RISC-V: Use ROM base address and size from memmap

Another case of replacing hard coded constants, this time
referring to the definition in the virt machine's memmap.

Cc: Sagar Karandikar <sagark@eecs.berkeley.edu>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

hw/riscv/virt.c

@@ -341,11 +341,11 @@ static void riscv_virt_board_init(MachineState *machine)
     };
 
     /* copy in the reset vector */
-    copy_le32_to_phys(ROM_BASE, reset_vec, sizeof(reset_vec));
+    copy_le32_to_phys(memmap[VIRT_MROM].base, reset_vec, sizeof(reset_vec));
 
     /* copy in the device tree */
     qemu_fdt_dumpdtb(s->fdt, s->fdt_size);
-    cpu_physical_memory_write(ROM_BASE + sizeof(reset_vec),
+    cpu_physical_memory_write(memmap[VIRT_MROM].base + sizeof(reset_vec),
         s->fdt, s->fdt_size);
 
     /* create PLIC hart topology configuration string */

include/hw/riscv/virt.h

@@ -23,8 +23,6 @@
 #define VIRT(obj) \
     OBJECT_CHECK(RISCVVirtState, (obj), TYPE_RISCV_VIRT_BOARD)
 
-enum { ROM_BASE = 0x1000 };
-
 typedef struct {
     /*< private >*/
     SysBusDevice parent_obj;