1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 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 os_warn("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 { .thread_info = 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 EXPORT_SYMBOL(physmem_size); 117 118 static const char *usage_string = 119 "User Mode Linux v%s\n" 120 " available at http://user-mode-linux.sourceforge.net/\n\n"; 121 122 static int __init uml_version_setup(char *line, int *add) 123 { 124 /* Explicitly use printf() to show version in stdout */ 125 printf("%s\n", init_utsname()->release); 126 exit(0); 127 128 return 0; 129 } 130 131 __uml_setup("--version", uml_version_setup, 132 "--version\n" 133 " Prints the version number of the kernel.\n\n" 134 ); 135 136 static int __init uml_root_setup(char *line, int *add) 137 { 138 have_root = 1; 139 return 0; 140 } 141 142 __uml_setup("root=", uml_root_setup, 143 "root=<file containing the root fs>\n" 144 " This is actually used by the generic kernel in exactly the same\n" 145 " way as in any other kernel. If you configure a number of block\n" 146 " devices and want to boot off something other than ubd0, you \n" 147 " would use something like:\n" 148 " root=/dev/ubd5\n\n" 149 ); 150 151 static int __init no_skas_debug_setup(char *line, int *add) 152 { 153 os_warn("'debug' is not necessary to gdb UML in skas mode - run\n"); 154 os_warn("'gdb linux'\n"); 155 156 return 0; 157 } 158 159 __uml_setup("debug", no_skas_debug_setup, 160 "debug\n" 161 " this flag is not needed to run gdb on UML in skas mode\n\n" 162 ); 163 164 static int __init Usage(char *line, int *add) 165 { 166 const char **p; 167 168 printf(usage_string, init_utsname()->release); 169 p = &__uml_help_start; 170 /* Explicitly use printf() to show help in stdout */ 171 while (p < &__uml_help_end) { 172 printf("%s", *p); 173 p++; 174 } 175 exit(0); 176 return 0; 177 } 178 179 __uml_setup("--help", Usage, 180 "--help\n" 181 " Prints this message.\n\n" 182 ); 183 184 static void __init uml_checksetup(char *line, int *add) 185 { 186 struct uml_param *p; 187 188 p = &__uml_setup_start; 189 while (p < &__uml_setup_end) { 190 size_t n; 191 192 n = strlen(p->str); 193 if (!strncmp(line, p->str, n) && p->setup_func(line + n, add)) 194 return; 195 p++; 196 } 197 } 198 199 static void __init uml_postsetup(void) 200 { 201 initcall_t *p; 202 203 p = &__uml_postsetup_start; 204 while (p < &__uml_postsetup_end) { 205 (*p)(); 206 p++; 207 } 208 return; 209 } 210 211 static int panic_exit(struct notifier_block *self, unsigned long unused1, 212 void *unused2) 213 { 214 kmsg_dump(KMSG_DUMP_PANIC); 215 bust_spinlocks(1); 216 bust_spinlocks(0); 217 uml_exitcode = 1; 218 os_dump_core(); 219 return 0; 220 } 221 222 static struct notifier_block panic_exit_notifier = { 223 .notifier_call = panic_exit, 224 .next = NULL, 225 .priority = 0 226 }; 227 228 void uml_finishsetup(void) 229 { 230 atomic_notifier_chain_register(&panic_notifier_list, 231 &panic_exit_notifier); 232 233 uml_postsetup(); 234 235 new_thread_handler(); 236 } 237 238 /* Set during early boot */ 239 unsigned long task_size; 240 EXPORT_SYMBOL(task_size); 241 242 unsigned long host_task_size; 243 244 unsigned long brk_start; 245 unsigned long end_iomem; 246 EXPORT_SYMBOL(end_iomem); 247 248 #define MIN_VMALLOC (32 * 1024 * 1024) 249 250 int __init linux_main(int argc, char **argv) 251 { 252 unsigned long avail, diff; 253 unsigned long virtmem_size, max_physmem; 254 unsigned long stack; 255 unsigned int i; 256 int add; 257 258 for (i = 1; i < argc; i++) { 259 if ((i == 1) && (argv[i][0] == ' ')) 260 continue; 261 add = 1; 262 uml_checksetup(argv[i], &add); 263 if (add) 264 add_arg(argv[i]); 265 } 266 if (have_root == 0) 267 add_arg(DEFAULT_COMMAND_LINE); 268 269 host_task_size = os_get_top_address(); 270 /* 271 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps 272 * out 273 */ 274 task_size = host_task_size & PGDIR_MASK; 275 276 /* OS sanity checks that need to happen before the kernel runs */ 277 os_early_checks(); 278 279 brk_start = (unsigned long) sbrk(0); 280 281 /* 282 * Increase physical memory size for exec-shield users 283 * so they actually get what they asked for. This should 284 * add zero for non-exec shield users 285 */ 286 287 diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end); 288 if (diff > 1024 * 1024) { 289 os_info("Adding %ld bytes to physical memory to account for " 290 "exec-shield gap\n", diff); 291 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end); 292 } 293 294 uml_physmem = (unsigned long) __binary_start & PAGE_MASK; 295 296 /* Reserve up to 4M after the current brk */ 297 uml_reserved = ROUND_4M(brk_start) + (1 << 22); 298 299 setup_machinename(init_utsname()->machine); 300 301 highmem = 0; 302 iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK; 303 max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC; 304 305 /* 306 * Zones have to begin on a 1 << MAX_ORDER page boundary, 307 * so this makes sure that's true for highmem 308 */ 309 max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1); 310 if (physmem_size + iomem_size > max_physmem) { 311 highmem = physmem_size + iomem_size - max_physmem; 312 physmem_size -= highmem; 313 } 314 315 high_physmem = uml_physmem + physmem_size; 316 end_iomem = high_physmem + iomem_size; 317 high_memory = (void *) end_iomem; 318 319 start_vm = VMALLOC_START; 320 321 virtmem_size = physmem_size; 322 stack = (unsigned long) argv; 323 stack &= ~(1024 * 1024 - 1); 324 avail = stack - start_vm; 325 if (physmem_size > avail) 326 virtmem_size = avail; 327 end_vm = start_vm + virtmem_size; 328 329 if (virtmem_size < physmem_size) 330 os_info("Kernel virtual memory size shrunk to %lu bytes\n", 331 virtmem_size); 332 333 os_flush_stdout(); 334 335 return start_uml(); 336 } 337 338 int __init __weak read_initrd(void) 339 { 340 return 0; 341 } 342 343 void __init setup_arch(char **cmdline_p) 344 { 345 stack_protections((unsigned long) &init_thread_info); 346 setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem); 347 mem_total_pages(physmem_size, iomem_size, highmem); 348 read_initrd(); 349 350 paging_init(); 351 strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); 352 *cmdline_p = command_line; 353 setup_hostinfo(host_info, sizeof host_info); 354 } 355 356 void __init check_bugs(void) 357 { 358 arch_check_bugs(); 359 os_check_bugs(); 360 } 361 362 void apply_alternatives(struct alt_instr *start, struct alt_instr *end) 363 { 364 } 365