Single mode for PIC i8259, by Bernhard Kauer.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2575 c046a42c-6fe2-441c-8c8c-71466251a162

hw/i8259.c

@@ -44,6 +44,7 @@ typedef struct PicState {
     uint8_t rotate_on_auto_eoi;
     uint8_t special_fully_nested_mode;
     uint8_t init4; /* true if 4 byte init */
+    uint8_t single_mode; /* true if slave pic is not initialized */
     uint8_t elcr; /* PIIX edge/trigger selection*/
     uint8_t elcr_mask;
     PicState2 *pics_state;
@@ -278,6 +279,7 @@ static void pic_reset(void *opaque)
     s->rotate_on_auto_eoi = 0;
     s->special_fully_nested_mode = 0;
     s->init4 = 0;
+    s->single_mode = 0;
     /* Note: ELCR is not reset */
 }
 
@@ -298,8 +300,7 @@ static void pic_ioport_write(void *opaque, uint32_t addr, uint32_t val)
             s->pics_state->irq_request(s->pics_state->irq_request_opaque, 0);
             s->init_state = 1;
             s->init4 = val & 1;
-            if (val & 0x02)
-                hw_error("single mode not supported");
+            s->single_mode = val & 2;
             if (val & 0x08)
                 hw_error("level sensitive irq not supported");
         } else if (val & 0x08) {
@@ -356,7 +357,7 @@ static void pic_ioport_write(void *opaque, uint32_t addr, uint32_t val)
             break;
         case 1:
             s->irq_base = val & 0xf8;
-            s->init_state = 2;
+            s->init_state = s->single_mode && s->init4 ? 3 : 2;
             break;
         case 2:
             if (s->init4) {
@@ -468,6 +469,7 @@ static void pic_save(QEMUFile *f, void *opaque)
     qemu_put_8s(f, &s->rotate_on_auto_eoi);
     qemu_put_8s(f, &s->special_fully_nested_mode);
     qemu_put_8s(f, &s->init4);
+    qemu_put_8s(f, &s->single_mode);
     qemu_put_8s(f, &s->elcr);
 }
 
@@ -492,6 +494,7 @@ static int pic_load(QEMUFile *f, void *opaque, int version_id)
     qemu_get_8s(f, &s->rotate_on_auto_eoi);
     qemu_get_8s(f, &s->special_fully_nested_mode);
     qemu_get_8s(f, &s->init4);
+    qemu_get_8s(f, &s->single_mode);
     qemu_get_8s(f, &s->elcr);
     return 0;
 }