Rockboy - gameboy emulation for rockbox, based on gnuboy. Still a bit early, but already playable on iRiver H1xx and the simulators. The archos recorder version is currently rather slow...

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@6104 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 183 insertions, 0 deletions

diff --git a/apps/plugins/rockboy/hw.c b/apps/plugins/rockboy/hw.c
new file mode 100644
index 0000000000..c287e24f8a
--- /dev/null
+++ b/apps/plugins/rockboy/hw.c
@@ -0,0 +1,183 @@
+
+
+
+#include "rockmacros.h"
+#include "defs.h"
+#include "cpu.h"
+#include "hw.h"
+#include "regs.h"
+#include "lcd.h"
+#include "mem.h"
+#include "fastmem.h"
+
+
+struct hw hw;
+
+
+
+/*
+ * hw_interrupt changes the virtual interrupt lines included in the
+ * specified mask to the values the corresponding bits in i take, and
+ * in doing so, raises the appropriate bit of R_IF for any interrupt
+ * lines that transition from low to high.
+ */
+
+void hw_interrupt(byte i, byte mask)
+{
+        byte oldif = R_IF;
+        i &= 0x1F & mask;
+        R_IF |= i & (hw.ilines ^ i);
+
+        /* FIXME - is this correct? not sure the docs understand... */
+        if ((R_IF & (R_IF ^ oldif) & R_IE) && cpu.ime) cpu.halt = 0;
+        /* if ((i & (hw.ilines ^ i) & R_IE) && cpu.ime) cpu.halt = 0; */
+        /* if ((i & R_IE) && cpu.ime) cpu.halt = 0; */
+        
+        hw.ilines &= ~mask;
+        hw.ilines |= i;
+}
+
+
+/*
+ * hw_dma performs plain old memory-to-oam dma, the original dmg
+ * dma. Although on the hardware it takes a good deal of time, the cpu
+ * continues running during this mode of dma, so no special tricks to
+ * stall the cpu are necessary.
+ */
+
+void hw_dma(byte b)
+{
+        int i;
+        addr a;
+
+        a = ((addr)b) << 8;
+        for (i = 0; i < 160; i++, a++)
+                lcd.oam.mem[i] = readb(a);
+}
+
+
+
+void hw_hdma_cmd(byte c)
+{
+        int cnt;
+        addr sa;
+        int da;
+
+        /* Begin or cancel HDMA */
+        if ((hw.hdma|c) & 0x80)
+        {
+                hw.hdma = c;
+                R_HDMA5 = c & 0x7f;
+                return;
+        }
+        
+        /* Perform GDMA */
+        sa = ((addr)R_HDMA1 << 8) | (R_HDMA2&0xf0);
+        da = 0x8000 | ((int)(R_HDMA3&0x1f) << 8) | (R_HDMA4&0xf0);
+        cnt = ((int)c)+1;
+        /* FIXME - this should use cpu time! */
+        /*cpu_timers(102 * cnt);*/
+        cnt <<= 4;
+        while (cnt--)
+                writeb(da++, readb(sa++));
+        R_HDMA1 = sa >> 8;
+        R_HDMA2 = sa & 0xF0;
+        R_HDMA3 = 0x1F & (da >> 8);
+        R_HDMA4 = da & 0xF0;
+        R_HDMA5 = 0xFF;
+}
+
+
+void hw_hdma(void)
+{
+        int cnt;
+        addr sa;
+        int da;
+
+        sa = ((addr)R_HDMA1 << 8) | (R_HDMA2&0xf0);
+        da = 0x8000 | ((int)(R_HDMA3&0x1f) << 8) | (R_HDMA4&0xf0);
+        cnt = 16;
+        while (cnt--)
+                writeb(da++, readb(sa++));
+        R_HDMA1 = sa >> 8;
+        R_HDMA2 = sa & 0xF0;
+        R_HDMA3 = 0x1F & (da >> 8);
+        R_HDMA4 = da & 0xF0;
+        R_HDMA5--;
+        hw.hdma--;
+}
+
+
+/*
+ * pad_refresh updates the P1 register from the pad states, generating
+ * the appropriate interrupts (by quickly raising and lowering the
+ * interrupt line) if a transition has been made.
+ */
+
+void pad_refresh()
+{
+        byte oldp1;
+        oldp1 = R_P1;
+        R_P1 &= 0x30;
+        R_P1 |= 0xc0;
+        if (!(R_P1 & 0x10))
+                R_P1 |= (hw.pad & 0x0F);
+        if (!(R_P1 & 0x20))
+                R_P1 |= (hw.pad >> 4);
+        R_P1 ^= 0x0F;
+        if (oldp1 & ~R_P1 & 0x0F)
+        {
+                hw_interrupt(IF_PAD, IF_PAD);
+                hw_interrupt(0, IF_PAD);
+        }
+}
+
+
+/*
+ * These simple functions just update the state of a button on the
+ * pad.
+ */
+
+void pad_press(byte k)
+{
+        if (hw.pad & k)
+                return;
+        hw.pad |= k;
+        pad_refresh();
+}
+
+void pad_release(byte k)
+{
+        if (!(hw.pad & k))
+                return;
+        hw.pad &= ~k;
+        pad_refresh();
+}
+
+void pad_set(byte k, int st)
+{
+        st ? pad_press(k) : pad_release(k);
+}
+
+void hw_reset()
+{
+        hw.ilines = hw.pad = 0;
+
+        memset(ram.hi, 0, sizeof ram.hi);
+
+        R_P1 = 0xFF;
+        R_LCDC = 0x91;
+        R_BGP = 0xFC;
+        R_OBP0 = 0xFF;
+        R_OBP1 = 0xFF;
+        R_SVBK = 0x01;
+        R_HDMA5 = 0xFF;
+        R_VBK = 0xFE;
+}
+
+
+
+
+
+
+