Navigation
- Accueil
- Présentation :
- FAQ
- Bugs et errata
- Contributions de lecteurs
- Téléchargements
- LXR (référencement des sources)
- Mailing-list
- Liens et Projets reliés
Site hébergé par :
Site hébergé par :
|
[ source navigation ] [ diff markup ] [ identifier search ] [ general search ] |
|||
|
||||
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 <sos/kmem_vmm.h> 030 #include <sos/kmem_vmm.h> 030 #include <sos/kmalloc.h> 031 #include <sos/kmalloc.h> 031 #include <sos/time.h> << 032 #include <sos/thread.h> << 033 #include <sos/klibc.h> 032 #include <sos/klibc.h> 034 #include <sos/assert.h> 033 #include <sos/assert.h> 035 #include <drivers/x86_videomem.h> 034 #include <drivers/x86_videomem.h> 036 #include <drivers/bochs.h> 035 #include <drivers/bochs.h> 037 036 038 037 039 /* Helper function to display each bits of a 3 038 /* Helper function to display each bits of a 32bits integer on the 040 screen as dark or light carrets */ 039 screen as dark or light carrets */ 041 void display_bits(unsigned char row, unsigned 040 void display_bits(unsigned char row, unsigned char col, 042 unsigned char attribute, 041 unsigned char attribute, 043 sos_ui32_t integer) 042 sos_ui32_t integer) 044 { 043 { 045 int i; 044 int i; 046 /* Scan each bit of the integer, MSb first * 045 /* Scan each bit of the integer, MSb first */ 047 for (i = 31 ; i >= 0 ; i--) 046 for (i = 31 ; i >= 0 ; i--) 048 { 047 { 049 /* Test if bit i of 'integer' is set */ 048 /* Test if bit i of 'integer' is set */ 050 int bit_i = (integer & (1 << i)); 049 int bit_i = (integer & (1 << i)); 051 /* Ascii 219 => dark carret, Ascii 177 = 050 /* Ascii 219 => dark carret, Ascii 177 => light carret */ 052 unsigned char ascii_code = bit_i?219:177 051 unsigned char ascii_code = bit_i?219:177; 053 sos_x86_videomem_putchar(row, col++, 052 sos_x86_videomem_putchar(row, col++, 054 attribute, 053 attribute, 055 ascii_code); 054 ascii_code); 056 } 055 } 057 } 056 } 058 057 059 058 060 /* Clock IRQ handler */ 059 /* Clock IRQ handler */ 061 static void clk_it(int intid) !! 060 static void clk_it(int intid, >> 061 const struct sos_cpu_kstate *cpu_kstate) 062 { 062 { 063 static sos_ui32_t clock_count = 0; 063 static sos_ui32_t clock_count = 0; 064 064 065 display_bits(0, 48, 065 display_bits(0, 48, 066 SOS_X86_VIDEO_FG_LTGREEN | SOS_ 066 SOS_X86_VIDEO_FG_LTGREEN | SOS_X86_VIDEO_BG_BLUE, 067 clock_count); 067 clock_count); 068 clock_count++; 068 clock_count++; 069 << 070 /* Execute the expired timeout actions (if a << 071 sos_time_do_tick(); << 072 } 069 } 073 070 074 071 075 /* =========================================== 072 /* ====================================================================== 076 * Page fault exception handling 073 * Page fault exception handling 077 */ 074 */ 078 075 079 /* Helper function to dump a backtrace on boch 076 /* Helper function to dump a backtrace on bochs and/or the console */ 080 static void dump_backtrace(const struct sos_cp !! 