celso · celso · Jan 3, 2024 · Jan 5, 2024 · Jan 5, 2024
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,3 @@
+.env
+yarn-error.log
+tokagetone/
diff --git a/LICENSE → asm/LICENSE b/LICENSE → asm/LICENSE
diff --git a/README.md → asm/README.md b/README.md → asm/README.md
diff --git a/card.asm → asm/card.asm b/card.asm → asm/card.asm
diff --git a/card.prg → asm/card.prg b/card.prg → asm/card.prg
diff --git a/img/assembly.png → asm/img/assembly.png b/img/assembly.png → asm/img/assembly.png
diff --git a/img/debugger.png → asm/img/debugger.png b/img/debugger.png → asm/img/debugger.png
diff --git a/img/demo.gif → asm/img/demo.gif b/img/demo.gif → asm/img/demo.gif
diff --git a/img/emulator.png → asm/img/emulator.png b/img/emulator.png → asm/img/emulator.png
diff --git a/message.asm → asm/message.asm b/message.asm → asm/message.asm
diff --git a/music.sid → asm/music.sid b/music.sid → asm/music.sid
diff --git a/screen1.koa → asm/screen1.koa b/screen1.koa → asm/screen1.koa
diff --git a/screen2.koa → asm/screen2.koa b/screen2.koa → asm/screen2.koa
diff --git a/sidinfo.asm → asm/sidinfo.asm b/sidinfo.asm → asm/sidinfo.asm
diff --git a/sprites.asm → asm/sprites.asm b/sprites.asm → asm/sprites.asm
diff --git a/llvm-mos/.gitignore b/llvm-mos/.gitignore
@@ -0,0 +1 @@
+build/
diff --git a/llvm-mos/Makefile b/llvm-mos/Makefile
@@ -0,0 +1,41 @@
+#
+# GNU Makefile
+#
+
+VICE=/Applications/vice-arm64-sdl2-3.7.1/bin/x64sc -autostartprgmode 1 -statusbar
+
+all: demo
+
+demo:
+	@echo "Compiling demo"
+	# -c Only run preprocess, compile, and assemble steps, do not link
+	mos-c64-clang -c -o build/music.o music.s
+	mos-c64-clang -c -o build/screens.o screens.s
+	mos-c64-clang -c -o build/demo.o demo.c
+	mos-c64-clang++ -std=c++20 -finput-charset=utf-8 -c -o build/strings.o strings.cpp
+	mos-c64-clang++ -std=c++20 -Os -flto \
+		-Wl,--section-start=.sid=0x1000, \
+		-Wl,--section-start=.bank0screen=0x0c00, \
+		-Wl,--section-start=.bank0bitmap=0x2000 \
+		-Wl,--section-start=.bank1screen=0x4c00, \
+		-Wl,--section-start=.bank1bitmap=0x6000 \
+		-o build/demo.prg build/demo.o build/music.o build/screens.o build/strings.o
+	mos-c64-clang++ -std=c++20 -Os -flto \
+		-Wl,--section-start=.sid=0x1000 \
+		-Wl,--section-start=.bank0screen=0x0c00 \
+		-Wl,--section-start=.bank0bitmap=0x2000 \
+		-Wl,--section-start=.bank1screen=0x4c00, \
+		-Wl,--section-start=.bank1bitmap=0x6000 \
+		-Wl,--lto-emit-asm -o build/demo.s build/demo.o build/music.o build/screens.o build/strings.o
+
+run: demo
+	@echo "Running demo"
+	$(VICE) build/demo.prg
+
+sid:
+	@echo "SID file info"
+	./tools/sidinfo.py music.sid
+
+.PHONY: all demo run
+
+# EOF - Makefile
diff --git a/llvm-mos/README.md b/llvm-mos/README.md
@@ -0,0 +1,21 @@
+# C64 Demo using llvm-mos
+
+This a follow up of my old [pure 6510 assembly demo](../asm), ported to llvm-mos.
