xen/arm: Reserve FDT via early module mechanism

This will stop us putting any heaps or relocating Xen itself over the FDT.

The devicetree will be copied to allocated memory in setup_mm and the
original copy will be freed by discard_initial_modules.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
index 9a16650ee1..793e9a8056 100644
--- a/xen/common/device_tree.c
+++ b/xen/common/device_tree.c
@@ -420,14 +420,21 @@ static void __init early_print_info(void)
  *
  * Returns the size of the DTB.
  */
-size_t __init device_tree_early_init(const void *fdt)
+size_t __init device_tree_early_init(const void *fdt, paddr_t paddr)
 {
+    struct dt_mb_module *mod;
     int ret;
 
     ret = fdt_check_header(fdt);
     if ( ret < 0 )
         early_panic("No valid device tree\n");
 
+    mod = &early_info.modules.module[MOD_FDT];
+    mod->start = paddr;
+    mod->size = fdt_totalsize(fdt);
+
+    early_info.modules.nr_mods = max(MOD_FDT, early_info.modules.nr_mods);
+
     device_tree_for_each_node((void *)fdt, early_scan_node, NULL);
     early_print_info();