077 static void dump_backtrace(const struct sos_cpu_kstate *cpu_kstate, 081 sos_vaddr_t stack_b 078 sos_vaddr_t stack_bottom, 082 sos_size_t stack_s 079 sos_size_t stack_size, 083 sos_bool_t on_conso 080 sos_bool_t on_console, 084 sos_bool_t on_bochs 081 sos_bool_t on_bochs) 085 { 082 { 086 static void backtracer(sos_vaddr_t PC, 083 static void backtracer(sos_vaddr_t PC, 087 sos_vaddr_t params, 084 sos_vaddr_t params, 088 sos_ui32_t depth, 085 sos_ui32_t depth, 089 void *custom_arg) 086 void *custom_arg) 090 { 087 { 091 sos_ui32_t invalid = 0xffffffff, *arg1, 088 sos_ui32_t invalid = 0xffffffff, *arg1, *arg2, *arg3, *arg4; 092 089 093 /* Get the address of the first 3 argume 090 /* Get the address of the first 3 arguments from the 094 frame. Among these arguments, 0, 1, 2 091 frame. Among these arguments, 0, 1, 2, 3 arguments might be 095 meaningful (depending on how many arg 092 meaningful (depending on how many arguments the function may 096 take). */ 093 take). */ 097 arg1 = (sos_ui32_t*)params; 094 arg1 = (sos_ui32_t*)params; 098 arg2 = (sos_ui32_t*)(params+4); 095 arg2 = (sos_ui32_t*)(params+4); 099 arg3 = (sos_ui32_t*)(params+8); 096 arg3 = (sos_ui32_t*)(params+8); 100 arg4 = (sos_ui32_t*)(params+12); 097 arg4 = (sos_ui32_t*)(params+12); 101 098 102 /* Make sure the addresses of these argu 099 /* Make sure the addresses of these arguments fit inside the 103 stack boundaries */ 100 stack boundaries */ 104 #define INTERVAL_OK(b,v,u) ( ((b) <= (sos_vadd 101 #define INTERVAL_OK(b,v,u) ( ((b) <= (sos_vaddr_t)(v)) \ 105 && ((sos_vaddr_t) 102 && ((sos_vaddr_t)(v) < (u)) ) 106 if (!INTERVAL_OK(stack_bottom, arg1, sta 103 if (!INTERVAL_OK(stack_bottom, arg1, stack_bottom + stack_size)) 107 arg1 = &invalid; 104 arg1 = &invalid; 108 if (!INTERVAL_OK(stack_bottom, arg2, sta 105 if (!INTERVAL_OK(stack_bottom, arg2, stack_bottom + stack_size)) 109 arg2 = &invalid; 106 arg2 = &invalid; 110 if (!INTERVAL_OK(stack_bottom, arg3, sta 107 if (!INTERVAL_OK(stack_bottom, arg3, stack_bottom + stack_size)) 111 arg3 = &invalid; 108 arg3 = &invalid; 112 if (!INTERVAL_OK(stack_bottom, arg4, sta 109 if (!INTERVAL_OK(stack_bottom, arg4, stack_bottom + stack_size)) 113 arg4 = &invalid; 110 arg4 = &invalid; 114 111 115 /* Print the function context for this f 112 /* Print the function context for this frame */ 116 if (on_bochs) 113 if (on_bochs) 117 sos_bochs_printf("[%d] PC=0x%x arg1=0x 114 sos_bochs_printf("[%d] PC=0x%x arg1=0x%x arg2=0x%x arg3=0x%x\n", 118 (unsigned)depth, (uns 115 (unsigned)depth, (unsigned)PC, 119 (unsigned)*arg1, (uns 116 (unsigned)*arg1, (unsigned)*arg2, 120 (unsigned)*arg3); 117 (unsigned)*arg3); 121 118 122 if (on_console) 119 if (on_console) 123 sos_x86_videomem_printf(23-depth, 3, 120 sos_x86_videomem_printf(23-depth, 3, 124 SOS_X86_VIDEO_ 121 SOS_X86_VIDEO_BG_BLUE 125 | SOS_X86_VI 122 | SOS_X86_VIDEO_FG_LTGREEN, 126 "[%d] PC=0x%x 123 "[%d] PC=0x%x arg1=0x%x arg2=0x%x arg3=0x%x arg4=0x%x", 127 (unsigned)dept 124 (unsigned)depth, PC, 128 (unsigned)*arg 125 (unsigned)*arg1, (unsigned)*arg2, 129 (unsigned)*arg 126 (unsigned)*arg3, (unsigned)*arg4); 130 127 131 } 128 } 132 129 133 sos_backtrace(cpu_state, 15, stack_bottom, s !! 130 sos_backtrace(cpu_kstate, 15, stack_bottom, stack_size, backtracer, NULL); 134 } 131 } 135 132 136 133 137 /* Page fault exception handler with demand pa 134 /* Page fault exception handler with demand paging for the kernel */ 138 static void pgflt_ex(int intid, const struct s !! 