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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 <asm/pgtable.h>
14 #include <asm/processor.h>
15 #include <asm/setup.h>
16 #include "as-layout.h"
17 #include "arch.h"
18 #include "init.h"
19 #include "kern.h"
20 #include "kern_util.h"
21 #include "mem_user.h"
22 #include "os.h"
23 
24 #define DEFAULT_COMMAND_LINE "root=98:0"
25 
26 /* Changed in add_arg and setup_arch, which run before SMP is started */
27 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
28 
add_arg(char * arg)29 static void __init add_arg(char *arg)
30 {
31 	if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
32 		printf("add_arg: Too many command line arguments!\n");
33 		exit(1);
34 	}
35 	if (strlen(command_line) > 0)
36 		strcat(command_line, " ");
37 	strcat(command_line, arg);
38 }
39 
40 /*
41  * These fields are initialized at boot time and not changed.
42  * XXX This structure is used only in the non-SMP case.  Maybe this
43  * should be moved to smp.c.
44  */
45 struct cpuinfo_um boot_cpu_data = {
46 	.loops_per_jiffy	= 0,
47 	.ipi_pipe		= { -1, -1 }
48 };
49 
thread_saved_pc(struct task_struct * task)50 unsigned long thread_saved_pc(struct task_struct *task)
51 {
52 	/* FIXME: Need to look up userspace_pid by cpu */
53 	return os_process_pc(userspace_pid[0]);
54 }
55 
56 /* Changed in setup_arch, which is called in early boot */
57 static char host_info[(__NEW_UTS_LEN + 1) * 5];
58 
show_cpuinfo(struct seq_file * m,void * v)59 static int show_cpuinfo(struct seq_file *m, void *v)
60 {
61 	int index = 0;
62 
63 #ifdef CONFIG_SMP
64 	index = (struct cpuinfo_um *) v - cpu_data;
65 	if (!cpu_online(index))
66 		return 0;
67 #endif
68 
69 	seq_printf(m, "processor\t: %d\n", index);
70 	seq_printf(m, "vendor_id\t: User Mode Linux\n");
71 	seq_printf(m, "model name\t: UML\n");
72 	seq_printf(m, "mode\t\t: skas\n");
73 	seq_printf(m, "host\t\t: %s\n", host_info);
74 	seq_printf(m, "bogomips\t: %lu.%02lu\n\n",
75 		   loops_per_jiffy/(500000/HZ),
76 		   (loops_per_jiffy/(5000/HZ)) % 100);
77 
78 	return 0;
79 }
80 
c_start(struct seq_file * m,loff_t * pos)81 static void *c_start(struct seq_file *m, loff_t *pos)
82 {
83 	return *pos < NR_CPUS ? cpu_data + *pos : NULL;
84 }
85 
c_next(struct seq_file * m,void * v,loff_t * pos)86 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
87 {
88 	++*pos;
89 	return c_start(m, pos);
90 }
91 
c_stop(struct seq_file * m,void * v)92 static void c_stop(struct seq_file *m, void *v)
93 {
94 }
95 
96 const struct seq_operations cpuinfo_op = {
97 	.start	= c_start,
98 	.next	= c_next,
99 	.stop	= c_stop,
100 	.show	= show_cpuinfo,
101 };
102 
103 /* Set in linux_main */
104 unsigned long uml_physmem;
105 EXPORT_SYMBOL(uml_physmem);
106 
107 unsigned long uml_reserved; /* Also modified in mem_init */
108 unsigned long start_vm;
109 unsigned long end_vm;
110 
111 /* Set in uml_ncpus_setup */
112 int ncpus = 1;
113 
114 /* Set in early boot */
115 static int have_root __initdata = 0;
116 
117 /* Set in uml_mem_setup and modified in linux_main */
118 long long physmem_size = 32 * 1024 * 1024;
119 
120 static const char *usage_string =
121 "User Mode Linux v%s\n"
122 "	available at http://user-mode-linux.sourceforge.net/\n\n";
123 
uml_version_setup(char * line,int * add)124 static int __init uml_version_setup(char *line, int *add)
125 {
126 	printf("%s\n", init_utsname()->release);
127 	exit(0);
128 
129 	return 0;
130 }
131 
132 __uml_setup("--version", uml_version_setup,
133 "--version\n"
134 "    Prints the version number of the kernel.\n\n"
135 );
136 
uml_root_setup(char * line,int * add)137 static int __init uml_root_setup(char *line, int *add)
138 {
139 	have_root = 1;
140 	return 0;