+
+## Requirements
+
+* https://github.com/llvm-mos/llvm-mos - Port of LLVM to the MOS 6502 and related processors
+* https://github.com/llvm-mos/llvm-mos-sdk - SDK for developing with the llvm-mos compiler
+
+
+## Useful links
+
+ * 6502 opcodes - http://6502.org/tutorials/6502opcodes.html
+ * 6502 / 6510 Instruction Set - https://c64os.com/post/6502instructions
+ * llm-mos Wiki - https://llvm-mos.org/wiki/Welcome
+ * Gnu Assembler - https://sourceware.org/binutils/docs/as
+
+## Other llvm-mos demos:
+
+ * C64 sprite example: https://gist.github.com/juj/84fc977c7f928e9343bb6f5f74c45a57
+ * sidplay: https://github.com/kklis/sidplay
diff --git a/llvm-mos/demo.c b/llvm-mos/demo.c
@@ -0,0 +1,137 @@
+#include "macros.h"
+#include <6502.h>
+#include <c64.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+extern unsigned bank0bgcolor;
+extern unsigned bank1bgcolor;
+extern char bank0bitmap;
+extern char bank1bitmap;
+
+extern char *message;
+extern unsigned char messageLength;
+
+unsigned char screen_state = 0;
+unsigned char counter = 254;
+
+unsigned char raster_h_offset = 7;
+unsigned char msg_offset = 0;
+
+void background(unsigned char color) {
+  poke(&VIC.bordercolor, color);
+  poke(&VIC.bgcolor0, color);
+}
+
+void recolor() {
+  // switch to Standard Bitmap Mode now (bit 5 set to 1)
+  // Bit #5: 0 = Text mode; 1 = Bitmap mode.
+  // see https://www.c64-wiki.com/wiki/Standard_Bitmap_Mode
+  poke(&VIC.ctrl1, 0b00111011);
+  // tells the VIC-II where to "look for graphics"
+  // in this case:
+  // 3 (%0011) * 1024 = $0c00 = address to start of color information
+  // bit 3 is set, then the bitmap starts at vic bank address + $2000 = $2000 or
+  // $6000 see https://www.c64-wiki.com/wiki/53272
+  poke(&VIC.addr, 0b00111000);
+  // bit 5 must be cleared to enter Standard Bitmap Mode
+  // see https://www.c64-wiki.com/wiki/Standard_Bitmap_Mode
+  poke(&VIC.ctrl2, 0b11011000);
+  if (screen_state == 0) {
+    background(bank1bgcolor);
+    vic_bank(0b0000010);
+  } else {
+    background(bank0bgcolor);
+    vic_bank(0b0000011);
+  }
+  counter++;
+  if (counter == 255) {
+    counter = 0;
+    screen_state = screen_state == 1 ? 0 : 1;
+  }
+}
+
+void scrollMessage() {
+  // use bank 0 $0000-$3FFF, ROM chars available at $1000-$1FFF
+  // see https://www.c64-wiki.com/wiki/VIC_bank
+  vic_bank(0b00000011);
+  // switch to Standard Character Mode now (bit 5 set to 0)
+  // Bit #5: 0 = Text mode; 1 = Bitmap mode.