135 static void pgflt_ex(int intid, const struct sos_cpu_kstate *ctxt) 139 { 136 { 140 static sos_ui32_t demand_paging_count = 0; 137 static sos_ui32_t demand_paging_count = 0; 141 sos_vaddr_t faulting_vaddr = sos_cpu_context !! 138 sos_vaddr_t faulting_vaddr = sos_cpu_kstate_get_EX_faulting_vaddr(ctxt); 142 sos_paddr_t ppage_paddr; 139 sos_paddr_t ppage_paddr; 143 140 144 /* Check if address is covered by any VMM ra 141 /* Check if address is covered by any VMM range */ 145 if (! sos_kmem_vmm_is_valid_vaddr(faulting_v 142 if (! sos_kmem_vmm_is_valid_vaddr(faulting_vaddr)) 146 { 143 { 147 /* No: The page fault is out of any kern 144 /* No: The page fault is out of any kernel virtual region. For 148 the moment, we don't handle this. */ 145 the moment, we don't handle this. */ 149 dump_backtrace(ctxt, 146 dump_backtrace(ctxt, 150 bootstrap_stack_bottom, 147 bootstrap_stack_bottom, 151 bootstrap_stack_size, 148 bootstrap_stack_size, 152 TRUE, TRUE); 149 TRUE, TRUE); 153 sos_display_fatal_error("Unresolved page !! 150 sos_display_fatal_error("Unresolved page Fault on access to address 0x%x (info=%x)!", 154 sos_cpu_context_ << 155 (unsigned)faulti 151 (unsigned)faulting_vaddr, 156 (unsigned)sos_cp !! 152 (unsigned)sos_cpu_kstate_get_EX_info(ctxt)); 157 SOS_ASSERT_FATAL(! "Got page fault (note 153 SOS_ASSERT_FATAL(! "Got page fault (note: demand paging is disabled)"); 158 } 154 } 159 155 160 156 161 /* 157 /* 162 * Demand paging 158 * Demand paging 163 */ 159 */ 164 160 165 /* Update the number of demand paging reques 161 /* Update the number of demand paging requests handled */ 166 demand_paging_count ++; 162 demand_paging_count ++; 167 display_bits(0, 0, 163 display_bits(0, 0, 168 SOS_X86_VIDEO_FG_LTRED | SOS_X8 164 SOS_X86_VIDEO_FG_LTRED | SOS_X86_VIDEO_BG_BLUE, 169 demand_paging_count); 165 demand_paging_count); 170 166 171 /* Allocate a new page for the virtual addre 167 /* Allocate a new page for the virtual address */ 172 ppage_paddr = sos_physmem_ref_physpage_new(F 168 ppage_paddr = sos_physmem_ref_physpage_new(FALSE); 173 if (! ppage_paddr) 169 if (! ppage_paddr) 174 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 !)"); 175 SOS_ASSERT_FATAL(SOS_OK == sos_paging_map(pp 171 SOS_ASSERT_FATAL(SOS_OK == sos_paging_map(ppage_paddr, 176 SO 172 SOS_PAGE_ALIGN_INF(faulting_vaddr), 177 FA 173 FALSE, 178 SO 174 SOS_VM_MAP_PROT_READ 179 | 175 | SOS_VM_MAP_PROT_WRITE 180 | 176 | SOS_VM_MAP_ATOMIC)); 181 sos_physmem_unref_physpage(ppage_paddr); 177 sos_physmem_unref_physpage(ppage_paddr); 182 178 183 /* Ok, we can now return to interrupted cont 179 /* Ok, we can now return to interrupted context */ 184 } 180 } 185 181 186 182 >> 183 187 /* =========================================== 184 /* ====================================================================== 188 * Demonstrate the use of SOS kernel threads !! 185 * Demonstrate the use of the CPU kernet context management API: 189 * - Kernel Threads are created with various !! 186 * - A coroutine prints "Hlowrd" and switches to the other after each 190 * state is printed on both the console and !! 187 * letter 191 * - For tests regarding threads' synchroniza !! 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. 192 */ 191 */ >> 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; 193 196 194 struct thr_arg !! 