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001 /* Copyright (C) 2004 The SOS Team 001 /* Copyright (C) 2004 The SOS Team 002 Copyright (C) 1999 Free Software Foundatio 002 Copyright (C) 1999 Free Software Foundation, Inc. 003 003 004 This program is free software; you can redi 004 This program is free software; you can redistribute it and/or 005 modify it under the terms of the GNU Genera 005 modify it under the terms of the GNU General Public License 006 as published by the Free Software Foundatio 006 as published by the Free Software Foundation; either version 2 007 of the License, or (at your option) any lat 007 of the License, or (at your option) any later version. 008 008 009 This program is distributed in the hope tha 009 This program is distributed in the hope that it will be useful, 010 but WITHOUT ANY WARRANTY; without even the 010 but WITHOUT ANY WARRANTY; without even the implied warranty of 011 MERCHANTABILITY or FITNESS FOR A PARTICULAR 011 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 012 GNU General Public License for more details 012 GNU General Public License for more details. 013 013 014 You should have received a copy of the GNU 014 You should have received a copy of the GNU General Public License 015 along with this program; if not, write to t 015 along with this program; if not, write to the Free Software 016 Foundation, Inc., 59 Temple Place - Suite 3 016 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 017 USA. 017 USA. 018 */ 018 */ 019 019 020 /* Include definitions of the multiboot standa 020 /* Include definitions of the multiboot standard */ 021 #include <bootstrap/multiboot.h> 021 #include <bootstrap/multiboot.h> 022 #include <hwcore/idt.h> 022 #include <hwcore/idt.h> 023 #include <hwcore/gdt.h> 023 #include <hwcore/gdt.h> 024 #include <hwcore/irq.h> 024 #include <hwcore/irq.h> 025 #include <hwcore/exception.h> 025 #include <hwcore/exception.h> 026 #include <hwcore/i8254.h> 026 #include <hwcore/i8254.h> >> 027 #include <sos/list.h> >> 028 #include <sos/physmem.h> >> 029 #include <hwcore/paging.h> >> 030 #include <sos/list.h> 027 #include <sos/klibc.h> 031 #include <sos/klibc.h> 028 #include <sos/assert.h> 032 #include <sos/assert.h> 029 #include <drivers/x86_videomem.h> 033 #include <drivers/x86_videomem.h> 030 #include <drivers/bochs.h> 034 #include <drivers/bochs.h> 031 035 032 036 033 /* Helper function to display each bits of a 3 037 /* Helper function to display each bits of a 32bits integer on the 034 screen as dark or light carrets */ 038 screen as dark or light carrets */ 035 static void display_bits(unsigned char row, un 039 static void display_bits(unsigned char row, unsigned char col, 036 unsigned char attribu 040 unsigned char attribute, 037 sos_ui32_t integer) 041 sos_ui32_t integer) 038 { 042 { 039 int i; 043 int i; 040 /* Scan each bit of the integer, MSb first * 044 /* Scan each bit of the integer, MSb first */ 041 for (i = 31 ; i >= 0 ; i--) 045 for (i = 31 ; i >= 0 ; i--) 042 { 046 { 043 /* Test if bit i of 'integer' is set */ 047 /* Test if bit i of 'integer' is set */ 044 int bit_i = (integer & (1 << i)); 048 int bit_i = (integer & (1 << i)); 045 /* Ascii 219 => dark carret, Ascii 177 = 049 /* Ascii 219 => dark carret, Ascii 177 => light carret */ 046 unsigned char ascii_code = bit_i?219:177 050 unsigned char ascii_code = bit_i?219:177; 047 sos_x86_videomem_putchar(row, col++, 051 sos_x86_videomem_putchar(row, col++, 048 attribute, 052 attribute, 049 ascii_code); 053 ascii_code); 050 } 054 } 051 } 055 } 052 056 053 057 054 /* Clock IRQ handler */ 058 /* Clock IRQ handler */ 055 static void clk_it(int intid) 059 static void clk_it(int intid) 056 { 060 { 057 static sos_ui32_t clock_count = 0; 061 static sos_ui32_t clock_count = 0; 058 062 059 display_bits(0, 48, 063 display_bits(0, 48, 060 SOS_X86_VIDEO_FG_LTGREEN | SOS_ 064 SOS_X86_VIDEO_FG_LTGREEN | SOS_X86_VIDEO_BG_BLUE, 061 clock_count); 065 clock_count); 062 clock_count++; 066 clock_count++; 063 067 064 } 068 } 065 069 066 /* Division by zero exception handler */ !! 