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Differences between /sos/main.c (Article 1) and /sos/main.c (Article 8)


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 
                                                   >> 019 #include <sos/errno.h>
                                                   >> 020 
020 /* Include definitions of the multiboot standa    021 /* Include definitions of the multiboot standard */
021 #include <bootstrap/multiboot.h>                  022 #include <bootstrap/multiboot.h>
                                                   >> 023 #include <hwcore/idt.h>
                                                   >> 024 #include <hwcore/gdt.h>
                                                   >> 025 #include <hwcore/irq.h>
                                                   >> 026 #include <hwcore/exception.h>
                                                   >> 027 #include <hwcore/i8254.h>
                                                   >> 028 #include <sos/list.h>
                                                   >> 029 #include <sos/physmem.h>
                                                   >> 030 #include <hwcore/paging.h>
                                                   >> 031 #include <hwcore/mm_context.h>
                                                   >> 032 #include <hwcore/swintr.h>
                                                   >> 033 #include <sos/kmem_vmm.h>
                                                   >> 034 #include <sos/kmalloc.h>
                                                   >> 035 #include <sos/time.h>
                                                   >> 036 #include <sos/thread.h>
                                                   >> 037 #include <sos/process.h>
                                                   >> 038 #include <sos/umem_vmm.h>
022 #include <sos/klibc.h>                            039 #include <sos/klibc.h>
023 #include <sos/assert.h>                           040 #include <sos/assert.h>
024 #include <drivers/x86_videomem.h>                 041 #include <drivers/x86_videomem.h>
025 #include <drivers/bochs.h>                        042 #include <drivers/bochs.h>
                                                   >> 043 #include <sos/calcload.h>
                                                   >> 044 #include <sos/umem_vmm.h>
                                                   >> 045 #include <sos/binfmt_elf32.h>
                                                   >> 046 #include <drivers/zero.h>
                                                   >> 047 #include <sos/fs.h>
                                                   >> 048 #include <drivers/fs_virtfs.h>
                                                   >> 049 
                                                   >> 050 /* Helper function to display each bits of a 32bits integer on the
                                                   >> 051    screen as dark or light carrets */
                                                   >> 052 void display_bits(unsigned char row, unsigned char col,
                                                   >> 053                   unsigned char attribute,
                                                   >> 054                   sos_ui32_t integer)
                                                   >> 055 {
                                                   >> 056   int i;
                                                   >> 057   /* Scan each bit of the integer, MSb first */
                                                   >> 058   for (i = 31 ; i >= 0 ; i--)
                                                   >> 059     {
                                                   >> 060       /* Test if bit i of 'integer' is set */
                                                   >> 061       int bit_i = (integer & (1 << i));
                                                   >> 062       /* Ascii 219 => dark carret, Ascii 177 => light carret */
                                                   >> 063       unsigned char ascii_code = bit_i?219:177;
                                                   >> 064       sos_x86_videomem_putchar(row, col++,
                                                   >> 065                                attribute,
                                                   >> 066                                ascii_code);
                                                   >> 067     }
                                                   >> 068 }
                                                   >> 069 
                                                   >> 070 /* Clock IRQ handler */
                                                   >> 071 static void clk_it(int intid)
                                                   >> 072 {
                                                   >> 073   static sos_ui32_t clock_count = 0;
                                                   >> 074 
                                                   >> 075   display_bits(0, 48,
                                                   >> 076                SOS_X86_VIDEO_FG_LTGREEN | SOS_X86_VIDEO_BG_BLUE,
                                                   >> 077                clock_count);
                                                   >> 078   clock_count++;
026                                                   079 
                                                   >> 080   /* Execute the expired timeout actions (if any) */
                                                   >> 081   sos_time_do_tick();
027                                                   082 
                                                   >> 083   /* Update scheduler statistics and status */
                                                   >> 084   sos_sched_do_timer_tick();
                                                   >> 085 }
028                                                   086 
029 /* The C entry point of our operating system * !! 087 
030 void sos_main(unsigned long magic, unsigned lo !! 088 /* ======================================================================
                                                   >> 089  * Page fault exception handling
                                                   >> 090  */
                                                   >> 091 
