cdrom: handle fifo overreads

based on nocash doc
notaz/pcsx_rearmed#269

diff --git a/libpcsxcore/cdrom.c b/libpcsxcore/cdrom.c
index 12945d6..e106573 100644 (file)
--- a/libpcsxcore/cdrom.c
+++ b/libpcsxcore/cdrom.c
@@ -1430,7 +1430,7 @@ void cdrWrite1(unsigned char rt) {
 }
 
 unsigned char cdrRead2(void) {
-       unsigned char ret = 0;
+       unsigned char ret = cdr.Transfer[0x920];
 
        if (cdr.FifoOffset < cdr.FifoSize)
                ret = cdr.Transfer[cdr.FifoOffset++];
@@ -1562,10 +1562,12 @@ void psxDma3(u32 madr, u32 bcr, u32 chcr) {
                        {
                                memcpy(ptr, cdr.Transfer + cdr.FifoOffset, size);
                                cdr.FifoOffset += size;
-                               psxCpu->Clear(madr, size / 4);
                        }
-                       if (size < cdsize)
+                       if (size < cdsize) {
                                CDR_LOG_I("cdrom: dma3 %d/%d\n", size, cdsize);
+                               memset(ptr + size, cdr.Transfer[0x920], cdsize - size);
+                       }
+                       psxCpu->Clear(madr, cdsize / 4);
 
                        CDRDMA_INT((cdsize/4) * 24);
 
@@ -1655,7 +1657,7 @@ int cdrFreeze(void *f, int Mode) {
        if (Mode == 0) {
                getCdInfo();
 
-               cdr.FifoOffset = tmp;
+               cdr.FifoOffset = tmp < DATA_SIZE ? tmp : DATA_SIZE;
                cdr.FifoSize = (cdr.Mode & 0x20) ? 2340 : 2048 + 12;
 
                // read right sub data