diff --git a/include/hw/arm/aspeed_soc.h b/include/hw/arm/aspeed_soc.h
index 02a5a9ffcbd3..e8a104823d35 100644
--- a/include/hw/arm/aspeed_soc.h
+++ b/include/hw/arm/aspeed_soc.h
@@ -50,6 +50,7 @@ struct AspeedSoCState {
     A15MPPrivState     a7mpcore;
     ARMv7MState        armv7m;
     MemoryRegion *dram_mr;
+    MemoryRegion dram_container;
     MemoryRegion sram;
     AspeedVICState vic;
     AspeedRtcState rtc;
@@ -165,5 +166,6 @@ enum {
 
 qemu_irq aspeed_soc_get_irq(AspeedSoCState *s, int dev);
 void aspeed_soc_uart_init(AspeedSoCState *s);
+bool aspeed_soc_dram_init(AspeedSoCState *s, Error **errp);
 
 #endif /* ASPEED_SOC_H */
diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c
index a06f7c1b62a9..dc09773b0ba5 100644
--- a/hw/arm/aspeed.c
+++ b/hw/arm/aspeed.c
@@ -174,27 +174,6 @@ struct AspeedMachineState {
 #define BLETCHLEY_BMC_HW_STRAP1 AST2600_EVB_HW_STRAP1
 #define BLETCHLEY_BMC_HW_STRAP2 AST2600_EVB_HW_STRAP2
 
-/*
- * The max ram region is for firmwares that scan the address space
- * with load/store to guess how much RAM the SoC has.
- */
-static uint64_t max_ram_read(void *opaque, hwaddr offset, unsigned size)
-{
-    return 0;
-}
-
-static void max_ram_write(void *opaque, hwaddr offset, uint64_t value,
-                           unsigned size)
-{
-    /* Discard writes */
-}
-
-static const MemoryRegionOps max_ram_ops = {
-    .read = max_ram_read,
-    .write = max_ram_write,
-    .endianness = DEVICE_NATIVE_ENDIAN,
-};
-
 #define AST_SMP_MAILBOX_BASE            0x1e6e2180
 #define AST_SMP_MBOX_FIELD_ENTRY        (AST_SMP_MAILBOX_BASE + 0x0)
 #define AST_SMP_MBOX_FIELD_GOSIGN       (AST_SMP_MAILBOX_BASE + 0x4)
@@ -324,20 +303,16 @@ static void aspeed_machine_init(MachineState *machine)
     AspeedMachineClass *amc = ASPEED_MACHINE_GET_CLASS(machine);
     AspeedSoCClass *sc;
     DriveInfo *drive0 = drive_get(IF_MTD, 0, 0);
-    ram_addr_t max_ram_size;
     int i;
     NICInfo *nd = &nd_table[0];
 
-    memory_region_init(&bmc->ram_container, NULL, "aspeed-ram-container",
-                       4 * GiB);
-    memory_region_add_subregion(&bmc->ram_container, 0, machine->ram);
-
     object_initialize_child(OBJECT(machine), "soc", &bmc->soc, amc->soc_name);
 
     sc = ASPEED_SOC_GET_CLASS(&bmc->soc);
 
     /*
-     * This will error out if isize is not supported by memory controller.
+     * This will error out if the RAM size is not supported by the
+     * memory controller of the SoC.
      */
     object_property_set_uint(OBJECT(&bmc->soc), "ram-size", machine->ram_size,
                              &error_fatal);
@@ -369,16 +344,6 @@ static void aspeed_machine_init(MachineState *machine)
                          amc->uart_default);
     qdev_realize(DEVICE(&bmc->soc), NULL, &error_abort);
 
-    memory_region_add_subregion(get_system_memory(),
-                                sc->memmap[ASPEED_DEV_SDRAM],
-                                &bmc->ram_container);
-
-    max_ram_size = object_property_get_uint(OBJECT(&bmc->soc), "max-ram-size",
-                                            &error_abort);
-    memory_region_init_io(&bmc->max_ram, NULL, &max_ram_ops, NULL,
-                          "max_ram", max_ram_size  - machine->ram_size);
-    memory_region_add_subregion(&bmc->ram_container, machine->ram_size, &bmc->max_ram);
-
     aspeed_board_init_flashes(&bmc->soc.fmc,
                               bmc->fmc_model ? bmc->fmc_model : amc->fmc_model,
                               amc->num_cs, 0);
diff --git a/hw/arm/aspeed_ast2600.c b/hw/arm/aspeed_ast2600.c
index b0a4199b6960..bb5927c36bbf 100644
--- a/hw/arm/aspeed_ast2600.c
+++ b/hw/arm/aspeed_ast2600.c
@@ -197,8 +197,6 @@ static void aspeed_soc_ast2600_init(Object *obj)
     object_initialize_child(obj, "sdmc", &s->sdmc, typename);
     object_property_add_alias(obj, "ram-size", OBJECT(&s->sdmc),
                               "ram-size");
-    object_property_add_alias(obj, "max-ram-size", OBJECT(&s->sdmc),
-                              "max-ram-size");
 
