efi_loader: print boot device and file path in helloworld

Let helloworld.efi print the device path of the boot device and the file
path as provided by the loaded image protocol.

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

diff --git a/lib/efi_loader/helloworld.c b/lib/efi_loader/helloworld.c
index 9ae2ee3..5c8b7a9 100644 (file)
--- a/lib/efi_loader/helloworld.c
+++ b/lib/efi_loader/helloworld.c
@@ -1,43 +1,41 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * EFI hello world
+ * Hello world EFI application
  *
- * Copyright (c) 2016 Google, Inc
- * Written by Simon Glass <sjg@chromium.org>
+ * Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
  *
- * This program demonstrates calling a boottime service.
- * It writes a greeting and the load options to the console.
+ * This test program is used to test the invocation of an EFI application.
+ * It writes
+ *
+ * * a greeting
+ * * the firmware's UEFI version
+ * * the installed configuration tables
+ * * the boot device's device path and the file path
+ *
+ * to the console.
  */
 
-#include <common.h>
 #include <efi_api.h>
 
 static const efi_guid_t loaded_image_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID;
+static const efi_guid_t device_path_to_text_protocol_guid =
+       EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID;
+static const efi_guid_t device_path_guid = EFI_DEVICE_PATH_PROTOCOL_GUID;
 static const efi_guid_t fdt_guid = EFI_FDT_GUID;
 static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_GUID;
 static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID;
 
+static struct efi_system_table *systable;
+static struct efi_boot_services *boottime;
+static struct efi_simple_text_output_protocol *con_out;
+
 /**
- * efi_main() - entry point of the EFI application.
- *
- * @handle:    handle of the loaded image
- * @systable:  system table
- * @return:    status code
+ * print_uefi_revision() - print UEFI revision number
  */
-efi_status_t EFIAPI efi_main(efi_handle_t handle,
-                            struct efi_system_table *systable)
+static void print_uefi_revision(void)
 {
-       struct efi_simple_text_output_protocol *con_out = systable->con_out;
-       struct efi_boot_services *boottime = systable->boottime;
-       struct efi_loaded_image *loaded_image;
-       efi_status_t ret;
-       efi_uintn_t i;
        u16 rev[] = L"0.0.0";
 
-       /* UEFI requires CR LF */
-       con_out->output_string(con_out, L"Hello, world!\r\n");
-
-       /* Print the revision number */
        rev[0] = (systable->hdr.revision >> 16) + '0';
        rev[4] = systable->hdr.revision & 0xffff;
        for (; rev[4] >= 10;) {
@@ -53,15 +51,15 @@ efi_status_t EFIAPI efi_main(efi_handle_t handle,
        con_out->output_string(con_out, L"Running on UEFI ");
        con_out->output_string(con_out, rev);
        con_out->output_string(con_out, L"\r\n");
+}
+
+/**
+ * print_config_tables() - print configuration tables
+ */
+static void print_config_tables(void)
+{
+       efi_uintn_t i;
 
