1 /* SPDX-License-Identifier: GPL-2.0-only */
2
3 #include <cbfs.h>
4 #include <console/console.h>
5 #include <security/vboot/misc.h>
6 #include <stddef.h>
7 #include <stdio.h>
8 #include <string.h>
9 #include <ux_locales.h>
10 #include <vb2_api.h>
11
12 #define LANG_ID_MAX 100
13 #define LANG_ID_LEN 3
14
15 #define PRERAM_LOCALES_VERSION_BYTE 0x01
16 #define PRERAM_LOCALES_NAME "preram_locales"
17
18 /* We need different delimiters to deal with the case where 'string_name' is the same as
19 'localized_string'. */
20 #define DELIM_STR 0x00
21 #define DELIM_NAME 0x01
22
23 /*
24 * Devices which support early vga have the capability to show localized text in
25 * Code Page 437 encoding. (see src/drivers/pc80/vga/vga_font_8x16.c)
26 *
27 * preram_locales located in CBFS is an uncompressed file located in either RO
28 * or RW CBFS. It contains the localization information in the following format:
29 *
30 * [PRERAM_LOCALES_VERSION_BYTE]
31 * [string_name_1] [\x00]
32 * [language_id_1] [\x00] [localized_string_1] [\x00]
33 * [language_id_2] [\x00] [localized_string_2] [\x00] ...
34 * [\x01]
35 * [string_name_2] [\x00] ...
36 *
37 * This file contains tools to locate the file and search for localized strings
38 * with specific language ID.
39 */
40
41 /* Cached state for map (locales_get_map) and unmap (ux_locales_unmap). */
42 struct preram_locales_state {
43 void *data;
44 size_t size;
45 bool initialized;
46 };
47
48 static struct preram_locales_state cached_state;
49
ux_locales_unmap(void)50 void ux_locales_unmap(void)
51 {
52 if (cached_state.initialized) {
53 if (cached_state.data)
54 cbfs_unmap(cached_state.data);
55 cached_state.initialized = false;
56 cached_state.size = 0;
57 cached_state.data = NULL;
58 }
59 }
60
61 /* Get the map address of preram_locales. */
locales_get_map(size_t * size_out,bool unmap)62 static void *locales_get_map(size_t *size_out, bool unmap)
63 {
64 if (cached_state.initialized) {
65 *size_out = cached_state.size;
66 return cached_state.data;
67 }
68 cached_state.initialized = true;
69 cached_state.data = cbfs_ro_map(PRERAM_LOCALES_NAME,
70 &cached_state.size);
71 *size_out = cached_state.size;
72 return cached_state.data;
73 }
74
75 /* Move to the next string in the data. Strings are separated by delim. */
move_next(const char * data,size_t offset,size_t size,char delim)76 static size_t move_next(const char *data, size_t offset, size_t size, char delim)
77 {
78 while (offset < size && data[offset] != delim)
79 offset++;
80 /* If we found delim, move to the start of the next string. */
81 if (offset < size)
82 offset++;
83 return offset;
84 }
85
86 /* Find the next occurrence of the specific string. Strings are separated by delim. */
search_for(const char * data,size_t offset,size_t size,const char * str,char delim)87 static size_t search_for(const char *data, size_t offset, size_t size,
88 const char *str, char delim)
89 {
90 while (offset < size) {
91 if (!strncmp(data + offset, str, size - offset))
92 return offset;
93 offset = move_next(data, offset, size, delim);
94 }
95 return size;
96 }
97
98 /* Find the next occurrence of the string_name, which should always follow a DELIM_NAME. */
search_for_name(const char * data,size_t offset,size_t size,const char * name)99 static inline size_t search_for_name(const char *data, size_t offset, size_t size,
100 const char *name)
101 {
102 return search_for(data, offset, size, name, DELIM_NAME);
103 }
104
105 /* Find the next occurrence of the integer ID, where ID is less than 100. */
search_for_id(const char * data,size_t offset,size_t size,int id)106 static size_t search_for_id(const char *data, size_t offset, size_t size,
107 int id)
108 {
109 if (id >= LANG_ID_MAX)
110 return offset;
111 char int_to_str[LANG_ID_LEN] = {};
112 snprintf(int_to_str, LANG_ID_LEN, "%d", id);
113 return search_for(data, offset, size, int_to_str, DELIM_STR);
114 }
115
ux_locales_get_text(const char * name)116 const char *ux_locales_get_text(const char *name)
117 {
118 const char *data;
119 size_t size, offset, name_offset, next_name_offset, next;
120 uint32_t lang_id = 0; /* default language English (0) */
121 unsigned char version;
122
123 data = locales_get_map(&size, false);
124 if (!data || size == 0) {
125 printk(BIOS_ERR, "%s: %s not found.\n", __func__,
126 PRERAM_LOCALES_NAME);
127 return NULL;
128 }
129
130 if (CONFIG(VBOOT)) {
131 /* Get the language ID from vboot API. */
132 lang_id = vb2api_get_locale_id(vboot_get_context());
133 /* Validity check: Language ID should smaller than LANG_ID_MAX. */
134 if (lang_id >= LANG_ID_MAX) {
135 printk(BIOS_WARNING, "%s: ID %d too big; fallback to 0.\n",
136 __func__, lang_id);
137 lang_id = 0;
138 }
139 }
140
141 printk(BIOS_INFO, "%s: Search for %s with language ID: %u\n",
142 __func__, name, lang_id);
143
144 /* Check if the version byte is the expected version. */
145 version = (unsigned char)data[0];
146 if (version != PRERAM_LOCALES_VERSION_BYTE) {
147 printk(BIOS_ERR, "%s: The version %u is not the expected one %u\n",
148 __func__, version, PRERAM_LOCALES_VERSION_BYTE);
149 return NULL;
150 }
151
152 /* Search for name. Skip the version byte. */
153 offset = search_for_name(data, 1, size, name);
154 if (offset >= size) {
155 printk(BIOS_ERR, "%s: Name %s not found.\n", __func__, name);
156 return NULL;
157 }
158 name_offset = offset;
159
160 /* Search for language ID. We should not search beyond the range of the current
161 string_name. */
162 next_name_offset = move_next(data, offset, size, DELIM_NAME);
163 assert(next_name_offset <= size);
164 offset = search_for_id(data, name_offset, next_name_offset, lang_id);
165 /* Language ID not supported; fallback to English if the current language is not
166 English (0). */
167 if (offset >= next_name_offset) {
168 /* Since we only support a limited charset, it is very normal that a language
169 is not supported and we fallback here silently. */
170 if (lang_id != 0)
171 offset = search_for_id(data, name_offset, next_name_offset, 0);
172 if (offset >= next_name_offset) {
173 printk(BIOS_ERR, "%s: Neither %d nor 0 found.\n", __func__, lang_id);
174 return NULL;
175 }
176 }
177
178 /* Move to the corresponding localized_string. */
179 offset = move_next(data, offset, next_name_offset, DELIM_STR);
180 if (offset >= next_name_offset)
181 return NULL;
182
183 /* Validity check that the returned string must be NULL terminated. */
184 next = move_next(data, offset, next_name_offset, DELIM_STR) - 1;
185 if (next >= next_name_offset || data[next] != '\0') {
186 printk(BIOS_ERR, "%s: %s is not NULL terminated.\n",
187 __func__, PRERAM_LOCALES_NAME);
188 return NULL;
189 }
190
191 return data + offset;
192 }
193