                                                   >> 092 
                                                   >> 093 /* Page fault exception handler with demand paging for the kernel */
                                                   >> 094 static void pgflt_ex(int intid, struct sos_cpu_state *ctxt)
                                                   >> 095 {
                                                   >> 096   static sos_ui32_t demand_paging_count = 0;
                                                   >> 097   struct sos_thread * cur_thr = sos_thread_get_current();
                                                   >> 098   sos_vaddr_t faulting_vaddr  = sos_cpu_context_get_EX_faulting_vaddr(ctxt);
                                                   >> 099   sos_paddr_t ppage_paddr;
                                                   >> 100 
                                                   >> 101   if (sos_cpu_context_is_in_user_mode(ctxt)
                                                   >> 102       || (cur_thr->fixup_uaccess.return_vaddr))
                                                   >> 103     {
                                                   >> 104       __label__ unforce_address_space;
                                                   >> 105       sos_bool_t need_to_setup_mmu;
                                                   >> 106       sos_ui32_t errcode = sos_cpu_context_get_EX_info(ctxt);
                                                   >> 107 
                                                   >> 108       /* Make sure to always stay in the interrupted thread's MMU
                                                   >> 109          configuration */
                                                   >> 110       need_to_setup_mmu = (cur_thr->squatted_mm_context
                                                   >> 111                            != sos_process_get_mm_context(cur_thr->process));
                                                   >> 112       if (need_to_setup_mmu)
                                                   >> 113         sos_thread_prepare_user_space_access(NULL, 0);
                                                   >> 114 
                                                   >> 115       if (SOS_OK ==
                                                   >> 116           sos_umem_vmm_try_resolve_page_fault(faulting_vaddr,
                                                   >> 117                                               errcode & (1 << 1),
                                                   >> 118                                               TRUE))
                                                   >> 119         goto unforce_address_space;
                                                   >> 120 
                                                   >> 121       /* If the page fault occured in kernel mode, return to kernel to
                                                   >> 122          the fixup address */
                                                   >> 123       if (! sos_cpu_context_is_in_user_mode(ctxt))
                                                   >> 124         {
                                                   >> 125           cur_thr->fixup_uaccess.faulted_uaddr = faulting_vaddr;
                                                   >> 126           sos_cpu_context_set_EX_return_address(ctxt,
                                                   >> 127                                                 cur_thr->fixup_uaccess.return_vaddr);
                                                   >> 128           goto unforce_address_space;
                                                   >> 129         }
                                                   >> 130 
                                                   >> 131       if (need_to_setup_mmu)
                                                   >> 132         sos_thread_end_user_space_access();
                                                   >> 133 
                                                   >> 134       sos_bochs_printf("Unresolved USER page Fault at instruction 0x%x on access to address 0x%x (info=%x)!\n",
                                                   >> 135                        sos_cpu_context_get_PC(ctxt),
                                                   >> 136                        (unsigned)faulting_vaddr,
                                                   >> 137                        (unsigned)sos_cpu_context_get_EX_info(ctxt));
                                                   >> 138       sos_bochs_printf("Terminating User thread\n");
                                                   >> 139       sos_thread_exit();
                                                   >> 140 
                                                   >> 141     unforce_address_space:
                                                   >> 142       if (need_to_setup_mmu)
                                                   >> 143         sos_thread_end_user_space_access();
                                                   >> 144       return;
                                                   >> 145     }
                                                   >> 146 
                                                   >> 147   /* Check if address is covered by any VMM range */
                                                   >> 148   if (! sos_kmem_vmm_is_valid_vaddr(faulting_vaddr))
                                                   >> 149     {
                                                   >> 150       /* No: The page fault is out of any kernel virtual region. For
                                                   >> 151          the moment, we don't handle this. */
                                                   >> 152       sos_display_fatal_error("Unresolved page Fault at instruction 0x%x on access to address 0x%x (info=%x)!",
                                                   >> 153                               sos_cpu_context_get_PC(ctxt),
                                                   >> 154                               (unsigned)faulting_vaddr,
                                                   >> 155                               (unsigned)sos_cpu_context_get_EX_info(ctxt));