141 }
142 
143 __uml_setup("root=", uml_root_setup,
144 "root=<file containing the root fs>\n"
145 "    This is actually used by the generic kernel in exactly the same\n"
146 "    way as in any other kernel. If you configure a number of block\n"
147 "    devices and want to boot off something other than ubd0, you \n"
148 "    would use something like:\n"
149 "        root=/dev/ubd5\n\n"
150 );
151 
no_skas_debug_setup(char * line,int * add)152 static int __init no_skas_debug_setup(char *line, int *add)
153 {
154 	printf("'debug' is not necessary to gdb UML in skas mode - run \n");
155 	printf("'gdb linux'\n");
156 
157 	return 0;
158 }
159 
160 __uml_setup("debug", no_skas_debug_setup,
161 "debug\n"
162 "    this flag is not needed to run gdb on UML in skas mode\n\n"
163 );
164 
165 #ifdef CONFIG_SMP
uml_ncpus_setup(char * line,int * add)166 static int __init uml_ncpus_setup(char *line, int *add)
167 {
168 	if (!sscanf(line, "%d", &ncpus)) {
169 		printf("Couldn't parse [%s]\n", line);
170 		return -1;
171 	}
172 
173 	return 0;
174 }
175 
176 __uml_setup("ncpus=", uml_ncpus_setup,
177 "ncpus=<# of desired CPUs>\n"
178 "    This tells an SMP kernel how many virtual processors to start.\n\n"
179 );
180 #endif
181 
Usage(char * line,int * add)182 static int __init Usage(char *line, int *add)
183 {
184 	const char **p;
185 
186 	printf(usage_string, init_utsname()->release);
187 	p = &__uml_help_start;
188 	while (p < &__uml_help_end) {
189 		printf("%s", *p);
190 		p++;
191 	}
192 	exit(0);
193 	return 0;
194 }
195 
196 __uml_setup("--help", Usage,
197 "--help\n"
198 "    Prints this message.\n\n"
199 );
200 
uml_checksetup(char * line,int * add)201 static void __init uml_checksetup(char *line, int *add)
202 {
203 	struct uml_param *p;
204 
205 	p = &__uml_setup_start;
206 	while (p < &__uml_setup_end) {
207 		size_t n;
208 
209 		n = strlen(p->str);
210 		if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
211 			return;
212 		p++;
213 	}
214 }
215 
uml_postsetup(void)216 static void __init uml_postsetup(void)
217 {
218 	initcall_t *p;
219 
220 	p = &__uml_postsetup_start;
221 	while (p < &__uml_postsetup_end) {
222 		(*p)();
223 		p++;
224 	}
225 	return;
226 }
227 
panic_exit(struct notifier_block * self,unsigned long unused1,void * unused2)228 static int panic_exit(struct notifier_block *self, unsigned long unused1,
229 		      void *unused2)
230 {
231 	bust_spinlocks(1);
232 	show_regs(&(current->thread.regs));
233 	bust_spinlocks(0);
234 	uml_exitcode = 1;
235 	os_dump_core();
236 	return 0;
237 }
238 
239 static struct notifier_block panic_exit_notifier = {
240 	.notifier_call 		= panic_exit,
241 	.next 			= NULL,
242 	.priority 		= 0
243 };
244 
245 /* Set during early boot */
246 unsigned long task_size;
247 EXPORT_SYMBOL(task_size);
248 
249 unsigned long host_task_size;
250 
251 unsigned long brk_start;
252 unsigned long end_iomem;
253 EXPORT_SYMBOL(end_iomem);
254 
255 #define MIN_VMALLOC (32 * 1024 * 1024)
256 
257 extern char __binary_start;
258 
linux_main(int argc,char ** argv)259 int __init linux_main(int argc, char **argv)
260 {
261 	unsigned long avail, diff;
262 	unsigned long virtmem_size, max_physmem;
263 	unsigned long stack;
264 	unsigned int i;
265 	int add;
266 	char * mode;
267 
268 	for (i = 1; i < argc; i++) {
269 		if ((i == 1) && (argv[i][0] == ' '))
270 			continue;
271 		add = 1;
272 		uml_checksetup(argv[i], &add);
273 		if (add)
274 			add_arg(argv[i]);
275 	}
276 	if (have_root == 0)
277 		add_arg(DEFAULT_COMMAND_LINE);
278 
279 	host_task_size = os_get_top_address();
280 	/*
281 	 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
282 	 * out
283 	 */
284 	task_size = host_task_size & PGDIR_MASK;
285 
