[PATCH v1 4/6] riscv/sifive_u: Add the start-in-flash property

[Alistair Francis]

Add a property that when set to true QEMU will jump from the ROM code to
the start of flash memory instead of DRAM which is the default
behaviour.

Signed-off-by: Alistair Francis <address@hidden>
---
 hw/riscv/sifive_u.c         | 27 +++++++++++++++++++++++++++
 include/hw/riscv/sifive_u.h |  2 ++
 2 files changed, 29 insertions(+)

diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
index c3949fb316..b7cd3631cd 100644
--- a/hw/riscv/sifive_u.c
+++ b/hw/riscv/sifive_u.c
@@ -373,6 +373,10 @@ static void riscv_sifive_u_init(MachineState *machine)
                                        /* dtb: */
     };
 
+    if (s->start_in_flash) {
+        reset_vec[6] = memmap[SIFIVE_U_FLASH0].base; /* start: .dword 
FLASH0_BASE */
+    }
+
     /* copy in the reset vector in little_endian byte order */
     for (i = 0; i < sizeof(reset_vec) >> 2; i++) {
         reset_vec[i] = cpu_to_le32(reset_vec[i]);
@@ -544,8 +548,31 @@ static void riscv_sifive_u_soc_realize(DeviceState *dev, 
Error **errp)
         memmap[SIFIVE_U_GEM_MGMT].base, memmap[SIFIVE_U_GEM_MGMT].size);
 }
 
+static bool virt_get_start_in_flash(Object *obj, Error **errp)
+{
+    SiFiveUState *s = RISCV_U_MACHINE(obj);
+
+    return s->start_in_flash;
+}
+
+static void virt_set_start_in_flash(Object *obj, bool value, Error **errp)
+{
+    SiFiveUState *s = RISCV_U_MACHINE(obj);
+
+    s->start_in_flash = value;
+}
+
 static void riscv_sifive_u_machine_instance_init(Object *obj)
 {
+    SiFiveUState *s = RISCV_U_MACHINE(obj);
+
+    s->start_in_flash = false;
+    object_property_add_bool(obj, "start-in-flash", virt_get_start_in_flash,
+                             virt_set_start_in_flash, NULL);
+    object_property_set_description(obj, "start-in-flash",
+                                    "Set on to tell QEMU's ROM to jump to " \
+                                    "flash. Otherwise QEMU will jump to DRAM",
+                                    NULL);
 
 }
 
diff --git a/include/hw/riscv/sifive_u.h b/include/hw/riscv/sifive_u.h
index a921079fbe..2656b43c58 100644
--- a/include/hw/riscv/sifive_u.h
+++ b/include/hw/riscv/sifive_u.h
@@ -57,6 +57,8 @@ typedef struct SiFiveUState {
 
     void *fdt;
     int fdt_size;
+
+    bool start_in_flash;
 } SiFiveUState;
 
 enum {
-- 
2.23.0