efi_loader: use hardware device tree by default

If the bootefi command is called without passing the address of a device
tree, the internal device tree is used. For devices with a hardware device
tree it is preferable to used the hardware device tree in this case.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index 2b190a3eddafd066e5c5e2191365a13cfbebf428..a3e2a051263da5a1604926613ccdf880fc3e8ef3 100644 (file)
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -200,14 +200,16 @@ static void *get_config_table(const efi_guid_t *guid)
  *
  * If fdt_addr is available, the device tree located at that memory address will
  * will be installed as configuration table, otherwise the device tree located
- * at the address indicated by environment variable fdtcontroladdr will be used.
+ * at the address indicated by environment variable fdt_addr or as fallback
+ * fdtcontroladdr will be used.
  *
  * On architectures using ACPI tables device trees shall not be installed as
  * configuration table.
  *
  * @fdt_addr:  address of device tree or EFI_FDT_USE_INTERNAL to use the
- *             internal device tree as indicated by environment variable
- *             fdtcontroladdr
+ *             the hardware device tree as indicated by environment variable
+ *             fdt_addr or as fallback the internal device tree as indicated by
+ *             the environment variable fdtcontroladdr
  * Return:     status code
  */
 static efi_status_t efi_install_fdt(uintptr_t fdt_addr)
@@ -232,15 +234,19 @@ static efi_status_t efi_install_fdt(uintptr_t fdt_addr)
                /* Look for device tree that is already installed */
                if (get_config_table(&efi_guid_fdt))
                        return EFI_SUCCESS;
-               /* Use our own device tree as default */
-               fdt_opt = env_get("fdtcontroladdr");
+               /* Check if there is a hardware device tree */
+               fdt_opt = env_get("fdt_addr");
+               /* Use our own device tree as fallback */
                if (!fdt_opt) {
-                       printf("ERROR: need device tree\n");
-                       return EFI_NOT_FOUND;
+                       fdt_opt = env_get("fdtcontroladdr");
+                       if (!fdt_opt) {
+                               printf("ERROR: need device tree\n");
+                               return EFI_NOT_FOUND;
+                       }
                }
                fdt_addr = simple_strtoul(fdt_opt, NULL, 16);
                if (!fdt_addr) {
-                       printf("ERROR: invalid $fdtcontroladdr\n");
+                       printf("ERROR: invalid $fdt_addr or $fdtcontroladdr\n");
                        return EFI_LOAD_ERROR;
                }
        }