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001 /* Copyright (C) 2004 The SOS Team 001 /* Copyright (C) 2004 The SOS Team 002 Copyright (C) 1999 Free Software Foundatio << 003 002 004 This program is free software; you can redi 003 This program is free software; you can redistribute it and/or 005 modify it under the terms of the GNU Genera 004 modify it under the terms of the GNU General Public License 006 as published by the Free Software Foundatio 005 as published by the Free Software Foundation; either version 2 007 of the License, or (at your option) any lat 006 of the License, or (at your option) any later version. 008 007 009 This program is distributed in the hope tha 008 This program is distributed in the hope that it will be useful, 010 but WITHOUT ANY WARRANTY; without even the 009 but WITHOUT ANY WARRANTY; without even the implied warranty of 011 MERCHANTABILITY or FITNESS FOR A PARTICULAR 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 012 GNU General Public License for more details 011 GNU General Public License for more details. 013 012 014 You should have received a copy of the GNU 013 You should have received a copy of the GNU General Public License 015 along with this program; if not, write to t 014 along with this program; if not, write to the Free Software 016 Foundation, Inc., 59 Temple Place - Suite 3 015 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 017 USA. 016 USA. 018 */ 017 */ 019 018 020 /* Include definitions of the multiboot standa 019 /* Include definitions of the multiboot standard */ 021 #include <bootstrap/multiboot.h> 020 #include <bootstrap/multiboot.h> >> 021 #include <hwcore/idt.h> >> 022 #include <hwcore/gdt.h> >> 023 #include <hwcore/irq.h> >> 024 #include <hwcore/exception.h> >> 025 #include <hwcore/i8254.h> >> 026 #include <sos/list.h> >> 027 #include <sos/physmem.h> >> 028 #include <hwcore/paging.h> >> 029 #include <hwcore/mm_context.h> >> 030 #include <hwcore/swintr.h> >> 031 #include <sos/kmem_vmm.h> >> 032 #include <sos/kmalloc.h> >> 033 #include <sos/time.h> >> 034 #include <sos/thread.h> >> 035 #include <sos/process.h> >> 036 #include <sos/umem_vmm.h> 022 #include <sos/klibc.h> 037 #include <sos/klibc.h> 023 #include <sos/assert.h> 038 #include <sos/assert.h> 024 #include <drivers/x86_videomem.h> 039 #include <drivers/x86_videomem.h> 025 #include <drivers/bochs.h> 040 #include <drivers/bochs.h> >> 041 #include <sos/calcload.h> >> 042 #include <sos/umem_vmm.h> >> 043 #include <sos/binfmt_elf32.h> >> 044 #include <drivers/zero.h> 026 045 027 046 >> 047 /* Helper function to display each bits of a 32bits integer on the >> 048 screen as dark or light carrets */ >> 049 void display_bits(unsigned char row, unsigned char col, >> 050 unsigned char attribute, >> 051 sos_ui32_t integer) >> 052 { >> 053 int i; >> 054 /* Scan each bit of the integer, MSb first */ >> 055 for (i = 31 ; i >= 0 ; i--) >> 056 { >> 057 /* Test if bit i of 'integer' is set */ >> 058 int bit_i = (integer & (1 << i)); >> 059 /* Ascii 219 => dark carret, Ascii 177 => light carret */ >> 060 unsigned char ascii_code = bit_i?219:177; >> 061 sos_x86_videomem_putchar(row, col++, >> 062 attribute, >> 063 ascii_code); >> 