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v5.14.15
  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/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
 
 20#include <asm/processor.h>
 21#include <asm/cpufeature.h>
 22#include <asm/sections.h>
 23#include <asm/setup.h>
 24#include <as-layout.h>
 25#include <arch.h>
 26#include <init.h>
 27#include <kern.h>
 28#include <kern_util.h>
 29#include <mem_user.h>
 30#include <os.h>
 31
 32#define DEFAULT_COMMAND_LINE_ROOT "root=98:0"
 33#define DEFAULT_COMMAND_LINE_CONSOLE "console=tty"
 34
 35/* Changed in add_arg and setup_arch, which run before SMP is started */
 36static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
 37
 38static void __init add_arg(char *arg)
 39{
 40	if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
 41		os_warn("add_arg: Too many command line arguments!\n");
 42		exit(1);
 43	}
 44	if (strlen(command_line) > 0)
 45		strcat(command_line, " ");
 46	strcat(command_line, arg);
 47}
 48
 49/*
 50 * These fields are initialized at boot time and not changed.
 51 * XXX This structure is used only in the non-SMP case.  Maybe this
 52 * should be moved to smp.c.
 53 */
 54struct cpuinfo_um boot_cpu_data = {
 55	.loops_per_jiffy	= 0,
 56	.ipi_pipe		= { -1, -1 },
 57	.cache_alignment	= L1_CACHE_BYTES,
 58	.x86_capability		= { 0 }
 59};
 60
 61EXPORT_SYMBOL(boot_cpu_data);
 62
 63union thread_union cpu0_irqstack
 64	__section(".data..init_irqstack") =
 65		{ .thread_info = INIT_THREAD_INFO(init_task) };
 66
 67/* Changed in setup_arch, which is called in early boot */
 68static char host_info[(__NEW_UTS_LEN + 1) * 5];
 69
 70static int show_cpuinfo(struct seq_file *m, void *v)
 71{
 72	int i = 0;
 73
 74	seq_printf(m, "processor\t: %d\n", i);
 75	seq_printf(m, "vendor_id\t: User Mode Linux\n");
 76	seq_printf(m, "model name\t: UML\n");
 77	seq_printf(m, "mode\t\t: skas\n");
 78	seq_printf(m, "host\t\t: %s\n", host_info);
 79	seq_printf(m, "fpu\t\t: %s\n", cpu_has(&boot_cpu_data, X86_FEATURE_FPU) ? "yes" : "no");
 80	seq_printf(m, "flags\t\t:");
 81	for (i = 0; i < 32*NCAPINTS; i++)
 82		if (cpu_has(&boot_cpu_data, i) && (x86_cap_flags[i] != NULL))
 83			seq_printf(m, " %s", x86_cap_flags[i]);
 84	seq_printf(m, "\n");
 85	seq_printf(m, "cache_alignment\t: %d\n", boot_cpu_data.cache_alignment);
 86	seq_printf(m, "bogomips\t: %lu.%02lu\n",
 87		   loops_per_jiffy/(500000/HZ),
 88		   (loops_per_jiffy/(5000/HZ)) % 100);
 89
 90
 91	return 0;
 92}
 93
 94static void *c_start(struct seq_file *m, loff_t *pos)
 95{
 96	return *pos < NR_CPUS ? cpu_data + *pos : NULL;
 97}
 98
 99static void *c_next(struct seq_file *m, void *v, loff_t *pos)
100{
101	++*pos;
102	return c_start(m, pos);
103}
104
105static void c_stop(struct seq_file *m, void *v)
106{
107}
108
109const struct seq_operations cpuinfo_op = {
110	.start	= c_start,
111	.next	= c_next,
112	.stop	= c_stop,
113	.show	= show_cpuinfo,
114};
115
116/* Set in linux_main */
117unsigned long uml_physmem;
118EXPORT_SYMBOL(uml_physmem);
119
120unsigned long uml_reserved; /* Also modified in mem_init */
121unsigned long start_vm;
122unsigned long end_vm;
123
124/* Set in uml_ncpus_setup */
125int ncpus = 1;
126
127/* Set in early boot */
128static int have_root __initdata;
129static int have_console __initdata;
130
131/* Set in uml_mem_setup and modified in linux_main */
132long long physmem_size = 32 * 1024 * 1024;
133EXPORT_SYMBOL(physmem_size);
134
135static const char *usage_string =
136"User Mode Linux v%s\n"
137"	available at http://user-mode-linux.sourceforge.net/\n\n";
138
139static int __init uml_version_setup(char *line, int *add)
140{
141	/* Explicitly use printf() to show version in stdout */
142	printf("%s\n", init_utsname()->release);
143	exit(0);
144
145	return 0;
146}
147
148__uml_setup("--version", uml_version_setup,
149"--version\n"
150"    Prints the version number of the kernel.\n\n"
151);
152
153static int __init uml_root_setup(char *line, int *add)
154{
155	have_root = 1;
156	return 0;
157}
158
159__uml_setup("root=", uml_root_setup,
160"root=<file containing the root fs>\n"
161"    This is actually used by the generic kernel in exactly the same\n"
162"    way as in any other kernel. If you configure a number of block\n"
163"    devices and want to boot off something other than ubd0, you \n"
164"    would use something like:\n"
165"        root=/dev/ubd5\n\n"
