1 /* 2 * EFI hello world 3 * 4 * Copyright (c) 2016 Google, Inc 5 * Written by Simon Glass <sjg@chromium.org> 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 * 9 * This program demonstrates calling a boottime service. 10 * It writes a greeting and the load options to the console. 11 */ 12 13 #include <common.h> 14 #include <efi_api.h> 15 16 static const efi_guid_t loaded_image_guid = LOADED_IMAGE_GUID; 17 static const efi_guid_t fdt_guid = EFI_FDT_GUID; 18 static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID; 19 20 static int hw_memcmp(const void *buf1, const void *buf2, size_t length) 21 { 22 const u8 *pos1 = buf1; 23 const u8 *pos2 = buf2; 24 25 for (; length; --length) { 26 if (*pos1 != *pos2) 27 return *pos1 - *pos2; 28 ++pos1; 29 ++pos2; 30 } 31 return 0; 32 } 33 34 /* 35 * Entry point of the EFI application. 36 * 37 * @handle handle of the loaded image 38 * @systable system table 39 * @return status code 40 */ 41 efi_status_t EFIAPI efi_main(efi_handle_t handle, 42 struct efi_system_table *systable) 43 { 44 struct efi_simple_text_output_protocol *con_out = systable->con_out; 45 struct efi_boot_services *boottime = systable->boottime; 46 struct efi_loaded_image *loaded_image; 47 efi_status_t ret; 48 efi_uintn_t i; 49 50 con_out->output_string(con_out, L"Hello, world!\n"); 51 52 /* Get the loaded image protocol */ 53 ret = boottime->handle_protocol(handle, &loaded_image_guid, 54 (void **)&loaded_image); 55 if (ret != EFI_SUCCESS) { 56 con_out->output_string(con_out, 57 L"Cannot open loaded image protocol\n"); 58 goto out; 59 } 60 /* Find configuration tables */ 61 for (i = 0; i < systable->nr_tables; ++i) { 62 if (!hw_memcmp(&systable->tables[i].guid, &fdt_guid, 63 sizeof(efi_guid_t))) 64 con_out->output_string(con_out, L"Have device tree\n"); 65 if (!hw_memcmp(&systable->tables[i].guid, &smbios_guid, 66 sizeof(efi_guid_t))) 67 con_out->output_string(con_out, L"Have SMBIOS table\n"); 68 } 69 /* Output the load options */ 70 con_out->output_string(con_out, L"Load options: "); 71 if (loaded_image->load_options_size && loaded_image->load_options) 72 con_out->output_string(con_out, 73 (u16 *)loaded_image->load_options); 74 else 75 con_out->output_string(con_out, L"<none>"); 76 con_out->output_string(con_out, L"\n"); 77 78 out: 79 boottime->exit(handle, ret, 0, NULL); 80 81 /* We should never arrive here */ 82 return ret; 83 } 84