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001 /* Copyright (C) 2004 The SOS Team 001 /* Copyright (C) 2004 The SOS Team >> 002 Copyright (C) 1999 Free Software Foundation, Inc. 002 003 003 This program is free software; you can redi 004 This program is free software; you can redistribute it and/or 004 modify it under the terms of the GNU Genera 005 modify it under the terms of the GNU General Public License 005 as published by the Free Software Foundatio 006 as published by the Free Software Foundation; either version 2 006 of the License, or (at your option) any lat 007 of the License, or (at your option) any later version. 007 008 008 This program is distributed in the hope tha 009 This program is distributed in the hope that it will be useful, 009 but WITHOUT ANY WARRANTY; without even the 010 but WITHOUT ANY WARRANTY; without even the implied warranty of 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR 011 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 011 GNU General Public License for more details 012 GNU General Public License for more details. 012 013 013 You should have received a copy of the GNU 014 You should have received a copy of the GNU General Public License 014 along with this program; if not, write to t 015 along with this program; if not, write to the Free Software 015 Foundation, Inc., 59 Temple Place - Suite 3 016 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 016 USA. 017 USA. 017 */ 018 */ 018 019 019 #include <sos/errno.h> << 020 << 021 /* Include definitions of the multiboot standa 020 /* Include definitions of the multiboot standard */ 022 #include <bootstrap/multiboot.h> 021 #include <bootstrap/multiboot.h> 023 #include <hwcore/idt.h> 022 #include <hwcore/idt.h> 024 #include <hwcore/gdt.h> 023 #include <hwcore/gdt.h> 025 #include <hwcore/irq.h> 024 #include <hwcore/irq.h> 026 #include <hwcore/exception.h> 025 #include <hwcore/exception.h> 027 #include <hwcore/i8254.h> 026 #include <hwcore/i8254.h> 028 #include <sos/list.h> 027 #include <sos/list.h> 029 #include <sos/physmem.h> 028 #include <sos/physmem.h> 030 #include <hwcore/paging.h> 029 #include <hwcore/paging.h> 031 #include <hwcore/mm_context.h> << 032 #include <hwcore/swintr.h> << 033 #include <sos/kmem_vmm.h> 030 #include <sos/kmem_vmm.h> 034 #include <sos/kmalloc.h> 031 #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> << 039 #include <sos/klibc.h> 032 #include <sos/klibc.h> 040 #include <sos/assert.h> 033 #include <sos/assert.h> 041 #include <drivers/x86_videomem.h> 034 #include <drivers/x86_videomem.h> 042 #include <drivers/bochs.h> 035 #include <drivers/bochs.h> 043 #include <sos/calcload.h> !! 036 044 #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> << 049 037 050 /* Helper function to display each bits of a 3 038 /* Helper function to display each bits of a 32bits integer on the 051 screen as dark or light carrets */ 039 screen as dark or light carrets */ 052 void display_bits(unsigned char row, unsigned 040 void display_bits(unsigned char row, unsigned char col, 053 unsigned char attribute, 041 unsigned char attribute, 054 sos_ui32_t integer) 042 sos_ui32_t integer) 055 { 043 { 056 int i; 044 int i; 057 /* Scan each bit of the integer, MSb first * 045 /* Scan each bit of the integer, MSb first */ 058 for (i = 31 ; i >= 0 ; i--) 046 for (i = 31 ; i >= 0 ; i--) 059 { 047 { 060 /* Test if bit i of 'integer' is set */ 048 /* Test if bit i of 'integer' is set */ 061 int bit_i = (integer & (1 << i)); 049 int bit_i = (integer & (1 << i)); 062 /* Ascii 219 => dark carret, Ascii 177 = 050 /* Ascii 219 => dark carret, Ascii 177 => light carret */ 063 unsigned char ascii_code = bit_i?219:177 051 unsigned char ascii_code = bit_i?219:177; 064 sos_x86_videomem_putchar(row, col++, 052 sos_x86_videomem_putchar(row, col++, 065 attribute, 053 attribute, 066 ascii_code); 054 ascii_code); 067 } 055 } 068 } 056 } 069 057 >> 058 070 /* Clock IRQ handler */ 059 /* Clock IRQ handler */ 071 static void clk_it(int intid) !! 060 static void clk_it(int intid, >> 061 const struct sos_cpu_kstate *cpu_kstate) 072 { 062 { 073 static sos_ui32_t clock_count = 0; 063 static sos_ui32_t clock_count = 0; 074 064 075 display_bits(0, 48, 065 display_bits(0, 48, 076 SOS_X86_VIDEO_FG_LTGREEN | SOS_ 066 SOS_X86_VIDEO_FG_LTGREEN | SOS_X86_VIDEO_BG_BLUE, 077 clock_count); 067 clock_count); 078 clock_count++; 068 clock_count++; 079 << 080 /* Execute the expired timeout actions (if a << 081 sos_time_do_tick(); << 082 << 083 /* Update scheduler statistics and status */ << 084 sos_sched_do_timer_tick(); << 085 } 069 } 086 070 087 071 088 /* =========================================== 072 /* ====================================================================== 089 * Page fault exception handling 073 * Page fault exception handling 090 */ 074 */ 091 075 >> 076 /* Helper function to dump a backtrace on bochs and/or the console */ >> 077 static void dump_backtrace(const struct sos_cpu_kstate *cpu_kstate, >> 078 sos_vaddr_t stack_bottom, >> 079 sos_size_t stack_size, >> 080 sos_bool_t on_console, >> 081 sos_bool_t on_bochs) >> 082 { >> 083 static void backtracer(sos_vaddr_t PC, >> 084 sos_vaddr_t params, >> 085 sos_ui32_t depth, >> 086 void *custom_arg) >> 087 { >> 088 sos_ui32_t invalid = 0xffffffff, *arg1, *arg2, *arg3, *arg4; >> 089 >> 090 /* Get the address of the first 3 arguments from the >> 091 frame. Among these arguments, 0, 1, 2, 3 arguments might be >> 092 meaningful (depending on how many arguments the function may >> 093 take). */ >> 094 arg1 = (sos_ui32_t*)params; >> 095 arg2 = (sos_ui32_t*)(params+4); >> 096 arg3 = (sos_ui32_t*)(params+8); >> 097 arg4 = (sos_ui32_t*)(params+12); >> 098 >> 099 /* Make sure the addresses of these arguments fit inside the >> 100 stack boundaries */ >> 101 #define INTERVAL_OK(b,v,u) ( ((b) <= (sos_vaddr_t)(v)) \ >> 102 && ((sos_vaddr_t)(v) < (u)) ) >> 103 if (!INTERVAL_OK(stack_bottom, arg1, stack_bottom + stack_size)) >> 104 arg1 = &invalid; >> 105 if (!INTERVAL_OK(stack_bottom, arg2, stack_bottom + stack_size)) >> 106 arg2 = &invalid; >> 107 if (!INTERVAL_OK(stack_bottom, arg3, stack_bottom + stack_size)) >> 108 arg3 = &invalid; >> 109 if (!INTERVAL_OK(stack_bottom, arg4, stack_bottom + stack_size)) >> 110 arg4 = &invalid; >> 111 >> 112 /* Print the function context for this frame */ >> 113 if (on_bochs) >> 114 sos_bochs_printf("[%d] PC=0x%x arg1=0x%x arg2=0x%x arg3=0x%x\n", >> 115 (unsigned)depth, (unsigned)PC, >> 116 (unsigned)*arg1, (unsigned)*arg2, >> 117 (unsigned)*arg3); >> 118 >> 119 if (on_console) >> 120 sos_x86_videomem_printf(23-depth, 3, >> 121 SOS_X86_VIDEO_BG_BLUE >> 122 | SOS_X86_VIDEO_FG_LTGREEN, >> 123 "[%d] PC=0x%x arg1=0x%x arg2=0x%x arg3=0x%x arg4=0x%x", >> 124 (unsigned)depth, PC, >> 125 (unsigned)*arg1, (unsigned)*arg2, >> 126 (unsigned)*arg3, (unsigned)*arg4); >> 127 >> 128 } >> 129 >> 130 sos_backtrace(cpu_kstate, 15, stack_bottom, stack_size, backtracer, NULL); >> 131 } >> 132 092 133 093 /* Page fault exception handler with demand pa 134 /* Page fault exception handler with demand paging for the kernel */ 094 static void pgflt_ex(int intid, struct sos_cpu !! 