+  // see https://www.c64-wiki.com/wiki/Standard_Character_Mode and
+  // http://sta.c64.org/cbm64mem.html
+  poke(&VIC.ctrl1, 0b00011011);
+  // tells the VIC-II where to "look for graphics"
+  // in this case:
+  // 15 (%1111) * 1024 = $3c00 = address to screen character RAM
+  // 2 (%010) * 2048 = $1000 = where to access the character set ROM address
+  // see https://www.c64-wiki.com/wiki/53272
+  poke(&VIC.addr, 0b11110100);
+
+  raster_h_offset--;
+  poke(&VIC.ctrl2, raster_h_offset);
+  if (raster_h_offset == 0) {
+    raster_h_offset = 7;
+
+    if (msg_offset == messageLength) {
+      msg_offset = 0;
+    }
+
+    for (uint8_t i = 0; i < 40; i++) {
+      poke(0x3fc0 + i, message[msg_offset + i]);
+    }
+
+    msg_offset++;
+  }
+}
+
+void clearBitmapLines(char *bitmap, uint16_t start, uint16_t end) {
+  for (uint16_t i = start; i < end; i = i + 1) {
+    bitmap[i] = 0;
+  }
+}
+
+// see https://llvm-mos.org/wiki/C_interrupts
+__attribute__((interrupt, no_isr)) void play() {
+  interrupt_ack();
+  scrollMessage();
+  sid_play($1021);
+  recolor();
+  interrupt_exit();
+}
+
+int main(void) {
+  // we don't need the BASIC ROM after we start
+  // see https://www.c64-wiki.com/wiki/Zeropage
+  poke(0x0001, 0b00110110);
+
+  // initialize the SID song
+  sid_init($1048);
+
+  cls();
+
+  // C64 bitmaps are 320x200 pixels, or 8000 bytes. Each line is 40 bytes.
+  clearBitmapLines(&bank0bitmap, 8000 - 40 * 16, 8000);
+  clearBitmapLines(&bank1bitmap, 8000 - 40 * 16, 8000);
+
+  SEI();
+  poke(&VIC.rasterline, 240);
+  pokew(IRQVec, (unsigned int)&play);
+  // interrupt control - enable all interrupts with $7b (icr=$DC0D)
+  // see http://sta.c64.org/cbm64mem.html
+  poke(&CIA1.icr, 0b01111011);
+  // interrupt control register - enable raster interrupt with $81 ($d01a)
+  // see http://sta.c64.org/cbm64mem.html
+  poke(&VIC.imr, 0b10000001);
+  CLI();
+
+  while (1) {
+    /*
+      if (raster_line == 255) {
+        recolor();
+        // call sid play routing
+        sid_play($1021);
+      }
+    */
+  }
+}
diff --git a/llvm-mos/macros.h b/llvm-mos/macros.h
@@ -0,0 +1,42 @@
+#include <c64.h>
+#include <6502.h>
+#include <_vic2.h>
+
+#define IRQVec           0x0314
+#define BRKVec           0x0316
+#define NMIVec           0x0318
+
+// https://github.com/cc65/cc65/blob/master/include/peekpoke.h
+
+#define poke(addr,val)     (*(unsigned char*) (addr) = (val))
+#define pokew(addr,val)    (*(unsigned*) (addr) = (val))
+#define peek(addr)         (*(unsigned char*) (addr))
+#define peekw(addr)        (*(unsigned*) (addr))
+
+// various
+#define sid_init(addr) __attribute__((leaf)) asm("LDA #$00\nTAX\nTAY\nJSR "#addr)
+#define sid_play(addr) __attribute__((leaf)) asm("JSR "#addr)
+#define raster_line (*((volatile unsigned char *)(struct __vic2 *)&VIC.rasterline))
+
+// clear screen. See http://sta.c64.org/cbm64scrfunc.html
+#define cls() __attribute__((leaf)) asm("JSR $e544")
+
+// https://www.c64-wiki.com/wiki/VIC_bank
+#define vic_bank(pattern) (*((volatile unsigned char *)(struct __6526 *)&CIA2.pra))=0b11111100|pattern
+
+#define raster_interrupt(line, fn) \
+  (*((volatile unsigned char *)(struct __vic2 *)&VIC.rasterline))=line; \