197 static void reclaim_stack(sos_vaddr_t stack_vaddr) 195 { 198 { 196 char character; !! 199 sos_kfree(stack_vaddr); 197 int color; !! 200 } 198 201 199 int col; !! 202 200 int row; !! 203 static void exit_hello12(sos_vaddr_t stack_vaddr) 201 }; !! 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++) >> 214 { >> 215 sos_bochs_printf("hello1: %c\n", *str); >> 216 sos_cpu_kstate_switch(& ctxt_hello1, ctxt_hello2); >> 217 } >> 218 >> 219 /* You can uncomment this in case you explicitly want to exit >> 220 now. But returning from the function will do the same */ >> 221 /* sos_cpu_kstate_exit_to(ctxt_main, >> 222 (sos_cpu_kstate_function_arg1_t*) reclaim_stack, >> 223 hello1_stack); */ >> 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); >> 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)"); >> 328 } >> 329 >> 330 >> 331 >> 332 /* ====================================================================== >> 333 * Shows how the backtrace stuff works >> 334 */ >> 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) >> 339 { >> 340 if (i <= 0) >> 341 { >> 342 /* The page fault exception handler will print the backtrace of >> 343 this function, because address 0x42 is not mapped */ >> 344 *((char*)0x42) = 12; >> 345 >> 346 /* More direct variant: */ >> 347 /* dump_backtrace(NULL, stack_bottom, stack_size, TRUE, TRUE); */ >> 348 } >> 349 else >> 350 test_backtrace(i-1, magic, stack_bottom, stack_size); >> 351 } >> 352 >> 353 >> 354 /* ====================================================================== >> 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 */ 202 432 203 433 204 static void demo_thread(void *arg) !! 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) 205 { 449 { 206 struct thr_arg *thr_arg = (struct thr_arg*)a !! 450 } 207 int progress = 0; !! 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 } 208 455 209 sos_bochs_printf("start %c", thr_arg->charac !! 456 210 while (1) !! 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++) 211 { 467 { 212 progress ++; !! 468 data_reader_to_lexer = *str; 213 display_bits(thr_arg->row, thr_arg->col+ !! 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 } >> 475 214 476 215 sos_bochs_putchar(thr_arg->character); !! 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; 216 494 217 /* Yield the CPU to another thread somet !! 495 static void func_lexer(sos_ui32_t unused) 218 if ((random() % 100) == 0) !! 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) ) 219 { 529 { 220 sos_bochs_printf("[37myield(%c)[m\ !! 530 /* return control back to the parser if the previous token 221 sos_x86_videomem_putchar(thr_arg->ro !! 531 has been recognized */ 222 SOS_ASSERT_FATAL(SOS_OK == sos_threa !! 532 if ( (got_what_before != GOT_SPACE) ) 223 sos_x86_videomem_putchar(thr_arg->ro !! 533 sos_cpu_kstate_switch(& st_lexer, st_parser); >> 534 >> 535 data_lexer_to_parser.number = 0; 224 } 536 } 225 537 226 /* Go to sleep some other times... */ !! 538 /* Update the token being currently recognized */ 227 else if ((random() % 200) == 0) !! 539 if (got_what == GOT_OP) 228 { 540 { 229 struct sos_time t = (struct sos_time !! 541 data_lexer_to_parser.type = LEX_IS_OPER; 230 sos_bochs_printf("[37msleep1(%c)[m !! 