src/device/oprom/realmode/x86.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <device/mmio.h>
   4 #include <arch/interrupt.h>
   5 #include <arch/registers.h>
   6 #include <boot/coreboot_tables.h>
   7 #include <console/console.h>
   8 #include <delay.h>
   9 #include <device/pci.h>
  10 #include <device/pci_ids.h>
  11 #include <pc80/i8259.h>
  12 #include <pc80/i8254.h>
  13 #include <stdint.h>
  14 #include <string.h>
  15 #include <vbe.h>
  16 #include <framebuffer_info.h>
  17
  18 /* we use x86emu's register file representation */
  19 #include <x86emu/regs.h>
  20
  21 #include "x86.h"
  22
  23 typedef struct {
  24         char signature[4];
  25         u16 version;
  26         u8 *oem_string_ptr;
  27         u32 capabilities;
  28         u32 video_mode_ptr;
  29         u16 total_memory;
  30         char reserved[236];
  31 } __packed vbe_info_block;
  32
  33 /* The following symbols cannot be used directly. They need to be fixed up
  34  * to point to the correct address location after the code has been copied
  35  * to REALMODE_BASE. Absolute symbols are not used because those symbols are
  36  * relocated when a relocatable ramstage is enabled.
  37  */
  38 extern unsigned char __realmode_call, __realmode_interrupt;
  39 extern unsigned char __realmode_buffer;
  40
  41 #define PTR_TO_REAL_MODE(sym)\
  42         (void *)(REALMODE_BASE + ((char *)&(sym) - (char *)&__realmode_code))
  43
  44 /* to have a common register file for interrupt handlers */
  45 X86EMU_sysEnv _X86EMU_env;
  46
  47 unsigned int (*realmode_call)(u32 addr, u32 eax, u32 ebx, u32 ecx, u32 edx,
  48                 u32 esi, u32 edi) asmlinkage;
  49
  50 unsigned int (*realmode_interrupt)(u32 intno, u32 eax, u32 ebx, u32 ecx,
  51                 u32 edx, u32 esi, u32 edi) asmlinkage;
  52
  53 static void setup_realmode_code(void)
  54 {
  55         memcpy(REALMODE_BASE, &__realmode_code, __realmode_code_size);
  56
  57         /* Ensure the global pointers are relocated properly. */
  58         realmode_call = PTR_TO_REAL_MODE(__realmode_call);
  59         realmode_interrupt = PTR_TO_REAL_MODE(__realmode_interrupt);
  60
  61         printk(BIOS_SPEW, "Real mode stub @%p: %d bytes\n", REALMODE_BASE,
  62                         __realmode_code_size);
  63 }
  64
  65 static void setup_rombios(void)
  66 {
  67         const char date[] = "06/11/99";
  68         memcpy((void *)0xffff5, &date, 8);
  69
  70         const char ident[] = "PCI_ISA";
  71         memcpy((void *)0xfffd9, &ident, 7);
  72
  73         /* system model: IBM-AT */
  74         write8((void *)0xffffe, 0xfc);
  75 }
  76
  77 static int (*intXX_handler[256])(void) = { NULL };
  78
  79 static int intXX_exception_handler(void)
  80 {
  81         /* compatibility shim */
  82         struct eregs reg_info = {
  83                 .eax=X86_EAX,
  84                 .ecx=X86_ECX,
  85                 .edx=X86_EDX,
  86                 .ebx=X86_EBX,
  87                 .esp=X86_ESP,
  88                 .ebp=X86_EBP,
  89                 .esi=X86_ESI,
  90                 .edi=X86_EDI,
  91                 .vector=M.x86.intno,
  92                 .error_code=0, // FIXME: fill in
  93                 .cs=X86_CS,
  94 #if ENV_X86_64
  95                 .rip=X86_EIP,
  96                 .rflags=X86_EFLAGS
  97 #else
  98                 .eip=X86_EIP,
  99                 .eflags=X86_EFLAGS
 100 #endif
 101         };
 102         struct eregs *regs = &reg_info;
 103
 104         printk(BIOS_INFO, "Oops, exception %d while executing option rom\n",
 105                (uint32_t)regs->vector);
 106         x86_exception(regs);    // Call coreboot exception handler
 107
 108         return 0;               // Never really returns
 109 }
 110
 111 static int intXX_unknown_handler(void)
 112 {
 113         printk(BIOS_INFO, "Unsupported software interrupt #0x%x eax 0x%x\n",
 114                         M.x86.intno, X86_EAX);
 115
 116         return -1;
 117 }
 118
 119 /* setup interrupt handlers for mainboard */
 120 void mainboard_interrupt_handlers(int intXX, int (*intXX_func)(void))
 121 {
 122         intXX_handler[intXX] = intXX_func;
 123 }
 124
 125 static void setup_interrupt_handlers(void)
 126 {
 127         int i;
 128
 129         /* The first 16 intXX functions are not BIOS services,
 130          * but the CPU-generated exceptions ("hardware interrupts")
 131          */
 132         for (i = 0; i < 0x10; i++)
 133                 intXX_handler[i] = &intXX_exception_handler;
 134
 135         /* Mark all other intXX calls as unknown first */
 136         for (i = 0x10; i < 0x100; i++)
 137         {
 138                 /* If the mainboard_interrupt_handler isn't called first.