064 } >> 065 } >> 066 >> 067 >> 068 /* Clock IRQ handler */ >> 069 static void clk_it(int intid) >> 070 { >> 071 static sos_ui32_t clock_count = 0; >> 072 >> 073 display_bits(0, 48, >> 074 SOS_X86_VIDEO_FG_LTGREEN | SOS_X86_VIDEO_BG_BLUE, >> 075 clock_count); >> 076 clock_count++; >> 077 >> 078 /* Execute the expired timeout actions (if any) */ >> 079 sos_time_do_tick(); >> 080 >> 081 /* Update scheduler statistics and status */ >> 082 sos_sched_do_timer_tick(); >> 083 } >> 084 >> 085 >> 086 /* ====================================================================== >> 087 * Page fault exception handling >> 088 */ 028 089 029 /* The C entry point of our operating system * !! 090 >> 091 /* Page fault exception handler with demand paging for the kernel */ >> 092 static void pgflt_ex(int intid, struct sos_cpu_state *ctxt) >> 093 { >> 094 static sos_ui32_t demand_paging_count = 0; >> 095 struct sos_thread * cur_thr = sos_thread_get_current(); >> 096 sos_vaddr_t faulting_vaddr = sos_cpu_context_get_EX_faulting_vaddr(ctxt); >> 097 sos_paddr_t ppage_paddr; >> 098 >> 099 if (sos_cpu_context_is_in_user_mode(ctxt) >> 100 || (cur_thr->fixup_uaccess.return_vaddr)) >> 101 { >> 102 __label__ unforce_address_space; >> 103 sos_bool_t need_to_setup_mmu; >> 104 sos_ui32_t errcode = sos_cpu_context_get_EX_info(ctxt); >> 105 >> 106 /* Make sure to always stay in the interrupted thread's MMU >> 107 configuration */ >> 108 need_to_setup_mmu = (cur_thr->squatted_mm_context >> 109 != sos_process_get_mm_context(cur_thr->process)); >> 110 if (need_to_setup_mmu) >> 111 sos_thread_prepare_user_space_access(NULL, 0); >> 112 >> 113 if (SOS_OK == >> 114 sos_umem_vmm_try_resolve_page_fault(faulting_vaddr, >> 115 errcode & (1 << 1), >> 116 TRUE)) >> 117 goto unforce_address_space; >> 118 >> 119 /* If the page fault occured in kernel mode, return to kernel to >> 120 the fixup address */ >> 121 if (! sos_cpu_context_is_in_user_mode(ctxt)) >> 122 { >> 123 cur_thr->fixup_uaccess.faulted_uaddr = faulting_vaddr; >> 124 sos_cpu_context_set_EX_return_address(ctxt, >> 125 cur_thr->fixup_uaccess.return_vaddr); >> 126 goto unforce_address_space; >> 127 } >> 128 >> 129 if (need_to_setup_mmu) >> 130 sos_thread_end_user_space_access(); >> 131 >> 132 sos_bochs_printf("Unresolved USER page Fault at instruction 0x%x on access to address 0x%x (info=%x)!\n", >> 133 sos_cpu_context_get_PC(ctxt), >> 134 (unsigned)faulting_vaddr, >> 135 (unsigned)sos_cpu_context_get_EX_info(ctxt)); >> 136 sos_bochs_printf("Terminating User thread\n"); >> 137 sos_thread_exit(); >> 138 >> 139 unforce_address_space: >> 140 if (need_to_setup_mmu) >> 141 sos_thread_end_user_space_access(); >> 142 return; >> 143 } >> 144 >> 145 /* Check if address is covered by any VMM range */ >> 146 if (! sos_kmem_vmm_is_valid_vaddr(faulting_vaddr)) >> 147 { >> 148 /* No: The page fault is out of any kernel virtual region. For >> 149 the moment, we don't handle this. */ >> 150 sos_display_fatal_error("Unresolved page Fault at instruction 0x%x on access to address 0x%x (info=%x)!", >> 151 sos_cpu_context_get_PC(ctxt), >> 152 (unsigned)faulting_vaddr, >> 153 (unsigned)sos_cpu_context_get_EX_info(ctxt)); >> 154 SOS_ASSERT_FATAL(! "Got page fault (note: demand paging is disabled)"); >> 155 } >> 156 >> 157 >> 158 /* >> 159 * Demand paging in kernel space >> 160 */ >> 161 >> 162 /* Update the number of demand paging requests handled */ >> 163 demand_paging_count ++; >> 164 display_bits(0, 0, >> 165 SOS_X86_VIDEO_FG_LTRED | SOS_X86_VIDEO_BG_BLUE, >> 166 demand_paging_count); >> 167 >> 168 /* Allocate a new page for the virtual address */ >> 169 ppage_paddr = sos_physmem_ref_physpage_new(FALSE); >> 170 if (! ppage_paddr) >> 171 SOS_ASSERT_FATAL(! "TODO: implement swap. (Out of mem in demand paging because no swap for kernel yet !)"); >> 172 SOS_ASSERT_FATAL(SOS_OK == sos_paging_map(ppage_paddr, >> 173 SOS_PAGE_ALIGN_INF(faulting_vaddr), >> 174 FALSE, >> 175 SOS_VM_MAP_PROT_READ >> 176 | SOS_VM_MAP_PROT_WRITE >> 177 | SOS_VM_MAP_ATOMIC)); >> 178 sos_physmem_unref_physpage(ppage_paddr); >> 179 >> 180 /* Ok, we can now return to interrupted context */ >> 181 } >> 182 >> 183 >> 184 >> 185 /* ====================================================================== >> 186 * An operating system MUST always have a ready thread ! Otherwise: >> 187 * what would the CPU have to execute ?! >> 188 */ >> 189 static void idle_thread() >> 190 { >> 191 sos_ui32_t idle_twiddle = 0; >> 192 >> 193 while (1) >> 194 { >> 195 /* Remove this instruction if you get an "Invalid opcode" CPU >> 196 exception (old 80386 CPU) */ >> 197 asm("hlt\n"); >> 198 >> 199 idle_twiddle ++; >> 200 display_bits(0, 0, SOS_X86_VIDEO_FG_GREEN | SOS_X86_VIDEO_BG_BLUE, >> 201 idle_twiddle); >> 202 >> 203 /* Lend the CPU to some other thread */ >> 204 sos_thread_yield(); >> 205 } >> 206 } >> 207 >> 208 >> 209 /* ====================================================================== >> 210 * Kernel thread showing some CPU usage statistics on the console every 1s >> 211 */ >> 212 static void stat_thread() >> 213 { >> 214 while (1) >> 215 { >> 216 sos_ui32_t flags; >> 217 sos_ui32_t load1, load5, load15; >> 218 char str1[11], str5[11], str15[11]; >> 219 struct sos_time t; >> 220 t.sec = 1; >> 221 t.nanosec = 0; >> 222 >> 223 sos_thread_sleep(& t); >> 224 >> 225 sos_disable_IRQs(flags); >> 226 >> 227 /* The IDLE task is EXcluded in the following computation */ >> 228 sos_load_get_sload(&load1, &load5, &load15); >> 229 sos_load_to_string(str1, load1); >> 230 sos_load_to_string(str5, load5); >> 231 sos_load_to_string(str15, load15); >> 232 sos_x86_videomem_printf(16, 34, >> 233 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, >> 234 "Kernel (- Idle): %s %s %s ", >> 235 str1, str5, str15); >> 236 >> 237 sos_load_get_uload(&load1, &load5, &load15); >> 238 sos_load_to_string(str1, load1); >> 239 sos_load_to_string(str5, load5); >> 240 sos_load_to_string(str15, load15); >> 241 sos_x86_videomem_printf(17, 34, >> 242 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, >> 243 "User: %s %s %s ", >> 244 str1, str5, str15); >> 245 >> 246 sos_load_get_uratio(&load1, &load5, &load15); >> 247 sos_load_to_string(str1, load1); >> 248 sos_load_to_string(str5, load5); >> 249 sos_load_to_string(str15, load15); >> 250 sos_x86_videomem_printf(18, 34, >> 251 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, >> 252 "User CPU %%: %s %s %s ", >> 253 