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 /* -r: Reboot after kernel tasks complete? */
54 static bool reboot_when_done;
56 static void ram_init (void);
57 static void paging_init (void);
59 static char **read_command_line (void);
60 static char **parse_options (char **argv);
61 static void run_actions (char **argv);
62 static void usage (void);
64 static void print_stats (void);
67 int main (void) NO_RETURN;
69 /* Pintos main program. */
75 /* Clear BSS and get machine's RAM size. */
78 /* Break command line into arguments and parse options. */
79 argv = read_command_line ();
80 argv = parse_options (argv);
82 /* Initialize ourselves as a thread so we can use locks,
83 then enable console locking. */
88 printf ("Pintos booting with %'zu kB RAM...\n", ram_pages * PGSIZE / 1024);
90 /* Initialize memory system. */
101 /* Initialize interrupt handlers. */
111 /* Start thread scheduler and enable interrupts. */
113 serial_init_queue ();
117 /* Initialize file system. */
119 filesys_init (format_filesys);
122 printf ("Boot complete.\n");
124 /* Run actions specified on kernel command line. */
128 if (reboot_when_done)
131 if (power_off_when_done)
136 /* Clear BSS and obtain RAM size from loader. */
140 /* The "BSS" is a segment that should be initialized to zeros.
141 It isn't actually stored on disk or zeroed by the kernel
142 loader, so we have to zero it ourselves.
144 The start and end of the BSS segment is recorded by the
145 linker as _start_bss and _end_bss. See kernel.lds. */
146 extern char _start_bss, _end_bss;
147 memset (&_start_bss, 0, &_end_bss - &_start_bss);
149 /* Get RAM size from loader. See loader.S. */
150 ram_pages = *(uint32_t *) ptov (LOADER_RAM_PGS);
153 /* Populates the base page directory and page table with the
154 kernel virtual mapping, and then sets up the CPU to use the
155 new page directory. Points base_page_dir to the page
156 directory it creates.
158 At the time this function is called, the active page table
159 (set up by loader.S) only maps the first 4 MB of RAM, so we
160 should not try to use extravagant amounts of memory.
161 Fortunately, there is no need to do so. */
167 extern char _start, _end_kernel_text;
169 pd = base_page_dir = palloc_get_page (PAL_ASSERT | PAL_ZERO);
171 for (page = 0; page < ram_pages; page++)
173 uintptr_t paddr = page * PGSIZE;
174 char *vaddr = ptov (paddr);
175 size_t pde_idx = pd_no (vaddr);
176 size_t pte_idx = pt_no (vaddr);
177 bool in_kernel_text = &_start <= vaddr && vaddr < &_end_kernel_text;
179 if (pd[pde_idx] == 0)
181 pt = palloc_get_page (PAL_ASSERT | PAL_ZERO);
182 pd[pde_idx] = pde_create (pt);
185 pt[pte_idx] = pte_create_kernel (vaddr, !in_kernel_text);
188 /* Store the physical address of the page directory into CR3
189 aka PDBR (page directory base register). This activates our
190 new page tables immediately. See [IA32-v2a] "MOV--Move
191 to/from Control Registers" and [IA32-v3a] 3.7.5 "Base Address
192 of the Page Directory". */
193 asm volatile ("movl %0, %%cr3" : : "r" (vtop (base_page_dir)));
196 /* Breaks the kernel command line into words and returns them as
197 an argv-like array. */
199 read_command_line (void)
201 static char *argv[LOADER_ARGS_LEN / 2 + 1];
206 argc = *(uint32_t *) ptov (LOADER_ARG_CNT);
207 p = ptov (LOADER_ARGS);
208 end = p + LOADER_ARGS_LEN;
209 for (i = 0; i < argc; i++)
212 PANIC ("command line arguments overflow");
215 p += strnlen (p, end - p) + 1;
219 /* Print kernel command line. */
220 printf ("Kernel command line:");
221 for (i = 0; i < argc; i++)
222 if (strchr (argv[i], ' ') == NULL)
223 printf (" %s", argv[i]);
225 printf (" '%s'", argv[i]);
231 /* Parses options in ARGV[]
232 and returns the first non-option argument. */
234 parse_options (char **argv)
236 for (; *argv != NULL && **argv == '-'; argv++)
239 char *name = strtok_r (*argv, "=", &save_ptr);
240 char *value = strtok_r (NULL, "", &save_ptr);
242 if (!strcmp (name, "-h"))
244 else if (!strcmp (name, "-q"))
245 power_off_when_done = true;
246 else if (!strcmp (name, "-r"))
247 reboot_when_done = true;
249 else if (!strcmp (name, "-f"))
250 format_filesys = true;
252 else if (!strcmp (name, "-rs"))
253 random_init (atoi (value));
254 else if (!strcmp (name, "-mlfqs"))
257 else if (!strcmp (name, "-ul"))
258 user_page_limit = atoi (value);
261 PANIC ("unknown option `%s' (use -h for help)", name);
264 /* Initialize the random number generator based on the system
265 time. This has no effect if an "-rs" option was specified.
