1 /* 2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3 * Licensed under the GPL 4 */ 5 6 #include <linux/delay.h> 7 #include <linux/init.h> 8 #include <linux/mm.h> 9 #include <linux/module.h> 10 #include <linux/seq_file.h> 11 #include <linux/string.h> 12 #include <linux/utsname.h> 13 #include <linux/sched.h> 14 #include <linux/sched/task.h> 15 #include <linux/kmsg_dump.h> 16 17 #include <asm/pgtable.h> 18 #include <asm/processor.h> 19 #include <asm/sections.h> 20 #include <asm/setup.h> 21 #include <as-layout.h> 22 #include <arch.h> 23 #include <init.h> 24 #include <kern.h> 25 #include <kern_util.h> 26 #include <mem_user.h> 27 #include <os.h> 28 29 #define DEFAULT_COMMAND_LINE "root=98:0" 30 31 /* Changed in add_arg and setup_arch, which run before SMP is started */ 32 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 }; 33 34 static void __init add_arg(char *arg) 35 { 36 if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) { 37 printf("add_arg: Too many command line arguments!\n"); 38 exit(1); 39 } 40 if (strlen(command_line) > 0) 41 strcat(command_line, " "); 42 strcat(command_line, arg); 43 } 44 45 /* 46 * These fields are initialized at boot time and not changed. 47 * XXX This structure is used only in the non-SMP case. Maybe this 48 * should be moved to smp.c. 49 */ 50 struct cpuinfo_um boot_cpu_data = { 51 .loops_per_jiffy = 0, 52 .ipi_pipe = { -1, -1 } 53 }; 54 55 union thread_union cpu0_irqstack 56 __attribute__((__section__(".data..init_irqstack"))) = 57 { INIT_THREAD_INFO(init_task) }; 58 59 /* Changed in setup_arch, which is called in early boot */ 60 static char host_info[(__NEW_UTS_LEN + 1) * 5]; 61 62 static int show_cpuinfo(struct seq_file *m, void *v) 63 { 64 int index = 0; 65 66 seq_printf(m, "processor\t: %d\n", index); 67 seq_printf(m, "vendor_id\t: User Mode Linux\n"); 68 seq_printf(m, "model name\t: UML\n"); 69 seq_printf(m, "mode\t\t: skas\n"); 70 seq_printf(m, "host\t\t: %s\n", host_info); 71 seq_printf(m, "bogomips\t: %lu.%02lu\n\n", 72 loops_per_jiffy/(500000/HZ), 73 (loops_per_jiffy/(5000/HZ)) % 100); 74 75 return 0; 76 } 77 78 static void *c_start(struct seq_file *m, loff_t *pos) 79 { 80 return *pos < NR_CPUS ? cpu_data + *pos : NULL; 81 } 82 83 static void *c_next(struct seq_file *m, void *v, loff_t *pos) 84 { 85 ++*pos; 86 return c_start(m, pos); 87 } 88 89 static void c_stop(struct seq_file *m, void *v) 90 { 91 } 92 93 const struct seq_operations cpuinfo_op = { 94 .start = c_start, 95 .next = c_next, 96 .stop = c_stop, 97 .show = show_cpuinfo, 98 }; 99 100 /* Set in linux_main */ 101 unsigned long uml_physmem; 102 EXPORT_SYMBOL(uml_physmem); 103 104 unsigned long uml_reserved; /* Also modified in mem_init */ 105 unsigned long start_vm; 106 unsigned long end_vm; 107 108 /* Set in uml_ncpus_setup */ 109 int ncpus = 1; 110 111 /* Set in early boot */ 112 static int have_root __initdata = 0; 113 114 /* Set in uml_mem_setup and modified in linux_main */ 115 long long physmem_size = 32 * 1024 * 1024; 116 117 static const char *usage_string = 118 "User Mode Linux v%s\n" 119 " available at http://user-mode-linux.sourceforge.net/\n\n"; 120 121 static int __init uml_version_setup(char *line, int *add) 122 { 123 printf("%s\n", init_utsname()->release); 124 exit(0); 125 126 return 0; 127 } 128 129 __uml_setup("--version", uml_version_setup, 130 "--version\n" 131 " Prints the version number of the kernel.\n\n" 132 ); 133 134 static int __init uml_root_setup(char *line, int *add) 135 { 136 have_root = 1; 137 return 0; 138 } 139 140 __uml_setup("root=", uml_root_setup, 141 "root=<file containing the root fs>\n" 142 " This is actually used by the generic kernel in exactly the same\n" 143 " way as in any other kernel. If you configure a number of block\n" 144 " devices and want to boot off something other than ubd0, you \n" 145 " would use something like:\n" 146 " root=/dev/ubd5\n\n" 147 ); 148 149 static int __init no_skas_debug_setup(char *line, int *add) 150 { 151 printf("'debug' is not necessary to gdb UML in skas mode - run \n"); 152 printf("'gdb linux'\n"); 153 154 return 0; 155 } 156 157 __uml_setup("debug", no_skas_debug_setup, 158 "debug\n" 159 " this flag is not needed to run gdb on UML in skas mode\n\n" 160 ); 161 162 static int __init Usage(char *line, int *add) 163 { 164 const char **p; 165 166 printf(usage_string, init_utsname()->release); 167 p = &__uml_help_start; 168 while (p < &__uml_help_end) { 169 printf("%s", *p); 170 p++; 171 } 172 exit(0); 173 return 0; 174 } 175 176 __uml_setup("--help", Usage, 177 "--help\n" 178 " Prints this message.