hw/openrisc/openrisc_sim: Add support for initrd loading

The initrd passed via the command line is loaded into memory.  It's
location and size is then added to the device tree so the kernel knows
where to find it.

Signed-off-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

hw/openrisc/openrisc_sim.c

@@ -315,6 +315,33 @@ static hwaddr openrisc_load_kernel(ram_addr_t ram_size,
     return 0;
 }
 
+static hwaddr openrisc_load_initrd(Or1ksimState *state, const char *filename,
+                                   hwaddr load_start, uint64_t mem_size)
+{
+    void *fdt = state->fdt;
+    int size;
+    hwaddr start;
+
+    /* We put the initrd right after the kernel; page aligned. */
+    start = TARGET_PAGE_ALIGN(load_start);
+
+    size = load_ramdisk(filename, start, mem_size - start);
+    if (size < 0) {
+        size = load_image_targphys(filename, start, mem_size - start);
+        if (size < 0) {
+            error_report("could not load ramdisk '%s'", filename);
+            exit(1);
+        }
+    }
+
+    qemu_fdt_setprop_cell(fdt, "/chosen",
+                          "linux,initrd-start", start);
+    qemu_fdt_setprop_cell(fdt, "/chosen",
+                          "linux,initrd-end", start + size);
+
+    return start + size;
+}
+
 static uint32_t openrisc_load_fdt(Or1ksimState *state, hwaddr load_start,
                                   uint64_t mem_size)
 {
@@ -393,6 +420,10 @@ static void openrisc_sim_init(MachineState *machine)
 
     load_addr = openrisc_load_kernel(ram_size, kernel_filename);
     if (load_addr > 0) {
+        if (machine->initrd_filename) {
+            load_addr = openrisc_load_initrd(state, machine->initrd_filename,
+                                             load_addr, machine->ram_size);
+        }
         boot_info.fdt_addr = openrisc_load_fdt(state, load_addr,
                                                machine->ram_size);
     }