267 When running under Bochs, this is not enough by itself to
268 get a good seed value, because the pintos script sets the
269 initial time to a predictable value, not to the local time,
270 for reproducibility. To fix this, give the "-r" option to
271 the pintos script to request real-time execution. */
272 random_init (rtc_get_time ());
277 /* Runs the task specified in ARGV[1]. */
279 run_task (char **argv)
281 const char *task = argv[1];
283 printf ("Executing '%s':\n", task);
285 process_wait (process_execute (task));
289 printf ("Execution of '%s' complete.\n", task);
292 /* Executes all of the actions specified in ARGV[]
293 up to the null pointer sentinel. */
295 run_actions (char **argv)
300 char *name; /* Action name. */
301 int argc; /* # of args, including action name. */
302 void (*function) (char **argv); /* Function to execute action. */
305 /* Table of supported actions. */
306 static const struct action actions[] =
308 {"run", 2, run_task},
310 {"ls", 1, fsutil_ls},
311 {"cat", 2, fsutil_cat},
312 {"rm", 2, fsutil_rm},
313 {"extract", 1, fsutil_extract},
314 {"append", 2, fsutil_append},
319 while (*argv != NULL)
321 const struct action *a;
324 /* Find action name. */
325 for (a = actions; ; a++)
327 PANIC ("unknown action `%s' (use -h for help)", *argv);
328 else if (!strcmp (*argv, a->name))
331 /* Check for required arguments. */
332 for (i = 1; i < a->argc; i++)
334 PANIC ("action `%s' requires %d argument(s)", *argv, a->argc - 1);
336 /* Invoke action and advance. */
343 /* Prints a kernel command line help message and powers off the
348 printf ("\nCommand line syntax: [OPTION...] [ACTION...]\n"
349 "Options must precede actions.\n"
350 "Actions are executed in the order specified.\n"
351 "\nAvailable actions:\n"
353 " run 'PROG [ARG...]' Run PROG and wait for it to complete.\n"
355 " run TEST Run TEST.\n"
358 " ls List files in the root directory.\n"
359 " cat FILE Print FILE to the console.\n"
360 " rm FILE Delete FILE.\n"
361 "Use these actions indirectly via `pintos' -g and -p options:\n"
362 " extract Untar from scratch disk into file system.\n"
363 " append FILE Append FILE to tar file on scratch disk.\n"
366 " -h Print this help message and power off.\n"
367 " -q Power off VM after actions or on panic.\n"
368 " -r Reboot after actions.\n"
369 " -f Format file system disk during startup.\n"
370 " -rs=SEED Set random number seed to SEED.\n"
371 " -mlfqs Use multi-level feedback queue scheduler.\n"
373 " -ul=COUNT Limit user memory to COUNT pages.\n"
379 /* Keyboard control register port. */
380 #define CONTROL_REG 0x64
382 /* Reboots the machine via the keyboard controller. */
388 printf ("Rebooting...\n");
390 /* See [kbd] for details on how to program the keyboard
392 for (i = 0; i < 100; i++)
396 /* Poll keyboard controller's status byte until
397 * 'input buffer empty' is reported. */
398 for (j = 0; j < 0x10000; j++)
400 if ((inb (CONTROL_REG) & 0x02) == 0)
407 /* Pulse bit 0 of the output port P2 of the keyboard controller.
408 * This will reset the CPU. */
409 outb (CONTROL_REG, 0xfe);
414 /* Powers down the machine we're running on,
415 as long as we're running on Bochs or QEMU. */
419 const char s[] = "Shutdown";
428 printf ("Powering off...\n");
431 for (p = s; *p != '\0'; p++)
433 asm volatile ("cli; hlt" : : : "memory");
434 printf ("still running...\n");
438 /* Print statistics about Pintos execution. */
442 timer_print_stats ();
443 thread_print_stats ();
447 console_print_stats ();
450 exception_print_stats ();