135 static void pgflt_ex(int intid, const struct sos_cpu_kstate *ctxt) 095 { 136 { 096 static sos_ui32_t demand_paging_count = 0; 137 static sos_ui32_t demand_paging_count = 0; 097 struct sos_thread * cur_thr = sos_thread_get !! 138 sos_vaddr_t faulting_vaddr = sos_cpu_kstate_get_EX_faulting_vaddr(ctxt); 098 sos_vaddr_t faulting_vaddr = sos_cpu_contex << 099 sos_paddr_t ppage_paddr; 139 sos_paddr_t ppage_paddr; 100 140 101 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 << 107 << 108 /* Make sure to always stay in the inter << 109 configuration */ << 110 need_to_setup_mmu = (cur_thr->squatted_m << 111 != sos_process_get_ << 112 if (need_to_setup_mmu) << 113 sos_thread_prepare_user_space_access(N << 114 << 115 if (SOS_OK == << 116 sos_umem_vmm_try_resolve_page_fault( << 117 << 118 << 119 goto unforce_address_space; << 120 << 121 /* If the page fault occured in kernel m << 122 the fixup address */ << 123 if (! sos_cpu_context_is_in_user_mode(ct << 124 { << 125 cur_thr->fixup_uaccess.faulted_uaddr << 126 sos_cpu_context_set_EX_return_addres << 127 << 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 F << 135 sos_cpu_context_get_PC( << 136 (unsigned)faulting_vadd << 137 (unsigned)sos_cpu_conte << 138 sos_bochs_printf("Terminating User threa << 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 ra 141 /* Check if address is covered by any VMM range */ 148 if (! sos_kmem_vmm_is_valid_vaddr(faulting_v 142 if (! sos_kmem_vmm_is_valid_vaddr(faulting_vaddr)) 149 { 143 { 150 /* No: The page fault is out of any kern 144 /* No: The page fault is out of any kernel virtual region. For 151 the moment, we don't handle this. */ 145 the moment, we don't handle this. */ 152 sos_display_fatal_error("Unresolved page !! 146 dump_backtrace(ctxt, 153 sos_cpu_context_ !! 147 bootstrap_stack_bottom, >> 148 bootstrap_stack_size, >> 149 TRUE, TRUE); >> 150 sos_display_fatal_error("Unresolved page Fault on access to address 0x%x (info=%x)!", 154 (unsigned)faulti 151 (unsigned)faulting_vaddr, 155 (unsigned)sos_cp !! 152 (unsigned)sos_cpu_kstate_get_EX_info(ctxt)); 156 SOS_ASSERT_FATAL(! "Got page fault (note 153 SOS_ASSERT_FATAL(! "Got page fault (note: demand paging is disabled)"); 157 } 154 } 158 155 159 156 160 /* 157 /* 161 * Demand paging in kernel space !! 158 * Demand paging 162 */ 159 */ 163 160 164 /* Update the number of demand paging reques 161 /* Update the number of demand paging requests handled */ 165 demand_paging_count ++; 162 demand_paging_count ++; 166 display_bits(0, 0, 163 display_bits(0, 0, 167 SOS_X86_VIDEO_FG_LTRED | SOS_X8 164 SOS_X86_VIDEO_FG_LTRED | SOS_X86_VIDEO_BG_BLUE, 168 demand_paging_count); 165 demand_paging_count); 169 166 170 /* Allocate a new page for the virtual addre 167 /* Allocate a new page for the virtual address */ 171 ppage_paddr = sos_physmem_ref_physpage_new(F 168 ppage_paddr = sos_physmem_ref_physpage_new(FALSE); 172 if (! ppage_paddr) 169 if (! ppage_paddr) 173 SOS_ASSERT_FATAL(! "TODO: implement swap. 170 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(pp 171 SOS_ASSERT_FATAL(SOS_OK == sos_paging_map(ppage_paddr, 175 SO 172 SOS_PAGE_ALIGN_INF(faulting_vaddr), 176 FA 173 FALSE, 177 SO 174 SOS_VM_MAP_PROT_READ 178 | 175 | SOS_VM_MAP_PROT_WRITE 179 | 176 | SOS_VM_MAP_ATOMIC)); 180 sos_physmem_unref_physpage(ppage_paddr); 177 sos_physmem_unref_physpage(ppage_paddr); 181 178 182 /* Ok, we can now return to interrupted cont 179 /* Ok, we can now return to interrupted context */ 183 } 180 } 184 181 185 182 186 183 187 /* =========================================== 184 /* ====================================================================== 188 * An operating system MUST always have a read !! 185 * Demonstrate the use of the CPU kernet context management API: 189 * what would the CPU have to execute ?! !! 186 * - A coroutine prints "Hlowrd" and switches to the other after each >> 187 * letter >> 188 * - A coroutine prints "el ol\n" and switches back to the other after >> 189 * each letter. >> 190 * The first to reach the '\n' returns back to main. 190 */ 191 */ 191 static void idle_thread() !! 192 struct sos_cpu_kstate *ctxt_hello1; >> 193 struct sos_cpu_kstate *ctxt_hello2; >> 194 struct sos_cpu_kstate *ctxt_main; >> 195 sos_vaddr_t hello1_stack, hello2_stack; >> 196 >> 197 static void reclaim_stack(sos_vaddr_t stack_vaddr) >> 198 { >> 199 sos_kfree(stack_vaddr); >> 200 } >> 201 >> 202 >> 203 static void exit_hello12(sos_vaddr_t stack_vaddr) 192 { 204 { 193 sos_ui32_t idle_twiddle = 0; !! 205 sos_cpu_kstate_exit_to(ctxt_main, >> 206 (sos_cpu_kstate_function_arg1_t*) reclaim_stack, >> 207 stack_vaddr); >> 208 } 194 209 195 while (1) !! 210 >> 211 static void hello1 (char *str) >> 212 { >> 213 for ( ; *str != '\n' ; str++) 196 { 214 { 197 /* Remove this instruction if you get an !! 215 sos_bochs_printf("hello1: %c\n", *str); 198 exception (old 80386 CPU) */ !! 216 sos_cpu_kstate_switch(& ctxt_hello1, ctxt_hello2); 199 asm("hlt\n"); !! 217 } 200 218 201 idle_twiddle ++; !! 219 /* You can uncomment this in case you explicitly want to exit 202 display_bits(0, 0, SOS_X86_VIDEO_FG_GREE !! 220 now. But returning from the function will do the same */ 203 idle_twiddle); !! 221 /* sos_cpu_kstate_exit_to(ctxt_main, 204 !! 222 (sos_cpu_kstate_function_arg1_t*) reclaim_stack, 205 /* Lend the CPU to some other thread */ !! 223 hello1_stack); */ 206 sos_thread_yield(); !! 224 } >> 225 >> 226 >> 227 static void hello2 (char *str) >> 228 { >> 229 for ( ; *str != '\n' ; str++) >> 230 { >> 231 sos_bochs_printf("hello2: %c\n", *str); >> 232 sos_cpu_kstate_switch(& ctxt_hello2, ctxt_hello1); 207 } 233 } >> 234 >> 235 /* You can uncomment this in case you explicitly want to exit >> 236 now. But returning from the function will do the same */ >> 237 /* sos_cpu_kstate_exit_to(ctxt_main, >> 238 (sos_cpu_kstate_function_arg1_t*) reclaim_stack, >> 239 hello2_stack); */ >> 240 } >> 241 >> 242 >> 243 void print_hello_world () >> 244 { >> 245 #define DEMO_STACK_SIZE 1024 >> 246 /* Allocate the stacks */ >> 247 hello1_stack = sos_kmalloc(DEMO_STACK_SIZE, 0); >> 248 hello2_stack = sos_kmalloc(DEMO_STACK_SIZE, 0); >> 249 >> 250 /* Initialize the coroutines' contexts */ >> 251 sos_cpu_kstate_init(&ctxt_hello1, >> 252 (sos_cpu_kstate_function_arg1_t*) hello1, >> 253 (sos_ui32_t) "Hlowrd", >> 254 (sos_vaddr_t) hello1_stack, DEMO_STACK_SIZE, >> 255 (sos_cpu_kstate_function_arg1_t*) exit_hello12, >> 256 (sos_ui32_t) hello1_stack); >> 257 sos_cpu_kstate_init(&ctxt_hello2, >> 258 (sos_cpu_kstate_function_arg1_t*) hello2, >> 259 (sos_ui32_t) "el ol\n", >> 260 (sos_vaddr_t) hello2_stack, DEMO_STACK_SIZE, >> 261 (sos_cpu_kstate_function_arg1_t*) exit_hello12, >> 262 (sos_ui32_t) hello2_stack); >> 263 >> 264 /* Go to first coroutine */ >> 265 sos_bochs_printf("Printing Hello World\\n...