sm501: Add some more unimplemented registers

These are not really implemented (just return zero or default values)
but add these so guests accessing them can run.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/display/sm501.c

@@ -795,6 +795,8 @@ static uint64_t sm501_system_config_read(void *opaque, hwaddr addr,
     case SM501_ARBTRTN_CONTROL:
         ret = s->arbitration_control;
         break;
+    case SM501_COMMAND_LIST_STATUS:
+        ret = 0x00180002; /* FIFOs are empty, everything idle */
     case SM501_IRQ_MASK:
         ret = s->irq_mask;
         break;
@@ -812,6 +814,9 @@ static uint64_t sm501_system_config_read(void *opaque, hwaddr addr,
     case SM501_POWER_MODE_CONTROL:
         ret = s->power_mode_control;
         break;
+    case SM501_ENDIAN_CONTROL:
+        ret = 0; /* Only default little endian mode is supported */
+        break;
 
     default:
         printf("sm501 system config : not implemented register read."
@@ -865,6 +870,12 @@ static void sm501_system_config_write(void *opaque, hwaddr addr,
     case SM501_POWER_MODE_CONTROL:
         s->power_mode_control = value & 0x00000003;
         break;
+    case SM501_ENDIAN_CONTROL:
+        if (value & 0x00000001) {
+            printf("sm501 system config : big endian mode not implemented.\n");
+            abort();
+        }
+        break;
 
     default:
         printf("sm501 system config : not implemented register write."
@@ -924,6 +935,9 @@ static uint64_t sm501_disp_ctrl_read(void *opaque, hwaddr addr,
     case SM501_DC_PANEL_PANNING_CONTROL:
         ret = s->dc_panel_panning_control;
         break;
+    case SM501_DC_PANEL_COLOR_KEY:
+        /* Not implemented yet */
+        break;
     case SM501_DC_PANEL_FB_ADDR:
         ret = s->dc_panel_fb_addr;
         break;
@@ -1035,6 +1049,9 @@ static void sm501_disp_ctrl_write(void *opaque, hwaddr addr,
     case SM501_DC_PANEL_PANNING_CONTROL:
         s->dc_panel_panning_control = value & 0xFF3FFF3F;
         break;
+    case SM501_DC_PANEL_COLOR_KEY:
+        /* Not implemented yet */
+        break;
     case SM501_DC_PANEL_FB_ADDR:
         s->dc_panel_fb_addr = value & 0x8FFFFFF0;
         break;