diff --git a/src/asahi/lib/cmdbuf.xml b/src/asahi/lib/cmdbuf.xml
index 47b0767bc9d..ebd33bf234b 100644
--- a/src/asahi/lib/cmdbuf.xml
+++ b/src/asahi/lib/cmdbuf.xml
@@ -529,9 +529,7 @@
     <field name="Unk 0" start="0:0" size="16" default="0x100" type="hex"/>
     <field name="Address" start="0:16" size="48" type="address"/>
     <field name="Type" start="2:16" size="16" type="IOGPU Attachment Type"/>
-    <field name="Unk 1" start="3:0" size="32" type="hex"/>
-    <field name="Unk 2" start="4:0" size="3" type="hex"/>
-    <field name="Bytes per pixel" start="4:3" size="5" type="uint"/>
+    <field name="Size" start="3:16" size="32" type="uint"/>
     <field name="Unk 3" start="4:16" size="4" type="hex" default="0xC"/>
     <!-- Percent of total attachment space used for this attachment, expressed
          in a decimal percentage [0, 100] <field name="Percent" start="5:16" -->
diff --git a/src/gallium/drivers/asahi/magic.c b/src/gallium/drivers/asahi/magic.c
index ed3ee08bd95..7117f4a3e55 100644
--- a/src/gallium/drivers/asahi/magic.c
+++ b/src/gallium/drivers/asahi/magic.c
@@ -141,9 +141,7 @@ demo_cmdbuf(uint64_t *buf, size_t size,
    agx_pack((map + (offset_attachments / 4) + 4), IOGPU_ATTACHMENT, cfg) {
       cfg.address = rt0;
       cfg.type = AGX_IOGPU_ATTACHMENT_TYPE_COLOUR;
-      cfg.unk_1 = 0x80000000;
-      cfg.unk_2 = 0x5;
-      cfg.bytes_per_pixel = 4;
+      cfg.size = 800*600*4;
       cfg.percent = 100;
    }