S390: Make IPL reset address dynamic

We can have different load addresses for different blobs we boot with.
Make the reset IP dynamic, so that we can handle things more flexibly.
Signed-off-by: NAlexander Graf <agraf@suse.de>

hw/s390x/ipl.c

@@ -48,8 +48,9 @@ typedef struct S390IPLClass {
 typedef struct S390IPLState {
     /*< private >*/
     SysBusDevice parent_obj;
-    /*< public >*/
+    uint64_t start_addr;
 
+    /*< public >*/
     char *kernel;
     char *initrd;
     char *cmdline;
@@ -82,6 +83,7 @@ static int s390_ipl_init(SysBusDevice *dev)
 
         bios_filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
         bios_size = load_image_targphys(bios_filename, ZIPL_IMAGE_START, 4096);
+        ipl->start_addr = ZIPL_IMAGE_START;
         g_free(bios_filename);
 
         if ((long)bios_size < 0) {
@@ -104,6 +106,13 @@ static int s390_ipl_init(SysBusDevice *dev)
         }
         /* we have to overwrite values in the kernel image, which are "rom" */
         strcpy(rom_ptr(KERN_PARM_AREA), ipl->cmdline);
+
+        /*
+         * we can not rely on the ELF entry point, since up to 3.2 this
+         * value was 0x800 (the SALIPL loader) and it wont work. For
+         * all (Linux) cases 0x10000 (KERN_IMAGE_START) should be fine.
+         */
+        ipl->start_addr = KERN_IMAGE_START;
     }
     if (ipl->initrd) {
         ram_addr_t initrd_offset, initrd_size;
@@ -138,16 +147,7 @@ static void s390_ipl_reset(DeviceState *dev)
 {
     S390IPLState *ipl = S390_IPL(dev);
 
-    if (ipl->kernel) {
-        /*
-         * we can not rely on the ELF entry point, since up to 3.2 this
-         * value was 0x800 (the SALIPL loader) and it wont work. For
-         * all (Linux) cases 0x10000 (KERN_IMAGE_START) should be fine.
-         */
-        return s390_ipl_cpu(KERN_IMAGE_START);
-    } else {
-        return s390_ipl_cpu(ZIPL_IMAGE_START);
-    }
+    s390_ipl_cpu(ipl->start_addr);
 }
 
 static void s390_ipl_class_init(ObjectClass *klass, void *data)