166);
167
168static int __init no_skas_debug_setup(char *line, int *add)
169{
170	os_warn("'debug' is not necessary to gdb UML in skas mode - run\n");
171	os_warn("'gdb linux'\n");
172
173	return 0;
174}
175
176__uml_setup("debug", no_skas_debug_setup,
177"debug\n"
178"    this flag is not needed to run gdb on UML in skas mode\n\n"
179);
180
181static int __init uml_console_setup(char *line, int *add)
182{
183	have_console = 1;
184	return 0;
185}
186
187__uml_setup("console=", uml_console_setup,
188"console=<preferred console>\n"
189"    Specify the preferred console output driver\n\n"
190);
191
192static int __init Usage(char *line, int *add)
193{
194	const char **p;
195
196	printf(usage_string, init_utsname()->release);
197	p = &__uml_help_start;
198	/* Explicitly use printf() to show help in stdout */
199	while (p < &__uml_help_end) {
200		printf("%s", *p);
201		p++;
202	}
203	exit(0);
204	return 0;
205}
206
207__uml_setup("--help", Usage,
208"--help\n"
209"    Prints this message.\n\n"
210);
211
212static void __init uml_checksetup(char *line, int *add)
213{
214	struct uml_param *p;
215
216	p = &__uml_setup_start;
217	while (p < &__uml_setup_end) {
218		size_t n;
219
220		n = strlen(p->str);
221		if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
222			return;
223		p++;
224	}
225}
226
227static void __init uml_postsetup(void)
228{
229	initcall_t *p;
230
231	p = &__uml_postsetup_start;
232	while (p < &__uml_postsetup_end) {
233		(*p)();
234		p++;
235	}
236	return;
237}
238
239static int panic_exit(struct notifier_block *self, unsigned long unused1,
240		      void *unused2)
241{
242	kmsg_dump(KMSG_DUMP_PANIC);
243	bust_spinlocks(1);
244	bust_spinlocks(0);
245	uml_exitcode = 1;
246	os_dump_core();
247	return 0;
248}
249
250static struct notifier_block panic_exit_notifier = {
251	.notifier_call 		= panic_exit,
252	.next 			= NULL,
253	.priority 		= 0
254};
255
256void uml_finishsetup(void)
257{
258	atomic_notifier_chain_register(&panic_notifier_list,
259				       &panic_exit_notifier);
260
261	uml_postsetup();
262
263	new_thread_handler();
264}
265
266/* Set during early boot */
267unsigned long stub_start;
268unsigned long task_size;
269EXPORT_SYMBOL(task_size);
270
271unsigned long host_task_size;
272
273unsigned long brk_start;
274unsigned long end_iomem;
275EXPORT_SYMBOL(end_iomem);
276
277#define MIN_VMALLOC (32 * 1024 * 1024)
278
279static void parse_host_cpu_flags(char *line)
280{
281	int i;
282	for (i = 0; i < 32*NCAPINTS; i++) {
283		if ((x86_cap_flags[i] != NULL) && strstr(line, x86_cap_flags[i]))
284			set_cpu_cap(&boot_cpu_data, i);
285	}
286}
287static void parse_cache_line(char *line)
288{
289	long res;
290	char *to_parse = strstr(line, ":");
291	if (to_parse) {
292		to_parse++;
293		while (*to_parse != 0 && isspace(*to_parse)) {
294			to_parse++;
295		}
296		if (kstrtoul(to_parse, 10, &res) == 0 && is_power_of_2(res))
297			boot_cpu_data.cache_alignment = res;
298		else
299			boot_cpu_data.cache_alignment = L1_CACHE_BYTES;
300	}
301}
302
303int __init linux_main(int argc, char **argv)
304{
305	unsigned long avail, diff;
306	unsigned long virtmem_size, max_physmem;
307	unsigned long stack;
308	unsigned int i;
309	int add;
310
311	for (i = 1; i < argc; i++) {
312		if ((i == 1) && (argv[i][0] == ' '))
313			continue;
314		add = 1;
315		uml_checksetup(argv[i], &add);
316		if (add)
317			add_arg(argv[i]);
318	}
319	if (have_root == 0)
320		add_arg(DEFAULT_COMMAND_LINE_ROOT);
321
322	if (have_console == 0)
323		add_arg(DEFAULT_COMMAND_LINE_CONSOLE);
324
325	host_task_size = os_get_top_address();
326	/* reserve two pages for the stubs */
327	host_task_size -= 2 * PAGE_SIZE;
328	stub_start = host_task_size;
329
330	/*
331	 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
332	 * out
333	 */
334	task_size = host_task_size & PGDIR_MASK;
335
336	/* OS sanity checks that need to happen before the kernel runs */
337	os_early_checks();
338
339	get_host_cpu_features(parse_host_cpu_flags, parse_cache_line);
340
341	brk_start = (unsigned long) sbrk(0);
342
343	/*
344	 * Increase physical memory size for exec-shield users
345	 * so they actually get what they asked for. This should
346	 * add zero for non-exec shield users
347	 */
348
349	diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
350	if (diff > 1024 * 1024) {
351		os_info("Adding %ld bytes to physical memory to account for "