542 data_lexer_to_parser.operator = c; 231 sos_x86_videomem_putchar(thr_arg->ro << 232 SOS_ASSERT_FATAL(SOS_OK == sos_threa << 233 SOS_ASSERT_FATAL(sos_time_is_zero(& << 234 sos_x86_videomem_putchar(thr_arg->ro << 235 } 543 } 236 !! 544 else if (got_what == GOT_NUM) 237 /* Go to sleep for a longer time some ot !! 545 { 238 else if ((random() % 300) == 0) !! 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) 239 { 551 { 240 struct sos_time t = (struct sos_time !! 552 char to_cat[] = { c, '\0' }; 241 sos_bochs_printf("[37msleep2(%c)[m !! 553 data_lexer_to_parser.type = LEX_IS_VAR; 242 sos_x86_videomem_putchar(thr_arg->ro !! 554 strzcat(data_lexer_to_parser.var, to_cat, STR_VAR_MAXLEN); 243 SOS_ASSERT_FATAL(SOS_OK == sos_threa << 244 SOS_ASSERT_FATAL(sos_time_is_zero(& << 245 sos_x86_videomem_putchar(thr_arg->ro << 246 } 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; 247 560 248 /* Infinite loop otherwise */ !! 561 got_what_before = got_what; 249 } 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); 250 } 577 } 251 578 252 579 253 static void test_thread() !! 580 /* >> 581 * The Parser coroutine and associated types/variables >> 582 */ >> 583 struct syntax_node 254 { 584 { 255 /* "static" variables because we want them t !! 585 enum { YY_IS_BINOP, YY_IS_UNAROP, YY_IS_NUM, YY_IS_VAR } type; 256 function returns */ !! 586 union 257 static struct thr_arg arg_b, arg_c, arg_d, a !! 587 { 258 sos_ui32_t flags; !! 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 }; 259 602 260 sos_disable_IRQs(flags); !! 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(); 261 618 262 arg_b = (struct thr_arg) { .character='b', . !! 619 /* Create a new node to store a number */ 263 sos_create_kernel_thread("YO[b]", demo_threa !! 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 } 264 661 265 arg_c = (struct thr_arg) { .character='c', . !! 662 /* Raise an exception: transfer control back to main context, 266 sos_create_kernel_thread("YO[c]", demo_threa !! 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 } 267 669 268 arg_d = (struct thr_arg) { .character='d', . !! 670 /* Consume the current terminal "number" token and ask for a new 269 sos_create_kernel_thread("YO[d]", demo_threa !! 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 } 270 710 271 arg_e = (struct thr_arg) { .character='e', . !! 711 /* Parse an Expression */ 272 sos_create_kernel_thread("YO[e]", demo_threa !! 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 } 273 783 274 arg_R = (struct thr_arg) { .character='R', . << 275 sos_create_kernel_thread("YO[R]", demo_threa << 276 784 277 arg_S = (struct thr_arg) { .character='S', . !! 785 /* 278 sos_create_kernel_thread("YO[S]", demo_threa !! 786 * Body of the function >> 787 */ >> 788 >> 789 /* Get the first token */ >> 790 sos_cpu_kstate_switch(& st_parser, st_lexer); 279 791 280 sos_restore_IRQs(flags); !! 792 /* Begin the parsing ! */ >> 793 *syntax_tree = get_expr(); >> 794 /* The result is returned in the syntax_tree parameter */ 281 } 795 } 282 796 283 797 284 /* =========================================== !! 798 /* 285 * An operating system MUST always have a read !! 799 * Setup the parser's pipeline 286 * what would the CPU have to execute ?! !! 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 287 */ 830 */ 288 static void idle_thread() !! 