efi_loader: load device-tree specified in boot option

We allow to specify the triple of binary, initrd, and device-tree in boot
options.

Add the code to actually load the specified device-tree.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index b0bf21cf841bc99621f9712712c23d5d53f4df0b..2c140bb70cd63dd776dc8e4fc1673d20af4e5f96 100644 (file)
--- a/lib/efi_loader/efi_bootmgr.c
+++ b/lib/efi_loader/efi_bootmgr.c
@@ -1185,6 +1185,59 @@ out:
        return ret;
 }
 
+/**
+ * load_fdt_from_load_option - load device-tree from load option
+ *
+ * @fdt:       pointer to loaded device-tree or NULL
+ * Return:     status code
+ */
+static efi_status_t load_fdt_from_load_option(void **fdt)
+{
+       struct efi_device_path *dp = NULL;
+       struct efi_file_handle *f = NULL;
+       efi_uintn_t filesize;
+       efi_status_t ret;
+
+       *fdt = NULL;
+
+       dp = efi_get_dp_from_boot(&efi_guid_fdt);
+       if (!dp)
+               return EFI_SUCCESS;
+
+       /* Open file */
+       f = efi_file_from_path(dp);
+       if (!f) {
+               log_err("Can't find %pD specified in Boot####\n", dp);
+               ret = EFI_NOT_FOUND;
+               goto out;
+       }
+
+       /* Get file size */
+       ret = efi_file_size(f, &filesize);
+       if (ret != EFI_SUCCESS)
+               goto out;
+
+       *fdt = calloc(1, filesize);
+       if (!*fdt) {
+               log_err("Out of memory\n");
+               ret = EFI_OUT_OF_RESOURCES;
+               goto out;
+       }
+       ret = EFI_CALL(f->read(f, &filesize, *fdt));
+       if (ret != EFI_SUCCESS) {
+               log_err("Can't read fdt\n");
+               free(*fdt);
+               *fdt = NULL;
+       }
+
+out:
+       efi_free_pool(dp);
+       if (f)
+               EFI_CALL(f->close(f));
+
+       return ret;
+}
+
 /**
  * efi_bootmgr_run() - execute EFI boot manager
  * @fdt:       Flat device tree
@@ -1200,6 +1253,7 @@ efi_status_t efi_bootmgr_run(void *fdt)
        efi_handle_t handle;
        void *load_options;
        efi_status_t ret;
+       void *fdt_lo;
 
        /* Initialize EFI drivers */
        ret = efi_init_obj_list();
@@ -1215,7 +1269,23 @@ efi_status_t efi_bootmgr_run(void *fdt)
                return ret;
        }
 
+       if (!IS_ENABLED(CONFIG_GENERATE_ACPI_TABLE)) {
+               ret = load_fdt_from_load_option(&fdt_lo);
+               if (ret != EFI_SUCCESS)
+                       return ret;
+               if (fdt_lo)
+                       fdt = fdt_lo;
+       }
+
+       /*
+        * Needed in ACPI case to create reservations based on
+        * control device-tree.
+        */
        ret = efi_install_fdt(fdt);
+
+       if (!IS_ENABLED(CONFIG_GENERATE_ACPI_TABLE))
+               free(fdt_lo);
+
        if (ret != EFI_SUCCESS) {
                if (EFI_CALL(efi_unload_image(handle)) == EFI_SUCCESS)
                        free(load_options);