\n\n" 179 ); 180 181 static void __init uml_checksetup(char *line, int *add) 182 { 183 struct uml_param *p; 184 185 p = &__uml_setup_start; 186 while (p < &__uml_setup_end) { 187 size_t n; 188 189 n = strlen(p->str); 190 if (!strncmp(line, p->str, n) && p->setup_func(line + n, add)) 191 return; 192 p++; 193 } 194 } 195 196 static void __init uml_postsetup(void) 197 { 198 initcall_t *p; 199 200 p = &__uml_postsetup_start; 201 while (p < &__uml_postsetup_end) { 202 (*p)(); 203 p++; 204 } 205 return; 206 } 207 208 static int panic_exit(struct notifier_block *self, unsigned long unused1, 209 void *unused2) 210 { 211 kmsg_dump(KMSG_DUMP_PANIC); 212 bust_spinlocks(1); 213 bust_spinlocks(0); 214 uml_exitcode = 1; 215 os_dump_core(); 216 return 0; 217 } 218 219 static struct notifier_block panic_exit_notifier = { 220 .notifier_call = panic_exit, 221 .next = NULL, 222 .priority = 0 223 }; 224 225 void uml_finishsetup(void) 226 { 227 atomic_notifier_chain_register(&panic_notifier_list, 228 &panic_exit_notifier); 229 230 uml_postsetup(); 231 232 new_thread_handler(); 233 } 234 235 /* Set during early boot */ 236 unsigned long task_size; 237 EXPORT_SYMBOL(task_size); 238 239 unsigned long host_task_size; 240 241 unsigned long brk_start; 242 unsigned long end_iomem; 243 EXPORT_SYMBOL(end_iomem); 244 245 #define MIN_VMALLOC (32 * 1024 * 1024) 246 247 int __init linux_main(int argc, char **argv) 248 { 249 unsigned long avail, diff; 250 unsigned long virtmem_size, max_physmem; 251 unsigned long stack; 252 unsigned int i; 253 int add; 254 255 for (i = 1; i < argc; i++) { 256 if ((i == 1) && (argv[i][0] == ' ')) 257 continue; 258 add = 1; 259 uml_checksetup(argv[i], &add); 260 if (add) 261 add_arg(argv[i]); 262 } 263 if (have_root == 0) 264 add_arg(DEFAULT_COMMAND_LINE); 265 266 host_task_size = os_get_top_address(); 267 /* 268 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps 269 * out 270 */ 271 task_size = host_task_size & PGDIR_MASK; 272 273 /* OS sanity checks that need to happen before the kernel runs */ 274 os_early_checks(); 275 276 brk_start = (unsigned long) sbrk(0); 277 278 /* 279 * Increase physical memory size for exec-shield users 280 * so they actually get what they asked for. This should 281 * add zero for non-exec shield users 282 */ 283 284 diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end); 285 if (diff > 1024 * 1024) { 286 printf("Adding %ld bytes to physical memory to account for " 287 "exec-shield gap\n", diff); 288 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end); 289 } 290 291 uml_physmem = (unsigned long) __binary_start & PAGE_MASK; 292 293 /* Reserve up to 4M after the current brk */ 294 uml_reserved = ROUND_4M(brk_start) + (1 << 22); 295 296 setup_machinename(init_utsname()->machine); 297 298 highmem = 0; 299 iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK; 300 max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC; 301 302 /* 303 * Zones have to begin on a 1 << MAX_ORDER page boundary, 304 * so this makes sure that's true for highmem 305 */ 306 max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1); 307 if (physmem_size + iomem_size > max_physmem) { 308 highmem = physmem_size + iomem_size - max_physmem; 309 physmem_size -= highmem; 310 } 311 312 high_physmem = uml_physmem + physmem_size; 313 end_iomem = high_physmem + iomem_size; 314 high_memory = (void *) end_iomem; 315 316 start_vm = VMALLOC_START; 317 318 virtmem_size = physmem_size; 319 stack = (unsigned long) argv; 320 stack &= ~(1024 * 1024 - 1); 321 avail = stack - start_vm; 322 if (physmem_size > avail) 323 virtmem_size = avail; 324 end_vm = start_vm + virtmem_size; 325 326 if (virtmem_size < physmem_size) 327 printf("Kernel virtual memory size shrunk to %lu bytes\n", 328 virtmem_size); 329 330 os_flush_stdout(); 331 332 return start_uml(); 333 } 334 335 int __init __weak read_initrd(void) 336 { 337 return 0; 338 } 339 340 void __init setup_arch(char **cmdline_p) 341 { 342 stack_protections((unsigned long) &init_thread_info); 343 setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem); 344 mem_total_pages(physmem_size, iomem_size, highmem); 345 read_initrd(); 346 347 paging_init(); 348 strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); 349 *cmdline_p = command_line; 350 setup_hostinfo(host_info, sizeof host_info); 351 } 352 353 void __init check_bugs(void) 354 { 355 arch_check_bugs(); 356 os_check_bugs(); 357 } 358 359 void apply_alternatives(struct alt_instr *start, struct alt_instr *end) 360 { 361 } 362