831 struct func_eval_params 289 { 832 { 290 sos_ui32_t idle_twiddle = 0; !! 833 const struct syntax_node *e; >> 834 const char **var_name; >> 835 int *var_val; >> 836 int nb_vars; >> 837 >> 838 int result; >> 839 }; 291 840 292 while (1) !! 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) 293 { 847 { 294 /* Remove this instruction if you get an !! 848 switch (n->type) 295 exception (old 80386 CPU) */ !! 849 { 296 asm("hlt\n"); !! 850 case YY_IS_NUM: >> 851 return n->number; 297 852 298 idle_twiddle ++; !! 853 case YY_IS_VAR: 299 display_bits(0, 0, SOS_X86_VIDEO_FG_GREE !! 854 { 300 idle_twiddle); !! 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 } 301 898 302 /* Lend the CPU to some other thread */ !! 899 /* Exception: no such syntax node (INTERNAL error) ! */ 303 sos_thread_yield(); !! 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 */ 304 } 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); 305 } 978 } 306 979 307 980 308 /* =========================================== 981 /* ====================================================================== 309 * The C entry point of our operating system 982 * The C entry point of our operating system 310 */ 983 */ 311 void sos_main(unsigned long magic, unsigned lo 984 void sos_main(unsigned long magic, unsigned long addr) 312 { 985 { 313 unsigned i; 986 unsigned i; 314 sos_paddr_t sos_kernel_core_base_paddr, sos_ 987 sos_paddr_t sos_kernel_core_base_paddr, sos_kernel_core_top_paddr; 315 struct sos_time tick_resolution; !! 988 struct syntax_node *syntax_tree; 316 989 317 /* Grub sends us a structure, called multibo 990 /* Grub sends us a structure, called multiboot_info_t with a lot of 318 precious informations about the system, s 991 precious informations about the system, see the multiboot 319 documentation for more information. */ 992 documentation for more information. */ 320 multiboot_info_t *mbi; 993 multiboot_info_t *mbi; 321 mbi = (multiboot_info_t *) addr; 994 mbi = (multiboot_info_t *) addr; 322 995 323 /* Setup bochs and console, and clear the co 996 /* Setup bochs and console, and clear the console */ 324 sos_bochs_setup(); 997 sos_bochs_setup(); 325 998 326 sos_x86_videomem_setup(); 999 sos_x86_videomem_setup(); 327 sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); 1000 sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); 328 1001 329 /* Greetings from SOS */ 1002 /* Greetings from SOS */ 330 if (magic == MULTIBOOT_BOOTLOADER_MAGIC) 1003 if (magic == MULTIBOOT_BOOTLOADER_MAGIC) 331 /* Loaded with Grub */ 1004 /* Loaded with Grub */ 332 sos_x86_videomem_printf(1, 0, 1005 sos_x86_videomem_printf(1, 0, 333 SOS_X86_VIDEO_FG_Y 1006 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 334 "Welcome From GRUB 1007 "Welcome From GRUB to %s%c RAM is %dMB (upper mem = 0x%x kB)", 335 "SOS article 6.5", !! 1008 "SOS", ',', 336 (unsigned)(mbi->me 1009 (unsigned)(mbi->mem_upper >> 10) + 1, 337 (unsigned)mbi->mem 1010 (unsigned)mbi->mem_upper); 338 else 1011 else 339 /* Not loaded with grub */ 1012 /* Not loaded with grub */ 340 sos_x86_videomem_printf(1, 0, 1013 sos_x86_videomem_printf(1, 0, 341 SOS_X86_VIDEO_FG_Y 1014 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 342 "Welcome to SOS ar !! 1015 "Welcome to SOS"); 343 1016 344 sos_bochs_putstring("Message in a bochs: Thi !! 