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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 definitions of the multiboot standa 020 /* Include definitions of the multiboot standard */ 020 #include <bootstrap/multiboot.h> 021 #include <bootstrap/multiboot.h> 021 #include <hwcore/idt.h> 022 #include <hwcore/idt.h> 022 #include <hwcore/gdt.h> 023 #include <hwcore/gdt.h> 023 #include <hwcore/irq.h> 024 #include <hwcore/irq.h> 024 #include <hwcore/exception.h> 025 #include <hwcore/exception.h> 025 #include <hwcore/i8254.h> 026 #include <hwcore/i8254.h> 026 #include <sos/list.h> 027 #include <sos/list.h> 027 #include <sos/physmem.h> 028 #include <sos/physmem.h> 028 #include <hwcore/paging.h> 029 #include <hwcore/paging.h> 029 #include <hwcore/mm_context.h> << 030 #include <hwcore/swintr.h> << 031 #include <sos/kmem_vmm.h> 030 #include <sos/kmem_vmm.h> 032 #include <sos/kmalloc.h> 031 #include <sos/kmalloc.h> 033 #include <sos/time.h> << 034 #include <sos/thread.h> << 035 #include <sos/process.h> << 036 #include <sos/umem_vmm.h> << 037 #include <sos/klibc.h> 032 #include <sos/klibc.h> 038 #include <sos/assert.h> 033 #include <sos/assert.h> 039 #include <drivers/x86_videomem.h> 034 #include <drivers/x86_videomem.h> 040 #include <drivers/bochs.h> 035 #include <drivers/bochs.h> 041 #include <sos/calcload.h> << 042 #include <sos/umem_vmm.h> << 043 #include <sos/binfmt_elf32.h> << 044 #include <drivers/zero.h> << 045 036 046 037 047 /* Helper function to display each bits of a 3 038 /* Helper function to display each bits of a 32bits integer on the 048 screen as dark or light carrets */ 039 screen as dark or light carrets */ 049 void display_bits(unsigned char row, unsigned 040 void display_bits(unsigned char row, unsigned char col, 050 unsigned char attribute, 041 unsigned char attribute, 051 sos_ui32_t integer) 042 sos_ui32_t integer) 052 { 043 { 053 int i; 044 int i; 054 /* Scan each bit of the integer, MSb first * 045 /* Scan each bit of the integer, MSb first */ 055 for (i = 31 ; i >= 0 ; i--) 046 for (i = 31 ; i >= 0 ; i--) 056 { 047 { 057 /* Test if bit i of 'integer' is set */ 048 /* Test if bit i of 'integer' is set */ 058 int bit_i = (integer & (1 << i)); 049 int bit_i = (integer & (1 << i)); 059 /* Ascii 219 => dark carret, Ascii 177 = 050 /* Ascii 219 => dark carret, Ascii 177 => light carret */ 060 unsigned char ascii_code = bit_i?219:177 051 unsigned char ascii_code = bit_i?219:177; 061 sos_x86_videomem_putchar(row, col++, 052 sos_x86_videomem_putchar(row, col++, 062 attribute, 053 attribute, 063 ascii_code); 054 ascii_code); 064 } 055 } 065 } 056 } 066 057 067 058 068 /* Clock IRQ handler */ 059 /* Clock IRQ handler */ 069 static void clk_it(int intid) !! 060 static void clk_it(int intid, >> 061 const struct sos_cpu_kstate *cpu_kstate) 070 { 062 { 071 static sos_ui32_t clock_count = 0; 063 static sos_ui32_t clock_count = 0; 072 064 073 display_bits(0, 48, 065 display_bits(0, 48, 074 SOS_X86_VIDEO_FG_LTGREEN | SOS_ 066 SOS_X86_VIDEO_FG_LTGREEN | SOS_X86_VIDEO_BG_BLUE, 075 clock_count); 067 clock_count); 076 clock_count++; 068 clock_count++; 077 << 078 /* Execute the expired timeout actions (if a << 079 sos_time_do_tick(); << 080 << 081 /* Update scheduler statistics and status */ << 082 sos_sched_do_timer_tick(); << 083 } 069 } 084 070 085 071 086 /* =========================================== 072 /* ====================================================================== 087 * Page fault exception handling 073 * Page fault exception handling 088 */ 074 */ 089 075 >> 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 } >> 132 090 133 091 /* Page fault exception handler with demand pa 134 /* Page fault exception handler with demand paging for the kernel */ 092 static void pgflt_ex(int intid, struct sos_cpu !! 