1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
6 #include <linux/delay.h>
7 #include <linux/init.h>
9 #include <linux/ctype.h>
10 #include <linux/module.h>
11 #include <linux/panic_notifier.h>
12 #include <linux/seq_file.h>
13 #include <linux/string.h>
14 #include <linux/utsname.h>
15 #include <linux/sched.h>
16 #include <linux/sched/task.h>
17 #include <linux/kmsg_dump.h>
18 #include <linux/suspend.h>
19 #include <linux/random.h>
21 #include <asm/processor.h>
22 #include <asm/cpufeature.h>
23 #include <asm/sections.h>
24 #include <asm/setup.h>
25 #include <as-layout.h>
29 #include <kern_util.h>
33 #define DEFAULT_COMMAND_LINE_ROOT "root=98:0"
34 #define DEFAULT_COMMAND_LINE_CONSOLE "console=tty0"
36 /* Changed in add_arg and setup_arch, which run before SMP is started */
37 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
39 static void __init add_arg(char *arg)
41 if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
42 os_warn("add_arg: Too many command line arguments!\n");
45 if (strlen(command_line) > 0)
46 strcat(command_line, " ");
47 strcat(command_line, arg);
51 * These fields are initialized at boot time and not changed.
52 * XXX This structure is used only in the non-SMP case. Maybe this
53 * should be moved to smp.c.
55 struct cpuinfo_um boot_cpu_data = {
57 .ipi_pipe = { -1, -1 },
58 .cache_alignment = L1_CACHE_BYTES,
59 .x86_capability = { 0 }
62 EXPORT_SYMBOL(boot_cpu_data);
64 union thread_union cpu0_irqstack
65 __section(".data..init_irqstack") =
66 { .thread_info = INIT_THREAD_INFO(init_task) };
68 /* Changed in setup_arch, which is called in early boot */
69 static char host_info[(__NEW_UTS_LEN + 1) * 5];
71 static int show_cpuinfo(struct seq_file *m, void *v)
75 seq_printf(m, "processor\t: %d\n", i);
76 seq_printf(m, "vendor_id\t: User Mode Linux\n");
77 seq_printf(m, "model name\t: UML\n");
78 seq_printf(m, "mode\t\t: skas\n");
79 seq_printf(m, "host\t\t: %s\n", host_info);
80 seq_printf(m, "fpu\t\t: %s\n", cpu_has(&boot_cpu_data, X86_FEATURE_FPU) ? "yes" : "no");
81 seq_printf(m, "flags\t\t:");
82 for (i = 0; i < 32*NCAPINTS; i++)
83 if (cpu_has(&boot_cpu_data, i) && (x86_cap_flags[i] != NULL))
84 seq_printf(m, " %s", x86_cap_flags[i]);
86 seq_printf(m, "cache_alignment\t: %d\n", boot_cpu_data.cache_alignment);
87 seq_printf(m, "bogomips\t: %lu.%02lu\n",
88 loops_per_jiffy/(500000/HZ),
89 (loops_per_jiffy/(5000/HZ)) % 100);
95 static void *c_start(struct seq_file *m, loff_t *pos)
97 return *pos < NR_CPUS ? cpu_data + *pos : NULL;
100 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
103 return c_start(m, pos);
106 static void c_stop(struct seq_file *m, void *v)
110 const struct seq_operations cpuinfo_op = {
114 .show = show_cpuinfo,
117 /* Set in linux_main */
118 unsigned long uml_physmem;
119 EXPORT_SYMBOL(uml_physmem);
121 unsigned long uml_reserved; /* Also modified in mem_init */
122 unsigned long start_vm;
123 unsigned long end_vm;
125 /* Set in uml_ncpus_setup */
128 /* Set in early boot */
129 static int have_root __initdata;
130 static int have_console __initdata;
132 /* Set in uml_mem_setup and modified in linux_main */
133 long long physmem_size = 32 * 1024 * 1024;
134 EXPORT_SYMBOL(physmem_size);
136 static const char *usage_string =
137 "User Mode Linux v%s\n"
138 " available at http://user-mode-linux.sourceforge.net/\n\n";
140 static int __init uml_version_setup(char *line, int *add)
142 /* Explicitly use printf() to show version in stdout */
143 printf("%s\n", init_utsname()->release);
149 __uml_setup("--version", uml_version_setup,
151 " Prints the version number of the kernel.\n\n"
154 static int __init uml_root_setup(char *line, int *add)
