xen: arm: support bootmodule type detection by ordering

Assign modules types based on the order in which they are defined in the FDT.
This is supported only for the dom0 kernel and ramdisk when given as the first
and second modules respectively, similar to how
http://wiki.xen.org/wiki?title=Xen_ARM_with_Virtualization_Extensions/Multiboot&oldid=11824
defined the default types from the bootloader side.

This is compatible with how Xen interprets the modules with x86 multiboot and I
think simplifies things for bootloaders which now need not contain similar
guessing code if they only care about the most basic case.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Julien Grall <julien.grall@linaro.org>

xen/arch/arm/bootfdt.c

@@ -165,6 +165,7 @@ static void __init process_multiboot_node(const void *fdt, int node,
                                           const char *name,
                                           u32 address_cells, u32 size_cells)
 {
+    static int kind_guess = 0;
     const struct fdt_property *prop;
     const __be32 *cell;
     bootmodule_kind kind;
@@ -181,7 +182,18 @@ static void __init process_multiboot_node(const void *fdt, int node,
     else if ( fdt_node_check_compatible(fdt, node, "xen,xsm-policy") == 0 )
         kind = BOOTMOD_XSM;
     else
-        panic("%s not a known xen multiboot type\n", name);
+        kind = BOOTMOD_UNKNOWN;
+
+    /* Guess that first two unknown are kernel and ramdisk respectively. */
+    if ( kind == BOOTMOD_UNKNOWN )
+    {
+        switch ( kind_guess++ )
+        {
+        case 0: kind = BOOTMOD_KERNEL; break;
+        case 1: kind = BOOTMOD_RAMDISK; break;
+        default: break;
+        }
+    }
 
     prop = fdt_get_property(fdt, node, "reg", &len);
     if ( !prop )
@@ -281,10 +293,11 @@ static void __init early_print_info(void)
                      mi->bank[i].start + mi->bank[i].size - 1);
     printk("\n");
     for ( i = 0 ; i < mods->nr_mods; i++ )
-        printk("MODULE[%d]: %"PRIpaddr" - %"PRIpaddr" %s\n",
+        printk("MODULE[%d]: %"PRIpaddr" - %"PRIpaddr" %-12s %s\n",
                      i,
                      mods->module[i].start,
                      mods->module[i].start + mods->module[i].size,
+                     boot_module_kind_as_string(mods->module[i].kind),
                      mods->module[i].cmdline);
     nr_rsvd = fdt_num_mem_rsv(device_tree_flattened);
     for ( i = 0; i < nr_rsvd; i++ )

xen/arch/arm/setup.c

@@ -223,6 +223,20 @@ struct bootmodule * __init boot_module_find_by_kind(bootmodule_kind kind)
     return NULL;
 }
 
+const char * __init boot_module_kind_as_string(bootmodule_kind kind)
+{
+    switch ( kind )
+    {
+    case BOOTMOD_XEN:     return "Xen";
+    case BOOTMOD_FDT:     return "Device Tree";
+    case BOOTMOD_KERNEL:  return "Kernel";
+    case BOOTMOD_RAMDISK: return "Ramdisk";
+    case BOOTMOD_XSM:     return "XSM";
+    case BOOTMOD_UNKNOWN: return "Unknown";
+    default: BUG();
+    }
+}
+
 void __init discard_initial_modules(void)
 {
     struct bootmodules *mi = &bootinfo.modules;

xen/include/asm-arm/setup.h

@@ -64,6 +64,7 @@ struct bootmodule *add_boot_module(bootmodule_kind kind,
                                    paddr_t start, paddr_t size,
                                    const char *cmdline);
 struct bootmodule *boot_module_find_by_kind(bootmodule_kind kind);
+const char * __init boot_module_kind_as_string(bootmodule_kind kind);
 
 #endif
 /*