135 static void pgflt_ex(int intid, const struct sos_cpu_kstate *ctxt) 093 { 136 { 094 static sos_ui32_t demand_paging_count = 0; 137 static sos_ui32_t demand_paging_count = 0; 095 struct sos_thread * cur_thr = sos_thread_get !! 138 sos_vaddr_t faulting_vaddr = sos_cpu_kstate_get_EX_faulting_vaddr(ctxt); 096 sos_vaddr_t faulting_vaddr = sos_cpu_contex << 097 sos_paddr_t ppage_paddr; 139 sos_paddr_t ppage_paddr; 098 140 099 if (sos_cpu_context_is_in_user_mode(ctxt) << 100 || (cur_thr->fixup_uaccess.return_vaddr) << 101 { << 102 __label__ unforce_address_space; << 103 sos_bool_t need_to_setup_mmu; << 104 sos_ui32_t errcode = sos_cpu_context_get << 105 << 106 /* Make sure to always stay in the inter << 107 configuration */ << 108 need_to_setup_mmu = (cur_thr->squatted_m << 109 != sos_process_get_ << 110 if (need_to_setup_mmu) << 111 sos_thread_prepare_user_space_access(N << 112 << 113 if (SOS_OK == << 114 sos_umem_vmm_try_resolve_page_fault( << 115 << 116 << 117 goto unforce_address_space; << 118 << 119 /* If the page fault occured in kernel m << 120 the fixup address */ << 121 if (! sos_cpu_context_is_in_user_mode(ct << 122 { << 123 cur_thr->fixup_uaccess.faulted_uaddr << 124 sos_cpu_context_set_EX_return_addres << 125 << 126 goto unforce_address_space; << 127 } << 128 << 129 if (need_to_setup_mmu) << 130 sos_thread_end_user_space_access(); << 131 << 132 sos_bochs_printf("Unresolved USER page F << 133 sos_cpu_context_get_PC( << 134 (unsigned)faulting_vadd << 135 (unsigned)sos_cpu_conte << 136 sos_bochs_printf("Terminating User threa << 137 sos_thread_exit(); << 138 << 139 unforce_address_space: << 140 if (need_to_setup_mmu) << 141 sos_thread_end_user_space_access(); << 142 return; << 143 } << 144 << 145 /* Check if address is covered by any VMM ra 141 /* Check if address is covered by any VMM range */ 146 if (! sos_kmem_vmm_is_valid_vaddr(faulting_v 142 if (! sos_kmem_vmm_is_valid_vaddr(faulting_vaddr)) 147 { 143 { 148 /* No: The page fault is out of any kern 144 /* No: The page fault is out of any kernel virtual region. For 149 the moment, we don't handle this. */ 145 the moment, we don't handle this. */ 150 sos_display_fatal_error("Unresolved page !! 146 dump_backtrace(ctxt, 151 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)!", 152 (unsigned)faulti 151 (unsigned)faulting_vaddr, 153 (unsigned)sos_cp !! 152 (unsigned)sos_cpu_kstate_get_EX_info(ctxt)); 154 SOS_ASSERT_FATAL(! "Got page fault (note 153 SOS_ASSERT_FATAL(! "Got page fault (note: demand paging is disabled)"); 155 } 154 } 156 155 157 156 158 /* 157 /* 159 * Demand paging in kernel space !! 