str1, str5, str15); >> 254 >> 255 /* The IDLE task is INcluded in the following computation */ >> 256 sos_load_get_sratio(&load1, &load5, &load15); >> 257 sos_load_to_string(str1, load1); >> 258 sos_load_to_string(str5, load5); >> 259 sos_load_to_string(str15, load15); >> 260 sos_x86_videomem_printf(19, 34, >> 261 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, >> 262 "Kernel CPU %% (+ Idle): %s %s %s ", >> 263 str1, str5, str15); >> 264 sos_restore_IRQs(flags); >> 265 } >> 266 } >> 267 >> 268 >> 269 /* ====================================================================== >> 270 * Start the "init" (userland) process >> 271 */ >> 272 static sos_ret_t start_init() >> 273 { >> 274 sos_ret_t retval; >> 275 struct sos_umem_vmm_as *as_init; >> 276 struct sos_process *proc_init; >> 277 struct sos_thread *new_thr; >> 278 sos_uaddr_t ustack, start_uaddr; >> 279 >> 280 /* Create the new process */ >> 281 proc_init = sos_process_create("init", FALSE); >> 282 if (! proc_init) >> 283 return -SOS_ENOMEM; >> 284 as_init = sos_process_get_address_space(proc_init); >> 285 >> 286 /* Map the 'init' program in user space */ >> 287 start_uaddr = sos_binfmt_elf32_map(as_init, "init"); >> 288 if (0 == start_uaddr) >> 289 { >> 290 sos_process_unref(proc_init); >> 291 return -SOS_ENOENT; >> 292 } >> 293 >> 294 /* Allocate the user stack */ >> 295 ustack = (SOS_PAGING_TOP_USER_ADDRESS - SOS_DEFAULT_USER_STACK_SIZE) + 1; >> 296 retval = sos_dev_zero_map(as_init, &ustack, SOS_DEFAULT_USER_STACK_SIZE, >> 297 SOS_VM_MAP_PROT_READ | SOS_VM_MAP_PROT_WRITE, >> 298 /* PRIVATE */ 0); >> 299 if (SOS_OK != retval) >> 300 { >> 301 sos_bochs_printf("ici 2\n"); >> 302 sos_process_unref(proc_init); >> 303 return -SOS_ENOMEM; >> 304 } >> 305 >> 306 /* Now create the user thread */ >> 307 new_thr = sos_create_user_thread(NULL, >> 308 proc_init, >> 309 start_uaddr, >> 310 0, 0, >> 311 ustack + SOS_DEFAULT_USER_STACK_SIZE - 4, >> 312 SOS_SCHED_PRIO_TS_LOWEST); >> 313 if (! new_thr) >> 314 { >> 315 sos_bochs_printf("ici 3\n"); >> 316 sos_process_unref(proc_init); >> 317 return -SOS_ENOMEM; >> 318 } >> 319 >> 320 sos_process_unref(proc_init); >> 321 return SOS_OK; >> 322 } >> 323 >> 324 >> 325 /* ====================================================================== >> 326 * The C entry point of our operating system >> 327 */ 030 void sos_main(unsigned long magic, unsigned lo 328 void sos_main(unsigned long magic, unsigned long addr) 031 { 329 { 032 unsigned i; 330 unsigned i; >> 331 sos_paddr_t sos_kernel_core_base_paddr, sos_kernel_core_top_paddr; >> 332 struct sos_time tick_resolution; 033 333 034 /* Grub sends us a structure, called multibo 334 /* Grub sends us a structure, called multiboot_info_t with a lot of 035 precious informations about the system, s 335 precious informations about the system, see the multiboot 036 documentation for more information. */ 336 documentation for more information. */ 037 multiboot_info_t *mbi; 337 multiboot_info_t *mbi; 038 mbi = (multiboot_info_t *) addr; 338 mbi = (multiboot_info_t *) addr; 039 339 040 /* Setup bochs and console, and clear the co 340 /* Setup bochs and console, and clear the console */ 041 sos_bochs_setup(); 341 sos_bochs_setup(); 