-       /* Get the loaded image protocol */
-       ret = boottime->handle_protocol(handle, &loaded_image_guid,
-                                       (void **)&loaded_image);
-       if (ret != EFI_SUCCESS) {
-               con_out->output_string
-                       (con_out, L"Cannot open loaded image protocol\r\n");
-               goto out;
-       }
        /* Find configuration tables */
        for (i = 0; i < systable->nr_tables; ++i) {
                if (!memcmp(&systable->tables[i].guid, &fdt_guid,
@@ -77,6 +75,16 @@ efi_status_t EFIAPI efi_main(efi_handle_t handle,
                        con_out->output_string
                                        (con_out, L"Have SMBIOS table\r\n");
        }
+}
+
+/**
+ * print_load_options() - print load options
+ *
+ * @systable:  system table
+ * @con_out:   simple text output protocol
+ */
+void print_load_options(struct efi_loaded_image *loaded_image)
+{
        /* Output the load options */
        con_out->output_string(con_out, L"Load options: ");
        if (loaded_image->load_options_size && loaded_image->load_options)
@@ -85,6 +93,105 @@ efi_status_t EFIAPI efi_main(efi_handle_t handle,
        else
                con_out->output_string(con_out, L"<none>");
        con_out->output_string(con_out, L"\r\n");
+}
+
+/**
+ * print_device_path() - print device path
+ *
+ * @device_path:       device path to print
+ * @dp2txt:            device path to text protocol
+ */
+efi_status_t print_device_path(struct efi_device_path *device_path,
+                              struct efi_device_path_to_text_protocol *dp2txt)
+{
+       u16 *string;
+       efi_status_t ret;
+
+       if (!device_path) {
+               con_out->output_string(con_out, L"<none>\r\n");
+               return EFI_SUCCESS;
+       }
+
+       string = dp2txt->convert_device_path_to_text(device_path, true, false);
+       if (!string) {
+               con_out->output_string
+                       (con_out, L"Cannot convert device path to text\r\n");
+               return EFI_OUT_OF_RESOURCES;
+       }
+       con_out->output_string(con_out, string);
+       con_out->output_string(con_out, L"\r\n");
+       ret = boottime->free_pool(string);
+       if (ret != EFI_SUCCESS) {
+               con_out->output_string(con_out, L"Cannot free pool memory\r\n");
+               return ret;
+       }
+       return EFI_SUCCESS;
+}
+
+/**
+ * efi_main() - entry point of the EFI application.
+ *
+ * @handle:    handle of the loaded image
+ * @systab:    system table
+ * @return:    status code
+ */
+efi_status_t EFIAPI efi_main(efi_handle_t handle,
+                            struct efi_system_table *systab)
+{
+       struct efi_loaded_image *loaded_image;
+       struct efi_device_path_to_text_protocol *device_path_to_text;
+       struct efi_device_path *device_path;
+       efi_status_t ret;
+
+       systable = systab;
+       boottime = systable->boottime;
+       con_out = systable->con_out;
+
+       /* UEFI requires CR LF */
+       con_out->output_string(con_out, L"Hello, world!\r\n");
+
+       print_uefi_revision();
+       print_config_tables();
+
+       /* Get the loaded image protocol */
+       ret = boottime->handle_protocol(handle, &loaded_image_guid,
+                                       (void **)&loaded_image);
+       if (ret != EFI_SUCCESS) {
+               con_out->output_string
+                       (con_out, L"Cannot open loaded image protocol\r\n");
+               goto out;
+       }
+       print_load_options(loaded_image);
+
+       /* Get the device path to text protocol */
+       ret = boottime->locate_protocol(&device_path_to_text_protocol_guid,
+                                       NULL, (void **)&device_path_to_text);
+       if (ret != EFI_SUCCESS) {
+               con_out->output_string
+                       (con_out, L"Cannot open device path to text protocol\r\n");
+               goto out;
+       }
+       if (!loaded_image->device_handle) {
+               con_out->output_string
+                       (con_out, L"Missing device handle\r\n");
+               goto out;
+       }
+       ret = boottime->handle_protocol(loaded_image->device_handle,
+                                       &device_path_guid,
+                                       (void **)&device_path);
+       if (ret != EFI_SUCCESS) {
+               con_out->output_string
+                       (con_out, L"Missing devide path for device handle\r\n");
+               goto out;
+       }
+       con_out->output_string(con_out, L"Boot device: ");
+       ret = print_device_path(device_path, device_path_to_text);
+       if (ret != EFI_SUCCESS)
+               goto out;
+       con_out->output_string(con_out, L"File path: ");
+       ret = print_device_path(loaded_image->file_path, device_path_to_text);
+       if (ret != EFI_SUCCESS)
+               goto out;
 
 out:
        boottime->exit(handle, ret, 0, NULL);