160 __uml_setup("root=", uml_root_setup,
161 "root=<file containing the root fs>\n"
162 " This is actually used by the generic kernel in exactly the same\n"
163 " way as in any other kernel. If you configure a number of block\n"
164 " devices and want to boot off something other than ubd0, you \n"
165 " would use something like:\n"
166 " root=/dev/ubd5\n\n"
169 static int __init no_skas_debug_setup(char *line, int *add)
171 os_warn("'debug' is not necessary to gdb UML in skas mode - run\n");
172 os_warn("'gdb linux'\n");
177 __uml_setup("debug", no_skas_debug_setup,
179 " this flag is not needed to run gdb on UML in skas mode\n\n"
182 static int __init uml_console_setup(char *line, int *add)
188 __uml_setup("console=", uml_console_setup,
189 "console=<preferred console>\n"
190 " Specify the preferred console output driver\n\n"
193 static int __init Usage(char *line, int *add)
197 printf(usage_string, init_utsname()->release);
198 p = &__uml_help_start;
199 /* Explicitly use printf() to show help in stdout */
200 while (p < &__uml_help_end) {
208 __uml_setup("--help", Usage,
210 " Prints this message.\n\n"
213 static void __init uml_checksetup(char *line, int *add)
217 p = &__uml_setup_start;
218 while (p < &__uml_setup_end) {
222 if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
228 static void __init uml_postsetup(void)
232 p = &__uml_postsetup_start;
233 while (p < &__uml_postsetup_end) {
240 static int panic_exit(struct notifier_block *self, unsigned long unused1,
243 kmsg_dump(KMSG_DUMP_PANIC);
251 static struct notifier_block panic_exit_notifier = {
252 .notifier_call = panic_exit,
257 void uml_finishsetup(void)
259 atomic_notifier_chain_register(&panic_notifier_list,
260 &panic_exit_notifier);
264 new_thread_handler();
267 /* Set during early boot */
268 unsigned long stub_start;
269 unsigned long task_size;
270 EXPORT_SYMBOL(task_size);
272 unsigned long host_task_size;
274 unsigned long brk_start;
275 unsigned long end_iomem;
276 EXPORT_SYMBOL(end_iomem);
278 #define MIN_VMALLOC (32 * 1024 * 1024)
280 static void parse_host_cpu_flags(char *line)
283 for (i = 0; i < 32*NCAPINTS; i++) {
284 if ((x86_cap_flags[i] != NULL) && strstr(line, x86_cap_flags[i]))
285 set_cpu_cap(&boot_cpu_data, i);
288 static void parse_cache_line(char *line)
291 char *to_parse = strstr(line, ":");
294 while (*to_parse != 0 && isspace(*to_parse)) {
297 if (kstrtoul(to_parse, 10, &res) == 0 && is_power_of_2(res))
298 boot_cpu_data.cache_alignment = res;
300 boot_cpu_data.cache_alignment = L1_CACHE_BYTES;
304 int __init linux_main(int argc, char **argv)
306 unsigned long avail, diff;
307 unsigned long virtmem_size, max_physmem;
312 for (i = 1; i < argc; i++) {
313 if ((i == 1) && (argv[i][0] == ' '))
316 uml_checksetup(argv[i], &add);
321 add_arg(DEFAULT_COMMAND_LINE_ROOT);
323 if (have_console == 0)
324 add_arg(DEFAULT_COMMAND_LINE_CONSOLE);
326 host_task_size = os_get_top_address();
327 /* reserve two pages for the stubs */
328 host_task_size -= 2 * PAGE_SIZE;
329 stub_start = host_task_size;
332 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
335 task_size = host_task_size & PGDIR_MASK;
337 /* OS sanity checks that need to happen before the kernel runs */
340 get_host_cpu_features(parse_host_cpu_flags, parse_cache_line);
342 brk_start = (unsigned long) sbrk(0);
345 * Increase physical memory size for exec-shield users
346 * so they actually get what they asked for. This should
347 * add zero for non-exec shield users
350 diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
351 if (diff > 1024 * 1024) {
352 os_info("Adding %ld bytes to physical memory to account for "