                                                   >> 156       SOS_ASSERT_FATAL(! "Got page fault (note: demand paging is disabled)");
                                                   >> 157     }
                                                   >> 158 
                                                   >> 159 
                                                   >> 160   /*
                                                   >> 161    * Demand paging in kernel space
                                                   >> 162    */
                                                   >> 163  
                                                   >> 164   /* Update the number of demand paging requests handled */
                                                   >> 165   demand_paging_count ++;
                                                   >> 166   display_bits(0, 0,
                                                   >> 167                SOS_X86_VIDEO_FG_LTRED | SOS_X86_VIDEO_BG_BLUE,
                                                   >> 168                demand_paging_count);
                                                   >> 169 
                                                   >> 170   /* Allocate a new page for the virtual address */
                                                   >> 171   ppage_paddr = sos_physmem_ref_physpage_new(FALSE);
                                                   >> 172   if (! ppage_paddr)
                                                   >> 173     SOS_ASSERT_FATAL(! "TODO: implement swap. (Out of mem in demand paging because no swap for kernel yet !)");
                                                   >> 174   SOS_ASSERT_FATAL(SOS_OK == sos_paging_map(ppage_paddr,
                                                   >> 175                                             SOS_PAGE_ALIGN_INF(faulting_vaddr),
                                                   >> 176                                             FALSE,
                                                   >> 177                                             SOS_VM_MAP_PROT_READ
                                                   >> 178                                             | SOS_VM_MAP_PROT_WRITE
                                                   >> 179                                             | SOS_VM_MAP_ATOMIC));
                                                   >> 180   sos_physmem_unref_physpage(ppage_paddr);
                                                   >> 181 
                                                   >> 182   /* Ok, we can now return to interrupted context */
                                                   >> 183 }
                                                   >> 184 
                                                   >> 185 
                                                   >> 186 
                                                   >> 187 /* ======================================================================
                                                   >> 188  * An operating system MUST always have a ready thread ! Otherwise:
                                                   >> 189  * what would the CPU have to execute ?!
                                                   >> 190  */
                                                   >> 191 static void idle_thread()
                                                   >> 192 {
                                                   >> 193   sos_ui32_t idle_twiddle = 0;
                                                   >> 194 
                                                   >> 195   while (1)
                                                   >> 196     {
                                                   >> 197       /* Remove this instruction if you get an "Invalid opcode" CPU
                                                   >> 198          exception (old 80386 CPU) */
                                                   >> 199       asm("hlt\n");
                                                   >> 200 
                                                   >> 201       idle_twiddle ++;
                                                   >> 202       display_bits(0, 0, SOS_X86_VIDEO_FG_GREEN | SOS_X86_VIDEO_BG_BLUE,
                                                   >> 203                    idle_twiddle);
                                                   >> 204       
                                                   >> 205       /* Lend the CPU to some other thread */
                                                   >> 206       sos_thread_yield();
                                                   >> 207     }
                                                   >> 208 }
                                                   >> 209 
                                                   >> 210 
                                                   >> 211 /* ======================================================================
                                                   >> 212  * Kernel thread showing some CPU usage statistics on the console every 1s
                                                   >> 213  */
                                                   >> 214 static void stat_thread()
                                                   >> 215 {
                                                   >> 216   while (1)
                                                   >> 217     {
                                                   >> 218       sos_ui32_t flags;
                                                   >> 219       sos_ui32_t load1, load5, load15;
                                                   >> 220       char str1[11], str5[11], str15[11];
                                                   >> 221       struct sos_time t;
                                                   >> 222       t.sec = 1;
                                                   >> 223       t.nanosec = 0;
                                                   >> 224 
                                                   >> 225       sos_thread_sleep(& t);
                                                   >> 226 
                                                   >> 227       sos_disable_IRQs(flags);
                                                   >> 228 
