hw/mips: Remove exit(1) in case of missing ROM

This patch updates MIPS-based machines to allow starting them without ROM.
In this case CPU starts to execute instructions from the empty memory,
but QEMU allows introspecting the machine configuration.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <159531210571.24117.231100997794891819.stgit@pasha-ThinkPad-X280>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

hw/mips/fuloong2e.c

@@ -337,10 +337,8 @@ static void mips_fuloong2e_init(MachineState *machine)
         kernel_entry = load_kernel(env);
         write_bootloader(env, memory_region_get_ram_ptr(bios), kernel_entry);
     } else {
-        if (bios_name == NULL) {
-                bios_name = FULOONG_BIOSNAME;
-        }
-        filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
+        filename = qemu_find_file(QEMU_FILE_TYPE_BIOS,
+                                  bios_name ?: FULOONG_BIOSNAME);
         if (filename) {
             bios_size = load_image_targphys(filename, 0x1fc00000LL,
                                             BIOS_SIZE);
@@ -350,7 +348,7 @@ static void mips_fuloong2e_init(MachineState *machine)
         }
 
         if ((bios_size < 0 || bios_size > BIOS_SIZE) &&
-            !kernel_filename && !qtest_enabled()) {
+            bios_name && !qtest_enabled()) {
             error_report("Could not load MIPS bios '%s'", bios_name);
             exit(1);
         }

hw/mips/jazz.c

@@ -218,10 +218,7 @@ static void mips_jazz_init(MachineState *machine,
     memory_region_add_subregion(address_space, 0xfff00000LL, bios2);
 
     /* load the BIOS image. */
-    if (bios_name == NULL) {
-        bios_name = BIOS_FILENAME;
-    }
-    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
+    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name ?: BIOS_FILENAME);
     if (filename) {
         bios_size = load_image_targphys(filename, 0xfff00000LL,
                                         MAGNUM_BIOS_SIZE);
@@ -229,7 +226,8 @@ static void mips_jazz_init(MachineState *machine,
     } else {
         bios_size = -1;
     }
-    if ((bios_size < 0 || bios_size > MAGNUM_BIOS_SIZE) && !qtest_enabled()) {
+    if ((bios_size < 0 || bios_size > MAGNUM_BIOS_SIZE)
+        && bios_name && !qtest_enabled()) {
         error_report("Could not load MIPS bios '%s'", bios_name);
         exit(1);
     }

hw/mips/malta.c

@@ -1332,10 +1332,8 @@ void mips_malta_init(MachineState *machine)
         /* Load firmware from flash. */
         if (!dinfo) {
             /* Load a BIOS image. */
-            if (bios_name == NULL) {
-                bios_name = BIOS_FILENAME;
-            }
-            filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
+            filename = qemu_find_file(QEMU_FILE_TYPE_BIOS,
+                                      bios_name ?: BIOS_FILENAME);
             if (filename) {
                 bios_size = load_image_targphys(filename, FLASH_ADDRESS,
                                                 BIOS_SIZE);
@@ -1344,9 +1342,8 @@ void mips_malta_init(MachineState *machine)
                 bios_size = -1;
             }
             if ((bios_size < 0 || bios_size > BIOS_SIZE) &&
-                !kernel_filename && !qtest_enabled()) {
-                error_report("Could not load MIPS bios '%s', and no "
-                             "-kernel argument was specified", bios_name);
+                bios_name && !qtest_enabled()) {
+                error_report("Could not load MIPS bios '%s'", bios_name);
                 exit(1);
             }
         }

hw/mips/mipssim.c

@@ -177,10 +177,7 @@ mips_mipssim_init(MachineState *machine)
     /* Map the BIOS / boot exception handler. */
     memory_region_add_subregion(address_space_mem, 0x1fc00000LL, bios);
     /* Load a BIOS / boot exception handler image. */
-    if (bios_name == NULL) {
-        bios_name = BIOS_FILENAME;
-    }
-    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
+    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name ?: BIOS_FILENAME);
     if (filename) {
         bios_size = load_image_targphys(filename, 0x1fc00000LL, BIOS_SIZE);
         g_free(filename);
@@ -188,10 +185,9 @@ mips_mipssim_init(MachineState *machine)
         bios_size = -1;
     }
     if ((bios_size < 0 || bios_size > BIOS_SIZE) &&
-        !kernel_filename && !qtest_enabled()) {
+        bios_name && !qtest_enabled()) {
         /* Bail out if we have neither a kernel image nor boot vector code. */
-        error_report("Could not load MIPS bios '%s', and no "
-                     "-kernel argument was specified", bios_name);
+        error_report("Could not load MIPS bios '%s'", bios_name);
         exit(1);
     } else {
         /* We have a boot vector start address. */