s390x/ipl: always load the bios for ccw machine

We will need bios support in order to be able to support selecting a
different boot device via diagnose 308 in the ccw machine, so let's
make the bios mandatory for the ccw machine.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

1 files changed, 59 insertions, 46 deletions

diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index 4ba8409668..4014a6a229 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -50,6 +50,8 @@ typedef struct S390IPLState {
     /*< private >*/
     SysBusDevice parent_obj;
     uint64_t start_addr;
+    uint64_t bios_start_addr;
+    bool enforce_bios;
 
     /*< public >*/
     char *kernel;
@@ -65,11 +67,14 @@ static int s390_ipl_init(SysBusDevice *dev)
     uint64_t pentry = KERN_IMAGE_START;
     int kernel_size;
 
-    if (!ipl->kernel) {
-        int bios_size;
-        char *bios_filename;
+    int bios_size;
+    char *bios_filename;
 
-        /* Load zipl bootloader */
+    /*
+     * Always load the bios if it was enforced,
+     * even if an external kernel has been defined.
+     */
+    if (!ipl->kernel || ipl->enforce_bios) {
         if (bios_name == NULL) {
             bios_name = ipl->firmware;
         }
@@ -79,12 +84,12 @@ static int s390_ipl_init(SysBusDevice *dev)
             hw_error("could not find stage1 bootloader\n");
         }
 
-        bios_size = load_elf(bios_filename, NULL, NULL, &ipl->start_addr, NULL,
-                             NULL, 1, ELF_MACHINE, 0);
+        bios_size = load_elf(bios_filename, NULL, NULL, &ipl->bios_start_addr,
+                             NULL, NULL, 1, ELF_MACHINE, 0);
         if (bios_size < 0) {
             bios_size = load_image_targphys(bios_filename, ZIPL_IMAGE_START,
                                             4096);
-            ipl->start_addr = ZIPL_IMAGE_START;
+            ipl->bios_start_addr = ZIPL_IMAGE_START;
             if (bios_size > 4096) {
                 hw_error("stage1 bootloader is > 4k\n");
             }
@@ -94,52 +99,59 @@ static int s390_ipl_init(SysBusDevice *dev)
         if (bios_size == -1) {
             hw_error("could not load bootloader '%s'\n", bios_name);
         }
-        return 0;
-    }
 
-    kernel_size = load_elf(ipl->kernel, NULL, NULL, &pentry, NULL,
-                           NULL, 1, ELF_MACHINE, 0);
-    if (kernel_size < 0) {
-        kernel_size = load_image_targphys(ipl->kernel, 0, ram_size);
-    }
-    if (kernel_size < 0) {
-        fprintf(stderr, "could not load kernel '%s'\n", ipl->kernel);
-        return -1;
-    }
-    /*
-     * Is it a Linux kernel (starting at 0x10000)? If yes, we fill in the
-     * kernel parameters here as well. Note: For old kernels (up to 3.2)
-     * we can not rely on the ELF entry point - it was 0x800 (the SALIPL
-     * loader) and it won't work. For this case we force it to 0x10000, too.
-     */
-    if (pentry == KERN_IMAGE_START || pentry == 0x800) {
-        ipl->start_addr = KERN_IMAGE_START;
-        /* Overwrite parameters in the kernel image, which are "rom" */
-        strcpy(rom_ptr(KERN_PARM_AREA), ipl->cmdline);
-    } else {
-        ipl->start_addr = pentry;
+        /* default boot target is the bios */
+        ipl->start_addr = ipl->bios_start_addr;
     }
 
-    if (ipl->initrd) {
-        ram_addr_t initrd_offset;
-        int initrd_size;
-
-        initrd_offset = INITRD_START;
-        while (kernel_size + 0x100000 > initrd_offset) {
-            initrd_offset += 0x100000;
+    if (ipl->kernel) {
+        kernel_size = load_elf(ipl->kernel, NULL, NULL, &pentry, NULL,
+                               NULL, 1, ELF_MACHINE, 0);
+        if (kernel_size < 0) {
+            kernel_size = load_image_targphys(ipl->kernel, 0, ram_size);
+        }
+        if (kernel_size < 0) {
+            fprintf(stderr, "could not load kernel '%s'\n", ipl->kernel);
+            return -1;
         }
-        initrd_size = load_image_targphys(ipl->initrd, initrd_offset,
-                                          ram_size - initrd_offset);
-        if (initrd_size == -1) {
-            fprintf(stderr, "qemu: could not load initrd '%s'\n", ipl->initrd);
-            exit(1);
+        /*
+         * Is it a Linux kernel (starting at 0x10000)? If yes, we fill in the
+         * kernel parameters here as well. Note: For old kernels (up to 3.2)
+         * we can not rely on the ELF entry point - it was 0x800 (the SALIPL
+         * loader) and it won't work. For this case we force it to 0x10000, too.
+         */
+        if (pentry == KERN_IMAGE_START || pentry == 0x800) {
+            ipl->start_addr = KERN_IMAGE_START;
+            /* Overwrite parameters in the kernel image, which are "rom" */
+            strcpy(rom_ptr(KERN_PARM_AREA), ipl->cmdline);
+        } else {
+            ipl->start_addr = pentry;
         }
 
-        /* we have to overwrite values in the kernel image, which are "rom" */
-        stq_p(rom_ptr(INITRD_PARM_START), initrd_offset);
-        stq_p(rom_ptr(INITRD_PARM_SIZE), initrd_size);
-    }
+        if (ipl->initrd) {
+            ram_addr_t initrd_offset;
+            int initrd_size;
+
+            initrd_offset = INITRD_START;
+            while (kernel_size + 0x100000 > initrd_offset) {
+                initrd_offset += 0x100000;
+            }
+            initrd_size = load_image_targphys(ipl->initrd, initrd_offset,
+                                              ram_size - initrd_offset);
+            if (initrd_size == -1) {
+                fprintf(stderr, "qemu: could not load initrd '%s'\n",
+                        ipl->initrd);
+                exit(1);
+            }
 
+            /*
+             * we have to overwrite values in the kernel image,
+             * which are "rom"
+             */
+            stq_p(rom_ptr(INITRD_PARM_START), initrd_offset);
+            stq_p(rom_ptr(INITRD_PARM_SIZE), initrd_size);
+        }
+    }
     return 0;
 }
 
@@ -148,6 +160,7 @@ static Property s390_ipl_properties[] = {
     DEFINE_PROP_STRING("initrd", S390IPLState, initrd),
     DEFINE_PROP_STRING("cmdline", S390IPLState, cmdline),
     DEFINE_PROP_STRING("firmware", S390IPLState, firmware),
+    DEFINE_PROP_BOOL("enforce_bios", S390IPLState, enforce_bios, false),
     DEFINE_PROP_END_OF_LIST(),
 };