psxbios: Add checks for memmove.

Always returns dst per documentation.

diff --git a/libpcsxcore/psxbios.c b/libpcsxcore/psxbios.c
index 97c7951..399df9a 100644 (file)
--- a/libpcsxcore/psxbios.c
+++ b/libpcsxcore/psxbios.c
@@ -824,7 +824,12 @@ void psxBios_memset() { // 0x2b
 
 void psxBios_memmove() { // 0x2c
        char *p1 = (char *)Ra0, *p2 = (char *)Ra1;
-
+       v0 = a0;
+       if (a0 == 0 || a2 > 0x7FFFFFFF)
+       {
+               pc0 = ra;
+               return;
+       }
        if (p2 <= p1 && p2 + a2 > p1) {
                a2++; // BUG: copy one more byte here
                p1 += a2;
@@ -833,8 +838,7 @@ void psxBios_memmove() { // 0x2c
        } else {
                while ((s32)a2-- > 0) *p1++ = *p2++;
        }
-
-       v0 = a0; pc0 = ra;
+       pc0 = ra;
 }
 
 void psxBios_memcmp() { // 0x2d