158 * Demand paging 160 */ 159 */ 161 160 162 /* Update the number of demand paging reques 161 /* Update the number of demand paging requests handled */ 163 demand_paging_count ++; 162 demand_paging_count ++; 164 display_bits(0, 0, 163 display_bits(0, 0, 165 SOS_X86_VIDEO_FG_LTRED | SOS_X8 164 SOS_X86_VIDEO_FG_LTRED | SOS_X86_VIDEO_BG_BLUE, 166 demand_paging_count); 165 demand_paging_count); 167 166 168 /* Allocate a new page for the virtual addre 167 /* Allocate a new page for the virtual address */ 169 ppage_paddr = sos_physmem_ref_physpage_new(F 168 ppage_paddr = sos_physmem_ref_physpage_new(FALSE); 170 if (! ppage_paddr) 169 if (! ppage_paddr) 171 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 !)"); 172 SOS_ASSERT_FATAL(SOS_OK == sos_paging_map(pp 171 SOS_ASSERT_FATAL(SOS_OK == sos_paging_map(ppage_paddr, 173 SO 172 SOS_PAGE_ALIGN_INF(faulting_vaddr), 174 FA 173 FALSE, 175 SO 174 SOS_VM_MAP_PROT_READ 176 | 175 | SOS_VM_MAP_PROT_WRITE 177 | 176 | SOS_VM_MAP_ATOMIC)); 178 sos_physmem_unref_physpage(ppage_paddr); 177 sos_physmem_unref_physpage(ppage_paddr); 179 178 180 /* Ok, we can now return to interrupted cont 179 /* Ok, we can now return to interrupted context */ 181 } 180 } 182 181 183 182 184 183 185 /* =========================================== 184 /* ====================================================================== 186 * An operating system MUST always have a read !! 185 * Demonstrate the use of the CPU kernet context management API: 187 * 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. 188 */ 191 */ 189 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) 190 { 198 { 191 sos_ui32_t idle_twiddle = 0; !! 199 sos_kfree(stack_vaddr); >> 200 } >> 201 192 202 193 while (1) !! 203 static void exit_hello12(sos_vaddr_t stack_vaddr) >> 204 { >> 205 sos_cpu_kstate_exit_to(ctxt_main, >> 206 (sos_cpu_kstate_function_arg1_t*) reclaim_stack, >> 207 stack_vaddr); >> 208 } >> 209 >> 210 >> 211 static void hello1 (char *str) >> 212 { >> 213 for ( ; *str != '\n' ; str++) 194 { 214 { 195 /* Remove this instruction if you get an !! 215 sos_bochs_printf("hello1: %c\n", *str); 196 exception (old 80386 CPU) */ !! 216 sos_cpu_kstate_switch(& ctxt_hello1, ctxt_hello2); 197 asm("hlt\n"); !! 217 } 198 218 199 idle_twiddle ++; !! 219 /* You can uncomment this in case you explicitly want to exit 200 display_bits(0, 0, SOS_X86_VIDEO_FG_GREE !! 220 now. But returning from the function will do the same */ 201 idle_twiddle); !! 221 /* sos_cpu_kstate_exit_to(ctxt_main, 202 !! 222 (sos_cpu_kstate_function_arg1_t*) reclaim_stack, 203 /* Lend the CPU to some other thread */ !! 223 hello1_stack); */ 204 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); >> 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"); >> 270 } >> 271 >> 272 >> 273 /* ====================================================================== >> 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. >> 277 */ >> 278 static void test_demand_paging(int nb_alloc_vpages, int nb_alloc_ppages) >> 279 { >> 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++) >> 300 { >> 301 /* Compute an address inside the range */ >> 302 sos_ui32_t *value, j; >> 303 sos_vaddr_t vaddr = base_vaddr; >> 304 vaddr += (nb_alloc_vpages - (i + 1))*SOS_PAGE_SIZE; >> 305 vaddr += 2345; >> 306 >> 307 sos_x86_videomem_printf(12, 0, >> 308 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, >> 309 "Writing %d at virtual address 0x%x...", >> 310 i, vaddr); >> 311 >> 312 /* Write at this address */ >> 313 value = (sos_ui32_t*)vaddr; >> 314 *value = i; >> 315 >> 316 /* Yep ! A new page should normally have been allocated for us */ >> 317 sos_x86_videomem_printf(13, 0, >> 318 SOS_X86_VIDEO_BG_BLUE | SOS_X86_VIDEO_FG_YELLOW, >> 319 "Value read at address 0x%x = %d", >> 320 vaddr, (unsigned)*value); 205 } 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)"); 206 } 328 } 207 329 208 330 >> 331 209 /* =========================================== 332 /* ====================================================================== 210 * Kernel thread showing some CPU usage statis !! 