pc-bios/s390-ccw/menu.c

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