add m68k example

Makefile

@@ -1,18 +1,11 @@
 CFLAGS = -Isaturn
 OPT = -Og
 LIBGCC = $(shell $(CC) -print-file-name=libgcc.a)
-
-all: raytracing/raytracing.iso vdp2/nbg0.iso
-
 LIB = ./saturn
-include $(LIB)/common.mk
 
-define BUILD_BINARY_O
-	$(OBJCOPY) \
-		-I binary -O elf32-sh -B sh2 \
-		--rename-section .data=.data.$(basename $@) \
-		$< $@
-endef
+all: 
+
+include $(LIB)/common.mk
 
 %.data.o: %.data
 	$(BUILD_BINARY_O)
@@ -81,6 +74,8 @@ scsp/sine-44100-s16be-1ch.pcm:
 
 scsp/slot.elf: scsp/slot.o scsp/sine-44100-s16be-1ch.pcm.o
 
+scsp/sound_cpu.elf: scsp/sound_cpu.o m68k/slot.bin.o
+
 # clean
 clean: clean-sh
 clean-sh:
@@ -90,4 +85,7 @@ clean-sh:
 		-regextype posix-egrep \
 		-regex '.*\.(iso|o|bin|elf|cue)$$' \
 		-exec rm {} \;
-	rm -f common/keyboard.cpp common/keyboard.hpp wordle/word_list.hpp
+	rm -f \
+		common/keyboard.cpp \
+		common/keyboard.hpp \
+		wordle/word_list.hpp

m68k/Makefile

@@ -0,0 +1,12 @@
+CFLAGS = -I../saturn
+OPT = -Og
+LIB = ../saturn
+
+all: 
+
+include $(LIB)/m68k/common.mk
+
+%.pcm.o: %.pcm
+	$(BUILD_BINARY_O)
+
+slot.elf: $(LIB)/m68k/vectors.o slot.o sine-44100-s16be-1ch.pcm.o

m68k/main.cpp

@@ -0,0 +1,5 @@
+extern "C"
+void start(void)
+{
+  while (1) {}
+}

m68k/sine-44100-s16be-1ch.pcm

@@ -0,0 +1 @@
+../scsp/sine-44100-s16be-1ch.pcm

m68k/slot.cpp

@@ -0,0 +1,37 @@
+#include <stdint.h>
+#include "smpc.h"
+#include "scsp.h"
+
+#include "../common/copy.hpp"
+
+extern void * _sine_start __asm("_binary_sine_44100_s16be_1ch_pcm_start");
+
+void main()
+{
+  for (long i = 0; i < 807; i++) { asm volatile ("nop"); }   // wait for (way) more than 30µs
+
+  scsp.reg.ctrl.MIXER = MIXER__MEM4MB | MIXER__DAC18B | MIXER__MVOL(0xf);
+
+  const uint32_t sine_start = reinterpret_cast<uint32_t>(&_sine_start);
+
+  scsp_slot& slot = scsp.reg.slot[0];
+  slot.LOOP = LOOP__KYONB | LOOP__LPCTL__NORMAL | LOOP__SA(sine_start); // kx kb sbctl[1:0] ssctl[1:0] lpctl[1:0] 8b sa[19:16]
+  slot.SA = SA__SA(sine_start); // start address (bytes)
+  slot.LSA = 0; // loop start address (samples)
+  slot.LEA = 44100; // loop end address (samples)
+  slot.EG = EG__AR(0x1f) | EG__EGHOLD; // d2r d1r ho ar krs dl rr
+  slot.VOLUME = 0; // stwinh sdir tl
+  slot.FM = 0; // mdl mdxsl mdysl
+  slot.PITCH = PITCH__OCT(0) | PITCH__FNS(0); // oct fns
+  slot.LFO = 0; // lfof plfows
+  slot.MIXER = MIXER__DISDL(0b101); // disdl dipan efsdl efpan
+
+  slot.LOOP |= LOOP__KYONEX;
+}
+
+extern "C"
+void start(void)
+{
+  main();
+  while (1);
+}

scsp/slot.cpp

@@ -15,7 +15,7 @@ void main()
 
   for (long i = 0; i < 807; i++) { asm volatile ("nop"); }   // wait for (way) more than 30µs
 
-  scsp.reg.ctrl.MIXER = MIXER__MEM4MB | MIXER__DAC18B | MIXER__MVOL(0xf);
+  scsp.reg.ctrl.MIXER = MIXER__MEM4MB | MIXER__MVOL(0xf);
 
   const uint32_t * buf = reinterpret_cast<uint32_t*>(&_sine_start);
   copy<uint32_t>(&scsp.ram.u32[0], buf, 44100 * 2);

scsp/sound_cpu.cpp

@@ -0,0 +1,53 @@
+#include <stdint.h>
+
+#include "smpc.h"
+#include "scsp.h"
+#include "vdp2.h"
+
+#include "../common/copy.hpp"
+#include "../common/vdp2_func.hpp"
+
+extern void * _binary_m68k_slot_bin_start __asm("_binary_m68k_slot_bin_start");
+extern void * _binary_m68k_slot_bin_size __asm("_binary_m68k_slot_bin_size");
+
+void main()
+{
+  v_blank_in();
+
+  /*
+  while ((smpc.reg.SF & 1) != 0);
+  smpc.reg.SF = 1;
+  smpc.reg.COMREG = COMREG__SNDOFF;
+  while (smpc.reg.oreg[31] != 0b00000111);
+  
+  while ((smpc.reg.SF & 1) != 0);
+  smpc.reg.SF = 1;
+  smpc.reg.COMREG = COMREG__SNDON;
+  while (smpc.reg.oreg[31] != 0b00000110);
+  */
+
+  scsp.reg.ctrl.MIXER = MIXER__MEM4MB | MIXER__DAC18B | MIXER__MVOL(0xf);
+  
+  uint32_t * m68k_main_start = (uint32_t *)&_binary_m68k_slot_bin_start;
+  uint32_t m68k_main_size = (uint32_t)&_binary_m68k_slot_bin_size;
+  copy<uint32_t>(&scsp.ram.u32[0], m68k_main_start, m68k_main_size);
+    
+  while ((smpc.reg.SF & 1) != 0);
+  smpc.reg.SF = 1;
+  smpc.reg.COMREG = COMREG__SNDOFF;
+  while (smpc.reg.oreg[31] != 0b00000111);
+  
+  while ((smpc.reg.SF & 1) != 0);
+  smpc.reg.SF = 1;
+  smpc.reg.COMREG = COMREG__SNDON;
+  while (smpc.reg.oreg[31] != 0b00000110);
+  
+  // do nothing while the sound CPU manipulates the SCSP
+}
+
+extern "C"
+void start(void)
+{
+  main();
+  while (1);
+}