333 * Shows how the backtrace stuff works 211 */ 334 */ 212 static void stat_thread() !! 335 >> 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) 213 { 339 { 214 while (1) !! 340 if (i <= 0) 215 { 341 { 216 sos_ui32_t flags; !! 342 /* The page fault exception handler will print the backtrace of 217 sos_ui32_t load1, load5, load15; !! 343 this function, because address 0x42 is not mapped */ 218 char str1[11], str5[11], str15[11]; !! 344 *((char*)0x42) = 12; 219 struct sos_time t; !! 345 220 t.sec = 1; !! 346 /* More direct variant: */ 221 t.nanosec = 0; !! 347 /* dump_backtrace(NULL, stack_bottom, stack_size, TRUE, TRUE); */ 222 << 223 sos_thread_sleep(& t); << 224 << 225 sos_disable_IRQs(flags); << 226 << 227 /* The IDLE task is EXcluded in the foll << 228 sos_load_get_sload(&load1, &load5, &load << 229 sos_load_to_string(str1, load1); << 230 sos_load_to_string(str5, load5); << 231 sos_load_to_string(str15, load15); << 232 sos_x86_videomem_printf(16, 34, << 233 SOS_X86_VIDEO_FG << 234 "Kernel (- Idle) << 235 str1, str5, str1 << 236 << 237 sos_load_get_uload(&load1, &load5, &load << 238 sos_load_to_string(str1, load1); << 239 sos_load_to_string(str5, load5); << 240 sos_load_to_string(str15, load15); << 241 sos_x86_videomem_printf(17, 34, << 242 SOS_X86_VIDEO_FG << 243 "User: %s %s %s << 244 str1, str5, str1 << 245 << 246 sos_load_get_uratio(&load1, &load5, &loa << 247 sos_load_to_string(str1, load1); << 248 sos_load_to_string(str5, load5); << 249 sos_load_to_string(str15, load15); << 250 sos_x86_videomem_printf(18, 34, << 251 SOS_X86_VIDEO_FG << 252 "User CPU %%: %s << 253 str1, str5, str1 << 254 << 255 /* The IDLE task is INcluded in the foll << 256 sos_load_get_sratio(&load1, &load5, &loa << 257 sos_load_to_string(str1, load1); << 258 sos_load_to_string(str5, load5); << 259 sos_load_to_string(str15, load15); << 260 sos_x86_videomem_printf(19, 34, << 261 SOS_X86_VIDEO_FG << 262 "Kernel CPU %% ( << 263 str1, str5, str1 << 264 sos_restore_IRQs(flags); << 265 } 348 } >> 349 else >> 350 test_backtrace(i-1, magic, stack_bottom, stack_size); 266 } 351 } 267 352 268 353 269 /* =========================================== 354 /* ====================================================================== 270 * Start the "init" (userland) process !! 355 * Parsing of Mathematical expressions >> 356 * >> 357 * This is a recursive lexer/parser/evaluator for arithmetical >> 358 * expressions. Supports both binary +/-* and unary +- operators, as >> 359 * well as parentheses. >> 360 * >> 361 * Terminal tokens (Lexer): >> 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 271 */ 447 */ 272 static sos_ret_t start_init() !! 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) 273 { 496 { 274 sos_ret_t retval; !! 497 char c; 275 struct sos_umem_vmm_as *as_init; !! 498 enum { GOT_SPACE, GOT_NUM, GOT_OP, GOT_STR, 276 struct sos_process *proc_init; !! 499 GOT_OPENPAR, GOT_CLOSEPAR } got_what, got_what_before; 277 struct sos_thread *new_thr; !! 500 278 sos_uaddr_t ustack, start_uaddr; !! 501 data_lexer_to_parser.number = 0; 279 !! 502 got_what_before = GOT_SPACE; 280 /* Create the new process */ !! 503 do 281 proc_init = sos_process_create("init", FALSE !! 504 { 282 if (! proc_init) !! 505 /* Consume one character from the reader */ 283 return -SOS_ENOMEM; !! 