353 "exec-shield gap\n", diff);
354 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
357 uml_physmem = (unsigned long) __binary_start & PAGE_MASK;
359 /* Reserve up to 4M after the current brk */
360 uml_reserved = ROUND_4M(brk_start) + (1 << 22);
362 setup_machinename(init_utsname()->machine);
365 iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
366 max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
369 * Zones have to begin on a 1 << MAX_ORDER page boundary,
370 * so this makes sure that's true for highmem
372 max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
373 if (physmem_size + iomem_size > max_physmem) {
374 highmem = physmem_size + iomem_size - max_physmem;
375 physmem_size -= highmem;
378 high_physmem = uml_physmem + physmem_size;
379 end_iomem = high_physmem + iomem_size;
380 high_memory = (void *) end_iomem;
382 start_vm = VMALLOC_START;
384 virtmem_size = physmem_size;
385 stack = (unsigned long) argv;
386 stack &= ~(1024 * 1024 - 1);
387 avail = stack - start_vm;
388 if (physmem_size > avail)
389 virtmem_size = avail;
390 end_vm = start_vm + virtmem_size;
392 if (virtmem_size < physmem_size)
393 os_info("Kernel virtual memory size shrunk to %lu bytes\n",
401 int __init __weak read_initrd(void)
406 void __init setup_arch(char **cmdline_p)
410 stack_protections((unsigned long) &init_thread_info);
411 setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
412 mem_total_pages(physmem_size, iomem_size, highmem);
416 strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
417 *cmdline_p = command_line;
418 setup_hostinfo(host_info, sizeof host_info);
420 if (os_getrandom(rng_seed, sizeof(rng_seed), 0) == sizeof(rng_seed)) {
421 add_bootloader_randomness(rng_seed, sizeof(rng_seed));
422 memzero_explicit(rng_seed, sizeof(rng_seed));
426 void __init check_bugs(void)
432 void apply_retpolines(s32 *start, s32 *end)
436 void apply_returns(s32 *start, s32 *end)
440 void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
444 void *text_poke(void *addr, const void *opcode, size_t len)
447 * In UML, the only reference to this function is in
448 * apply_relocate_add(), which shouldn't ever actually call this
449 * because UML doesn't have live patching.
453 return memcpy(addr, opcode, len);
456 void text_poke_sync(void)
460 void uml_pm_wake(void)
465 #ifdef CONFIG_PM_SLEEP
466 static int um_suspend_valid(suspend_state_t state)
468 return state == PM_SUSPEND_MEM;
471 static int um_suspend_prepare(void)
477 static int um_suspend_enter(suspend_state_t state)
479 if (WARN_ON(state != PM_SUSPEND_MEM))
483 * This is identical to the idle sleep, but we've just
484 * (during suspend) turned off all interrupt sources
485 * except for the ones we want, so now we can only wake
486 * up on something we actually want to wake up on. All
487 * timing has also been suspended.
493 static void um_suspend_finish(void)
498 const struct platform_suspend_ops um_suspend_ops = {
499 .valid = um_suspend_valid,
500 .prepare = um_suspend_prepare,
501 .enter = um_suspend_enter,
502 .finish = um_suspend_finish,
505 static int init_pm_wake_signal(void)
508 * In external time-travel mode we can't use signals to wake up
509 * since that would mess with the scheduling. We'll have to do
510 * some additional work to support wakeup on virtio devices or
511 * similar, perhaps implementing a fake RTC controller that can
512 * trigger wakeup (and request the appropriate scheduling from
513 * the external scheduler when going to suspend.)
515 if (time_travel_mode != TT_MODE_EXTERNAL)
516 register_pm_wake_signal();
518 suspend_set_ops(&um_suspend_ops);
523 late_initcall(init_pm_wake_signal);