1 #include "threads/init.h"
11 #include "devices/kbd.h"
12 #include "devices/input.h"
13 #include "devices/serial.h"
14 #include "devices/timer.h"
15 #include "devices/vga.h"
16 #include "devices/rtc.h"
17 #include "threads/interrupt.h"
18 #include "threads/io.h"
19 #include "threads/loader.h"
20 #include "threads/malloc.h"
21 #include "threads/palloc.h"
22 #include "threads/pte.h"
23 #include "threads/thread.h"
25 #include "userprog/process.h"
26 #include "userprog/exception.h"
27 #include "userprog/gdt.h"
28 #include "userprog/syscall.h"
29 #include "userprog/tss.h"
31 #include "tests/threads/tests.h"
34 #include "devices/disk.h"
35 #include "filesys/filesys.h"
36 #include "filesys/fsutil.h"
39 /* Amount of physical memory, in 4 kB pages. */
42 /* Page directory with kernel mappings only. */
43 uint32_t *base_page_dir;
46 /* -f: Format the file system? */
47 static bool format_filesys;
50 /* -q: Power off after kernel tasks complete? */
51 bool power_off_when_done;
53 static void ram_init (void);
54 static void paging_init (void);
56 static char **read_command_line (void);
57 static char **parse_options (char **argv);
58 static void run_actions (char **argv);
59 static void usage (void);
61 static void print_stats (void);
64 int main (void) NO_RETURN;
66 /* Pintos main program. */
72 /* Clear BSS and get machine's RAM size. */
75 /* Break command line into arguments and parse options. */
76 argv = read_command_line ();
77 argv = parse_options (argv);
79 /* Initialize ourselves as a thread so we can use locks,
80 then enable console locking. */
85 printf ("Pintos booting with %'zu kB RAM...\n", ram_pages * PGSIZE / 1024);
87 /* Initialize memory system. */
98 /* Initialize interrupt handlers. */
108 /* Start thread scheduler and enable interrupts. */
110 serial_init_queue ();
114 /* Initialize file system. */
116 filesys_init (format_filesys);
119 printf ("Boot complete.\n");
121 /* Run actions specified on kernel command line. */
125 if (power_off_when_done)
130 /* Clear BSS and obtain RAM size from loader. */
134 /* The "BSS" is a segment that should be initialized to zeros.
135 It isn't actually stored on disk or zeroed by the kernel
136 loader, so we have to zero it ourselves.
138 The start and end of the BSS segment is recorded by the
139 linker as _start_bss and _end_bss. See kernel.lds. */
140 extern char _start_bss, _end_bss;
141 memset (&_start_bss, 0, &_end_bss - &_start_bss);
143 /* Get RAM size from loader. See loader.S. */
144 ram_pages = *(uint32_t *) ptov (LOADER_RAM_PGS);
147 /* Populates the base page directory and page table with the
148 kernel virtual mapping, and then sets up the CPU to use the
149 new page directory. Points base_page_dir to the page
150 directory it creates.
152 At the time this function is called, the active page table
153 (set up by loader.S) only maps the first 4 MB of RAM, so we
154 should not try to use extravagant amounts of memory.
155 Fortunately, there is no need to do so. */
161 extern char _start, _end_kernel_text;
163 pd = base_page_dir = palloc_get_page (PAL_ASSERT | PAL_ZERO);
165 for (page = 0; page < ram_pages; page++)
167 uintptr_t paddr = page * PGSIZE;
168 char *vaddr = ptov (paddr);
169 size_t pde_idx = pd_no (vaddr);
170 size_t pte_idx = pt_no (vaddr);
171 bool in_kernel_text = &_start <= vaddr && vaddr < &_end_kernel_text;
173 if (pd[pde_idx] == 0)
175 pt = palloc_get_page (PAL_ASSERT | PAL_ZERO);
176 pd[pde_idx] = pde_create (pt);
179 pt[pte_idx] = pte_create_kernel (vaddr, !in_kernel_text);
182 /* Store the physical address of the page directory into CR3
183 aka PDBR (page directory base register). This activates our
184 new page tables immediately. See [IA32-v2a] "MOV--Move
185 to/from Control Registers" and [IA32-v3a] 3.7.5 "Base Address
186 of the Page Directory". */
187 asm volatile ("movl %0, %%cr3" : : "r" (vtop (base_page_dir)));
190 /* Breaks the kernel command line into words and returns them as
191 an argv-like array. */
193 read_command_line (void)
195 static char *argv[LOADER_ARGS_LEN / 2 + 1];
200 argc = *(uint32_t *) ptov (LOADER_ARG_CNT);
