hw/riscv: sifive_u: Add a new property msel for MSEL pin state

On SiFive FU540 SoC, the value stored at physical address 0x1000
stores the MSEL pin state that is used to control the next boot
location that ROM codes jump to.

Add a new property msel to sifive_u machine for this.

Signed-off-by: Bin Meng <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Message-id: [email protected]
Message-Id: <[email protected]>
Signed-off-by: Alistair Francis <[email protected]>

Author: lbmeng

hw/riscv/sifive_u.c

@@ -504,6 +504,13 @@ static void sifive_u_machine_instance_init(Object *obj)
                                     "Set on to tell QEMU's ROM to jump to "
                                     "flash. Otherwise QEMU will jump to DRAM");
 
+    s->msel = 0;
+    object_property_add(obj, "msel", "uint32",
+                        sifive_u_machine_get_uint32_prop,
+                        sifive_u_machine_set_uint32_prop, NULL, &s->msel);
+    object_property_set_description(obj, "msel",
+                                    "Mode Select (MSEL[3:0]) pin state");
+
     s->serial = OTP_SERIAL;
     object_property_add(obj, "serial", "uint32",
                         sifive_u_machine_get_uint32_prop,

include/hw/riscv/sifive_u.h

@@ -63,6 +63,7 @@ typedef struct SiFiveUState {
     int fdt_size;
 
     bool start_in_flash;
+    uint32_t msel;
     uint32_t serial;
 } SiFiveUState;