hw/lm32: print error if cpu model is not found

QEMU crashed if a the given cpu_model is not found.
Signed-off-by: NMichael Walle <michael@walle.cc>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>

hw/lm32/lm32_boards.c

@@ -101,6 +101,11 @@ static void lm32_evr_init(QEMUMachineInitArgs *args)
         cpu_model = "lm32-full";
     }
     cpu = cpu_lm32_init(cpu_model);
+    if (cpu == NULL) {
+        fprintf(stderr, "qemu: unable to find CPU '%s'\n", cpu_model);
+        exit(1);
+    }
+
     env = &cpu->env;
     reset_info->cpu = cpu;
 
@@ -198,6 +203,11 @@ static void lm32_uclinux_init(QEMUMachineInitArgs *args)
         cpu_model = "lm32-full";
     }
     cpu = cpu_lm32_init(cpu_model);
+    if (cpu == NULL) {
+        fprintf(stderr, "qemu: unable to find CPU '%s'\n", cpu_model);
+        exit(1);
+    }
+
     env = &cpu->env;
     reset_info->cpu = cpu;
 

hw/lm32/milkymist.c

@@ -108,6 +108,11 @@ milkymist_init(QEMUMachineInitArgs *args)
         cpu_model = "lm32-full";
     }
     cpu = cpu_lm32_init(cpu_model);
+    if (cpu == NULL) {
+        fprintf(stderr, "qemu: unable to find CPU '%s'\n", cpu_model);
+        exit(1);
+    }
+
     env = &cpu->env;
     reset_info->cpu = cpu;