1017 sos_bochs_putstring("Message in a bochs\n"); 345 1018 346 /* Setup CPU segmentation and IRQ subsystem 1019 /* Setup CPU segmentation and IRQ subsystem */ 347 sos_gdt_subsystem_setup(); 1020 sos_gdt_subsystem_setup(); 348 sos_idt_subsystem_setup(); 1021 sos_idt_subsystem_setup(); 349 1022 350 /* Setup SOS IRQs and exceptions subsystem * 1023 /* Setup SOS IRQs and exceptions subsystem */ 351 sos_exception_subsystem_setup(); 1024 sos_exception_subsystem_setup(); 352 sos_irq_subsystem_setup(); 1025 sos_irq_subsystem_setup(); 353 1026 354 /* Configure the timer so as to raise the IR 1027 /* Configure the timer so as to raise the IRQ0 at a 100Hz rate */ 355 sos_i8254_set_frequency(100); 1028 sos_i8254_set_frequency(100); 356 1029 357 /* Setup the kernel time subsystem to get pr << 358 ticks into account */ << 359 tick_resolution = (struct sos_time) { .sec=0 << 360 sos_time_subsysem_setup(& tick_resolution); << 361 << 362 /* We need a multiboot-compliant boot loader 1030 /* We need a multiboot-compliant boot loader to get the size of the RAM */ 363 if (magic != MULTIBOOT_BOOTLOADER_MAGIC) 1031 if (magic != MULTIBOOT_BOOTLOADER_MAGIC) 364 { 1032 { 365 sos_x86_videomem_putstring(20, 0, 1033 sos_x86_videomem_putstring(20, 0, 366 SOS_X86_VIDEO 1034 SOS_X86_VIDEO_FG_LTRED 367 | SOS_X86_V 1035 | SOS_X86_VIDEO_BG_BLUE 368 | SOS_X86_V 1036 | SOS_X86_VIDEO_FG_BLINKING, 369 "I'm not load 1037 "I'm not loaded with Grub !"); 370 /* STOP ! */ 1038 /* STOP ! */ 371 for (;;) 1039 for (;;) 372 continue; 1040 continue; 373 } 1041 } 374 1042 375 /* 1043 /* 376 * Some interrupt handlers 1044 * Some interrupt handlers 377 */ 1045 */ 378 1046 379 /* Binding some HW interrupts and exceptions 1047 /* Binding some HW interrupts and exceptions to software routines */ 380 sos_irq_set_routine(SOS_IRQ_TIMER, 1048 sos_irq_set_routine(SOS_IRQ_TIMER, 381 clk_it); 1049 clk_it); 382 1050 383 /* 1051 /* 384 * Setup physical memory management 1052 * Setup physical memory management 385 */ 1053 */ 386 1054 387 /* Multiboot says: "The value returned for u 1055 /* Multiboot says: "The value returned for upper memory is maximally 388 the address of the first upper memory hol 1056 the address of the first upper memory hole minus 1 megabyte.". It 389 also adds: "It is not guaranteed to be th 1057 also adds: "It is not guaranteed to be this value." aka "YMMV" ;) */ 390 sos_physmem_subsystem_setup((mbi->mem_upper< 1058 sos_physmem_subsystem_setup((mbi->mem_upper<<10) + (1<<20), 391 & sos_kernel_cor 1059 & sos_kernel_core_base_paddr, 392 & sos_kernel_cor 1060 & sos_kernel_core_top_paddr); 393 1061 394 /* 1062 /* 395 * Switch to paged-memory mode 1063 * Switch to paged-memory mode 396 */ 1064 */ 397 1065 398 /* Disabling interrupts should seem more cor 1066 /* Disabling interrupts should seem more correct, but it's not really 399 necessary at this stage */ 1067 necessary at this stage */ 400 SOS_ASSERT_FATAL(SOS_OK == 1068 SOS_ASSERT_FATAL(SOS_OK == 401 sos_paging_subsystem_setup( 1069 sos_paging_subsystem_setup(sos_kernel_core_base_paddr, 402 1070 sos_kernel_core_top_paddr)); 403 1071 404 /* Bind the page fault exception */ 1072 /* Bind the page fault exception */ 405 sos_exception_set_routine(SOS_EXCEPT_PAGE_FA 1073 sos_exception_set_routine(SOS_EXCEPT_PAGE_FAULT, 406 pgflt_ex); 1074 pgflt_ex); 407 1075 408 /* 1076 /* 409 * Setup kernel virtual memory allocator 1077 * Setup kernel virtual memory allocator 410 */ !! 