\n"); >> 266 sos_cpu_kstate_switch(& ctxt_main, ctxt_hello1); >> 267 >> 268 /* The first coroutine to reach the '\n' switched back to us */ >> 269 sos_bochs_printf("Back in main !\n"); 208 } 270 } 209 271 210 272 211 /* =========================================== 273 /* ====================================================================== 212 * Kernel thread showing some CPU usage statis !! 274 * Generate page faults on an unmapped but allocated kernel virtual >> 275 * region, which results in a series of physical memory mappings for the >> 276 * faulted pages. 213 */ 277 */ 214 static void stat_thread() !! 278 static void test_demand_paging(int nb_alloc_vpages, int nb_alloc_ppages) 215 { 279 { 216 while (1) !! 280 int i; >> 281 sos_vaddr_t base_vaddr; >> 282 >> 283 sos_x86_videomem_printf(10, 0, >> 284 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_LTGREEN, >> 285 "Demand paging test (alloc %dMB of VMM, test %dkB RAM)", >> 286 nb_alloc_vpages >> 8, nb_alloc_ppages << 2); >> 287 >> 288 /* Allocate virtual memory */ >> 289 base_vaddr = sos_kmem_vmm_alloc(nb_alloc_vpages, 0); >> 290 >> 291 SOS_ASSERT_FATAL(base_vaddr != (sos_vaddr_t)NULL); >> 292 sos_x86_videomem_printf(11, 0, >> 293 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, >> 294 "Allocated virtual region [0x%x, 0x%x[", >> 295 base_vaddr, >> 296 base_vaddr + nb_alloc_vpages*SOS_PAGE_SIZE); >> 297 >> 298 /* Now use part of it in physical memory */ >> 299 for (i = 0 ; (i < nb_alloc_ppages) && (i < nb_alloc_vpages) ; i++) 217 { 300 { 218 sos_ui32_t flags; !! 301 /* Compute an address inside the range */ 219 sos_ui32_t load1, load5, load15; !! 302 sos_ui32_t *value, j; 220 char str1[11], str5[11], str15[11]; !! 303 sos_vaddr_t vaddr = base_vaddr; 221 struct sos_time t; !! 304 vaddr += (nb_alloc_vpages - (i + 1))*SOS_PAGE_SIZE; 222 t.sec = 1; !! 305 vaddr += 2345; 223 t.nanosec = 0; !! 306 224 !! 307 sos_x86_videomem_printf(12, 0, 225 sos_thread_sleep(& t); !! 308 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, 226 !! 309 "Writing %d at virtual address 0x%x...", 227 sos_disable_IRQs(flags); !! 310 i, vaddr); 228 !! 311 229 /* The IDLE task is EXcluded in the foll !! 312 /* Write at this address */ 230 sos_load_get_sload(&load1, &load5, &load !! 313 value = (sos_ui32_t*)vaddr; 231 sos_load_to_string(str1, load1); !! 314 *value = i; 232 sos_load_to_string(str5, load5); !! 315 233 sos_load_to_string(str15, load15); !! 316 /* Yep ! A new page should normally have been allocated for us */ 234 sos_x86_videomem_printf(16, 34, !! 317 sos_x86_videomem_printf(13, 0, 235 SOS_X86_VIDEO_FG !! 318 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, 236 "Kernel (- Idle) !! 319 "Value read at address 0x%x = %d", 237 str1, str5, str1 !! 320 vaddr, (unsigned)*value); 238 << 239 sos_load_get_uload(&load1, &load5, &load << 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 << 245 "User: %s %s %s << 246 str1, str5, str1 << 247 << 248 sos_load_get_uratio(&load1, &load5, &loa << 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 << 254 "User CPU %%: %s << 255 str1, str5, str1 << 256 << 257 /* The IDLE task is INcluded in the foll << 258 sos_load_get_sratio(&load1, &load5, &loa << 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 << 264 "Kernel CPU %% ( << 265 str1, str5, str1 << 266 sos_restore_IRQs(flags); << 267 } 321 } >> 322 >> 323 SOS_ASSERT_FATAL(SOS_OK == sos_kmem_vmm_free(base_vaddr)); >> 324 /* Yep ! A new page should normally have been allocated for us */ >> 325 sos_x86_videomem_printf(14, 0, >> 326 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, >> 327 "Done (area un-allocated)"); 268 } 328 } 269 329 270 330 >> 331 271 /* =========================================== 332 /* ====================================================================== 272 * Start the "init" (userland) process !! 333 * Shows how the backtrace stuff works 273 */ 334 */ 274 static sos_ret_t !! 335 275 start_init(struct sos_fs_manager_instance * ro !! 336 /* Recursive function. Print the backtrace from the innermost function */ >> 337 static void test_backtrace(int i, int magic, sos_vaddr_t stack_bottom, >> 338 sos_size_t stack_size) 276 { 339 { 277 sos_ret_t retval; !! 340 if (i <= 0) 278 struct sos_umem_vmm_as *as_init; !! 341 { 279 struct sos_process *proc_init; !! 342 /* The page fault exception handler will print the backtrace of 280 struct sos_thread *new_thr; !! 343 this function, because address 0x42 is not mapped */ 281 sos_uaddr_t ustack, start_uaddr; !! 344 *((char*)0x42) = 12; 282 struct sos_fs_opened_file * init_root, * ini << 283 345 284 /* Create the new process */ !! 346 /* More direct variant: */ 285 proc_init = sos_process_create("init", FALSE !! 347 /* dump_backtrace(NULL, stack_bottom, stack_size, TRUE, TRUE); */ 286 if (! proc_init) !! 348 } 287 return -SOS_ENOMEM; !! 349 else 288 as_init = sos_process_get_address_space(proc !! 350 test_backtrace(i-1, magic, stack_bottom, stack_size); >> 351 } 289 352 290 353 291 /* !! 354 /* ====================================================================== 292 * Setup the root and CWD directories of the !! 355 * Parsing of Mathematical expressions 293 * this process will correspond to the "glob !! 356 * 294 * system since all the future processes wil !! 357 * This is a recursive lexer/parser/evaluator for arithmetical 295 */ !! 358 * expressions. Supports both binary +/-* and unary +- operators, as 296 retval = sos_fs_new_opened_file(proc_init, r !! 359 * well as parentheses. 297 SOS_FS_OPEN_ !! 360 * 298 & init_root) !! 361 * Terminal tokens (Lexer): 299 if (SOS_OK != retval) !! 