506 sos_cpu_kstate_switch(& st_lexer, st_reader); 284 as_init = sos_process_get_address_space(proc !! 507 c = data_reader_to_lexer; 285 !! 508 286 /* Map the 'init' program in user space */ !! 509 /* Classify the consumed character */ 287 start_uaddr = sos_binfmt_elf32_map(as_init, !! 510 if ( (c >= '0') && (c <= '9') ) 288 if (0 == start_uaddr) !! 511 got_what = GOT_NUM; 289 { !! 512 else if ( (c == '+') || (c == '-') || (c == '*') || (c == '/') ) 290 sos_process_unref(proc_init); !! 513 got_what = GOT_OP; 291 return -SOS_ENOENT; !! 514 else if ( ( (c >= 'a') && (c <= 'z') ) 292 } !! 515 || ( (c >= 'A') && (c <= 'Z') ) ) 293 !! 516 got_what = GOT_STR; 294 /* Allocate the user stack */ !! 517 else if (c == '(') 295 ustack = (SOS_PAGING_TOP_USER_ADDRESS - SOS_ !! 518 got_what = GOT_OPENPAR; 296 retval = sos_dev_zero_map(as_init, &ustack, !! 519 else if (c == ')') 297 SOS_VM_MAP_PROT_RE !! 520 got_what = GOT_CLOSEPAR; 298 /* PRIVATE */ 0); !! 521 else 299 if (SOS_OK != retval) !! 522 got_what = GOT_SPACE; 300 { !! 523 301 sos_bochs_printf("ici 2\n"); !! 524 /* Determine whether the current token is ended */ 302 sos_process_unref(proc_init); !! 525 if ( (got_what != got_what_before) 303 return -SOS_ENOMEM; !! 526 || (got_what_before == GOT_OP) 304 } !! 527 || (got_what_before == GOT_OPENPAR) 305 !! 528 || (got_what_before == GOT_CLOSEPAR) ) 306 /* Now create the user thread */ !! 529 { 307 new_thr = sos_create_user_thread(NULL, !! 530 /* return control back to the parser if the previous token 308 proc_init, !! 531 has been recognized */ 309 start_uaddr !! 532 if ( (got_what_before != GOT_SPACE) ) 310 0, 0, !! 533 sos_cpu_kstate_switch(& st_lexer, st_parser); 311 ustack + SO !! 534 312 SOS_SCHED_P !! 535 data_lexer_to_parser.number = 0; 313 if (! new_thr) !! 536 } 314 { !! 537 315 sos_bochs_printf("ici 3\n"); !! 538 /* Update the token being currently recognized */ 316 sos_process_unref(proc_init); !! 539 if (got_what == GOT_OP) 317 return -SOS_ENOMEM; !! 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; 318 } 562 } >> 563 while (c != '\0'); 319 564 320 sos_process_unref(proc_init); !! 565 /* Transfer last recognized token to the parser */ 321 return SOS_OK; !! 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 >> 591 { >> 592 char op; >> 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; >> 660 } >> 661 >> 662 /* Raise an exception: transfer control back to main context, >> 663 without unrolling the whole recursion */ >> 664 static void parser_exception(const char *str) >> 665 { >> 666 sos_bochs_printf("Parser exception: %s\n", str); >> 667 sos_cpu_kstate_switch(& st_parser, st_main); >> 668 } >> 669 >> 670 /* Consume the current terminal "number" token and ask for a new >> 671 token */ >> 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]) >> 684 { >> 685 if (data_lexer_to_parser.type != LEX_IS_VAR) >> 686 parser_exception("Expected variable"); >> 687 strzcpy(name, data_lexer_to_parser.var, STR_VAR_MAXLEN); >> 688 sos_cpu_kstate_switch(& st_parser, st_lexer); >> 689 } >> 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); >> 709 } >> 710 >> 711 /* Parse an Expression */ >> 712 static struct syntax_node * get_expr() >> 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() >> 753 { >> 754 if ( (data_lexer_to_parser.type == LEX_IS_OPER) >> 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(); >> 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 } >> 796 >> 797 >> 798 /* >> 799 * Setup the parser's pipeline >> 800 */ >> 801 static struct syntax_node * parse_expression(const char *expr) >> 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) >> 847 { >> 848 switch (n->type) >> 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 */ >> 903 } >> 904 >> 905 >> 906 /* >> 907 * Function BODY >> 908 */ >> 909 /* Update p.result returned back to calling function */ >> 910 parms->result >> 911 = rec_eval(parms->e, parms->var_name, parms->var_val, parms->nb_vars); >> 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) >> 946 { >> 947 case YY_IS_NUM: >> 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; >> 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); >> 975 >> 976 /* Go ! */ >> 977 sos_cpu_kstate_switch(& st_main, st_free); 322 } 978 } 323 979 324 980 325 /* =========================================== 981 /* ====================================================================== 326 * The C entry point of our operating system 982 * The C entry point of our operating system 327 */ 983 */ 328 void sos_main(unsigned long magic, unsigned lo 984 void sos_main(unsigned long magic, unsigned long addr) 329 { 985 { 330 unsigned i; 986 unsigned i; 331 sos_paddr_t sos_kernel_core_base_paddr, sos_ 987 sos_paddr_t sos_kernel_core_base_paddr, sos_kernel_core_top_paddr; 332 struct sos_time tick_resolution; !! 988 struct syntax_node *syntax_tree; 333 989 334 /* Grub sends us a structure, called multibo 990 /* Grub sends us a structure, called multiboot_info_t with a lot of 335 precious informations about the system, s 991 precious informations about the system, see the multiboot 336 documentation for more information. */ 992 documentation for more information. */ 337 multiboot_info_t *mbi; 993 multiboot_info_t *mbi; 338 mbi = (multiboot_info_t *) addr; 994 mbi = (multiboot_info_t *) addr; 339 995 340 /* Setup bochs and console, and clear the co 996 /* Setup bochs and console, and clear the console */ 341 sos_bochs_setup(); 997 sos_bochs_setup(); 342 998 343 sos_x86_videomem_setup(); 999 sos_x86_videomem_setup(); 344 sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); 1000 sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); 345 1001 346 /* Greetings from SOS */ 1002 /* Greetings from SOS */ 347 if (magic == MULTIBOOT_BOOTLOADER_MAGIC) 1003 if (magic == MULTIBOOT_BOOTLOADER_MAGIC) 348 /* Loaded with Grub */ 1004 /* Loaded with Grub */ 349 sos_x86_videomem_printf(1, 0, 1005 sos_x86_videomem_printf(1, 0, 350 SOS_X86_VIDEO_FG_Y 1006 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 351 "Welcome From GRUB 1007 "Welcome From GRUB to %s%c RAM is %dMB (upper mem = 0x%x kB)", 352 "SOS article 7.5", !! 1008 "SOS", ',', 353 (unsigned)(mbi->me 1009 (unsigned)(mbi->mem_upper >> 10) + 1, 354 (unsigned)mbi->mem 1010 (unsigned)mbi->mem_upper); 355 else 1011 else 356 /* Not loaded with grub */ 1012 /* Not loaded with grub */ 357 sos_x86_videomem_printf(1, 0, 1013 sos_x86_videomem_printf(1, 0, 358 SOS_X86_VIDEO_FG_Y 1014 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 359 "Welcome to SOS ar !! 1015 "Welcome to SOS"); 360 1016 361 sos_bochs_putstring("Message in a bochs: Thi !! 