1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Hello world EFI application
4 *
5 * Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
6 *
7 * This test program is used to test the invocation of an EFI application.
8 * It writes
9 *
10 * * a greeting
11 * * the firmware's UEFI version
12 * * the installed configuration tables
13 * * the boot device's device path and the file path
14 *
15 * to the console.
16 */
17
18 #include <efi_api.h>
19
20 static const efi_guid_t loaded_image_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID;
21 static const efi_guid_t device_path_to_text_protocol_guid =
22 EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID;
23 static const efi_guid_t device_path_guid = EFI_DEVICE_PATH_PROTOCOL_GUID;
24 static const efi_guid_t fdt_guid = EFI_FDT_GUID;
25 static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_GUID;
26 static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID;
27
28 static struct efi_system_table *systable;
29 static struct efi_boot_services *boottime;
30 static struct efi_simple_text_output_protocol *con_out;
31
32 /**
33 * print_uefi_revision() - print UEFI revision number
34 */
print_uefi_revision(void)35 static void print_uefi_revision(void)
36 {
37 u16 rev[] = L"0.0.0";
38
39 rev[0] = (systable->hdr.revision >> 16) + '0';
40 rev[4] = systable->hdr.revision & 0xffff;
41 for (; rev[4] >= 10;) {
42 rev[4] -= 10;
43 ++rev[2];
44 }
45 /* Third digit is only to be shown if non-zero */
46 if (rev[4])
47 rev[4] += '0';
48 else
49 rev[3] = 0;
50
51 con_out->output_string(con_out, L"Running on UEFI ");
52 con_out->output_string(con_out, rev);
53 con_out->output_string(con_out, L"\r\n");
54 }
55
56 /**
57 * print_config_tables() - print configuration tables
58 */
print_config_tables(void)59 static void print_config_tables(void)
60 {
61 efi_uintn_t i;
62
63 /* Find configuration tables */
64 for (i = 0; i < systable->nr_tables; ++i) {
65 if (!memcmp(&systable->tables[i].guid, &fdt_guid,
66 sizeof(efi_guid_t)))
67 con_out->output_string
68 (con_out, L"Have device tree\r\n");
69 if (!memcmp(&systable->tables[i].guid, &acpi_guid,
70 sizeof(efi_guid_t)))
71 con_out->output_string
72 (con_out, L"Have ACPI 2.0 table\r\n");
73 if (!memcmp(&systable->tables[i].guid, &smbios_guid,
74 sizeof(efi_guid_t)))
75 con_out->output_string
76 (con_out, L"Have SMBIOS table\r\n");
77 }
78 }
79
80 /**
81 * print_load_options() - print load options
82 *
83 * @systable: system table
84 * @con_out: simple text output protocol
85 */
print_load_options(struct efi_loaded_image * loaded_image)86 void print_load_options(struct efi_loaded_image *loaded_image)
87 {
88 /* Output the load options */
89 con_out->output_string(con_out, L"Load options: ");
90 if (loaded_image->load_options_size && loaded_image->load_options)
91 con_out->output_string(con_out,
92 (u16 *)loaded_image->load_options);
93 else
94 con_out->output_string(con_out, L"<none>");
95 con_out->output_string(con_out, L"\r\n");
96 }
97
98 /**
99 * print_device_path() - print device path
100 *
101 * @device_path: device path to print
102 * @dp2txt: device path to text protocol
103 */
print_device_path(struct efi_device_path * device_path,struct efi_device_path_to_text_protocol * dp2txt)104 efi_status_t print_device_path(struct efi_device_path *device_path,
105 struct efi_device_path_to_text_protocol *dp2txt)
106 {
107 u16 *string;
108 efi_status_t ret;
109
110 if (!device_path) {
111 con_out->output_string(con_out, L"<none>\r\n");
112 return EFI_SUCCESS;
113 }
114
115 string = dp2txt->convert_device_path_to_text(device_path, true, false);
116 if (!string) {
117 con_out->output_string
118 (con_out, L"Cannot convert device path to text\r\n");
119 return EFI_OUT_OF_RESOURCES;
120 }
121 con_out->output_string(con_out, string);
122 con_out->output_string(con_out, L"\r\n");
123 ret = boottime->free_pool(string);
124 if (ret != EFI_SUCCESS) {
125 con_out->output_string(con_out, L"Cannot free pool memory\r\n");
126 return ret;
127 }
128 return EFI_SUCCESS;
129 }
130
131 /**
132 * efi_main() - entry point of the EFI application.
133 *
134 * @handle: handle of the loaded image
135 * @systab: system table
136 * @return: status code
137 */
efi_main(efi_handle_t handle,struct efi_system_table * systab)138 efi_status_t EFIAPI efi_main(efi_handle_t handle,
139 struct efi_system_table *systab)
140 {
141 struct efi_loaded_image *loaded_image;
142 struct efi_device_path_to_text_protocol *device_path_to_text;
143 struct efi_device_path *device_path;
144 efi_status_t ret;
145
146 systable = systab;
147 boottime = systable->boottime;
148 con_out = systable->con_out;
149
150 /* UEFI requires CR LF */
151 con_out->output_string(con_out, L"Hello, world!\r\n");
152
153 print_uefi_revision();
154 print_config_tables();
155
156 /* Get the loaded image protocol */
157 ret = boottime->handle_protocol(handle, &loaded_image_guid,
158 (void **)&loaded_image);
159 if (ret != EFI_SUCCESS) {
160 con_out->output_string
161 (con_out, L"Cannot open loaded image protocol\r\n");
162 goto out;
163 }
164 print_load_options(loaded_image);
165
166 /* Get the device path to text protocol */
167 ret = boottime->locate_protocol(&device_path_to_text_protocol_guid,
168 NULL, (void **)&device_path_to_text);
169 if (ret != EFI_SUCCESS) {
170 con_out->output_string
171 (con_out, L"Cannot open device path to text protocol\r\n");
172 goto out;
173 }
174 if (!loaded_image->device_handle) {
175 con_out->output_string
176 (con_out, L"Missing device handle\r\n");
177 goto out;
178 }
179 ret = boottime->handle_protocol(loaded_image->device_handle,
180 &device_path_guid,
181 (void **)&device_path);
182 if (ret != EFI_SUCCESS) {
183 con_out->output_string
184 (con_out, L"Missing device path for device handle\r\n");
185 goto out;
186 }
187 con_out->output_string(con_out, L"Boot device: ");
188 ret = print_device_path(device_path, device_path_to_text);
189 if (ret != EFI_SUCCESS)
190 goto out;
191 con_out->output_string(con_out, L"File path: ");
192 ret = print_device_path(loaded_image->file_path, device_path_to_text);
193 if (ret != EFI_SUCCESS)
194 goto out;
195
196 out:
197 boottime->exit(handle, ret, 0, NULL);
198
199 /* We should never arrive here */
200 return ret;
201 }
202