362 * - Number: positive integer number >> 363 * - Variable: ascii name (regexp: [a-zA-Z]+) >> 364 * - Operator: +*-/ >> 365 * - Opening/closing parentheses >> 366 * >> 367 * Grammar (Parser): >> 368 * Expression ::= Term E' >> 369 * Expr_lr ::= + Term Expr_lr | - Term Expr_lr | Nothing >> 370 * Term ::= Factor Term_lr >> 371 * Term_lr ::= * Factor Term_lr | / Factor Term_lr | Nothing >> 372 * Factor ::= - Factor | + Factor | Scalar | ( Expression ) >> 373 * Scalar ::= Number | Variable >> 374 * >> 375 * Note. This is the left-recursive equivalent of the following basic grammar: >> 376 * Expression ::= Expression + Term | Expression - Term >> 377 * Term ::= Term * Factor | Term / Factor >> 378 * factor ::= - Factor | + Factor | Scalar | Variable | ( Expression ) >> 379 * Scalar ::= Number | Variable >> 380 * >> 381 * The parsing is composed of a 3 stages pipeline: >> 382 * - The reader: reads a string 1 character at a time, transferring >> 383 * the control back to lexer after each char. This function shows the >> 384 * interest in using coroutines, because its state (str) is >> 385 * implicitely stored in the stack between each iteration. >> 386 * - The lexer: consumes the characters from the reader and identifies >> 387 * the terminal tokens, 1 token at a time, transferring control back >> 388 * to the parser after each token. This function shows the interest >> 389 * in using coroutines, because its state (c and got_what_before) is >> 390 * implicitely stored in the stack between each iteration. >> 391 * - The parser: consumes the tokens from the lexer and builds the >> 392 * syntax tree of the expression. There is no real algorithmic >> 393 * interest in defining a coroutine devoted to do this. HOWEVER, we >> 394 * do use one for that because this allows us to switch to a much >> 395 * deeper stack. Actually, the parser is highly recursive, so that >> 396 * the default 16kB stack of the sos_main() function might not be >> 397 * enough. Here, we switch to a 64kB stack, which is safer for >> 398 * recursive functions. The Parser uses intermediary functions: these >> 399 * are defined and implemented as internal nested functions. This is >> 400 * just for the sake of clarity, and is absolutely not mandatory for >> 401 * the algorithm: one can transfer these functions out of the parser >> 402 * function without restriction. >> 403 * >> 404 * The evaluator is another recursive function that reuses the >> 405 * parser's stack to evaluate the parsed expression with the given >> 406 * values for the variables present in the expression. As for the >> 407 * parser function, this function defines and uses a nested function, >> 408 * which can be extracted from the main evaluation function at will. >> 409 * >> 410 * All these functions support a kind of "exception" feature: when >> 411 * something goes wrong, control is transferred DIRECTLY back to the >> 412 * sos_main() context, without unrolling the recursions. This shows >> 413 * how exceptions basically work, but one should not consider this as >> 414 * a reference exceptions implementation. Real exception mechanisms >> 415 * (such as that in the C++ language) call the destructors to the >> 416 * objects allocated on the stack during the "stack unwinding" process >> 417 * upon exception handling, which complicates a lot the mechanism. We >> 418 * don't have real Objects here (in the OOP sense, full-featured with >> 419 * destructors), so we don't have to complicate things. >> 420 * >> 421 * After this little coroutine demo, one should forget all about such >> 422 * a low-level manual direct manipulation of stacks. This would >> 423 * probably mess up the whole kernel to do what we do here (locked >> 424 * resources such as mutex/semaphore won't be correctly unlocked, >> 425 * ...). Higher level "kernel thread" primitives will soon be >> 426 * presented, which provide a higher-level set of APIs to manage CPU >> 427 * contexts. You'll have to use EXCLUSIVELY those APIs. If you still >> 428 * need a huge stack to do recursion for example, please don't even >> 429 * think of changing manually the stack for something bigger ! Simply >> 430 * rethink your algorithm, making it non-recursive. >> 431 */ >> 432 >> 433 >> 434 /* The stacks involved */ >> 435 static char stack_reader[1024]; >> 436 static char stack_lexer[1024]; >> 437 static char deep_stack[65536]; /* For the parser and the evaluator */ >> 438 >> 439 /* The CPU states for the various coroutines */ >> 440 static struct sos_cpu_kstate *st_reader, *st_lexer, *st_parser, >> 441 *st_eval, *st_free, *st_main; >> 442 >> 443 >> 444 /* >> 445 * Default exit/reclaim functions: return control to the "sos_main()" >> 446 * context >> 447 */ >> 448 static void reclaim(int unused) >> 449 { >> 450 } >> 451 static void func_exit(sos_ui32_t unused) >> 452 { >> 453 sos_cpu_kstate_exit_to(st_main, (sos_cpu_kstate_function_arg1_t*)reclaim, 0); >> 454 } >> 455 >> 456 >> 457 /* >> 458 * The reader coroutine and associated variable. This coroutine could >> 459 * have been a normal function, except that the current parsed >> 460 * character would have to be stored somewhere. >> 461 */ >> 462 static char data_reader_to_lexer; >> 463 >> 464 static void func_reader(const char *str) >> 465 { >> 466 for ( ; str && (*str != '\0') ; str++) >> 467 { >> 468 data_reader_to_lexer = *str; >> 469 sos_cpu_kstate_switch(& st_reader, st_lexer); >> 470 } >> 471 >> 472 data_reader_to_lexer = '\0'; >> 473 sos_cpu_kstate_switch(& st_reader, st_lexer); >> 474 } >> 475 >> 476 >> 477 /* >> 478 * The Lexer coroutine and associated types/variables. This coroutine >> 479 * could have been a normal function, except that the current parsed >> 480 * character, token and previous token would have to be stored >> 481 * somewhere. >> 482 */ >> 483 #define STR_VAR_MAXLEN 16 >> 484 static struct lex_elem >> 485 { >> 486 enum { LEX_IS_NUMBER, LEX_IS_OPER, LEX_IS_VAR, >> 487 LEX_IS_OPENPAR, LEX_IS_CLOSEPAR, LEX_END } type; >> 488 union { >> 489 int number; >> 490 char operator; >> 491 char var[STR_VAR_MAXLEN]; >> 492 }; >> 493 } data_lexer_to_parser; >> 494 >> 495 static void func_lexer(sos_ui32_t unused) >> 496 { >> 497 char c; >> 498 enum { GOT_SPACE, GOT_NUM, GOT_OP, GOT_STR, >> 499 GOT_OPENPAR, GOT_CLOSEPAR } got_what, got_what_before; >> 500 >> 501 data_lexer_to_parser.number = 0; >> 502 got_what_before = GOT_SPACE; >> 503 do >> 504 { >> 505 /* Consume one character from the reader */ >> 506 sos_cpu_kstate_switch(& st_lexer, st_reader); >> 507 c = data_reader_to_lexer; >> 508 >> 509 /* Classify the consumed character */ >> 510 if ( (c >= '0') && (c <= '9') ) >> 511 got_what = GOT_NUM; >> 512 else if ( (c == '+') || (c == '-') || (c == '*') || (c == '/') ) >> 513 got_what = GOT_OP; >> 514 else if ( ( (c >= 'a') && (c <= 'z') ) >> 515 || ( (c >= 'A') && (c <= 'Z') ) ) >> 516 got_what = GOT_STR; >> 517 else if (c == '(') >> 518 got_what = GOT_OPENPAR; >> 519 else if (c == ')') >> 520 got_what = GOT_CLOSEPAR; >> 521 else >> 522 got_what = GOT_SPACE; >> 523 >> 524 /* Determine whether the current token is ended */ >> 525 if ( (got_what != got_what_before) >> 526 || (got_what_before == GOT_OP) >> 527 || (got_what_before == GOT_OPENPAR) >> 528 || (got_what_before == GOT_CLOSEPAR) ) >> 529 { >> 530 /* return control back to the parser if the previous token >> 531 has been recognized */ >> 532 if ( (got_what_before != GOT_SPACE) ) >> 533 sos_cpu_kstate_switch(& st_lexer, st_parser); >> 534 >> 535 data_lexer_to_parser.number = 0; >> 536 } >> 537 >> 538 /* Update the token being currently recognized */ >> 539 if (got_what == GOT_OP) >> 540 { >> 541 data_lexer_to_parser.type = LEX_IS_OPER; >> 542 data_lexer_to_parser.operator = c; >> 543 } >> 544 else if (got_what == GOT_NUM) >> 545 { >> 546 data_lexer_to_parser.type = LEX_IS_NUMBER; >> 547 data_lexer_to_parser.number *= 10; >> 548 data_lexer_to_parser.number += (c - '0'); >> 549 } >> 550 else if (got_what == GOT_STR) >> 551 { >> 552 char to_cat[] = { c, '\0' }; >> 553 data_lexer_to_parser.type = LEX_IS_VAR; >> 554 strzcat(data_lexer_to_parser.var, to_cat, STR_VAR_MAXLEN); >> 555 } >> 556 else if (got_what == GOT_OPENPAR) >> 557 data_lexer_to_parser.type = LEX_IS_OPENPAR; >> 558 else if (got_what == GOT_CLOSEPAR) >> 559 data_lexer_to_parser.type = LEX_IS_CLOSEPAR; >> 560 >> 561 got_what_before = got_what; >> 562 } >> 563 while (c != '\0'); >> 564 >> 565 /* Transfer last recognized token to the parser */ >> 566 if ( (got_what_before != GOT_SPACE) ) >> 567 sos_cpu_kstate_switch(& st_lexer, st_parser); >> 568 >> 569 /* Signal that no more token are available */ >> 570 data_lexer_to_parser.type = LEX_END; >> 571 sos_cpu_kstate_switch(& st_lexer, st_parser); >> 572 >> 573 /* Exception: parser asks for a token AFTER having received the last >> 574 one */ >> 575 sos_bochs_printf("Error: end of string already reached !\n"); >> 576 sos_cpu_kstate_switch(& st_lexer, st_main); >> 577 } >> 578 >> 579 >> 580 /* >> 581 * The Parser coroutine and associated types/variables >> 582 */ >> 583 struct syntax_node >> 584 { >> 585 enum { YY_IS_BINOP, YY_IS_UNAROP, YY_IS_NUM, YY_IS_VAR } type; >> 586 union >> 587 { >> 588 int number; >> 589 char var[STR_VAR_MAXLEN]; >> 590 struct 300 { 591 { 301 sos_process_unref(proc_init); !! 592 char op; 302 return -SOS_ENOENT; !! 593 struct syntax_node *parm_left, *parm_right; >> 594 } binop; >> 595 struct >> 596 { >> 597 char op; >> 598 struct syntax_node *parm; >> 599 } unarop; >> 600 }; >> 601 }; >> 602 >> 603 static void func_parser(struct syntax_node ** syntax_tree) >> 604 { >> 605 static struct syntax_node *alloc_node_num(int val); >> 606 static struct syntax_node *alloc_node_var(const char * name); >> 607 static struct syntax_node *alloc_node_binop(char op, >> 608 struct syntax_node *parm_left, >> 609 struct syntax_node *parm_right); >> 610 static struct syntax_node *alloc_node_unarop(char op, >> 611 struct syntax_node *parm); >> 612 static struct syntax_node * get_expr(); >> 613 static struct syntax_node * get_expr_lr(struct syntax_node *n); >> 614 static struct syntax_node * get_term(); >> 615 static struct syntax_node * get_term_lr(struct syntax_node *n); >> 616 static struct syntax_node * get_factor(); >> 617 static struct syntax_node * get_scalar(); >> 618 >> 619 /* Create a new node to store a number */ >> 620 static struct syntax_node *alloc_node_num(int val) >> 621 { >> 622 struct syntax_node *n >> 623 = (struct syntax_node*) sos_kmalloc(sizeof(struct syntax_node), 0); >> 624 n->type = YY_IS_NUM; >> 625 n->number = val; >> 626 return n; >> 627 } >> 628 /* Create a new node to store a variable */ >> 629 static struct syntax_node *alloc_node_var(const char * name) >> 630 { >> 631 struct syntax_node *n >> 632 = (struct syntax_node*) sos_kmalloc(sizeof(struct syntax_node), 0); >> 633 n->type = YY_IS_VAR; >> 634 strzcpy(n->var, name, STR_VAR_MAXLEN); >> 635 return n; >> 636 } >> 637 /* Create a new node to store a binary operator */ >> 638 static struct syntax_node *alloc_node_binop(char op, >> 639 struct syntax_node *parm_left, >> 640 struct syntax_node *parm_right) >> 641 { >> 642 struct syntax_node *n >> 643 = (struct syntax_node*) sos_kmalloc(sizeof(struct syntax_node), 0); >> 644 n->type = YY_IS_BINOP; >> 645 n->binop.op = op; >> 646 n->binop.parm_left = parm_left; >> 647 n->binop.parm_right = parm_right; >> 648 return n; >> 649 } >> 650 /* Create a new node to store a unary operator */ >> 651 static struct syntax_node *alloc_node_unarop(char op, >> 652 struct syntax_node *parm) >> 653 { >> 654 struct syntax_node *n >> 655 = (struct syntax_node*) sos_kmalloc(sizeof(struct syntax_node), 0); >> 656 n->type = YY_IS_UNAROP; >> 657 n->unarop.op = op; >> 658 n->unarop.parm = parm; >> 659 return n; 303 } 660 } 304 661 305 /* Duplicate the root file to set the curren !! 662 /* Raise an exception: transfer control back to main context, 306 the init process */ !! 663 without unrolling the whole recursion */ 307 retval = sos_fs_duplicate_opened_file(init_r !! 664 static void parser_exception(const char *str) 308 & init << 309 if (SOS_OK != retval) << 310 { 665 { 311 sos_fs_close(init_root); !! 666 sos_bochs_printf("Parser exception: %s\n", str); 312 sos_process_unref(proc_init); !! 667 sos_cpu_kstate_switch(& st_parser, st_main); 313 return -SOS_ENOENT; << 314 } 668 } 315 669 316 /* Now update the process ! */ !! 670 /* Consume the current terminal "number" token and ask for a new 317 if ( ( SOS_OK != sos_process_chroot(proc_ini !! 671 token */ 318 || ( SOS_OK != sos_process_chdir(proc_i !! 672 static int get_number() >> 673 { >> 674 int v; >> 675 if (data_lexer_to_parser.type != LEX_IS_NUMBER) >> 676 parser_exception("Expected number"); >> 677 v = data_lexer_to_parser.number; >> 678 sos_cpu_kstate_switch(& st_parser, st_lexer); >> 679 return v; >> 680 } >> 681 /* Consume the current terminal "variable" token and ask for a new >> 682 token */ >> 683 static void get_str(char name[STR_VAR_MAXLEN]) 319 { 684 { 320 sos_fs_close(init_root); !! 685 if (data_lexer_to_parser.type != LEX_IS_VAR) 321 sos_fs_close(init_cwd); !! 686 parser_exception("Expected variable"); 322 sos_process_chroot(proc_init, NULL, & un !! 687 strzcpy(name, data_lexer_to_parser.var, STR_VAR_MAXLEN); 323 sos_process_chdir(proc_init, NULL, & unu !! 688 sos_cpu_kstate_switch(& st_parser, st_lexer); 324 sos_process_unref(proc_init); !! 689 } 325 return -SOS_ENOENT; !! 690 /* Consume the current terminal "operator" token and ask for a new >> 691 token */ >> 692 static char get_op() >> 693 { >> 694 char op; >> 695 if (data_lexer_to_parser.type != LEX_IS_OPER) >> 696 parser_exception("Expected operator"); >> 697 op = data_lexer_to_parser.operator; >> 698 sos_cpu_kstate_switch(& st_parser, st_lexer); >> 699 return op; >> 700 } >> 701 /* Consume the current terminal "parenthese" token and ask for a new >> 702 token */ >> 703 static void get_par() >> 704 { >> 705 if ( (data_lexer_to_parser.type != LEX_IS_OPENPAR) >> 706 && (data_lexer_to_parser.type != LEX_IS_CLOSEPAR) ) >> 707 parser_exception("Expected parenthese"); >> 708 sos_cpu_kstate_switch(& st_parser, st_lexer); 326 } 709 } 327 710 328 /* Map the 'init' program in user space */ !! 