                                                   >> 229       /* The IDLE task is EXcluded in the following computation */
                                                   >> 230       sos_load_get_sload(&load1, &load5, &load15);
                                                   >> 231       sos_load_to_string(str1, load1);
                                                   >> 232       sos_load_to_string(str5, load5);
                                                   >> 233       sos_load_to_string(str15, load15);
                                                   >> 234       sos_x86_videomem_printf(16, 34,
                                                   >> 235                               SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE,
                                                   >> 236                               "Kernel (- Idle): %s %s %s    ",
                                                   >> 237                               str1, str5, str15);
                                                   >> 238 
                                                   >> 239       sos_load_get_uload(&load1, &load5, &load15);
                                                   >> 240       sos_load_to_string(str1, load1);
                                                   >> 241       sos_load_to_string(str5, load5);
                                                   >> 242       sos_load_to_string(str15, load15);
                                                   >> 243       sos_x86_videomem_printf(17, 34,
                                                   >> 244                               SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE,
                                                   >> 245                               "User: %s %s %s        ",
                                                   >> 246                               str1, str5, str15);
                                                   >> 247 
                                                   >> 248       sos_load_get_uratio(&load1, &load5, &load15);
                                                   >> 249       sos_load_to_string(str1, load1);
                                                   >> 250       sos_load_to_string(str5, load5);
                                                   >> 251       sos_load_to_string(str15, load15);
                                                   >> 252       sos_x86_videomem_printf(18, 34,
                                                   >> 253                               SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE,
                                                   >> 254                               "User CPU %%: %s %s %s        ",
                                                   >> 255                               str1, str5, str15);
                                                   >> 256 
                                                   >> 257       /* The IDLE task is INcluded in the following computation */
                                                   >> 258       sos_load_get_sratio(&load1, &load5, &load15);
                                                   >> 259       sos_load_to_string(str1, load1);
                                                   >> 260       sos_load_to_string(str5, load5);
                                                   >> 261       sos_load_to_string(str15, load15);
                                                   >> 262       sos_x86_videomem_printf(19, 34,
                                                   >> 263                               SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE,
                                                   >> 264                               "Kernel CPU %% (+ Idle): %s %s %s    ",
                                                   >> 265                               str1, str5, str15);
                                                   >> 266       sos_restore_IRQs(flags);
                                                   >> 267     }
                                                   >> 268 }
                                                   >> 269 
                                                   >> 270 
                                                   >> 271 /* ======================================================================
                                                   >> 272  * Start the "init" (userland) process
                                                   >> 273  */
                                                   >> 274 static sos_ret_t
                                                   >> 275 start_init(struct sos_fs_manager_instance * rootfs)
                                                   >> 276 {
                                                   >> 277   sos_ret_t retval;
                                                   >> 278   struct sos_umem_vmm_as *as_init;
                                                   >> 279   struct sos_process *proc_init;
                                                   >> 280   struct sos_thread *new_thr;
                                                   >> 281   sos_uaddr_t ustack, start_uaddr;
                                                   >> 282   struct sos_fs_opened_file * init_root, * init_cwd, * unused_of;
                                                   >> 283 
                                                   >> 284   /* Create the new process */
                                                   >> 285   proc_init = sos_process_create("init", FALSE);
                                                   >> 286   if (! proc_init)
                                                   >> 287     return -SOS_ENOMEM;
                                                   >> 288   as_init = sos_process_get_address_space(proc_init);
                                                   >> 289 
                                                   >> 290 
                                                   >> 291   /*
                                                   >> 292    * Setup the root and CWD directories of the process. The root of
                                                   >> 293    * this process will correspond to the "global" root of the whole
                                                   >> 294    * system since all the future processes will duplicate it !
