cdrom: try emulating fifo status bit

is this good enough?
notaz/pcsx_rearmed#354

diff --git a/libpcsxcore/cdrom.c b/libpcsxcore/cdrom.c
index 3fc5801..e9c6f88 100644 (file)
--- a/libpcsxcore/cdrom.c
+++ b/libpcsxcore/cdrom.c
@@ -1455,21 +1455,19 @@ static void cdrReadInterrupt(void)
 cdrRead0:
        bit 0,1 - reg index
        bit 2 - adpcm active
-       bit 5 - 1 result ready
-       bit 6 - 1 dma ready
+       bit 3 - 1 parameter fifo empty
+       bit 4 - 1 parameter fifo not full
+       bit 5 - 1 response fifo not empty
+       bit 6 - 1 data fifo not empty
        bit 7 - 1 command being processed
 */
 
 unsigned char cdrRead0(void) {
-       cdr.Ctrl &= ~0x24;
+       cdr.Ctrl &= ~0x64;
        cdr.Ctrl |= cdr.AdpcmActive << 2;
        cdr.Ctrl |= cdr.ResultReady << 5;
+       cdr.Ctrl |= ((signed int)(cdr.FifoOffset - cdr.FifoSize) >> 31) & 0x40;
 
-       //cdr.Ctrl &= ~0x40;
-       //if (cdr.FifoOffset != DATA_SIZE)
-       cdr.Ctrl |= 0x40; // data fifo not empty
-
-       // What means the 0x10 and the 0x08 bits? I only saw it used by the bios
        cdr.Ctrl |= 0x18;
 
        CDR_LOG_IO("cdr r0.sta: %02x\n", cdr.Ctrl);