352			"exec-shield gap\n", diff);
353		physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
354	}
355
356	uml_physmem = (unsigned long) __binary_start & PAGE_MASK;
357
358	/* Reserve up to 4M after the current brk */
359	uml_reserved = ROUND_4M(brk_start) + (1 << 22);
360
361	setup_machinename(init_utsname()->machine);
362
363	highmem = 0;
364	iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
365	max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
366
367	/*
368	 * Zones have to begin on a 1 << MAX_ORDER page boundary,
369	 * so this makes sure that's true for highmem
370	 */
371	max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
372	if (physmem_size + iomem_size > max_physmem) {
373		highmem = physmem_size + iomem_size - max_physmem;
374		physmem_size -= highmem;
375	}
376
377	high_physmem = uml_physmem + physmem_size;
378	end_iomem = high_physmem + iomem_size;
379	high_memory = (void *) end_iomem;
380
381	start_vm = VMALLOC_START;
382
383	virtmem_size = physmem_size;
384	stack = (unsigned long) argv;
385	stack &= ~(1024 * 1024 - 1);
386	avail = stack - start_vm;
387	if (physmem_size > avail)
388		virtmem_size = avail;
389	end_vm = start_vm + virtmem_size;
390
391	if (virtmem_size < physmem_size)
392		os_info("Kernel virtual memory size shrunk to %lu bytes\n",
393			virtmem_size);
394
395	os_flush_stdout();
396
397	return start_uml();
398}
399
400int __init __weak read_initrd(void)
401{
402	return 0;
403}
404
405void __init setup_arch(char **cmdline_p)
406{
407	stack_protections((unsigned long) &init_thread_info);
408	setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
409	mem_total_pages(physmem_size, iomem_size, highmem);
410	read_initrd();
411
412	paging_init();
413	strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
414	*cmdline_p = command_line;
415	setup_hostinfo(host_info, sizeof host_info);
416}
417
418void __init check_bugs(void)
419{
420	arch_check_bugs();
421	os_check_bugs();
422}
423
424void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
425{
426}
427
428void *text_poke(void *addr, const void *opcode, size_t len)
429{
430	/*
431	 * In UML, the only reference to this function is in
432	 * apply_relocate_add(), which shouldn't ever actually call this
433	 * because UML doesn't have live patching.
434	 */
435	WARN_ON(1);
436
437	return memcpy(addr, opcode, len);
438}
439
440void text_poke_sync(void)
441{
442}
443
444void uml_pm_wake(void)
445{
446	pm_system_wakeup();
447}
448
449#ifdef CONFIG_PM_SLEEP
450static int um_suspend_valid(suspend_state_t state)
451{
452	return state == PM_SUSPEND_MEM;
453}
454
455static int um_suspend_prepare(void)
456{
457	um_irqs_suspend();
458	return 0;
459}
460
461static int um_suspend_enter(suspend_state_t state)
462{
463	if (WARN_ON(state != PM_SUSPEND_MEM))
464		return -EINVAL;
465
466	/*
467	 * This is identical to the idle sleep, but we've just
468	 * (during suspend) turned off all interrupt sources
469	 * except for the ones we want, so now we can only wake
470	 * up on something we actually want to wake up on. All
471	 * timing has also been suspended.
472	 */
473	um_idle_sleep();
474	return 0;
475}
476
477static void um_suspend_finish(void)
478{
479	um_irqs_resume();
480}
481
482const struct platform_suspend_ops um_suspend_ops = {
483	.valid = um_suspend_valid,
484	.prepare = um_suspend_prepare,
485	.enter = um_suspend_enter,
486	.finish = um_suspend_finish,
487};
488
489static int init_pm_wake_signal(void)
490{
491	/*
492	 * In external time-travel mode we can't use signals to wake up
493	 * since that would mess with the scheduling. We'll have to do
494	 * some additional work to support wakeup on virtio devices or
495	 * similar, perhaps implementing a fake RTC controller that can
496	 * trigger wakeup (and request the appropriate scheduling from
497	 * the external scheduler when going to suspend.)
498	 */
499	if (time_travel_mode != TT_MODE_EXTERNAL)
500		register_pm_wake_signal();
501
502	suspend_set_ops(&um_suspend_ops);
503
504	return 0;
505}
506
507late_initcall(init_pm_wake_signal);
508#endif
v5.4
  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 */
 32static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
 33
 34static 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 */
 50struct cpuinfo_um boot_cpu_data = {
 51	.loops_per_jiffy	= 0,
 52	.ipi_pipe		= { -1, -1 }
 