+  (*(volatile unsigned char *)0x0314)=(unsigned int)fn & 0xffff; \
+  (*(volatile unsigned char *)0x0315)=(unsigned int)fn >> 8;
+
+#define interrupts_disable() __attribute__((leaf)) asm("SEI")
+#define interrupts_enable() __attribute__((leaf)) asm("CLI")
+
+// everytime an interrupt triggers, we need to acknowledge it by setting the
+// corresponding VIC interrupt flag
+// if we don't ack the irq, then it will be called again after we exit it
+// see http://sta.c64.org/cbm64mem.html
+#define interrupt_ack() (*((volatile unsigned char *)(struct __vic2 *)&VIC.irr)) = 0b11111111
+
+// when exiting an irq, we need to restore the accumulator, and indexes y and x from the stack first
+#define interrupt_exit() __attribute__((leaf)) asm("PLA\nTAY\nPLA\nTAX\nPLA\nRTI\n")
diff --git a/llvm-mos/music.s b/llvm-mos/music.s
@@ -0,0 +1,14 @@
+# SID music section
+# see --section-start=.sid=0x1000 in Makefile for sid address
+# R flag is needed to avoid linker garbage collection
+# see https://sourceware.org/binutils/docs/as/Section.html
+#
+# First 126 bytes of music.sid are header, so skip them
+# .incbin "file"[,skip[,count]]
+#  https://www.hvsc.c64.org/download/C64Music/DOCUMENTS/SID_file_format.txt
+
+.global sid
+.type       sid,@object
+.section    .sid,"awR",@progbits
+sid:
+.incbin "music.sid", 126
diff --git a/llvm-mos/music.sid b/llvm-mos/music.sid
diff --git a/llvm-mos/screen1.koa b/llvm-mos/screen1.koa
diff --git a/llvm-mos/screen2.koa b/llvm-mos/screen2.koa
diff --git a/llvm-mos/screens.s b/llvm-mos/screens.s
@@ -0,0 +1,48 @@
+# https://www.c64-wiki.de/wiki/Koala_Painter
+
+.global bank0bitmap
+.type       bank0bitmap,@object
+.section    .bank0bitmap,"awR",@progbits
+bank0bitmap:
+.incbin "screen1.koa", 2, 8000
+
+.global bank0screen
+.type       bank0screen,@object
+.section    .bank0screen,"awR",@progbits
+bank0screen:
+.incbin "screen1.koa", 8002, 1000
+
+# .global bank0color
+# .type       bank0color,@object
+# .section    .bank0color,"awR",@progbits
+# bank0color:
+# .incbin "screen1.koa", 9002, 1000
+
+.global bank0bgcolor
+.type       bank0bgcolor,@object
+bank0bgcolor:
+.incbin "screen1.koa", 10002, 1
+
+.global bank1bitmap
+.type       bank1bitmap,@object
+.section    .bank1bitmap,"awR",@progbits
+bank1bitmap:
+.incbin "screen2.koa", 2, 8000
+
+.global bank1screen
+.type       bank1screen,@object
+.section    .bank1screen,"awR",@progbits
+bank1screen:
+.incbin "screen2.koa", 8002, 1000
+
+# .global bank1color
+# .type       bank1color,@object
+# .section    .bank1color,"awR",@progbits
+# bank1color:
+# .incbin "screen2.koa", 9002, 1000
+
+.global bank1bgcolor
+.type       bank1bgcolor,@object
+bank1bgcolor:
+.incbin "screen2.koa", 10002, 1
+
diff --git a/llvm-mos/strings.cpp b/llvm-mos/strings.cpp
@@ -0,0 +1,5 @@
+// https://llvm-mos.org/wiki/Character_set
+#include <charset.h>
+
+const char *message = U"THIS C64 DEMO USES VIC-II GRAPHICS, SPRITES, RASTER INTERRUPTS, A RANDOM GENERATOR AND SID MUSIC - MORE AT HTTPS://HITHUB.COM/CELSO/C64 "_uv;
+unsigned char messageLength = 136;
diff --git a/llvm-mos/tools.s b/llvm-mos/tools.s
@@ -0,0 +1,7 @@
+.include "c64.inc"
+
+.global ack
+.type  ack,@function
+ack:
+STA VIC_IRR
+RTS