5 Commits
main ... main

7 changed files with 105 additions and 31 deletions

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@@ -5,3 +5,6 @@
*.s19
map.txt
build/
# Build system generated files
src/version.s

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@@ -1,31 +1,37 @@
# Boot Firmware for CHIBI PC-09
TODO: Description of what the firmware does for the PC-09.
This is the firmware for the CHIBI PC-09. In the future it will provide the
CHIBI with initialization code, a UART driver, some self test features.
## Building the Firmware
You will need GNU `make`, and [`asm6809`](https://www.6809.org.uk/asm6809) to
build the firmware. Obtaining a working copy of `asm6809` could be difficult if
you aren't on Debian, Ubuntu, or Windows as instructions for building it are not
given on the `asm6809` website. Functional instructions for building from Git or
tarball are given here:
Building the firmware from source requires [LWTOOLS](http://www.lwtools.ca/) for
building S-Records of the ROM, and `mot2bin` from
[F9DASM](https://github.com/Arakula/f9dasm) for building binary images. A GNU
Make makefile is provided for building on Linux.
### Using the Makefile
To generate an S-Record run:
```sh
git clone https://www.6809.org.uk/git/asm6809.git
cd asm6809
./configure
make
sudo make install
make generate
make boot.s19
```
From there all you should have to do to generate a `boot.bin` is:
To generate a binary run:
```sh
git clone https://github.com/amberisvibin/chibi-pc09.git
cd chibi-pc09/code/boot
make generate
make
```
The makefile also can clean up after itself:
```sh
make clean
```
## Firmware Licensing
This firmware like the rest of the CHIBI PC-09 is licensed under the MIT

33
code/boot/genver.sh Executable file
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@@ -0,0 +1,33 @@
#!/usr/bin/env sh
# Script to generate version information
# Current git tag
TAG="$(git describe --always --dirty --tags)"
DATE="$(date)"
# Output filename
OUTFILE='src/version.s'
sed -e "s/<TAG>/$TAG/g" -e "s/<DATE>/$DATE/g" <<EOF > "$OUTFILE"
; CHIBI PC-09 Prototype #1 Boot ROM -- Version Information
; Copyright (c) 2024-2025 Amber Zeller, Gale Faraday
; Licensed under MIT
; This file generated by genver.sh
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; Boot ROM Version & Build Information
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
SECTION VERSION
EXPORT VERMSG
VERMSG
fcc "CHIBI PC-09 BOOT ROM <TAG>"
fcb \$0A
fcn "BUILT <DATE>"
EOF

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@@ -3,3 +3,4 @@ section SERIAL
section MEMTEST
section VECTORS high 100000
section VERSION high

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@@ -1,6 +1,6 @@
# Makefile for CHIBI PC-09 Firmware
.PHONY: all clean
.PHONY: generate all clean
.IGNORE: clean
.DEFAULT_GOAL := all
@@ -8,13 +8,15 @@
# Project Defaults & Folders
# ------------------------------------------------------------------------------
TARGET := boot
TARGROM := $(TARGET).bin
SRCDIR := src/
TARGET := boot
TARGREC := $(TARGET).s19
TARGROM := $(TARGET).bin
SRCDIR := src/
BUILDDIR := build/
SRCS := $(wildcard $(SRCDIR)*.s)
OBJS := $(patsubst $(SRCDIR)%.s,$(BUILDDIR)%.o,$(SRCS))
INCS := $(wildcard $(SRCDIR)*.inc)
GENS := $(SRCDIR)version.s
SRCS := $(wildcard $(SRCDIR)*.s)
OBJS := $(patsubst $(SRCDIR)%.s,$(BUILDDIR)%.o,$(SRCS))
INCS := $(wildcard $(SRCDIR)*.inc)
# ------------------------------------------------------------------------------
# Toolchain Definitions
@@ -22,7 +24,7 @@ INCS := $(wildcard $(SRCDIR)*.inc)
AS := lwasm
LD := lwlink
FIX := mot2bin
FIX := objcopy
ASFLAGS := -f obj
LDFLAGS := -f srec -m map.txt -s linkscript
@@ -34,11 +36,11 @@ LDFLAGS := -f srec -m map.txt -s linkscript
all: $(TARGROM)
# Fix srec into flashable bin file
$(TARGROM): $(TARGET).s19
$(FIX) -out $@ $<
$(TARGROM): $(TARGREC)
$(FIX) -I srec -O binary $< $@
# Link objects
$(TARGET).s19: $(OBJS)
$(TARGREC): $(OBJS)
$(LD) $(LDFLAGS) -o $@ $^
# Assemble objects
@@ -46,7 +48,12 @@ $(OBJS): $(BUILDDIR)%.o : $(SRCDIR)%.s
-@mkdir -p $(BUILDDIR)
$(AS) $(ASFLAGS) -o $@ $<
.IGNORE: clean
generate: $(GENS)
$(GENS):
./genver.sh
clean:
@echo 'Cleaning up intermediary files...'
@rm -rv $(TARGROM) $(TARGET).s19 map.txt $(BUILDDIR)
@rm -rv $(TARGROM) $(TARGREC) map.txt $(BUILDDIR)
@rm -rv $(GENS)

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@@ -15,6 +15,16 @@ UART_BASE EQU $7F00 ; UART Base Address
ROM_BASE EQU $8000 ; ROM Base Address and Entry Point
VECS_BASE EQU $FFF0 ; Vectors Base Address
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; Stack Base Address and Size Information
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
STACK_BOTTOM EQU $0100 ; Bottom address of system stack
STACK_DEPTH EQU $FF ; System stack's depth
STACK_TOP EQU STACK_BOTTOM+STACK_DEPTH ; Top address of system stack
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; UART Registers and Flags

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@@ -16,8 +16,21 @@
EXPORT RESET
RESET
CLRSTACK
; Initialize the system stack
lda #$00 ; Initialize A & X to zero out the stack
ldx #$0000
NEXT@
sta STACK_BOTTOM,x ; Write a zero and progress to the next byte
leax 1,x
cmpx #STACK_DEPTH ; See if we're at the top of the stack yet
blo NEXT@ ; Loop if we aren't at the end yet
lds #STACK_TOP ; Set S to top of newly cleared stack
SERINIT
; 8n1 Serial Enable DLAB
lda #UARTF_LCR_WLS | UARTF_LCR_DLAB
lda #UARTF_LCR_WLS|UARTF_LCR_DLAB
sta UART_LCR
; REVIEW: Potential endianness hiccough here
ldd #$0C00 ; Set divisor to 12 (9600 baud)
@@ -27,9 +40,10 @@ RESET
sta UART_LCR
lda #(UARTF_MCR_RTS) ; Enable Request-to-Send
sta UART_MCR
lda #'H ; send 'H'
lda #'H ; send 'H'
sta UART_BUFR
WAIT@
WAIT
sync ; Wait for interrupts
nop
bra WAIT@
bra WAIT