                                                   >> 295    */
                                                   >> 296   retval = sos_fs_new_opened_file(proc_init, rootfs->root,
                                                   >> 297                                   SOS_FS_OPEN_READ | SOS_FS_OPEN_WRITE,
                                                   >> 298                                   & init_root);
                                                   >> 299   if (SOS_OK != retval)
                                                   >> 300     {
                                                   >> 301       sos_process_unref(proc_init);
                                                   >> 302       return -SOS_ENOENT;
                                                   >> 303     }
                                                   >> 304 
                                                   >> 305   /* Duplicate the root file to set the current working directory of
                                                   >> 306      the init process */
                                                   >> 307   retval = sos_fs_duplicate_opened_file(init_root, proc_init,
                                                   >> 308                                         & init_cwd);
                                                   >> 309   if (SOS_OK != retval)
                                                   >> 310     {
                                                   >> 311       sos_fs_close(init_root);
                                                   >> 312       sos_process_unref(proc_init);
                                                   >> 313       return -SOS_ENOENT;
                                                   >> 314     }
                                                   >> 315 
                                                   >> 316   /* Now update the process ! */
                                                   >> 317   if ( ( SOS_OK != sos_process_chroot(proc_init, init_root, & unused_of) )
                                                   >> 318        || ( SOS_OK != sos_process_chdir(proc_init, init_cwd, & unused_of) ) )
                                                   >> 319     {
                                                   >> 320       sos_fs_close(init_root);
                                                   >> 321       sos_fs_close(init_cwd);
                                                   >> 322       sos_process_chroot(proc_init, NULL, & unused_of);
                                                   >> 323       sos_process_chdir(proc_init, NULL, & unused_of);
                                                   >> 324       sos_process_unref(proc_init);
                                                   >> 325       return -SOS_ENOENT;
                                                   >> 326     }
                                                   >> 327 
                                                   >> 328   /* Map the 'init' program in user space */
                                                   >> 329   start_uaddr = sos_binfmt_elf32_map(as_init, "init");
                                                   >> 330   if (0 == start_uaddr)
                                                   >> 331     {
                                                   >> 332       sos_process_unref(proc_init);
                                                   >> 333       return -SOS_ENOENT;
                                                   >> 334     }
                                                   >> 335 
                                                   >> 336   /* Allocate the user stack */
                                                   >> 337   ustack = (SOS_PAGING_TOP_USER_ADDRESS - SOS_DEFAULT_USER_STACK_SIZE) + 1;
                                                   >> 338   retval = sos_dev_zero_map(as_init, &ustack, SOS_DEFAULT_USER_STACK_SIZE,
                                                   >> 339                             SOS_VM_MAP_PROT_READ | SOS_VM_MAP_PROT_WRITE,
                                                   >> 340                             /* PRIVATE */ 0);
                                                   >> 341   if (SOS_OK != retval)
                                                   >> 342     {
                                                   >> 343       sos_process_unref(proc_init);
                                                   >> 344       return -SOS_ENOMEM;
                                                   >> 345     }
                                                   >> 346 
                                                   >> 347   /* Now create the user thread */
                                                   >> 348   new_thr = sos_create_user_thread(NULL,
                                                   >> 349                                    proc_init,
                                                   >> 350                                    start_uaddr,
                                                   >> 351                                    0, 0,
                                                   >> 352                                    ustack + SOS_DEFAULT_USER_STACK_SIZE - 4,
                                                   >> 353                                    SOS_SCHED_PRIO_TS_LOWEST);
                                                   >> 354   if (! new_thr)
                                                   >> 355     {
                                                   >> 356       sos_process_unref(proc_init);
                                                   >> 357       return -SOS_ENOMEM;
                                                   >> 358     }
                                                   >> 359 
                                                   >> 360   sos_process_unref(proc_init);
                                                   >> 361   return SOS_OK;
                                                   >> 362 }
                                                   >> 363 
                                                   >> 364 
                                                   >> 365 /* ======================================================================
                                                   >> 366  * The C entry point of our operating system
                                                   >> 367  */
                                                   >> 368 void sos_main(unsigned long magic, unsigned long arg)
031 {                                                 369 {