201 p = ptov (LOADER_ARGS);
202 end = p + LOADER_ARGS_LEN;
203 for (i = 0; i < argc; i++)
206 PANIC ("command line arguments overflow");
209 p += strnlen (p, end - p) + 1;
213 /* Print kernel command line. */
214 printf ("Kernel command line:");
215 for (i = 0; i < argc; i++)
216 if (strchr (argv[i], ' ') == NULL)
217 printf (" %s", argv[i]);
219 printf (" '%s'", argv[i]);
225 /* Parses options in ARGV[]
226 and returns the first non-option argument. */
228 parse_options (char **argv)
230 for (; *argv != NULL && **argv == '-'; argv++)
233 char *name = strtok_r (*argv, "=", &save_ptr);
234 char *value = strtok_r (NULL, "", &save_ptr);
236 if (!strcmp (name, "-h"))
238 else if (!strcmp (name, "-q"))
239 power_off_when_done = true;
241 else if (!strcmp (name, "-f"))
242 format_filesys = true;
244 else if (!strcmp (name, "-rs"))
245 random_init (atoi (value));
246 else if (!strcmp (name, "-mlfqs"))
249 else if (!strcmp (name, "-ul"))
250 user_page_limit = atoi (value);
253 PANIC ("unknown option `%s' (use -h for help)", name);
256 /* Initialize the random number generator based on the system
257 time. This has no effect if an "-rs" option was specified.
259 When running under Bochs, this is not enough by itself to
260 get a good seed value, because the pintos script sets the
261 initial time to a predictable value, not to the local time,
262 for reproducibility. To fix this, give the "-r" option to
263 the pintos script to request real-time execution. */
264 random_init (rtc_get_time ());
269 /* Runs the task specified in ARGV[1]. */
271 run_task (char **argv)
273 const char *task = argv[1];
275 printf ("Executing '%s':\n", task);
277 process_wait (process_execute (task));
281 printf ("Execution of '%s' complete.\n", task);
284 /* Executes all of the actions specified in ARGV[]
285 up to the null pointer sentinel. */
287 run_actions (char **argv)
292 char *name; /* Action name. */
293 int argc; /* # of args, including action name. */
294 void (*function) (char **argv); /* Function to execute action. */
297 /* Table of supported actions. */
298 static const struct action actions[] =
300 {"run", 2, run_task},
302 {"ls", 1, fsutil_ls},
303 {"cat", 2, fsutil_cat},
304 {"rm", 2, fsutil_rm},
305 {"put", 2, fsutil_put},
306 {"get", 2, fsutil_get},
311 while (*argv != NULL)
313 const struct action *a;
316 /* Find action name. */
317 for (a = actions; ; a++)
319 PANIC ("unknown action `%s' (use -h for help)", *argv);
320 else if (!strcmp (*argv, a->name))
323 /* Check for required arguments. */
324 for (i = 1; i < a->argc; i++)
326 PANIC ("action `%s' requires %d argument(s)", *argv, a->argc - 1);
328 /* Invoke action and advance. */
335 /* Prints a kernel command line help message and powers off the
340 printf ("\nCommand line syntax: [OPTION...] [ACTION...]\n"
341 "Options must precede actions.\n"
342 "Actions are executed in the order specified.\n"
343 "\nAvailable actions:\n"
345 " run 'PROG [ARG...]' Run PROG and wait for it to complete.\n"
347 " run TEST Run TEST.\n"
350 " ls List files in the root directory.\n"
351 " cat FILE Print FILE to the console.\n"
352 " rm FILE Delete FILE.\n"
353 "Use these actions indirectly via `pintos' -g and -p options:\n"
354 " put FILE Put FILE into file system from scratch disk.\n"
355 " get FILE Get FILE from file system into scratch disk.\n"
358 " -h Print this help message and power off.\n"
359 " -q Power off VM after actions or on panic.\n"
360 " -f Format file system disk during startup.\n"
361 " -rs=SEED Set random number seed to SEED.\n"
362 " -mlfqs Use multi-level feedback queue scheduler.\n"
364 " -ul=COUNT Limit user memory to COUNT pages.\n"
371 /* Powers down the machine we're running on,
372 as long as we're running on Bochs or QEMU. */
376 const char s[] = "Shutdown";
385 printf ("Powering off...\n");
388 for (p = s; *p != '\0'; p++)
390 asm volatile ("cli; hlt" : : : "memory");
391 printf ("still running...\n");
395 /* Print statistics about Pintos execution. */
399 timer_print_stats ();
400 thread_print_stats ();
404 console_print_stats ();
407 exception_print_stats ();