to the next byte
leax 1,x leax 1,x
@@ -36,18 +36,12 @@ BOOTSCR
lda #13 ; 9600 baud lda #13 ; 9600 baud
ldb #%11 ; 8N1 ldb #%11 ; 8N1
jsr INITUART ; Initialize serial console jsr INITUART ; Initialize serial console
ldx #VERMSG ; Print version information PZSTR VERMSG ; Print version information
jsr POUTZSTR
; Progress to POST
POST
jsr RAMTEST
; Hand off control to the BUZBEE monitor and print notification of leaving the ; Hand off control to the BUZBEE monitor and print notification of leaving the
; firmware ; firmware
ENTERMON ENTERMON
ldx #TXTRUN PZSTR TXTRUN
jsr POUTZSTR
jmp BUZBEE jmp BUZBEE
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;