shithub: riscv

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games/md: small cpu and vdp bug fixes

--- a/sys/src/games/md/cpu.c

+++ b/sys/src/games/md/cpu.c

@@ -252,7 +252,7 @@

 		if((v >> 32) != 0)

 			rS |= FLAGC;

 		if((v >> 31) != 0)

-			rS |= FLAGV;

+			rS |= FLAGN;

 		if((~(w ^ u) & (v ^ u) & (1<<31)) != 0)

 			rS |= FLAGV;

 		if((u32int)v != 0)

@@ -461,7 +461,7 @@

 	int n, m, d;

 	static int cnt;

-	if(0 && pc == 0x13dc4){

+	if(0 && pc == 0x48ee){

 		trace++;

 		print("%x\n", curpc);

 	}

--- a/sys/src/games/md/dat.h

+++ b/sys/src/games/md/dat.h

@@ -3,6 +3,7 @@

 typedef signed long s32int;

 extern u32int curpc, irq;

+extern int trace;

 extern u8int reg[32];

 extern u8int dma;

--- a/sys/src/games/md/md.c

+++ b/sys/src/games/md/md.c

@@ -91,6 +91,8 @@

 				close(fd);

 				threadexitsall(nil);

 			}

+			if(utfrune(buf, 't'))

+				trace = !trace;

 		}

 		if(buf[0] != 'k' && buf[0] != 'K')

 			continue;

--- a/sys/src/games/md/vdp.c

+++ b/sys/src/games/md/vdp.c

@@ -187,13 +187,13 @@

 static void

 spritesinit(void)

 {

-	u16int *t, *p, dy, *c;

+	u16int t, *p, dy, *c;

 	u32int v;

 	int i, ns, np;

 	struct sprite *q;

-	t = vram + (reg[SPRTAB] << 8 & 0x7f00);

-	p = t;

+	t = (reg[SPRTAB] << 8 & 0x7f00);

+	p = vram + t;

 	q = spr;

 	ns = (reg[MODE4] & WIDE) != 0 ? 20 : 16;

 	np = 0;

@@ -229,7 +229,7 @@

 			vdpstat |= STATOVR;

 			break;

 		}

-	}while(p = t + ((p[1] & 0x7f) << 2), p != t);

+	}while(p = vram + (u16int)(t + ((p[1] & 0x7f) << 2)), p - vram != t);

 	lsp = q;

 }