mips/boston: re-randomize rng-seed on reboot

When the system reboots, the rng-seed that the FDT has should be
re-randomized, so that the new boot gets a new seed. Since the FDT is in
the ROM region at this point, we add a hook right after the ROM has been
added, so that we have a pointer to that copy of the FDT.

Cc: Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-id: 20221025004327.568476-9-Jason@zx2c4.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/mips/boston.c

@@ -41,6 +41,7 @@
 #include "sysemu/sysemu.h"
 #include "sysemu/qtest.h"
 #include "sysemu/runstate.h"
+#include "sysemu/reset.h"
 
 #include <libfdt.h>
 #include "qom/object.h"
@@ -810,6 +811,8 @@ static void boston_mach_init(MachineState *machine)
             /* Calculate real fdt size after filter */
             dt_size = fdt_totalsize(dtb_load_data);
             rom_add_blob_fixed("dtb", dtb_load_data, dt_size, dtb_paddr);
+            qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
+                                rom_ptr(dtb_paddr, dt_size));
         } else {
             /* Try to load file as FIT */
             fit_err = load_fit(&boston_fit_loader, machine->kernel_filename, s);