1017 sos_bochs_putstring("Message in a bochs\n"); 362 1018 363 /* Setup CPU segmentation and IRQ subsystem 1019 /* Setup CPU segmentation and IRQ subsystem */ 364 sos_gdt_subsystem_setup(); 1020 sos_gdt_subsystem_setup(); 365 sos_idt_subsystem_setup(); 1021 sos_idt_subsystem_setup(); 366 1022 367 /* Setup SOS IRQs and exceptions subsystem * 1023 /* Setup SOS IRQs and exceptions subsystem */ 368 sos_exception_subsystem_setup(); 1024 sos_exception_subsystem_setup(); 369 sos_irq_subsystem_setup(); 1025 sos_irq_subsystem_setup(); 370 1026 371 /* Configure the timer so as to raise the IR 1027 /* Configure the timer so as to raise the IRQ0 at a 100Hz rate */ 372 sos_i8254_set_frequency(100); 1028 sos_i8254_set_frequency(100); 373 1029 374 /* Setup the kernel time subsystem to get pr << 375 ticks into account */ << 376 tick_resolution = (struct sos_time) { .sec=0 << 377 sos_time_subsysem_setup(& tick_resolution); << 378 << 379 /* We need a multiboot-compliant boot loader 1030 /* We need a multiboot-compliant boot loader to get the size of the RAM */ 380 if (magic != MULTIBOOT_BOOTLOADER_MAGIC) 1031 if (magic != MULTIBOOT_BOOTLOADER_MAGIC) 381 { 1032 { 382 sos_x86_videomem_putstring(20, 0, 1033 sos_x86_videomem_putstring(20, 0, 383 SOS_X86_VIDEO 1034 SOS_X86_VIDEO_FG_LTRED 384 | SOS_X86_V 1035 | SOS_X86_VIDEO_BG_BLUE 385 | SOS_X86_V 1036 | SOS_X86_VIDEO_FG_BLINKING, 386 "I'm not load 1037 "I'm not loaded with Grub !"); 387 /* STOP ! */ 1038 /* STOP ! */ 388 for (;;) 1039 for (;;) 389 continue; 1040 continue; 390 } 1041 } 391 1042 392 /* 1043 /* 393 * Some interrupt handlers 1044 * Some interrupt handlers 394 */ 1045 */ 395 1046 396 /* Binding some HW interrupts and exceptions 1047 /* Binding some HW interrupts and exceptions to software routines */ 397 sos_irq_set_routine(SOS_IRQ_TIMER, 1048 sos_irq_set_routine(SOS_IRQ_TIMER, 398 clk_it); 1049 clk_it); 399 1050 400 /* 1051 /* 401 * Setup physical memory management 1052 * Setup physical memory management 402 */ 1053 */ 403 1054 404 /* Multiboot says: "The value returned for u 1055 /* Multiboot says: "The value returned for upper memory is maximally 405 the address of the first upper memory hol 1056 the address of the first upper memory hole minus 1 megabyte.". It 406 also adds: "It is not guaranteed to be th 1057 also adds: "It is not guaranteed to be this value." aka "YMMV" ;) */ 407 sos_physmem_subsystem_setup((mbi->mem_upper< 1058 sos_physmem_subsystem_setup((mbi->mem_upper<<10) + (1<<20), 408 & sos_kernel_cor 1059 & sos_kernel_core_base_paddr, 409 & sos_kernel_cor 1060 & sos_kernel_core_top_paddr); 410 1061 411 /* 1062 /* 412 * Switch to paged-memory mode 1063 * Switch to paged-memory mode 413 */ 1064 */ 414 1065 415 /* Disabling interrupts should seem more cor 1066 /* Disabling interrupts should seem more correct, but it's not really 416 necessary at this stage */ 1067 necessary at this stage */ 417 SOS_ASSERT_FATAL(SOS_OK == 1068 SOS_ASSERT_FATAL(SOS_OK == 418 sos_paging_subsystem_setup( 1069 sos_paging_subsystem_setup(sos_kernel_core_base_paddr, 419 1070 sos_kernel_core_top_paddr)); 420 1071 421 /* Bind the page fault exception */ 1072 /* Bind the page fault exception */ 422 sos_exception_set_routine(SOS_EXCEPT_PAGE_FA 1073 sos_exception_set_routine(SOS_EXCEPT_PAGE_FAULT, 423 pgflt_ex); 1074 pgflt_ex); 424 1075 425 /* 1076 /* 426 * Setup kernel virtual memory allocator 1077 * Setup kernel virtual memory allocator 427 */ !! 