070 /* Page fault exception handler */ 067 static void divide_ex(int exid) !! 071 static void pgflt_ex(int exid) 068 { 072 { 069 static sos_ui32_t div_count = 0; !! 073 sos_bochs_printf("Got page fault\n"); 070 display_bits(0, 0, !! 074 sos_x86_videomem_printf(10, 30, 071 SOS_X86_VIDEO_FG_LTRED | SOS_X8 !! 075 SOS_X86_VIDEO_FG_LTRED | SOS_X86_VIDEO_BG_BLUE, 072 div_count); !! 076 "Got EXPECTED (?) Page fault ! But where ???"); 073 div_count++; !! 077 for (;;) ; >> 078 } >> 079 >> 080 static void test_paging(sos_vaddr_t sos_kernel_core_top_vaddr) >> 081 { >> 082 /* The (linear) address of the page holding the code we are >> 083 currently executing */ >> 084 sos_vaddr_t vpage_code = SOS_PAGE_ALIGN_INF(test_paging); >> 085 >> 086 /* The new physical page that will hold the code */ >> 087 sos_paddr_t ppage_new; >> 088 >> 089 /* Where this page will be mapped temporarily in order to copy the >> 090 code into it: right after the kernel code/data */ >> 091 sos_vaddr_t vpage_tmp = sos_kernel_core_top_vaddr; >> 092 >> 093 unsigned i; >> 094 >> 095 /* Bind the page fault exception to one of our routines */ >> 096 sos_exception_set_routine(SOS_EXCEPT_PAGE_FAULT, >> 097 pgflt_ex); >> 098 >> 099 /* >> 100 * Test 1: move the page where we execute the code elsewhere in >> 101 * physical memory >> 102 */ >> 103 sos_x86_videomem_printf(4, 0, >> 104 SOS_X86_VIDEO_FG_LTGREEN | SOS_X86_VIDEO_BG_BLUE, >> 105 "Moving current code elsewhere in physical memory:"); >> 106 >> 107 >> 108 /* Allocate a new physical page */ >> 109 ppage_new = sos_physmem_ref_physpage_new(FALSE); >> 110 if (! ppage_new) >> 111 { >> 112 /* STOP ! No memory left */ >> 113 sos_x86_videomem_putstring(20, 0, >> 114 SOS_X86_VIDEO_FG_LTRED >> 115 | SOS_X86_VIDEO_BG_BLUE, >> 116 "test_paging : Cannot allocate page"); >> 117 return; >> 118 } >> 119 >> 120 sos_x86_videomem_printf(5, 0, >> 121 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, >> 122 "Hello from the address 0x%x in physical memory", >> 123 sos_paging_get_paddr(vpage_code)); >> 124 >> 125 sos_x86_videomem_printf(6, 0, >> 126 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, >> 127 "Transfer vpage 0x%x: ppage 0x%x -> 0x%x (tmp vpage 0x%x)", >> 128 vpage_code, >> 129 sos_paging_get_paddr(vpage_code), >> 130 ppage_new, >> 131 (unsigned)vpage_tmp); >> 132 >> 133 /* Map the page somewhere (right after the kernel mapping) in order >> 134 to copy the code we are currently executing */ >> 135 sos_paging_map(ppage_new, vpage_tmp, >> 136 FALSE, >> 137 SOS_VM_MAP_ATOMIC >> 138 | SOS_VM_MAP_PROT_READ >> 139 | SOS_VM_MAP_PROT_WRITE); >> 140 >> 141 /* Ok, the new page is referenced by the mapping, we can release our >> 142 reference to it */ >> 143 sos_physmem_unref_physpage(ppage_new); >> 144 >> 145 /* Copy the contents of the current page of code to this new page >> 146 mapping */ >> 147 memcpy((void*)vpage_tmp, >> 148 (void*)vpage_code, >> 149 SOS_PAGE_SIZE); >> 150 >> 151 /* Transfer the mapping of the current page of code to this new page */ >> 152 sos_paging_map(ppage_new, vpage_code, >> 153 FALSE, >> 154 SOS_VM_MAP_ATOMIC >> 155 | SOS_VM_MAP_PROT_READ >> 156 | SOS_VM_MAP_PROT_WRITE); >> 157 >> 158 /* Ok, here we are: we have changed the physcal page that holds the >> 159 code we are executing ;). However, this new page is mapped at 2 >> 160 virtual addresses: >> 161 - vpage_tmp >> 162 - vpage_code >> 163 We can safely unmap it from sos_kernel_core_top_vaddr, while >> 164 still keeping the vpage_code mapping */ >> 165 sos_paging_unmap(vpage_tmp); >> 166 >> 167 sos_x86_videomem_printf(7, 0, >> 168 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, >> 169 "Hello from the address 0x%x in physical memory", >> 170 sos_paging_get_paddr(vpage_code)); >> 171 >> 172 sos_x86_videomem_printf(9, 0, >> 173 SOS_X86_VIDEO_FG_LTGREEN | SOS_X86_VIDEO_BG_BLUE, >> 174 "Provoking a page fault:"); >> 175 >> 176 /* >> 177 * Test 2: make sure the #PF handler works >> 178 */ >> 179 >> 180 /* Scan part of the kernel up to a page fault. This page fault >> 181 should occur on the first page unmapped after the kernel area, >> 182 which is exactly the page we temporarily mapped/unmapped >> 183 (vpage_tmp) above to move the kernel code we are executing */ >> 184 for (i = vpage_code ; /* none */ ; i += SOS_PAGE_SIZE) >> 185 { >> 186 unsigned *pint = (unsigned *)SOS_PAGE_ALIGN_INF(i); >> 187 sos_bochs_printf("Test vaddr 0x%x : val=", (unsigned)pint); >> 188 sos_x86_videomem_printf(10, 0, >> 189 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, >> 190 "Test vaddr 0x%x : val= ", >> 191 (unsigned)pint); >> 192 sos_bochs_printf("0x%x\n", *pint); >> 193 sos_x86_videomem_printf(10, 30, >> 194 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, >> 195 "0x%x ", *pint); >> 196 } >> 197 >> 198 /* BAD ! Did not get the page fault... */ >> 199 sos_x86_videomem_printf(20, 0, >> 200 SOS_X86_VIDEO_FG_LTRED | SOS_X86_VIDEO_BG_BLUE, >> 201 "We should have had a #PF at vaddr 0x%x !", >> 202 vpage_tmp); 074 } 203 } 075 204 076 /* The C entry point of our operating system * 205 /* The C entry point of our operating system */ 077 void sos_main(unsigned long magic, unsigned lo 206 void sos_main(unsigned long magic, unsigned long addr) 078 { 207 { 079 unsigned i; 208 unsigned i; >> 209 sos_paddr_t sos_kernel_core_base_paddr, sos_kernel_core_top_paddr; 080 210 081 /* Grub sends us a structure, called multibo 211 /* Grub sends us a structure, called multiboot_info_t with a lot of 082 precious informations about the system, s 212 precious informations about the system, see the multiboot 083 documentation for more information. */ 213 documentation for more information. */ 084 multiboot_info_t *mbi; 214 multiboot_info_t *mbi; 085 mbi = (multiboot_info_t *) addr; 215 mbi = (multiboot_info_t *) addr; 086 216 087 /* Setup bochs and console, and clear the co 217 /* Setup bochs and console, and clear the console */ 088 sos_bochs_setup(); 218 sos_bochs_setup(); 089 219 090 sos_x86_videomem_setup(); 220 sos_x86_videomem_setup(); 091 sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); 221 sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); 092 222 093 /* Greetings from SOS */ 223 /* Greetings from SOS */ 094 if (magic == MULTIBOOT_BOOTLOADER_MAGIC) 224 if (magic == MULTIBOOT_BOOTLOADER_MAGIC) 095 /* Loaded with Grub */ 225 /* Loaded with Grub */ 096 sos_x86_videomem_printf(1, 0, 226 sos_x86_videomem_printf(1, 0, 097 SOS_X86_VIDEO_FG_Y 227 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 098 "Welcome From GRUB 228 "Welcome From GRUB to %s%c RAM is %dMB (upper mem = 0x%x kB)", 099 "SOS", ',', 229 "SOS", ',', 100 (unsigned)(mbi->me 230 (unsigned)(mbi->mem_upper >> 10) + 1, 101 (unsigned)mbi->mem 231 (unsigned)mbi->mem_upper); 102 else 232 else 103 /* Not loaded with grub */ 233 /* Not loaded with grub */ 104 sos_x86_videomem_printf(1, 0, 234 sos_x86_videomem_printf(1, 0, 105 SOS_X86_VIDEO_FG_Y 235 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 106 "Welcome to SOS"); 236 "Welcome to SOS"); 107 237 108 sos_bochs_putstring("Message in a bochs\n"); 238 sos_bochs_putstring("Message in a bochs\n"); 109 239 110 /* Setup CPU segmentation and IRQ subsystem 240 /* Setup CPU segmentation and IRQ subsystem */ 111 sos_gdt_setup(); 241 sos_gdt_setup(); 112 sos_idt_setup(); 242 sos_idt_setup(); 113 243 114 /* Setup SOS IRQs and exceptions subsystem * 244 /* Setup SOS IRQs and exceptions subsystem */ 115 sos_exceptions_setup(); 245 sos_exceptions_setup(); 116 sos_irq_setup(); 246 sos_irq_setup(); 117 247 118 /* Configure the timer so as to raise the IR 248 /* Configure the timer so as to raise the IRQ0 at a 100Hz rate */ 119 sos_i8254_set_frequency(100); 249 sos_i8254_set_frequency(100); 120 250 >> 251 >> 252 /* We need a multiboot-compliant boot loader to get the size of the RAM */ >> 253 if (magic != MULTIBOOT_BOOTLOADER_MAGIC) >> 254 { >> 255 sos_x86_videomem_putstring(20, 0, >> 256 SOS_X86_VIDEO_FG_LTRED >> 257 | SOS_X86_VIDEO_BG_BLUE >> 258 | SOS_X86_VIDEO_FG_BLINKING, >> 259 "I'm not loaded with Grub !"); >> 260 /* STOP ! */ >> 261 for (;;) >> 262 continue; >> 263 } >> 264 121 /* Binding some HW interrupts and exceptions 265 /* Binding some HW interrupts and exceptions to software routines */ 122 sos_irq_set_routine(SOS_IRQ_TIMER, 266 sos_irq_set_routine(SOS_IRQ_TIMER, 123 clk_it); 267 clk_it); 124 sos_exception_set_routine(SOS_EXCEPT_DIVIDE_ << 125 divide_ex); << 126 /* Enabling the HW interrupts here, this wil 268 /* Enabling the HW interrupts here, this will make the timer HW 127 interrupt call our clk_it handler */ 269 interrupt call our clk_it handler */ 128 asm volatile ("sti\n"); 270 asm volatile ("sti\n"); 129 !! 271 /* Multiboot says: "The value returned for upper memory is maximally 130 /* Raise a rafale of 'division by 0' excepti !! 272 the address of the first upper memory hole minus 1 megabyte.". It 131 not really needed (equivalent to a bare " !! 273 also adds: "It is not guaranteed to be this value." aka "YMMV" ;) */ 132 compiling with -O3: "i=1/0;" is considere !! 274 sos_physmem_setup((mbi->mem_upper<<10) + (1<<20), 133 -O3. */ !! 275 & sos_kernel_core_base_paddr, 134 i = 10; !! 276 & sos_kernel_core_top_paddr); 135 while (1) !! 277 136 { !! 278 /* 137 /* Stupid function call to fool gcc opti !! 279 * Switch to paged-memory mode 138 sos_bochs_printf("i = 1 / %d...\n", i); !! 280 */ 139 i = 1 / i; !! 281 140 } !! 282 /* Disabling interrupts should seem more correct, but it's not really 141 !! 283 necessary at this stage */ 142 /* Will never print this since the "divide b !! 284 if (sos_paging_setup(sos_kernel_core_base_paddr, 143 returns to the faulting instruction (see !! 285 sos_kernel_core_top_paddr)) 144 section 5.12), thus re-evaluating the "di !! 286 sos_bochs_printf("Could not setup paged memory mode\n"); 145 and raising the "divide by zero" exceptio !! 287 sos_x86_videomem_printf(2, 0, 146 sos_x86_videomem_putstring(2, 0, !! 288 SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, 147 SOS_X86_VIDEO_FG_ !! 289 "Paged-memory mode is activated"); 148 "Invisible"); !! 290 >> 291 test_paging(sos_kernel_core_top_paddr); >> 292 >> 293 /* An operatig system never ends */ >> 294 for (;;) >> 295 continue; 149 296 150 return; 297 return; 151 } 298 }
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