1 /*
2 * QEMU S390 Interactive Boot Menu
3 *
4 * Copyright 2018 IBM Corp.
5 * Author: Collin L. Walling <walling@linux.vnet.ibm.com>
6 *
7 * This work is licensed under the terms of the GNU GPL, version 2 or (at
8 * your option) any later version. See the COPYING file in the top-level
9 * directory.
10 */
11
12 #include "libc.h"
13 #include "s390-ccw.h"
14 #include "sclp.h"
15 #include "s390-time.h"
16
17 #define KEYCODE_NO_INP '\0'
18 #define KEYCODE_ESCAPE '\033'
19 #define KEYCODE_BACKSP '\177'
20 #define KEYCODE_ENTER '\r'
21
22 /* Offsets from zipl fields to zipl banner start */
23 #define ZIPL_TIMEOUT_OFFSET 138
24 #define ZIPL_FLAG_OFFSET 140
25
26 #define TOD_CLOCK_MILLISECOND 0x3e8000
27
28 #define LOW_CORE_EXTERNAL_INT_ADDR 0x86
29 #define CLOCK_COMPARATOR_INT 0X1004
30
31 static uint8_t flag;
32 static uint64_t timeout;
33
enable_clock_int(void)34 static inline void enable_clock_int(void)
35 {
36 uint64_t tmp = 0;
37
38 asm volatile(
39 "stctg %%c0,%%c0,%0\n"
40 "oi 6+%0, 0x8\n"
41 "lctlg %%c0,%%c0,%0"
42 : : "Q" (tmp) : "memory"
43 );
44 }
45
disable_clock_int(void)46 static inline void disable_clock_int(void)
47 {
48 uint64_t tmp = 0;
49
50 asm volatile(
51 "stctg %%c0,%%c0,%0\n"
52 "ni 6+%0, 0xf7\n"
53 "lctlg %%c0,%%c0,%0"
54 : : "Q" (tmp) : "memory"
55 );
56 }
57
set_clock_comparator(uint64_t time)58 static inline void set_clock_comparator(uint64_t time)
59 {
60 asm volatile("sckc %0" : : "Q" (time));
61 }
62
check_clock_int(void)63 static inline bool check_clock_int(void)
64 {
65 uint16_t *code = (uint16_t *)LOW_CORE_EXTERNAL_INT_ADDR;
66
67 consume_sclp_int();
68
69 return *code == CLOCK_COMPARATOR_INT;
70 }
71
read_prompt(char * buf,size_t len)72 static int read_prompt(char *buf, size_t len)
73 {
74 char inp[2] = {};
75 uint8_t idx = 0;
76 uint64_t time;
77
78 if (timeout) {
79 time = get_clock() + timeout * TOD_CLOCK_MILLISECOND;
80 set_clock_comparator(time);
81 enable_clock_int();
82 timeout = 0;
83 }
84
85 while (!check_clock_int()) {
86
87 sclp_read(inp, 1); /* Process only one character at a time */
88
89 switch (inp[0]) {
90 case KEYCODE_NO_INP:
91 case KEYCODE_ESCAPE:
92 continue;
93 case KEYCODE_BACKSP:
94 if (idx > 0) {
95 buf[--idx] = 0;
96 sclp_print("\b \b");
97 }
98 continue;
99 case KEYCODE_ENTER:
100 disable_clock_int();
101 return idx;
102 default:
103 /* Echo input and add to buffer */
104 if (idx < len) {
105 buf[idx++] = inp[0];
106 sclp_print(inp);
107 }
108 }
109 }
110
111 disable_clock_int();
112 *buf = 0;
113
114 return 0;
115 }
116
get_index(void)117 static int get_index(void)
118 {
119 char buf[11];
120 int len;
121 int i;
122
123 memset(buf, 0, sizeof(buf));
124
125 sclp_set_write_mask(SCLP_EVENT_MASK_MSG_ASCII, SCLP_EVENT_MASK_MSG_ASCII);
126
127 len = read_prompt(buf, sizeof(buf) - 1);
128
129 sclp_set_write_mask(0, SCLP_EVENT_MASK_MSG_ASCII);
130
131 /* If no input, boot default */
132 if (len == 0) {
133 return 0;
134 }
135
136 /* Check for erroneous input */
137 for (i = 0; i < len; i++) {
138 if (!isdigit((unsigned char)buf[i])) {
139 return -1;
140 }
141 }
142
143 return atoui(buf);
144 }
145
boot_menu_prompt(bool retry)146 static void boot_menu_prompt(bool retry)
147 {
148 char tmp[11];
