[PATCH v4 08/14] none-machine: add 'ram-addr' property

[Damien Hedde <damien.hedde@greensocs.com>]

Add the property to configure a the base address of the ram.
The default value remains zero.

This commit is needed to use the 'none' machine as a base, and
subsequently to dynamically populate it using qapi commands. Having
a non null 'ram' is really hard to workaround because of the actual
constraints on the generic loader: it prevents loading binaries
bigger than ram_size (with a null ram, we cannot load anything).
For now we need to be able to use the existing ram creation
feature of the none machine with a configurable base address.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
---
 hw/core/null-machine.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/hw/core/null-machine.c b/hw/core/null-machine.c
index 7eb258af07..5fd1cc0218 100644
--- a/hw/core/null-machine.c
+++ b/hw/core/null-machine.c
@@ -16,9 +16,11 @@
 #include "hw/boards.h"
 #include "exec/address-spaces.h"
 #include "hw/core/cpu.h"
+#include "qapi/visitor.h"
 
 struct NoneMachineState {
     MachineState parent;
+    uint64_t ram_addr;
 };
 
 #define TYPE_NONE_MACHINE MACHINE_TYPE_NAME("none")
@@ -26,6 +28,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(NoneMachineState, NONE_MACHINE)
 
 static void machine_none_init(MachineState *mch)
 {
+    NoneMachineState *nms = NONE_MACHINE(mch);
     CPUState *cpu = NULL;
 
     /* Initialize CPU (if user asked for it) */
@@ -37,9 +40,13 @@ static void machine_none_init(MachineState *mch)
         }
     }
 
-    /* RAM at address zero */
+    /* RAM at configured address (default: 0) */
     if (mch->ram) {
-        memory_region_add_subregion(get_system_memory(), 0, mch->ram);
+        memory_region_add_subregion(get_system_memory(), nms->ram_addr,
+                                    mch->ram);
+    } else if (nms->ram_addr) {
+        error_report("'ram-addr' has been specified but the size is zero");
+        exit(1);
     }
 
     if (mch->kernel_filename) {
@@ -49,6 +56,22 @@ static void machine_none_init(MachineState *mch)
     }
 }
 
+static void machine_none_get_ram_addr(Object *obj, Visitor *v, const char *name,
+                                      void *opaque, Error **errp)
+{
+    NoneMachineState *nms = NONE_MACHINE(obj);
+
+    visit_type_uint64(v, name, &nms->ram_addr, errp);
+}
+
+static void machine_none_set_ram_addr(Object *obj, Visitor *v, const char *name,
+                                      void *opaque, Error **errp)
+{
+    NoneMachineState *nms = NONE_MACHINE(obj);
+
+    visit_type_uint64(v, name, &nms->ram_addr, errp);
+}
+
 static void machine_none_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
@@ -63,6 +86,13 @@ static void machine_none_class_init(ObjectClass *oc, void *data)
     mc->no_floppy = 1;
     mc->no_cdrom = 1;
     mc->no_sdcard = 1;
+
+    object_class_property_add(oc, "ram-addr", "int",
+        machine_none_get_ram_addr,
+        machine_none_set_ram_addr,
+        NULL, NULL);
+    object_class_property_set_description(oc, "ram-addr",
+        "Base address of the RAM (default is 0)");
 }
 
 static const TypeInfo none_machine_info = {
-- 
2.35.1