add 6502 CPU emu

3rdparty/6502-illegal-opcode.patch

@@ -0,0 +1,26 @@
+commit 800f1f7b0393d61fb03aad776e79e8f801014512
+Author: Thomas Bernard <miniupnp@free.fr>
+Date:   Sat Nov 23 16:32:04 2019 +0100
+
+    silent "unused parameter" warning
+    
+    6502.c:379:53: warning: unused parameter 'object' [-Wunused-parameter]
+      379 | #define INSTRUCTION(name) static zuint8 name(M6502 *object)
+          |                                              ~~~~~~~^~~~~~
+    6502.c:766:1: note: in expansion of macro 'INSTRUCTION'
+      766 | INSTRUCTION(illegal) {return 2;}
+          | ^~~~~~~~~~~
+
+diff --git a/sources/6502.c b/sources/6502.c
+index 9a95cf0..6b8f8d5 100644
+--- a/sources/6502.c
++++ b/sources/6502.c
+@@ -763,7 +763,7 @@ INSTRUCTION(brk)
+ 	}
+ 
+ 
+-INSTRUCTION(illegal) {return 2;}
++INSTRUCTION(illegal) {(void)object;	return 2;}
+ 
+ 
+ /* MARK: - Instruction Function Table */

3rdparty/Makefile

@@ -129,6 +129,12 @@ RECOILARCH=$(RECOIL).tar.gz
 RECOILURL=https://downloads.sourceforge.net/project/recoil/recoil/$(RECOILVER)/$(RECOILARCH)
 RECOILURLALT=http://nanard.free.fr/grafx2/$(RECOILARCH)
 RECOILSHA256=b9691db9e0d2b6cec23c9dec8628ecf6870f1e9d34ce95513fb4a671d781b19c
+#https://github.com/redcode/6502/releases/download/v0.1/6502-v0.1.tar.xz
+REDCODE6502=6502-v0.1
+REDCODE6502ARCH=6502-v0.1.tar.xz
+REDCODE6502URL=https://github.com/redcode/6502/releases/download/v0.1/$(REDCODE6502ARCH)
+REDCODE6502SHA256=bba50f327163d40b1014f5affc8042137f37b200dae50a4f0fe56b5769b3940f
+REDCODE6502PATCHES = 6502-illegal-opcode.patch
 
 ARCHIVES = $(addprefix archives/, $(SDLARCH) $(SDLIMAGEARCH) $(SDLTTFARCH) \
              $(SDL2ARCH) $(SDL2IMAGEARCH) $(SDL2TTFARCH) $(LIBPNGARCH) \
@@ -604,17 +610,30 @@ endif
 recoil:	$(RECOIL)/.ok
 	$(CP) $(RECOIL)/README ../doc/README-recoil.txt
 
+6502:	6502/.ok
+	$(CP) 6502/README ../doc/README-6502.txt
+
+6502/.ok:	archives/$(REDCODE6502ARCH)
+	$(TAR) xJf $<
+	cd $(@D) ; for p in $(REDCODE6502PATCHES) ; do echo "applying $$p" ; patch -p1 < ../$$p ; done
+	touch $@
+
 # generic rule to unpack tarball and apply patches
 %/.ok:	archives/%.tar.gz
 	$(TAR) xzf $<
 	cd $(@D) ; for p in $($(shell echo $* | cut -d- -f1 | tr a-z A-Z | tr -d _)PATCHES) ; do echo "applying $$p" ; patch -p1 < ../$$p ; done
 	touch $@
 
-# the following archive name won't work with the generic rule
+# the following archive names won't work with the generic rule
 archives/$(JPEGARCH):
 	@$(MKDIR) $(@D)
 	cd $(@D) && $(GETURL) $(JPEGURL)
 
+archives/$(REDCODE6502ARCH):
+	@$(MKDIR) $(@D)
+	cd $(@D) && $(GETURL) $(REDCODE6502URL)
+	@[ "`$(SHA256CMD) < $@`" = "$(REDCODE6502SHA256)" ] || ( $(RM) $@ && echo "$@ SHA256 mismatch !" && false )
+
 # generic rule to download tarballs
 archives/%.tar.gz:
 	@$(MKDIR) $(@D)