nubus-device: add romfile property for loading declaration ROMs

The declaration ROM is located at the top-most address of the standard slot
space.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210924073808.1041-12-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

hw/nubus/nubus-device.c

@@ -9,16 +9,21 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/datadir.h"
+#include "hw/loader.h"
 #include "hw/nubus/nubus.h"
 #include "qapi/error.h"
+#include "qemu/error-report.h"
 
 
 static void nubus_device_realize(DeviceState *dev, Error **errp)
 {
     NubusBus *nubus = NUBUS_BUS(qdev_get_parent_bus(dev));
     NubusDevice *nd = NUBUS_DEVICE(dev);
-    char *name;
+    char *name, *path;
     hwaddr slot_offset;
+    int64_t size;
+    int ret;
 
     /* Super */
     slot_offset = nd->slot * NUBUS_SUPER_SLOT_SIZE;
@@ -38,10 +43,47 @@ static void nubus_device_realize(DeviceState *dev, Error **errp)
     memory_region_add_subregion(&nubus->slot_io, slot_offset,
                                 &nd->slot_mem);
     g_free(name);
+
+    /* Declaration ROM */
+    if (nd->romfile != NULL) {
+        path = qemu_find_file(QEMU_FILE_TYPE_BIOS, nd->romfile);
+        if (path == NULL) {
+            path = g_strdup(nd->romfile);
+        }
+
+        size = get_image_size(path);
+        if (size < 0) {
+            error_setg(errp, "failed to find romfile \"%s\"", nd->romfile);
+            g_free(path);
+            return;
+        } else if (size == 0) {
+            error_setg(errp, "romfile \"%s\" is empty", nd->romfile);
+            g_free(path);
+            return;
+        } else if (size > NUBUS_DECL_ROM_MAX_SIZE) {
+            error_setg(errp, "romfile \"%s\" too large (maximum size 128K)",
+                       nd->romfile);
+            g_free(path);
+            return;
+        }
+
+        name = g_strdup_printf("nubus-slot-%x-declaration-rom", nd->slot);
+        memory_region_init_rom(&nd->decl_rom, OBJECT(dev), name, size,
+                               &error_abort);
+        ret = load_image_mr(path, &nd->decl_rom);
+        g_free(path);
+        if (ret < 0) {
+            error_setg(errp, "could not load romfile \"%s\"", nd->romfile);
+            return;
+        }
+        memory_region_add_subregion(&nd->slot_mem, NUBUS_SLOT_SIZE - size,
+                                    &nd->decl_rom);
+    }
 }
 
 static Property nubus_device_properties[] = {
     DEFINE_PROP_INT32("slot", NubusDevice, slot, -1),
+    DEFINE_PROP_STRING("romfile", NubusDevice, romfile),
     DEFINE_PROP_END_OF_LIST()
 };
 

include/hw/nubus/nubus.h

@@ -12,6 +12,7 @@
 #include "hw/qdev-properties.h"
 #include "exec/address-spaces.h"
 #include "qom/object.h"
+#include "qemu/units.h"
 
 #define NUBUS_SUPER_SLOT_SIZE 0x10000000U
 #define NUBUS_SUPER_SLOT_NB   0xe
@@ -38,12 +39,17 @@ struct NubusBus {
     uint16_t slot_available_mask;
 };
 
+#define NUBUS_DECL_ROM_MAX_SIZE    (128 * KiB)
+
 struct NubusDevice {
     DeviceState qdev;
 
     int32_t slot;
     MemoryRegion super_slot_mem;
     MemoryRegion slot_mem;
+
+    char *romfile;
+    MemoryRegion decl_rom;
 };
 
 #endif