286 	/* OS sanity checks that need to happen before the kernel runs */
287 	os_early_checks();
288 
289 	can_do_skas();
290 
291 	if (proc_mm && ptrace_faultinfo)
292 		mode = "SKAS3";
293 	else
294 		mode = "SKAS0";
295 
296 	printf("UML running in %s mode\n", mode);
297 
298 	brk_start = (unsigned long) sbrk(0);
299 
300 	/*
301 	 * Increase physical memory size for exec-shield users
302 	 * so they actually get what they asked for. This should
303 	 * add zero for non-exec shield users
304 	 */
305 
306 	diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
307 	if (diff > 1024 * 1024) {
308 		printf("Adding %ld bytes to physical memory to account for "
309 		       "exec-shield gap\n", diff);
310 		physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
311 	}
312 
313 	uml_physmem = (unsigned long) &__binary_start & PAGE_MASK;
314 
315 	/* Reserve up to 4M after the current brk */
316 	uml_reserved = ROUND_4M(brk_start) + (1 << 22);
317 
318 	setup_machinename(init_utsname()->machine);
319 
320 	highmem = 0;
321 	iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
322 	max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
323 
324 	/*
325 	 * Zones have to begin on a 1 << MAX_ORDER page boundary,
326 	 * so this makes sure that's true for highmem
327 	 */
328 	max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
329 	if (physmem_size + iomem_size > max_physmem) {
330 		highmem = physmem_size + iomem_size - max_physmem;
331 		physmem_size -= highmem;
332 #ifndef CONFIG_HIGHMEM
333 		highmem = 0;
334 		printf("CONFIG_HIGHMEM not enabled - physical memory shrunk "
335 		       "to %Lu bytes\n", physmem_size);
336 #endif
337 	}
338 
339 	high_physmem = uml_physmem + physmem_size;
340 	end_iomem = high_physmem + iomem_size;
341 	high_memory = (void *) end_iomem;
342 
343 	start_vm = VMALLOC_START;
344 
345 	setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
346 	if (init_maps(physmem_size, iomem_size, highmem)) {
347 		printf("Failed to allocate mem_map for %Lu bytes of physical "
348 		       "memory and %Lu bytes of highmem\n", physmem_size,
349 		       highmem);
350 		exit(1);
351 	}
352 
353 	virtmem_size = physmem_size;
354 	stack = (unsigned long) argv;
355 	stack &= ~(1024 * 1024 - 1);
356 	avail = stack - start_vm;
357 	if (physmem_size > avail)
358 		virtmem_size = avail;
359 	end_vm = start_vm + virtmem_size;
360 
361 	if (virtmem_size < physmem_size)
362 		printf("Kernel virtual memory size shrunk to %lu bytes\n",
363 		       virtmem_size);
364 
365 	atomic_notifier_chain_register(&panic_notifier_list,
366 				       &panic_exit_notifier);
367 
368 	uml_postsetup();
369 
370 	stack_protections((unsigned long) &init_thread_info);
371 	os_flush_stdout();
372 
373 	return start_uml();
374 }
375 
setup_arch(char ** cmdline_p)376 void __init setup_arch(char **cmdline_p)
377 {
378 	paging_init();
379 	strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
380 	*cmdline_p = command_line;
381 	setup_hostinfo(host_info, sizeof host_info);
382 }
383 
check_bugs(void)384 void __init check_bugs(void)
385 {
386 	arch_check_bugs();
387 	os_check_bugs();
388 }
389 
apply_alternatives(struct alt_instr * start,struct alt_instr * end)390 void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
391 {
392 }
393 
394 #ifdef CONFIG_SMP
alternatives_smp_module_add(struct module * mod,char * name,void * locks,void * locks_end,void * text,void * text_end)395 void alternatives_smp_module_add(struct module *mod, char *name,
396 				 void *locks, void *locks_end,
397 				 void *text,  void *text_end)
398 {
399 }
400 
alternatives_smp_module_del(struct module * mod)401 void alternatives_smp_module_del(struct module *mod)
402 {
403 }
404 #endif
405