1078 */ 411 1079 412 if (sos_kmem_vmm_subsystem_setup(sos_kernel_ 1080 if (sos_kmem_vmm_subsystem_setup(sos_kernel_core_base_paddr, 413 sos_kernel_ 1081 sos_kernel_core_top_paddr, 414 bootstrap_s 1082 bootstrap_stack_bottom, 415 bootstrap_s 1083 bootstrap_stack_bottom 416 + bootstrap 1084 + bootstrap_stack_size)) 417 sos_bochs_printf("Could not setup the Kern 1085 sos_bochs_printf("Could not setup the Kernel virtual space allocator\n"); 418 1086 419 if (sos_kmalloc_subsystem_setup()) 1087 if (sos_kmalloc_subsystem_setup()) 420 sos_bochs_printf("Could not setup the Kmal 1088 sos_bochs_printf("Could not setup the Kmalloc subsystem\n"); 421 1089 422 /* 1090 /* 423 * Initialize the Kernel thread and schedule !! 1091 * Enabling the HW interrupts here, this will make the timer HW >> 1092 * interrupt call our clk_it handler 424 */ 1093 */ 425 !! 1094 asm volatile ("sti\n"); 426 /* Initialize kernel thread subsystem */ << 427 sos_thread_subsystem_setup(bootstrap_stack_b << 428 bootstrap_stack_s << 429 1095 430 /* Initialize the scheduler */ !! 1096 /* 431 sos_sched_subsystem_setup(); !! 1097 * Print hello world using coroutines >> 1098 */ >> 1099 print_hello_world(); 432 1100 433 /* Declare the IDLE thread */ << 434 SOS_ASSERT_FATAL(sos_create_kernel_thread("i << 435 1101 436 /* Enabling the HW interrupts here, this wil !! 1102 /* 437 interrupt call the scheduler */ !! 1103 * Run coroutine tests 438 asm volatile ("sti\n"); !! 1104 */ >> 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)"); >> 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 } >> 1136 >> 1137 /* >> 1138 * Run some demand-paging tests >> 1139 */ >> 1140 test_demand_paging(234567, 500); >> 1141 >> 1142 >> 1143 /* >> 1144 * Create an un-resolved page fault, which will make the page fault >> 1145 * handler print the backtrace. >> 1146 */ >> 1147 test_backtrace(6, 0xdeadbeef, bootstrap_stack_bottom, bootstrap_stack_size); >> 1148 >> 1149 /* >> 1150 * System should be halted BEFORE here ! >> 1151 */ 439 1152 440 1153 441 /* Now run some Kernel threads just for fun !! 1154 /* An operatig system never ends */ 442 extern void MouseSim(); !! 1155 for (;;) 443 MouseSim(); !! 1156 { 444 test_thread(); !! 1157 /* Remove this instruction if you get an "Invalid opcode" CPU 445 !! 1158 exception (old 80386 CPU) */ 446 /* !! 1159 asm("hlt\n"); 447 * We can safely exit from this function now !! 1160 448 * an idle Kernel thread ready to make the C !! 1161 continue; 449 * !! 1162 } 450 * However, we must EXPLICITELY call sos_thr << 451 * simple "return" will return nowhere ! Act << 452 * was initialized by the Grub bootstrap sta << 453 * word "thread" did not exist. This means t << 454 * setup in order for a return here to call << 455 * automagically. Hence we must call it manu << 456 * kernel thread where we must do this manua << 457 */ << 458 sos_bochs_printf("Bye from primary thread !\ << 459 sos_thread_exit(); << 460 SOS_FATAL_ERROR("No trespassing !"); << 461 } 1163 }
| [ source navigation ] | [ diff markup ] | [ identifier search ] | [ general search ] |