032   unsigned i;                                     370   unsigned i;
                                                   >> 371   sos_paddr_t sos_kernel_core_base_paddr, sos_kernel_core_top_paddr;
                                                   >> 372   struct sos_time tick_resolution;
                                                   >> 373   struct sos_fs_manager_instance * rootfs;
033                                                   374 
034   /* Grub sends us a structure, called multibo !! 375   /* Size of RAM above 1MB. Might be undefined ! */
035      precious informations about the system, s !! 376   unsigned long int upper_mem = 0;
036      documentation for more information. */    << 
037   multiboot_info_t *mbi;                       << 
038   mbi = (multiboot_info_t *) addr;             << 
039                                                   377 
040   /* Setup bochs and console, and clear the co    378   /* Setup bochs and console, and clear the console */
041   sos_bochs_setup();                              379   sos_bochs_setup();
042                                                   380 
043   sos_x86_videomem_setup();                       381   sos_x86_videomem_setup();
044   sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE);    382   sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE);
045                                                   383 
046   /* Greetings from SOS */                        384   /* Greetings from SOS */
047   if (magic == MULTIBOOT_BOOTLOADER_MAGIC)        385   if (magic == MULTIBOOT_BOOTLOADER_MAGIC)
048     /* Loaded with Grub */                     !! 386     {
049     sos_x86_videomem_printf(1, 0,              !! 387       /* Grub sends us a structure, called multiboot_info_t with a lot of
050                             SOS_X86_VIDEO_FG_Y !! 388          precious informations about the system, see the multiboot
051                             "Welcome From GRUB !! 389          documentation for more information. */
052                             "SOS", ',',        !! 390       multiboot_info_t *mbi = (multiboot_info_t *) arg;
053                             (unsigned)(mbi->me !! 391 
054                             (unsigned)mbi->mem !! 392       /* Multiboot says: "The value returned for upper memory is
                                                   >> 393          maximally the address of the first upper memory hole minus 1
                                                   >> 394          megabyte.". It also adds: "It is not guaranteed to be this
                                                   >> 395          value." aka "YMMV" ;) */
                                                   >> 396       upper_mem = mbi->mem_upper;
                                                   >> 397       sos_x86_videomem_printf(1, 0,
                                                   >> 398                               SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE,
                                                   >> 399                               "Welcome From GRUB to %s%c RAM is %dMB (upper mem = 0x%x kB)",
                                                   >> 400                               "SOS article 8", ',',
                                                   >> 401                               (unsigned)(upper_mem >> 10) + 1,
                                                   >> 402                               (unsigned)upper_mem);
                                                   >> 403     }
                                                   >> 404   else if (magic == 0x42244224)
                                                   >> 405     {
                                                   >> 406       /* Loaded with SOS bootsect */
                                                   >> 407       upper_mem = arg;
                                                   >> 408       sos_x86_videomem_printf(1, 0,
                                                   >> 409                               SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE,
                                                   >> 410                               "Welcome to %s%c RAM is %dMB (upper mem = 0x%x kB)",
                                                   >> 411                               "SOS article 8", ',',
                                                   >> 412                               (unsigned)(upper_mem >> 10) + 1,
                                                   >> 413                               (unsigned)upper_mem);
                                                   >> 414     }
055   else                                            415   else
056     /* Not loaded with grub */                 !! 416     /* Not loaded with grub, not from an enhanced bootsect */
057     sos_x86_videomem_printf(1, 0,                 417     sos_x86_videomem_printf(1, 0,
058                             SOS_X86_VIDEO_FG_Y    418                             SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE,
059                             "Welcome to SOS"); !! 419                             "Welcome to SOS article 8");
060                                                << 
061   sos_bochs_putstring("Message in a bochs\n"); << 
062                                                << 
063                                                   420 
064   /* An operatig system never ends */          !! 421   sos_bochs_putstring("Message in a bochs: This is SOS article 8.\n");
065   for (;;)                                     << 
066     continue;                                  << 
067                                                   422 
068   return;                                      !! 423   /* Setup CPU segmentation and IRQ subsystem */
                                                   >> 424   sos_gdt_subsystem_setup();
                                                   >> 425   sos_idt_subsystem_setup();
                                                   >> 426 
                                                   >> 427   /* Setup SOS IRQs and exceptions subsystem */
                                                   >> 428   sos_exception_subsystem_setup();
                                                   >> 429   sos_irq_subsystem_setup();
                                                   >> 430 
                                                   >> 431   /* Configure the timer so as to raise the IRQ0 at a 100Hz rate */
                                                   >> 432   sos_i8254_set_frequency(100);