711 /* Parse an Expression */ 329 start_uaddr = sos_binfmt_elf32_map(as_init, !! 712 static struct syntax_node * get_expr() 330 if (0 == start_uaddr) !! 713 { >> 714 struct syntax_node *t = get_term(); >> 715 return get_expr_lr(t); >> 716 } >> 717 /* Parse an Expr_lr */ >> 718 static struct syntax_node * get_expr_lr(struct syntax_node *n) >> 719 { >> 720 if ( (data_lexer_to_parser.type == LEX_IS_OPER) >> 721 && ( (data_lexer_to_parser.operator == '+') >> 722 || (data_lexer_to_parser.operator == '-') ) ) >> 723 { >> 724 char op = get_op(); >> 725 struct syntax_node *term = get_term(); >> 726 struct syntax_node *node_op = alloc_node_binop(op, n, term); >> 727 return get_expr_lr(node_op); >> 728 } >> 729 return n; >> 730 } >> 731 /* Parse a Term */ >> 732 static struct syntax_node * get_term() >> 733 { >> 734 struct syntax_node *f1 = get_factor(); >> 735 return get_term_lr(f1); >> 736 } >> 737 /* Parse a Term_lr */ >> 738 static struct syntax_node * get_term_lr(struct syntax_node *n) >> 739 { >> 740 if ( (data_lexer_to_parser.type == LEX_IS_OPER) >> 741 && ( (data_lexer_to_parser.operator == '*') >> 742 || (data_lexer_to_parser.operator == '/') ) ) >> 743 { >> 744 char op = get_op(); >> 745 struct syntax_node *factor = get_factor(); >> 746 struct syntax_node *node_op = alloc_node_binop(op, n, factor); >> 747 return get_term_lr(node_op); >> 748 } >> 749 return n; >> 750 } >> 751 /* Parse a Factor */ >> 752 static struct syntax_node * get_factor() 331 { 753 { 332 sos_process_unref(proc_init); !! 754 if ( (data_lexer_to_parser.type == LEX_IS_OPER) 333 return -SOS_ENOENT; !! 755 && ( (data_lexer_to_parser.operator == '-') >> 756 || (data_lexer_to_parser.operator == '+') ) ) >> 757 { char op = data_lexer_to_parser.operator; >> 758 get_op(); return alloc_node_unarop(op, get_factor()); } >> 759 else if (data_lexer_to_parser.type == LEX_IS_OPENPAR) >> 760 { >> 761 struct syntax_node *expr; >> 762 get_par(); >> 763 expr = get_expr(); >> 764 if (data_lexer_to_parser.type != LEX_IS_CLOSEPAR) >> 765 parser_exception("Mismatched parentheses"); >> 766 get_par(); >> 767 return expr; >> 768 } >> 769 >> 770 return get_scalar(); 334 } 771 } >> 772 /* Parse a Scalar */ >> 773 static struct syntax_node * get_scalar() >> 774 { >> 775 if (data_lexer_to_parser.type != LEX_IS_NUMBER) >> 776 { >> 777 char var[STR_VAR_MAXLEN]; >> 778 get_str(var); >> 779 return alloc_node_var(var); >> 780 } >> 781 return alloc_node_num(get_number()); >> 782 } >> 783 >> 784 >> 785 /* >> 786 * Body of the function >> 787 */ >> 788 >> 789 /* Get the first token */ >> 790 sos_cpu_kstate_switch(& st_parser, st_lexer); >> 791 >> 792 /* Begin the parsing ! */ >> 793 *syntax_tree = get_expr(); >> 794 /* The result is returned in the syntax_tree parameter */ >> 795 } 335 796 336 /* Allocate the user stack */ !! 797 337 ustack = (SOS_PAGING_TOP_USER_ADDRESS - SOS_ !! 798 /* 338 retval = sos_dev_zero_map(as_init, &ustack, !! 799 * Setup the parser's pipeline 339 SOS_VM_MAP_PROT_RE !! 800 */ 340 /* PRIVATE */ 0); !! 801 static struct syntax_node * parse_expression(const char *expr) 341 if (SOS_OK != retval) !! 802 { >> 803 struct syntax_node *retval = NULL; >> 804 >> 805 /* Build the context of the functions in the pipeline */ >> 806 sos_cpu_kstate_init(& st_reader, >> 807 (sos_cpu_kstate_function_arg1_t*)func_reader, >> 808 (sos_ui32_t)expr, >> 809 (sos_vaddr_t)stack_reader, sizeof(stack_reader), >> 810 (sos_cpu_kstate_function_arg1_t*)func_exit, 0); >> 811 sos_cpu_kstate_init(& st_lexer, >> 812 (sos_cpu_kstate_function_arg1_t*)func_lexer, >> 813 0, >> 814 (sos_vaddr_t)stack_lexer, sizeof(stack_lexer), >> 815 (sos_cpu_kstate_function_arg1_t*)func_exit, 0); >> 816 sos_cpu_kstate_init(& st_parser, >> 817 (sos_cpu_kstate_function_arg1_t*)func_parser, >> 818 (sos_ui32_t) /* syntax tree ! */&retval, >> 819 (sos_vaddr_t)deep_stack, sizeof(deep_stack), >> 820 (sos_cpu_kstate_function_arg1_t*)func_exit, 0); >> 821 >> 822 /* Parse the expression */ >> 823 sos_cpu_kstate_switch(& st_main, st_parser); >> 824 return retval; >> 825 } >> 826 >> 827 >> 828 /* >> 829 * The Evaluator coroutine and associated types/variables >> 830 */ >> 831 struct func_eval_params >> 832 { >> 833 const struct syntax_node *e; >> 834 const char **var_name; >> 835 int *var_val; >> 836 int nb_vars; >> 837 >> 838 int result; >> 839 }; >> 840 >> 841 static void func_eval(struct func_eval_params *parms) >> 842 { >> 843 /* The internal (recursive) nested function to evaluate each node of >> 844 the syntax tree */ >> 845 static int rec_eval(const struct syntax_node *n, >> 846 const char* var_name[], int var_val[], int nb_vars) 342 { 847 { 343 sos_process_unref(proc_init); !! 848 switch (n->type) 344 return -SOS_ENOMEM; !! 849 { >> 850 case YY_IS_NUM: >> 851 return n->number; >> 852 >> 853 case YY_IS_VAR: >> 854 { >> 855 int i; >> 856 for (i = 0 ; i < nb_vars ; i++) >> 857 if (0 == strcmp(var_name[i], n->var)) >> 858 return var_val[i]; >> 859 >> 860 /* Exception: no variable with that name ! */ >> 861 sos_bochs_printf("ERROR: unknown variable %s\n", n->var); >> 862 sos_cpu_kstate_switch(& st_eval, st_main); >> 863 } >> 864 >> 865 case YY_IS_BINOP: >> 866 { >> 867 int left = rec_eval(n->binop.parm_left, >> 868 var_name, var_val, nb_vars); >> 869 int right = rec_eval(n->binop.parm_right, >> 870 var_name, var_val, nb_vars); >> 871 switch (n->binop.op) >> 872 { >> 873 case '+': return left + right; >> 874 case '-': return left - right; >> 875 case '*': return left * right; >> 876 case '/': return left / right; >> 877 default: >> 878 /* Exception: no such operator (INTERNAL error) ! */ >> 879 sos_bochs_printf("ERROR: unknown binop %c\n", n->binop.op); >> 880 sos_cpu_kstate_switch(& st_eval, st_main); >> 881 } >> 882 } >> 883 >> 884 case YY_IS_UNAROP: >> 885 { >> 886 int arg = rec_eval(n->unarop.parm, var_name, var_val, nb_vars); >> 887 switch (n->unarop.op) >> 888 { >> 889 case '-': return -arg; >> 890 case '+': return arg; >> 891 default: >> 892 /* Exception: no such operator (INTERNAL error) ! */ >> 893 sos_bochs_printf("ERROR: unknown unarop %c\n", n->unarop.op); >> 894 sos_cpu_kstate_switch(& st_eval, st_main); >> 895 } >> 896 } >> 897 } >> 898 >> 899 /* Exception: no such syntax node (INTERNAL error) ! */ >> 900 sos_bochs_printf("ERROR: invalid node type\n"); >> 901 sos_cpu_kstate_switch(& st_eval, st_main); >> 902 return -1; /* let's make gcc happy */ 345 } 903 } 346 904 347 /* Now create the user thread */ !! 