runs code in 1M wram, cell arrange, decode (untested)

[picodrive.git] / Pico / cd / Misc.c

diff --git a/Pico/cd/Misc.c b/Pico/cd/Misc.c
index 981e71a..905e919 100644 (file)
--- a/Pico/cd/Misc.c
+++ b/Pico/cd/Misc.c
@@ -16,3 +16,41 @@ unsigned char formatted_bram[4*0x10] =
 };
 
 
+// offs | 2Mbit  | 1Mbit  |
+//   0  | [ 2M   | unused |
+// 128K |  bit ] | bank0  |
+// 256K | unused | bank1  |
+
+void wram_2M_to_1M(unsigned char *m)
+{
+       unsigned short *m1M_b0, *m1M_b1;
+       unsigned int i, tmp, *m2M;
+
+       m2M = (unsigned int *) (m + 0x40000);
+       m1M_b0 = (unsigned short *) m2M;
+       m1M_b1 = (unsigned short *) (m + 0x60000);
+
+       for (i = 0x40000/4; i; i--)
+       {
+               tmp = *(--m2M);
+               *(--m1M_b0) = tmp;
+               *(--m1M_b1) = tmp >> 16;
+       }
+}
+
+void wram_1M_to_2M(unsigned char *m)
+{
+       unsigned short *m1M_b0, *m1M_b1;
+       unsigned int i, tmp, *m2M;
+
+       m2M = (unsigned int *) m;
+       m1M_b0 = (unsigned short *) (m + 0x20000);
+       m1M_b1 = (unsigned short *) (m + 0x40000);
+
+       for (i = 0x40000/4; i; i--)
+       {
+               tmp = *m1M_b0++ | (*m1M_b1++ << 16);
+               *m2M++ = tmp;
+       }
+}
+