                                                   >> 433 
                                                   >> 434   /* Setup the kernel time subsystem to get prepared to take the timer
                                                   >> 435      ticks into account */
                                                   >> 436   tick_resolution = (struct sos_time) { .sec=0, .nanosec=10000000UL };
                                                   >> 437   sos_time_subsysem_setup(& tick_resolution);
                                                   >> 438 
                                                   >> 439   /* We need to know the RAM size */
                                                   >> 440   if (upper_mem == 0)
                                                   >> 441     {
                                                   >> 442       sos_x86_videomem_putstring(20, 0,
                                                   >> 443                                  SOS_X86_VIDEO_FG_LTRED
                                                   >> 444                                    | SOS_X86_VIDEO_BG_BLUE
                                                   >> 445                                    | SOS_X86_VIDEO_FG_BLINKING,
                                                   >> 446                                  "I don't know RAM size ! Load me with Grub...");
                                                   >> 447       /* STOP ! */
                                                   >> 448       for (;;)
                                                   >> 449         continue;
                                                   >> 450     }
                                                   >> 451 
                                                   >> 452   /*
                                                   >> 453    * Some interrupt handlers
                                                   >> 454    */
                                                   >> 455 
                                                   >> 456   /* Binding some HW interrupts and exceptions to software routines */
                                                   >> 457   sos_irq_set_routine(SOS_IRQ_TIMER,
                                                   >> 458                       clk_it);
                                                   >> 459 
                                                   >> 460   /*
                                                   >> 461    * Setup physical memory management
                                                   >> 462    */
                                                   >> 463 
                                                   >> 464   SOS_ASSERT_FATAL(SOS_OK
                                                   >> 465                    == sos_physmem_subsystem_setup((upper_mem<<10) + (1<<20),
                                                   >> 466                                                   &sos_kernel_core_base_paddr,
                                                   >> 467                                                   &sos_kernel_core_top_paddr));
                                                   >> 468   
                                                   >> 469   /*
                                                   >> 470    * Switch to paged-memory mode
                                                   >> 471    */
                                                   >> 472 
                                                   >> 473   /* Disabling interrupts should seem more correct, but it's not really
                                                   >> 474      necessary at this stage */
                                                   >> 475   SOS_ASSERT_FATAL(SOS_OK ==
                                                   >> 476                    sos_paging_subsystem_setup(sos_kernel_core_base_paddr,
                                                   >> 477                                               sos_kernel_core_top_paddr));
                                                   >> 478   
                                                   >> 479   /* Bind the page fault exception */
                                                   >> 480   sos_exception_set_routine(SOS_EXCEPT_PAGE_FAULT,
                                                   >> 481                             pgflt_ex);
                                                   >> 482 
                                                   >> 483   /*
                                                   >> 484    * Setup kernel virtual memory allocator
                                                   >> 485    */
                                                   >> 486 
                                                   >> 487   if (sos_kmem_vmm_subsystem_setup(sos_kernel_core_base_paddr,
                                                   >> 488                                    sos_kernel_core_top_paddr,
                                                   >> 489                                    bootstrap_stack_bottom,
                                                   >> 490                                    bootstrap_stack_bottom
                                                   >> 491                                    + bootstrap_stack_size))
                                                   >> 492     sos_bochs_printf("Could not setup the Kernel virtual space allocator\n");
                                                   >> 493 
                                                   >> 494   if (sos_kmalloc_subsystem_setup())
                                                   >> 495     sos_bochs_printf("Could not setup the Kmalloc subsystem\n");
                                                   >> 496 
                                                   >> 497   /*
                                                   >> 498    * Initialize the MMU context subsystem
                                                   >> 499    */
                                                   >> 500   sos_mm_context_subsystem_setup();
                                                   >> 501 
                                                   >> 502   /*
                                                   >> 503    * Initialize the CPU context subsystem
                                                   >> 504    */
                                                   >> 505   sos_cpu_context_subsystem_setup();
                                                   >> 506 
                                                   >> 507   /*