1078 */ 428 1079 429 if (sos_kmem_vmm_subsystem_setup(sos_kernel_ 1080 if (sos_kmem_vmm_subsystem_setup(sos_kernel_core_base_paddr, 430 sos_kernel_ 1081 sos_kernel_core_top_paddr, 431 bootstrap_s 1082 bootstrap_stack_bottom, 432 bootstrap_s 1083 bootstrap_stack_bottom 433 + bootstrap 1084 + bootstrap_stack_size)) 434 sos_bochs_printf("Could not setup the Kern 1085 sos_bochs_printf("Could not setup the Kernel virtual space allocator\n"); 435 1086 436 if (sos_kmalloc_subsystem_setup()) 1087 if (sos_kmalloc_subsystem_setup()) 437 sos_bochs_printf("Could not setup the Kmal 1088 sos_bochs_printf("Could not setup the Kmalloc subsystem\n"); 438 1089 439 /* 1090 /* 440 * Initialize the MMU context subsystem !! 1091 * Enabling the HW interrupts here, this will make the timer HW >> 1092 * interrupt call our clk_it handler 441 */ 1093 */ 442 sos_mm_context_subsystem_setup(); !! 1094 asm volatile ("sti\n"); 443 1095 444 /* 1096 /* 445 * Initialize the CPU context subsystem !! 1097 * Print hello world using coroutines 446 */ 1098 */ 447 sos_cpu_context_subsystem_setup(); !! 1099 print_hello_world(); >> 1100 448 1101 449 /* 1102 /* 450 * Bind the syscall handler to its software !! 1103 * Run coroutine tests 451 */ 1104 */ 452 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)"); 453 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 } 454 1136 455 /* 1137 /* 456 * Initialize the Kernel thread and schedule !! 1138 * Run some demand-paging tests 457 */ 1139 */ 458 !! 1140 test_demand_paging(234567, 500); 459 /* Initialize kernel thread subsystem */ << 460 sos_thread_subsystem_setup(bootstrap_stack_b << 461 bootstrap_stack_s << 462 << 463 /* Initialize the scheduler */ << 464 sos_sched_subsystem_setup(); << 465 << 466 /* Declare the IDLE thread */ << 467 SOS_ASSERT_FATAL(sos_create_kernel_thread("i << 468 SO << 469 << 470 /* Prepare the stats subsystem */ << 471 sos_load_subsystem_setup(); << 472 << 473 /* Declare a thread that prints some stats * << 474 SOS_ASSERT_FATAL(sos_create_kernel_thread("s << 475 NU << 476 SO << 477 1141 478 1142 479 /* 1143 /* 480 * Initialise user address space management !! 1144 * Create an un-resolved page fault, which will make the page fault >> 1145 * handler print the backtrace. 481 */ 1146 */ 482 sos_umem_vmm_subsystem_setup(); !! 1147 test_backtrace(6, 0xdeadbeef, bootstrap_stack_bottom, bootstrap_stack_size); 483 sos_dev_zero_subsystem_setup(); << 484 1148 485 /* 1149 /* 486 * Initialize process stuff !! 1150 * System should be halted BEFORE here ! 487 */ 1151 */ 488 sos_process_subsystem_setup(); << 489 1152 490 1153 491 /* Enabling the HW interrupts here, this wil !! 1154 /* An operatig system never ends */ 492 interrupt call the scheduler */ !! 1155 for (;;) 493 asm volatile ("sti\n"); !! 1156 { >> 1157 /* Remove this instruction if you get an "Invalid opcode" CPU >> 1158 exception (old 80386 CPU) */ >> 1159 asm("hlt\n"); 494 1160 495 /* Start the 'init' process, which in turns !! 1161 continue; 496 programs */ !! 1162 } 497 start_init(); << 498 << 499 /* << 500 * We can safely exit from this function now << 501 * an idle Kernel thread ready to make the C << 502 * << 503 * However, we must EXPLICITELY call sos_thr << 504 * simple "return" will return nowhere ! Act << 505 * was initialized by the Grub bootstrap sta << 506 * word "thread" did not exist. This means t << 507 * setup in order for a return here to call << 508 * automagically. Hence we must call it manu << 509 * kernel thread where we must do this manua << 510 */ << 511 sos_bochs_printf("Bye from primary thread !\ << 512 sos_thread_exit(); << 513 SOS_FATAL_ERROR("No trespassing !"); << 514 } 1163 }
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