[Qemu-devel] [patch] incorrect VGA initialization, can provide image

[Piotr Krysik]

Hi!

This patch should fix the problem.


Piotrek



                
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diff -ru qemu-snapshot-2004-08-04_23/hw/vga.c 
qemu-snapshot-2004-08-04_23-vga-update/hw/vga.c
--- qemu-snapshot-2004-08-04_23/hw/vga.c        2004-06-26 18:12:26.000000000 
+0200
+++ qemu-snapshot-2004-08-04_23-vga-update/hw/vga.c     2004-09-09 
23:40:51.000000000 +0200
@@ -696,10 +696,14 @@
         /* chain 4 mode : simplest access */
         plane = addr & 3;
         if (s->sr[2] & (1 << plane)) {
-            s->vram_ptr[addr] = val;
 #ifdef DEBUG_VGA_MEM
             printf("vga: chain4: [0x%x]\n", addr);
 #endif
+            s->vram_ptr[addr] = val;
+            /* force full update for vga_draw_text when writing font memory */
+            if (((s->font_offsets[0] ^ addr) & ~0x7ffc) == 0 ||
+                ((s->font_offsets[1] ^ addr) & ~0x7ffc) == 0)
+                s->font_offsets[0] = -1;
             cpu_physical_memory_set_dirty(s->vram_offset + addr);
         }
     } else if (s->gr[5] & 0x10) {
@@ -707,10 +711,14 @@
         plane = (s->gr[4] & 2) | (addr & 1);
         if (s->sr[2] & (1 << plane)) {
             addr = ((addr & ~1) << 1) | plane;
-            s->vram_ptr[addr] = val;
 #ifdef DEBUG_VGA_MEM
             printf("vga: odd/even: [0x%x]\n", addr);
 #endif
+            s->vram_ptr[addr] = val;
+            /* force full update for vga_draw_text when writing font memory */
+            if (((s->font_offsets[0] ^ addr) & ~0x7ffc) == 0 ||
+                ((s->font_offsets[1] ^ addr) & ~0x7ffc) == 0)
+                s->font_offsets[0] = -1;
             cpu_physical_memory_set_dirty(s->vram_offset + addr);
         }
     } else {
@@ -776,14 +784,19 @@
     do_write:
         /* mask data according to sr[2] */
         write_mask = mask16[s->sr[2]];
+#ifdef DEBUG_VGA_MEM
+        printf("vga: latch: [0x%x] mask=0x%08x val=0x%08x\n", 
+               addr * 4, write_mask, val);
+#endif
         ((uint32_t *)s->vram_ptr)[addr] = 
             (((uint32_t *)s->vram_ptr)[addr] & ~write_mask) | 
             (val & write_mask);
-#ifdef DEBUG_VGA_MEM
-            printf("vga: latch: [0x%x] mask=0x%08x val=0x%08x\n", 
-                   addr * 4, write_mask, val);
-#endif
-            cpu_physical_memory_set_dirty(s->vram_offset + (addr << 2));
+        /* force full update for vga_draw_text when writing font memory */
+        if ((s->sr[2] & 4) &&
+            (((s->font_offsets[0] ^ ((addr << 2) + 2)) & ~0x7ffc) == 0 ||
+            ((s->font_offsets[1] ^ ((addr << 2) + 2)) & ~0x7ffc) == 0))
+            s->font_offsets[0] = -1;
+        cpu_physical_memory_set_dirty(s->vram_offset + (addr << 2));
     }
 }