                                                   >> 508    * Bind the syscall handler to its software interrupt handler
                                                   >> 509    */
                                                   >> 510   sos_swintr_subsystem_setup();
                                                   >> 511 
                                                   >> 512 
                                                   >> 513   /*
                                                   >> 514    * Initialize the Kernel thread and scheduler subsystems
                                                   >> 515    */
                                                   >> 516   
                                                   >> 517   /* Initialize kernel thread subsystem */
                                                   >> 518   sos_thread_subsystem_setup(bootstrap_stack_bottom,
                                                   >> 519                              bootstrap_stack_size);
                                                   >> 520 
                                                   >> 521   /* Initialize the scheduler */
                                                   >> 522   sos_sched_subsystem_setup();
                                                   >> 523 
                                                   >> 524   /* Declare the IDLE thread */
                                                   >> 525   SOS_ASSERT_FATAL(sos_create_kernel_thread("idle", idle_thread, NULL,
                                                   >> 526                                             SOS_SCHED_PRIO_TS_LOWEST) != NULL);
                                                   >> 527 
                                                   >> 528   /* Prepare the stats subsystem */
                                                   >> 529   sos_load_subsystem_setup();
                                                   >> 530 
                                                   >> 531   /* Declare a thread that prints some stats */
                                                   >> 532   SOS_ASSERT_FATAL(sos_create_kernel_thread("stat_thread", stat_thread,
                                                   >> 533                                             NULL,
                                                   >> 534                                             SOS_SCHED_PRIO_TS_LOWEST) != NULL);
                                                   >> 535 
                                                   >> 536 
                                                   >> 537   /*
                                                   >> 538    * Initialise user address space management subsystem
                                                   >> 539    */
                                                   >> 540   sos_umem_vmm_subsystem_setup();
                                                   >> 541   sos_dev_zero_subsystem_setup();
                                                   >> 542 
                                                   >> 543   /*
                                                   >> 544    * Initialize process stuff
                                                   >> 545    */
                                                   >> 546   sos_process_subsystem_setup();
                                                   >> 547 
                                                   >> 548 
                                                   >> 549   /* Enabling the HW interrupts here, this will make the timer HW
                                                   >> 550      interrupt call the scheduler */
                                                   >> 551   asm volatile ("sti\n");
                                                   >> 552 
                                                   >> 553 
                                                   >> 554   SOS_ASSERT_FATAL(SOS_OK == sos_fs_virtfs_subsystem_setup());
                                                   >> 555   SOS_ASSERT_FATAL(SOS_OK == sos_fs_subsystem_setup(NULL,
                                                   >> 556                                                     "virtfs",
                                                   >> 557                                                     NULL,
                                                   >> 558                                                     & rootfs));
                                                   >> 559 
                                                   >> 560 
                                                   >> 561   /* Start the 'init' process, which in turns launches the other
                                                   >> 562      programs */
                                                   >> 563   start_init(rootfs);
                                                   >> 564   /*
                                                   >> 565    * We can safely exit from this function now, for there is already
                                                   >> 566    * an idle Kernel thread ready to make the CPU busy working...
                                                   >> 567    *
                                                   >> 568    * However, we must EXPLICITELY call sos_thread_exit() because a
                                                   >> 569    * simple "return" will return nowhere ! Actually this first thread
                                                   >> 570    * was initialized by the Grub bootstrap stage, at a time when the
                                                   >> 571    * word "thread" did not exist. This means that the stack was not
                                                   >> 572    * setup in order for a return here to call sos_thread_exit()
                                                   >> 573    * automagically. Hence we must call it manually. This is the ONLY
                                                   >> 574    * kernel thread where we must do this manually.
                                                   >> 575    */
                                                   >> 576   sos_bochs_printf("Bye from primary thread !\n");
                                                   >> 577   sos_thread_exit();
                                                   >> 578   SOS_FATAL_ERROR("No trespassing !");
069 }                                                 579 }
                                                      

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