042 342 043 sos_x86_videomem_setup(); 343 sos_x86_videomem_setup(); 044 sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); 344 sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); 045 345 046 /* Greetings from SOS */ 346 /* Greetings from SOS */ 047 if (magic == MULTIBOOT_BOOTLOADER_MAGIC) 347 if (magic == MULTIBOOT_BOOTLOADER_MAGIC) 048 /* Loaded with Grub */ 348 /* Loaded with Grub */ 049 sos_x86_videomem_printf(1, 0, 349 sos_x86_videomem_printf(1, 0, 050 SOS_X86_VIDEO_FG_Y 350 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 051 "Welcome From GRUB 351 "Welcome From GRUB to %s%c RAM is %dMB (upper mem = 0x%x kB)", 052 "SOS", ',', !! 352 "SOS article 7.5", ',', 053 (unsigned)(mbi->me 353 (unsigned)(mbi->mem_upper >> 10) + 1, 054 (unsigned)mbi->mem 354 (unsigned)mbi->mem_upper); 055 else 355 else 056 /* Not loaded with grub */ 356 /* Not loaded with grub */ 057 sos_x86_videomem_printf(1, 0, 357 sos_x86_videomem_printf(1, 0, 058 SOS_X86_VIDEO_FG_Y 358 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 059 "Welcome to SOS"); !! 359 "Welcome to SOS article 7.5"); 060 << 061 sos_bochs_putstring("Message in a bochs\n"); << 062 << 063 360 064 /* An operatig system never ends */ !! 361 sos_bochs_putstring("Message in a bochs: This is SOS article 7.5.\n"); 065 for (;;) << 066 continue; << 067 362 068 return; !! 363 /* Setup CPU segmentation and IRQ subsystem */ >> 364 sos_gdt_subsystem_setup(); >> 365 sos_idt_subsystem_setup(); >> 366 >> 367 /* Setup SOS IRQs and exceptions subsystem */ >> 368 sos_exception_subsystem_setup(); >> 369 sos_irq_subsystem_setup(); >> 370 >> 371 /* Configure the timer so as to raise the IRQ0 at a 100Hz rate */ >> 372 sos_i8254_set_frequency(100); >> 373 >> 374 /* Setup the kernel time subsystem to get prepared to take the timer >> 375 ticks into account */ >> 376 tick_resolution = (struct sos_time) { .sec=0, .nanosec=10000000UL }; >> 377 sos_time_subsysem_setup(& tick_resolution); >> 378 >> 379 /* We need a multiboot-compliant boot loader to get the size of the RAM */ >> 380 if (magic != MULTIBOOT_BOOTLOADER_MAGIC) >> 381 { >> 382 sos_x86_videomem_putstring(20, 0, >> 383 SOS_X86_VIDEO_FG_LTRED >> 384 | SOS_X86_VIDEO_BG_BLUE >> 385 | SOS_X86_VIDEO_FG_BLINKING, >> 386 "I'm not loaded with Grub !"); >> 387 /* STOP ! */ >> 388 for (;;) >> 389 continue; >> 390 } >> 391 >> 392 /* >> 393 * Some interrupt handlers >> 394 */ >> 395 >> 396 /* Binding some HW interrupts and exceptions to software routines */ >> 397 sos_irq_set_routine(SOS_IRQ_TIMER, >> 398 clk_it); >> 399 >> 400 /* >> 401 * Setup physical memory management >> 402 */ >> 403 >> 404 /* Multiboot says: "The value returned for upper memory is maximally >> 405 the address of the first upper memory hole minus 1 megabyte.". It >> 406 also adds: "It is not guaranteed to be this value." aka "YMMV" ;) */ >> 407 sos_physmem_subsystem_setup((mbi->mem_upper<<10) + (1<<20), >> 408 & sos_kernel_core_base_paddr, >> 409 & sos_kernel_core_top_paddr); >> 410 >> 411 /* >> 412 * Switch to paged-memory mode >> 413 */ >> 414 >> 415 /* Disabling interrupts should seem more correct, but it's not really >> 416 necessary at this stage */ >> 417 SOS_ASSERT_FATAL(SOS_OK == >> 418 