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 15 #define KEYCODE_NO_INP '\0' 16 #define KEYCODE_ESCAPE '\033' 17 #define KEYCODE_BACKSP '\177' 18 #define KEYCODE_ENTER '\r' 19 20 #define TOD_CLOCK_MILLISECOND 0x3e8000 21 22 #define LOW_CORE_EXTERNAL_INT_ADDR 0x86 23 #define CLOCK_COMPARATOR_INT 0X1004 24 25 static uint8_t flag; 26 static uint64_t timeout; 27 28 static inline void enable_clock_int(void) 29 { 30 uint64_t tmp = 0; 31 32 asm volatile( 33 "stctg 0,0,%0\n" 34 "oi 6+%0, 0x8\n" 35 "lctlg 0,0,%0" 36 : : "Q" (tmp) : "memory" 37 ); 38 } 39 40 static inline void disable_clock_int(void) 41 { 42 uint64_t tmp = 0; 43 44 asm volatile( 45 "stctg 0,0,%0\n" 46 "ni 6+%0, 0xf7\n" 47 "lctlg 0,0,%0" 48 : : "Q" (tmp) : "memory" 49 ); 50 } 51 52 static inline void set_clock_comparator(uint64_t time) 53 { 54 asm volatile("sckc %0" : : "Q" (time)); 55 } 56 57 static inline bool check_clock_int(void) 58 { 59 uint16_t *code = (uint16_t *)LOW_CORE_EXTERNAL_INT_ADDR; 60 61 consume_sclp_int(); 62 63 return *code == CLOCK_COMPARATOR_INT; 64 } 65 66 static int read_prompt(char *buf, size_t len) 67 { 68 char inp[2] = {}; 69 uint8_t idx = 0; 70 uint64_t time; 71 72 if (timeout) { 73 time = get_clock() + timeout * TOD_CLOCK_MILLISECOND; 74 set_clock_comparator(time); 75 enable_clock_int(); 76 timeout = 0; 77 } 78 79 while (!check_clock_int()) { 80 81 sclp_read(inp, 1); /* Process only one character at a time */ 82 83 switch (inp[0]) { 84 case KEYCODE_NO_INP: 85 case KEYCODE_ESCAPE: 86 continue; 87 case KEYCODE_BACKSP: 88 if (idx > 0) { 89 buf[--idx] = 0; 90 sclp_print("\b \b"); 91 } 92 continue; 93 case KEYCODE_ENTER: 94 disable_clock_int(); 95 return idx; 96 default: 97 /* Echo input and add to buffer */ 98 if (idx < len) { 99 buf[idx++] = inp[0]; 100 sclp_print(inp); 101 } 102 } 103 } 104 105 disable_clock_int(); 106 *buf = 0; 107 108 return 0; 109 } 110 111 static int get_index(void) 112 { 113 char buf[11]; 114 int len; 115 int i; 116 117 memset(buf, 0, sizeof(buf)); 118 119 len = read_prompt(buf, sizeof(buf) - 1); 120 121 /* If no input, boot default */ 122 if (len == 0) { 123 return 0; 124 } 125 126 /* Check for erroneous input */ 127 for (i = 0; i < len; i++) { 128 if (!isdigit(buf[i])) { 129 return -1; 130 } 131 } 132 133 return atoui(buf); 134 } 135 136 static void boot_menu_prompt(bool retry) 137 { 138 char tmp[11]; 139 140 if (retry) { 141 sclp_print("\nError: undefined configuration" 142 "\nPlease choose:\n"); 143 } else if (timeout > 0) { 144 sclp_print("Please choose (default will boot in "); 145 sclp_print(uitoa(timeout / 1000, tmp, sizeof(tmp))); 146 sclp_print(" seconds):\n"); 147 } else { 148 sclp_print("Please choose:\n"); 149 } 150 } 151 152 static int get_boot_index(int entries) 153 { 154 int boot_index; 155 bool retry = false; 156 char tmp[5]; 157 158 do { 159 boot_menu_prompt(retry); 160 boot_index = get_index(); 161 retry = true; 162 } while (boot_index < 0 || boot_index >= entries); 163 164 sclp_print("\nBooting entry #"); 165 sclp_print(uitoa(boot_index, tmp, sizeof(tmp))); 166 167 return boot_index; 168 } 169 170 static void zipl_println(const char *data, size_t len) 171 { 172 char buf[len + 2]; 173 174 ebcdic_to_ascii(data, buf, len); 175 buf[len] = '\n'; 176 buf[len + 1] = '\0'; 177 178 sclp_print(buf); 179 } 180 181 int menu_get_zipl_boot_index(const char *menu_data) 182 { 183 size_t len; 184 int entries; 185 186 /* Print and count all menu items, including the banner */ 187 for (entries = 0; *menu_data; entries++) { 188 len = strlen(menu_data); 189 zipl_println(menu_data, len); 190 menu_data += len + 1; 191 192 if (entries < 2) { 193 sclp_print("\n"); 194 } 195 } 196 197 sclp_print("\n"); 198 return get_boot_index(entries - 1); /* subtract 1 to exclude banner */ 199 } 200 201 void menu_set_parms(uint8_t boot_menu_flag, uint32_t boot_menu_timeout) 202 { 203 flag = boot_menu_flag; 204 timeout = boot_menu_timeout; 205 } 206 207 bool menu_is_enabled_zipl(void) 208 { 209 return flag & QIPL_FLAG_BM_OPTS_CMD; 210 } 211