xen: arm: Select ramdisk bootmodule early enough when building dom0

I thought in 0040b649d6 "xen: arm: Only lookup kernel/initrd bootmodule once
while building dom0" that I had identified place_modules as being soon enough,
but I was wrong, since write_properties wants to use it sooner.

Select the initrd boot module in kernel_probe at the same time we select the
kernel to avoid all this.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>

xen/arch/arm/kernel.c

@@ -68,7 +68,7 @@ static void place_modules(struct kernel_info *info,
                           paddr_t kernbase, paddr_t kernend)
 {
     /* Align DTB and initrd size to 2Mb. Linux only requires 4 byte alignment */
-    const struct bootmodule *mod = boot_module_find_by_kind(BOOTMOD_RAMDISK);
+    const struct bootmodule *mod = info->initrd_bootmodule;
     const paddr_t initrd_len = ROUNDUP(mod ? mod->size : 0, MB(2));
     const paddr_t dtb_len = ROUNDUP(fdt_totalsize(info->fdt), MB(2));
     const paddr_t modsize = initrd_len + dtb_len;
@@ -116,7 +116,6 @@ static void place_modules(struct kernel_info *info,
 
     info->dtb_paddr = modbase;
     info->initrd_paddr = info->dtb_paddr + dtb_len;
-    info->initrd_bootmodule = mod;
 }
 
 static paddr_t kernel_zimage_place(struct kernel_info *info)
@@ -390,6 +389,11 @@ int kernel_probe(struct kernel_info *info)
 
     printk("Loading kernel from boot module @ %"PRIpaddr"\n", start);
 
+    info->initrd_bootmodule = boot_module_find_by_kind(BOOTMOD_RAMDISK);
+    if ( info->initrd_bootmodule )
+        printk("Loading ramdisk from boot module @ %"PRIpaddr"\n",
+               info->initrd_bootmodule->start);
+
 #ifdef CONFIG_ARM_64
     rc = kernel_zimage64_probe(info, start, size);
     if (rc < 0)