905 348 new_thr = sos_create_user_thread(NULL, !! 906 /* 349 proc_init, !! 907 * Function BODY 350 start_uaddr !! 908 */ 351 0, 0, !! 909 /* Update p.result returned back to calling function */ 352 ustack + SO !! 910 parms->result 353 SOS_SCHED_P !! 911 = rec_eval(parms->e, parms->var_name, parms->var_val, parms->nb_vars); 354 if (! new_thr) !! 912 } >> 913 >> 914 /* >> 915 * Change the stack for something larger in order to call the >> 916 * recursive function above in a safe way >> 917 */ >> 918 static int eval_expression(const struct syntax_node *e, >> 919 const char* var_name[], int var_val[], int nb_vars) >> 920 { >> 921 struct func_eval_params p >> 922 = (struct func_eval_params){ .e=e, >> 923 .var_name=var_name, >> 924 .var_val=var_val, >> 925 .nb_vars=nb_vars, >> 926 .result = 0 }; >> 927 >> 928 sos_cpu_kstate_init(& st_eval, >> 929 (sos_cpu_kstate_function_arg1_t*)func_eval, >> 930 (sos_ui32_t)/* p.result is modified upon success */&p, >> 931 (sos_vaddr_t)deep_stack, sizeof(deep_stack), >> 932 (sos_cpu_kstate_function_arg1_t*)func_exit, 0); >> 933 >> 934 /* Go ! */ >> 935 sos_cpu_kstate_switch(& st_main, st_eval); >> 936 return p.result; >> 937 } >> 938 >> 939 >> 940 /* >> 941 * Function to free the syntax tree >> 942 */ >> 943 static void func_free(struct syntax_node *n) >> 944 { >> 945 switch (n->type) 355 { 946 { 356 sos_process_unref(proc_init); !! 947 case YY_IS_NUM: 357 return -SOS_ENOMEM; !! 948 case YY_IS_VAR: >> 949 break; >> 950 >> 951 case YY_IS_BINOP: >> 952 func_free(n->binop.parm_left); >> 953 func_free(n->binop.parm_right); >> 954 break; >> 955 >> 956 case YY_IS_UNAROP: >> 957 func_free(n->unarop.parm); >> 958 break; 358 } 959 } >> 960 >> 961 sos_kfree((sos_vaddr_t)n); >> 962 } >> 963 >> 964 /* >> 965 * Change the stack for something larger in order to call the >> 966 * recursive function above in a safe way >> 967 */ >> 968 static void free_syntax_tree(struct syntax_node *tree) >> 969 { >> 970 sos_cpu_kstate_init(& st_free, >> 971 (sos_cpu_kstate_function_arg1_t*)func_free, >> 972 (sos_ui32_t)tree, >> 973 (sos_vaddr_t)deep_stack, sizeof(deep_stack), >> 974 (sos_cpu_kstate_function_arg1_t*)func_exit, 0); 359 975 360 sos_process_unref(proc_init); !! 976 /* Go ! */ 361 return SOS_OK; !! 977 sos_cpu_kstate_switch(& st_main, st_free); 362 } 978 } 363 979 364 980 365 /* =========================================== 981 /* ====================================================================== 366 * The C entry point of our operating system 982 * The C entry point of our operating system 367 */ 983 */ 368 void sos_main(unsigned long magic, unsigned lo !! 984 void sos_main(unsigned long magic, unsigned long addr) 369 { 985 { 370 unsigned i; 986 unsigned i; 371 sos_paddr_t sos_kernel_core_base_paddr, sos_ 987 sos_paddr_t sos_kernel_core_base_paddr, sos_kernel_core_top_paddr; 372 struct sos_time tick_resolution; !! 988 struct syntax_node *syntax_tree; 373 struct sos_fs_manager_instance * rootfs; << 374 989 375 /* Size of RAM above 1MB. Might be undefined !! 990 /* Grub sends us a structure, called multiboot_info_t with a lot of 376 unsigned long int upper_mem = 0; !! 991 precious informations about the system, see the multiboot >> 992 documentation for more information. */ >> 993 multiboot_info_t *mbi; >> 994 mbi = (multiboot_info_t *) addr; 377 995 378 /* Setup bochs and console, and clear the co 996 /* Setup bochs and console, and clear the console */ 379 sos_bochs_setup(); 997 sos_bochs_setup(); 380 998 381 sos_x86_videomem_setup(); 999 sos_x86_videomem_setup(); 382 sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); 1000 sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); 383 1001 384 /* Greetings from SOS */ 1002 /* Greetings from SOS */ 385 if (magic == MULTIBOOT_BOOTLOADER_MAGIC) 1003 if (magic == MULTIBOOT_BOOTLOADER_MAGIC) 386 { !! 1004 /* Loaded with Grub */ 387 /* Grub sends us a structure, called mul !! 1005 sos_x86_videomem_printf(1, 0, 388 precious informations about the syste !! 1006 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 389 documentation for more information. * !! 1007 "Welcome From GRUB to %s%c RAM is %dMB (upper mem = 0x%x kB)", 390 multiboot_info_t *mbi = (multiboot_info_ !! 1008 "SOS", ',', 391 !! 1009 (unsigned)(mbi->mem_upper >> 10) + 1, 392 /* Multiboot says: "The value returned f !! 1010 (unsigned)mbi->mem_upper); 393 maximally the address of the first up << 394 megabyte.". It also adds: "It is not << 395 value." aka "YMMV" ;) */ << 396 upper_mem = mbi->mem_upper; << 397 sos_x86_videomem_printf(1, 0, << 398 SOS_X86_VIDEO_FG << 399 "Welcome From GR << 400 "SOS article 8", << 401 (unsigned)(upper << 402 (unsigned)upper_ << 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 << 410 "Welcome to %s%c << 411 "SOS article 8", << 412 (unsigned)(upper << 413 (unsigned)upper_ << 414 } << 415 else 1011 else 416 /* Not loaded with grub, not from an enhan !! 1012 /* Not loaded with grub */ 417 sos_x86_videomem_printf(1, 0, 1013 sos_x86_videomem_printf(1, 0, 418 SOS_X86_VIDEO_FG_Y 1014 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 419 "Welcome to SOS ar !! 1015 "Welcome to SOS"); 420 1016 421 sos_bochs_putstring("Message in a bochs: Thi !! 1017 sos_bochs_putstring("Message in a bochs\n"); 422 1018 423 /* Setup CPU segmentation and IRQ subsystem 1019 /* Setup CPU segmentation and IRQ subsystem */ 424 sos_gdt_subsystem_setup(); 1020 sos_gdt_subsystem_setup(); 425 sos_idt_subsystem_setup(); 1021 sos_idt_subsystem_setup(); 426 1022 427 /* Setup SOS IRQs and exceptions subsystem * 1023 /* Setup SOS IRQs and exceptions subsystem */ 428 sos_exception_subsystem_setup(); 1024 sos_exception_subsystem_setup(); 429 sos_irq_subsystem_setup(); 1025 sos_irq_subsystem_setup(); 430 1026 431 /* Configure the timer so as to raise the IR 1027 /* Configure the timer so as to raise the IRQ0 at a 100Hz rate */ 432 sos_i8254_set_frequency(100); 1028 sos_i8254_set_frequency(100); 433 1029 434 /* Setup the kernel time subsystem to get pr !! 1030 /* We need a multiboot-compliant boot loader to get the size of the RAM */ 435 ticks into account */ !! 1031 if (magic != MULTIBOOT_BOOTLOADER_MAGIC) 436 tick_resolution = (struct sos_time) { .sec=0 << 437 sos_time_subsysem_setup(& tick_resolution); << 438 << 439 /* We need to know the RAM size */ << 440 if (upper_mem == 0) << 441 { 1032 { 442 sos_x86_videomem_putstring(20, 0, 1033 sos_x86_videomem_putstring(20, 0, 443 SOS_X86_VIDEO 1034 SOS_X86_VIDEO_FG_LTRED 444 | SOS_X86_V 1035 | SOS_X86_VIDEO_BG_BLUE 445 | SOS_X86_V 1036 | SOS_X86_VIDEO_FG_BLINKING, 446 "I don't know !! 