149
150 if (retry) {
151 sclp_print("\nError: undefined configuration"
152 "\nPlease choose:\n");
153 } else if (timeout > 0) {
154 sclp_print("Please choose (default will boot in ");
155 sclp_print(uitoa(timeout / 1000, tmp, sizeof(tmp)));
156 sclp_print(" seconds):\n");
157 } else {
158 sclp_print("Please choose:\n");
159 }
160 }
161
get_boot_index(bool * valid_entries)162 static int get_boot_index(bool *valid_entries)
163 {
164 int boot_index;
165 bool retry = false;
166 char tmp[5];
167
168 do {
169 boot_menu_prompt(retry);
170 boot_index = get_index();
171 retry = true;
172 } while (boot_index < 0 || boot_index >= MAX_BOOT_ENTRIES ||
173 !valid_entries[boot_index]);
174
175 sclp_print("\nBooting entry #");
176 sclp_print(uitoa(boot_index, tmp, sizeof(tmp)));
177
178 return boot_index;
179 }
180
181 /* Returns the entry number that was printed */
zipl_print_entry(const char * data,size_t len)182 static int zipl_print_entry(const char *data, size_t len)
183 {
184 char buf[len + 2];
185
186 ebcdic_to_ascii(data, buf, len);
187 buf[len] = '\n';
188 buf[len + 1] = '\0';
189
190 sclp_print(buf);
191
192 return buf[0] == ' ' ? atoui(buf + 1) : atoui(buf);
193 }
194
menu_get_zipl_boot_index(const char * menu_data)195 int menu_get_zipl_boot_index(const char *menu_data)
196 {
197 size_t len;
198 int entry;
199 bool valid_entries[MAX_BOOT_ENTRIES] = {false};
200 uint16_t zipl_flag = *(uint16_t *)(menu_data - ZIPL_FLAG_OFFSET);
201 uint16_t zipl_timeout = *(uint16_t *)(menu_data - ZIPL_TIMEOUT_OFFSET);
202
203 if (flag == QIPL_FLAG_BM_OPTS_ZIPL) {
204 if (!zipl_flag) {
205 return 0; /* Boot default */
206 }
207 /* zipl stores timeout as seconds */
208 timeout = zipl_timeout * 1000;
209 }
210
211 /* Print banner */
212 sclp_print("s390-ccw zIPL Boot Menu\n\n");
213 menu_data += strlen(menu_data) + 1;
214
215 /* Print entries */
216 while (*menu_data) {
217 len = strlen(menu_data);
218 entry = zipl_print_entry(menu_data, len);
219 menu_data += len + 1;
220
221 valid_entries[entry] = true;
222
223 if (entry == 0) {
224 sclp_print("\n");
225 }
226 }
227
228 sclp_print("\n");
229 return get_boot_index(valid_entries);
230 }
231
menu_get_enum_boot_index(bool * valid_entries)232 int menu_get_enum_boot_index(bool *valid_entries)
233 {
234 char tmp[3];
235 int i;
236
237 sclp_print("s390-ccw Enumerated Boot Menu.\n\n");
238
239 for (i = 0; i < MAX_BOOT_ENTRIES; i++) {
240 if (valid_entries[i]) {
241 if (i < 10) {
242 sclp_print(" ");
243 }
244 sclp_print("[");
245 sclp_print(uitoa(i, tmp, sizeof(tmp)));
246 sclp_print("]");
247 if (i == 0) {
248 sclp_print(" default\n");
249 }
250 sclp_print("\n");
251 }
252 }
253
254 sclp_print("\n");
255 return get_boot_index(valid_entries);
256 }
257
menu_set_parms(uint8_t boot_menu_flag,uint32_t boot_menu_timeout)258 void menu_set_parms(uint8_t boot_menu_flag, uint32_t boot_menu_timeout)
259 {
260 flag = boot_menu_flag;
261 timeout = boot_menu_timeout;
262 }
263
menu_is_enabled_zipl(void)264 bool menu_is_enabled_zipl(void)
265 {
266 return flag & (QIPL_FLAG_BM_OPTS_CMD | QIPL_FLAG_BM_OPTS_ZIPL);
267 }
268
menu_is_enabled_enum(void)269 bool menu_is_enabled_enum(void)
270 {
271 return flag & QIPL_FLAG_BM_OPTS_CMD;
272 }
273