     for (i = 0; i < sc->wdts_num; i++) {
         snprintf(typename, sizeof(typename), "aspeed.wdt-%s", socname);
@@ -443,6 +441,11 @@ static void aspeed_soc_ast2600_realize(DeviceState *dev, Error **errp)
                         sc->memmap[ASPEED_DEV_WDT] + i * awc->offset);
     }
 
+    /* RAM */
+    if (!aspeed_soc_dram_init(s, errp)) {
+        return;
+    }
+
     /* Net */
     for (i = 0; i < sc->macs_num; i++) {
         object_property_set_bool(OBJECT(&s->ftgmac100[i]), "aspeed", true,
diff --git a/hw/arm/aspeed_soc.c b/hw/arm/aspeed_soc.c
index 30574d4276ab..3e6055ac9129 100644
--- a/hw/arm/aspeed_soc.c
+++ b/hw/arm/aspeed_soc.c
@@ -11,6 +11,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/units.h"
 #include "qapi/error.h"
 #include "hw/misc/unimp.h"
 #include "hw/arm/aspeed_soc.h"
@@ -191,8 +192,6 @@ static void aspeed_soc_init(Object *obj)
     object_initialize_child(obj, "sdmc", &s->sdmc, typename);
     object_property_add_alias(obj, "ram-size", OBJECT(&s->sdmc),
                               "ram-size");
-    object_property_add_alias(obj, "max-ram-size", OBJECT(&s->sdmc),
-                              "max-ram-size");
 
     for (i = 0; i < sc->wdts_num; i++) {
         snprintf(typename, sizeof(typename), "aspeed.wdt-%s", socname);
@@ -369,6 +368,11 @@ static void aspeed_soc_realize(DeviceState *dev, Error **errp)
                         sc->memmap[ASPEED_DEV_WDT] + i * awc->offset);
     }
 
+    /* RAM  */
+    if (!aspeed_soc_dram_init(s, errp)) {
+        return;
+    }
+
     /* Net */
     for (i = 0; i < sc->macs_num; i++) {
         object_property_set_bool(OBJECT(&s->ftgmac100[i]), "aspeed", true,
@@ -561,3 +565,44 @@ void aspeed_soc_uart_init(AspeedSoCState *s)
                        serial_hd(i), DEVICE_LITTLE_ENDIAN);
     }
 }
+
+/*
+ * SDMC should be realized first to get correct RAM size and max size
+ * values
+ */
+bool aspeed_soc_dram_init(AspeedSoCState *s, Error **errp)
+{
+    AspeedSoCClass *sc = ASPEED_SOC_GET_CLASS(s);
+    ram_addr_t ram_size, max_ram_size;
+
+    ram_size = object_property_get_uint(OBJECT(&s->sdmc), "ram-size",
+                                        &error_abort);
+    max_ram_size = object_property_get_uint(OBJECT(&s->sdmc), "max-ram-size",
+                                            &error_abort);
+
+    memory_region_init(&s->dram_container, OBJECT(s), "ram-container",
+                       max_ram_size);
+    memory_region_add_subregion(&s->dram_container, 0, s->dram_mr);
+
+    /*
+     * Add a memory region beyond the RAM region to let firmwares scan
+     * the address space with load/store and guess how much RAM the
+     * SoC has.
+     */
+    if (ram_size < max_ram_size) {
+        DeviceState *dev = qdev_new(TYPE_UNIMPLEMENTED_DEVICE);
+
+        qdev_prop_set_string(dev, "name", "ram-empty");
+        qdev_prop_set_uint64(dev, "size", max_ram_size  - ram_size);
+        if (!sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), errp)) {
+            return false;
+        }
+
+        memory_region_add_subregion_overlap(&s->dram_container, ram_size,
+                      sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 0), -1000);
+    }
+
+    memory_region_add_subregion(get_system_memory(),
+                      sc->memmap[ASPEED_DEV_SDRAM], &s->dram_container);
+    return true;
+}