1037 "I'm not loaded with Grub !"); 447 /* STOP ! */ 1038 /* STOP ! */ 448 for (;;) 1039 for (;;) 449 continue; 1040 continue; 450 } 1041 } 451 1042 452 /* 1043 /* 453 * Some interrupt handlers 1044 * Some interrupt handlers 454 */ 1045 */ 455 1046 456 /* Binding some HW interrupts and exceptions 1047 /* Binding some HW interrupts and exceptions to software routines */ 457 sos_irq_set_routine(SOS_IRQ_TIMER, 1048 sos_irq_set_routine(SOS_IRQ_TIMER, 458 clk_it); 1049 clk_it); 459 1050 460 /* 1051 /* 461 * Setup physical memory management 1052 * Setup physical memory management 462 */ 1053 */ 463 1054 464 SOS_ASSERT_FATAL(SOS_OK !! 1055 /* Multiboot says: "The value returned for upper memory is maximally 465 == sos_physmem_subsystem_se !! 1056 the address of the first upper memory hole minus 1 megabyte.". It 466 !! 1057 also adds: "It is not guaranteed to be this value." aka "YMMV" ;) */ 467 !! 1058 sos_physmem_subsystem_setup((mbi->mem_upper<<10) + (1<<20), >> 1059 & sos_kernel_core_base_paddr, >> 1060 & sos_kernel_core_top_paddr); 468 1061 469 /* 1062 /* 470 * Switch to paged-memory mode 1063 * Switch to paged-memory mode 471 */ 1064 */ 472 1065 473 /* Disabling interrupts should seem more cor 1066 /* Disabling interrupts should seem more correct, but it's not really 474 necessary at this stage */ 1067 necessary at this stage */ 475 SOS_ASSERT_FATAL(SOS_OK == 1068 SOS_ASSERT_FATAL(SOS_OK == 476 sos_paging_subsystem_setup( 1069 sos_paging_subsystem_setup(sos_kernel_core_base_paddr, 477 1070 sos_kernel_core_top_paddr)); 478 1071 479 /* Bind the page fault exception */ 1072 /* Bind the page fault exception */ 480 sos_exception_set_routine(SOS_EXCEPT_PAGE_FA 1073 sos_exception_set_routine(SOS_EXCEPT_PAGE_FAULT, 481 pgflt_ex); 1074 pgflt_ex); 482 1075 483 /* 1076 /* 484 * Setup kernel virtual memory allocator 1077 * Setup kernel virtual memory allocator 485 */ !! 1078 */ 486 1079 487 if (sos_kmem_vmm_subsystem_setup(sos_kernel_ 1080 if (sos_kmem_vmm_subsystem_setup(sos_kernel_core_base_paddr, 488 sos_kernel_ 1081 sos_kernel_core_top_paddr, 489 bootstrap_s 1082 bootstrap_stack_bottom, 490 bootstrap_s 1083 bootstrap_stack_bottom 491 + bootstrap 1084 + bootstrap_stack_size)) 492 sos_bochs_printf("Could not setup the Kern 1085 sos_bochs_printf("Could not setup the Kernel virtual space allocator\n"); 493 1086 494 if (sos_kmalloc_subsystem_setup()) 1087 if (sos_kmalloc_subsystem_setup()) 495 sos_bochs_printf("Could not setup the Kmal 1088 sos_bochs_printf("Could not setup the Kmalloc subsystem\n"); 496 1089 497 /* 1090 /* 498 * Initialize the MMU context subsystem !! 1091 * Enabling the HW interrupts here, this will make the timer HW >> 1092 * interrupt call our clk_it handler 499 */ 1093 */ 500 sos_mm_context_subsystem_setup(); !! 1094 asm volatile ("sti\n"); 501 1095 502 /* 1096 /* 503 * Initialize the CPU context subsystem !! 1097 * Print hello world using coroutines 504 */ 1098 */ 505 sos_cpu_context_subsystem_setup(); !! 1099 print_hello_world(); >> 1100 506 1101 507 /* 1102 /* 508 * Bind the syscall handler to its software !! 1103 * Run coroutine tests 509 */ 1104 */ 510 sos_swintr_subsystem_setup(); !! 1105 sos_x86_videomem_printf(4, 0, >> 1106 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_LTGREEN, >> 1107 "Coroutine test"); >> 1108 sos_x86_videomem_printf(5, 0, >> 1109 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, >> 1110 "Parsing..."); >> 1111 syntax_tree = parse_expression(" - ( (69/ toto)+ ( (( - +-- 1))) + --toto*((toto+ - - y - +2*(y-toto))*y) +2*(y-toto) )/- (( y - toto)*2)"); 511 1112 >> 1113 if (syntax_tree != NULL) >> 1114 { >> 1115 sos_x86_videomem_printf(6, 0, >> 1116 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, >> 1117 "Evaluating..."); >> 1118 sos_x86_videomem_printf(7, 0, >> 1119 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, >> 1120 "Result=%d (if 0: check bochs output)", >> 1121 eval_expression(syntax_tree, >> 1122 (const char*[]){"toto", "y"}, >> 1123 (int[]){3, 4}, >> 1124 2)); >> 1125 free_syntax_tree(syntax_tree); >> 1126 sos_x86_videomem_printf(8, 0, >> 1127 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, >> 1128 "Done (un-allocated syntax tree)"); >> 1129 } >> 1130 else >> 1131 { >> 1132 sos_x86_videomem_printf(6, 0, >> 1133 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, >> 1134 "Error in parsing (see bochs output)"); >> 1135 } 512 1136 513 /* 1137 /* 514 * Initialize the Kernel thread and schedule !! 1138 * Run some demand-paging tests 515 */ 1139 */ 516 !! 1140 test_demand_paging(234567, 500); 517 /* Initialize kernel thread subsystem */ << 518 sos_thread_subsystem_setup(bootstrap_stack_b << 519 bootstrap_stack_s << 520 << 521 /* Initialize the scheduler */ << 522 sos_sched_subsystem_setup(); << 523 << 524 /* Declare the IDLE thread */ << 525 SOS_ASSERT_FATAL(sos_create_kernel_thread("i << 526 SO << 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("s << 533 NU << 534 SO << 535 1141 536 1142 537 /* 1143 /* 538 * Initialise user address space management !! 1144 * Create an un-resolved page fault, which will make the page fault >> 1145 * handler print the backtrace. 539 */ 1146 */ 540 sos_umem_vmm_subsystem_setup(); !! 1147 test_backtrace(6, 0xdeadbeef, bootstrap_stack_bottom, bootstrap_stack_size); 541 sos_dev_zero_subsystem_setup(); << 542 1148 543 /* 1149 /* 544 * Initialize process stuff !! 1150 * System should be halted BEFORE here ! 545 */ 1151 */ 546 sos_process_subsystem_setup(); << 547 << 548 1152 549 /* Enabling the HW interrupts here, this wil << 550 interrupt call the scheduler */ << 551 asm volatile ("sti\n"); << 552 1153 >> 1154 /* An operatig system never ends */ >> 1155 for (;;) >> 1156 { >> 1157 /* Remove this instruction if you get an "Invalid opcode" CPU >> 1158 exception (old 80386 CPU) */ >> 1159 asm("hlt\n"); 553 1160 554 SOS_ASSERT_FATAL(SOS_OK == sos_fs_virtfs_sub !! 1161 continue; 555 SOS_ASSERT_FATAL(SOS_OK == sos_fs_subsystem_ !! 1162 } 556 << 557 << 558 << 559 << 560 << 561 /* Start the 'init' process, which in turns << 562 programs */ << 563 start_init(rootfs); << 564 /* << 565 * We can safely exit from this function now << 566 * an idle Kernel thread ready to make the C << 567 * << 568 * However, we must EXPLICITELY call sos_thr << 569 * simple "return" will return nowhere ! Act << 570 * was initialized by the Grub bootstrap sta << 571 * word "thread" did not exist. This means t << 572 * setup in order for a return here to call << 573 * automagically. Hence we must call it manu << 574 * kernel thread where we must do this manua << 575 */ << 576 sos_bochs_printf("Bye from primary thread !\ << 577 sos_thread_exit(); << 578 SOS_FATAL_ERROR("No trespassing !"); << 579 } 1163 }
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