sos_paging_subsystem_setup(sos_kernel_core_base_paddr, >> 419 sos_kernel_core_top_paddr)); >> 420 >> 421 /* Bind the page fault exception */ >> 422 sos_exception_set_routine(SOS_EXCEPT_PAGE_FAULT, >> 423 pgflt_ex); >> 424 >> 425 /* >> 426 * Setup kernel virtual memory allocator >> 427 */ >> 428 >> 429 if (sos_kmem_vmm_subsystem_setup(sos_kernel_core_base_paddr, >> 430 sos_kernel_core_top_paddr, >> 431 bootstrap_stack_bottom, >> 432 bootstrap_stack_bottom >> 433 + bootstrap_stack_size)) >> 434 sos_bochs_printf("Could not setup the Kernel virtual space allocator\n"); >> 435 >> 436 if (sos_kmalloc_subsystem_setup()) >> 437 sos_bochs_printf("Could not setup the Kmalloc subsystem\n"); >> 438 >> 439 /* >> 440 * Initialize the MMU context subsystem >> 441 */ >> 442 sos_mm_context_subsystem_setup(); >> 443 >> 444 /* >> 445 * Initialize the CPU context subsystem >> 446 */ >> 447 sos_cpu_context_subsystem_setup(); >> 448 >> 449 /* >> 450 * Bind the syscall handler to its software interrupt handler >> 451 */ >> 452 sos_swintr_subsystem_setup(); >> 453 >> 454 >> 455 /* >> 456 * Initialize the Kernel thread and scheduler subsystems >> 457 */ >> 458 >> 459 /* Initialize kernel thread subsystem */ >> 460 sos_thread_subsystem_setup(bootstrap_stack_bottom, >> 461 bootstrap_stack_size); >> 462 >> 463 /* Initialize the scheduler */ >> 464 sos_sched_subsystem_setup(); >> 465 >> 466 /* Declare the IDLE thread */ >> 467 SOS_ASSERT_FATAL(sos_create_kernel_thread("idle", idle_thread, NULL, >> 468 SOS_SCHED_PRIO_TS_LOWEST) != NULL); >> 469 >> 470 /* Prepare the stats subsystem */ >> 471 sos_load_subsystem_setup(); >> 472 >> 473 /* Declare a thread that prints some stats */ >> 474 SOS_ASSERT_FATAL(sos_create_kernel_thread("stat_thread", stat_thread, >> 475 NULL, >> 476 SOS_SCHED_PRIO_TS_LOWEST) != NULL); >> 477 >> 478 >> 479 /* >> 480 * Initialise user address space management subsystem >> 481 */ >> 482 sos_umem_vmm_subsystem_setup(); >> 483 sos_dev_zero_subsystem_setup(); >> 484 >> 485 /* >> 486 * Initialize process stuff >> 487 */ >> 488 sos_process_subsystem_setup(); >> 489 >> 490 >> 491 /* Enabling the HW interrupts here, this will make the timer HW >> 492 interrupt call the scheduler */ >> 493 asm volatile ("sti\n"); >> 494 >> 495 /* Start the 'init' process, which in turns launches the other >> 496 programs */ >> 497 start_init(); >> 498 >> 499 /* >> 500 * We can safely exit from this function now, for there is already >> 501 * an idle Kernel thread ready to make the CPU busy working... >> 502 * >> 503 * However, we must EXPLICITELY call sos_thread_exit() because a >> 504 * simple "return" will return nowhere ! Actually this first thread >> 505 * was initialized by the Grub bootstrap stage, at a time when the >> 506 * word "thread" did not exist. This means that the stack was not >> 507 * setup in order for a return here to call sos_thread_exit() >> 508 * automagically. Hence we must call it manually. This is the ONLY >> 509 * kernel thread where we must do this manually. >> 510 */ >> 511 sos_bochs_printf("Bye from primary thread !\n"); >> 512 sos_thread_exit(); >> 513 SOS_FATAL_ERROR("No trespassing !"); 069 } 514 }
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