1 /*
2  * efi_selftest_pos
3  *
4  * Copyright (c) 2018 Heinrich Schuchardt <xypron.glpk@gmx.de>
5  *
6  * SPDX-License-Identifier:     GPL-2.0+
7  *
8  * Test the EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL.
9  *
10  * The following services are tested:
11  * OutputString, TestString, SetAttribute.
12  */
13 
14 #include <efi_selftest.h>
15 #include <linux/libfdt.h>
16 
17 static struct efi_boot_services *boottime;
18 static const char *fdt;
19 
20 /* This should be sufficent for */
21 #define BUFFERSIZE 0x100000
22 
23 static efi_guid_t fdt_guid = EFI_FDT_GUID;
24 
25 /*
26  * Convert FDT value to host endianness.
27  *
28  * @val		FDT value
29  * @return	converted value
30  */
31 static uint32_t f2h(fdt32_t val)
32 {
33 	char *buf = (char *)&val;
34 	char i;
35 
36 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
37 	/* Swap the bytes */
38 	i = buf[0]; buf[0] = buf[3]; buf[3] = i;
39 	i = buf[1]; buf[1] = buf[2]; buf[2] = i;
40 #endif
41 	return *(uint32_t *)buf;
42 }
43 
44 /*
45  * Return the value of a property of the FDT root node.
46  *
47  * @name	name of the property
48  * @return	value of the property
49  */
50 static char *get_property(const u16 *property)
51 {
52 	struct fdt_header *header = (struct fdt_header *)fdt;
53 	const fdt32_t *pos;
54 	const char *strings;
55 
56 	if (!header)
57 		return NULL;
58 
59 	if (f2h(header->magic) != FDT_MAGIC) {
60 		printf("Wrong magic\n");
61 		return NULL;
62 	}
63 
64 	pos = (fdt32_t *)(fdt + f2h(header->off_dt_struct));
65 	strings = fdt + f2h(header->off_dt_strings);
66 
67 	for (;;) {
68 		switch (f2h(pos[0])) {
69 		case FDT_BEGIN_NODE: {
70 			char *c = (char *)&pos[1];
71 			size_t i;
72 
73 			for (i = 0; c[i]; ++i)
74 				;
75 			pos = &pos[2 + (i >> 2)];
76 			break;
77 		}
78 		case FDT_PROP: {
79 			struct fdt_property *prop = (struct fdt_property *)pos;
80 			const char *label = &strings[f2h(prop->nameoff)];
81 			efi_status_t ret;
82 
83 			/* Check if this is the property to be returned */
84 			if (!efi_st_strcmp_16_8(property, label)) {
85 				char *str;
86 				efi_uintn_t len = f2h(prop->len);
87 
88 				if (!len)
89 					return NULL;
90 				/*
91 				 * The string might not be 0 terminated.
92 				 * It is safer to make a copy.
93 				 */
94 				ret = boottime->allocate_pool(
95 					EFI_LOADER_DATA, len + 1,
96 					(void **)&str);
97 				if (ret != EFI_SUCCESS) {
98 					efi_st_printf("AllocatePool failed\n");
99 					return NULL;
100 				}
101 				boottime->copy_mem(str, &pos[3], len);
102 				str[len] = 0;
103 
104 				return str;
105 			}
106 
107 			pos = &pos[3 + ((f2h(prop->len) + 3) >> 2)];
108 			break;
109 		}
110 		case FDT_NOP:
111 			pos = &pos[1];
112 			break;
113 		default:
114 			return NULL;
115 		}
116 	}
117 }
118 
119 /*
120  * Setup unit test.
121  *
122  * @handle:	handle of the loaded image
123  * @systable:	system table
124  * @return:	EFI_ST_SUCCESS for success
125  */
126 static int setup(const efi_handle_t img_handle,
127 		 const struct efi_system_table *systable)
128 {
129 	efi_uintn_t i;
130 
131 	boottime = systable->boottime;
132 
133 	/* Find configuration tables */
134 	for (i = 0; i < systable->nr_tables; ++i) {
135 		if (!efi_st_memcmp(&systable->tables[i].guid, &fdt_guid,
136 				   sizeof(efi_guid_t)))
137 			fdt = systable->tables[i].table;
138 	}
139 	if (!fdt) {
140 		efi_st_error("Missing device tree\n");
141 		return EFI_ST_FAILURE;
142 	}
143 
144 	return EFI_ST_SUCCESS;
145 }
146 
147 /*
148  * Execute unit test.
149  *
150  * @return:	EFI_ST_SUCCESS for success
151  */
152 static int execute(void)
153 {
154 	char *str;
155 	efi_status_t ret;
156 
157 	str = get_property(L"compatible");
158 	if (str) {
159 		efi_st_printf("compatible: %s\n", str);
160 		ret = boottime->free_pool(str);
161 		if (ret != EFI_SUCCESS) {
162 			efi_st_error("FreePool failed\n");
163 			return EFI_ST_FAILURE;
164 		}
165 	} else {
166 		efi_st_printf("Missing property 'compatible'\n");
167 		return EFI_ST_FAILURE;
168 	}
169 	str = get_property(L"serial-number");
170 	if (str) {
171 		efi_st_printf("serial-number: %s\n", str);
172 		ret = boottime->free_pool(str);
173 		if (ret != EFI_SUCCESS) {
174 			efi_st_error("FreePool failed\n");
175 			return EFI_ST_FAILURE;
176 		}
177 	}
178 
179 	return EFI_ST_SUCCESS;
180 }
181 
182 EFI_UNIT_TEST(fdt) = {
183 	.name = "device tree",
184 	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
185 	.setup = setup,
186 	.execute = execute,
187 	.on_request = true,
188 };
189