 
 53};
 54
 
 
 55union 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 */
 60static char host_info[(__NEW_UTS_LEN + 1) * 5];
 61
 62static 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
 78static void *c_start(struct seq_file *m, loff_t *pos)
 79{
 80	return *pos < NR_CPUS ? cpu_data + *pos : NULL;
 81}
 82
 83static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 84{
 85	++*pos;
 86	return c_start(m, pos);
 87}
 88
 89static void c_stop(struct seq_file *m, void *v)
 90{
 91}
 92
 93const 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 */
101unsigned long uml_physmem;
102EXPORT_SYMBOL(uml_physmem);
103
104unsigned long uml_reserved; /* Also modified in mem_init */
105unsigned long start_vm;
106unsigned long end_vm;
107
108/* Set in uml_ncpus_setup */
109int ncpus = 1;
110
111/* Set in early boot */
112static int have_root __initdata = 0;
 
113
114/* Set in uml_mem_setup and modified in linux_main */
115long long physmem_size = 32 * 1024 * 1024;
116EXPORT_SYMBOL(physmem_size);
117
118static const char *usage_string =
119"User Mode Linux v%s\n"
120"	available at http://user-mode-linux.sourceforge.net/\n\n";
121
122static 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
136static 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
151static 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
 
 
 
 
 
 
 
 
 
 
 
164static 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
184static 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
199static 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
211static 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
222static struct notifier_block panic_exit_notifier = {
223	.notifier_call 		= panic_exit,
224	.next 			= NULL,
225	.priority 		= 0
226};
227
228void 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 */
 
239unsigned long task_size;
240EXPORT_SYMBOL(task_size);
241
242unsigned long host_task_size;
243
244unsigned long brk_start;
245unsigned long end_iomem;
246EXPORT_SYMBOL(end_iomem);
247
248#define MIN_VMALLOC (32 * 1024 * 1024)
249
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
250int __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
338int __init __weak read_initrd(void)
339{
340	return 0;
341}
342
343void __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
356void __init check_bugs(void)
357{
358	arch_check_bugs();
359	os_check_bugs();
360}
361
362void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
363{
364}