 139                  */
 140                 if (!intXX_handler[i])
 141                 {
 142                         /* Now set the default functions that are actually
 143                          * needed to initialize the option roms. This is
 144                          * very slick, as it allows us to implement mainboard
 145                          * specific interrupt handlers, such as the int15.
 146                          */
 147                         switch (i) {
 148                         case 0x10:
 149                                 intXX_handler[0x10] = &int10_handler;
 150                                 break;
 151                         case 0x12:
 152                                 intXX_handler[0x12] = &int12_handler;
 153                                 break;
 154                         case 0x16:
 155                                 intXX_handler[0x16] = &int16_handler;
 156                                 break;
 157                         case 0x1a:
 158                                 intXX_handler[0x1a] = &int1a_handler;
 159                                 break;
 160                         default:
 161                                 intXX_handler[i] = &intXX_unknown_handler;
 162                                 break;
 163                         }
 164                 }
 165         }
 166 }
 167
 168 static void write_idt_stub(void *target, u8 intnum)
 169 {
 170         unsigned char *codeptr;
 171         codeptr = (unsigned char *) target;
 172         memcpy(codeptr, &__idt_handler, __idt_handler_size);
 173         codeptr[3] = intnum; /* modify int# in the code stub. */
 174 }
 175
 176 static void setup_realmode_idt(void)
 177 {
 178         struct realmode_idt *idts = (struct realmode_idt *) 0;
 179         int i;
 180
 181         /* Copy IDT stub code for each interrupt. This might seem wasteful
 182          * but it is really simple
 183          */
 184          for (i = 0; i < 256; i++) {
 185                 idts[i].cs = 0;
 186                 idts[i].offset = 0x1000 + (i * __idt_handler_size);
 187                 write_idt_stub((void *)((uintptr_t)idts[i].offset), i);
 188         }
 189
 190         /* Many option ROMs use the hard coded interrupt entry points in the
 191          * system bios. So install them at the known locations.
 192          */
 193
 194         /* int42 is the relocated int10 */
 195         write_idt_stub((void *)0xff065, 0x42);
 196         /* BIOS Int 11 Handler F000:F84D */
 197         write_idt_stub((void *)0xff84d, 0x11);
 198         /* BIOS Int 12 Handler F000:F841 */
 199         write_idt_stub((void *)0xff841, 0x12);
 200         /* BIOS Int 13 Handler F000:EC59 */
 201         write_idt_stub((void *)0xfec59, 0x13);
 202         /* BIOS Int 14 Handler F000:E739 */
 203         write_idt_stub((void *)0xfe739, 0x14);
 204         /* BIOS Int 15 Handler F000:F859 */
 205         write_idt_stub((void *)0xff859, 0x15);
 206         /* BIOS Int 16 Handler F000:E82E */
 207         write_idt_stub((void *)0xfe82e, 0x16);
 208         /* BIOS Int 17 Handler F000:EFD2 */
 209         write_idt_stub((void *)0xfefd2, 0x17);
 210         /* ROM BIOS Int 1A Handler F000:FE6E */
 211         write_idt_stub((void *)0xffe6e, 0x1a);
 212 }
 213
 214 #if CONFIG(FRAMEBUFFER_SET_VESA_MODE)
 215 static vbe_mode_info_t mode_info;
 216 static int mode_info_valid;
 217
 218 const vbe_mode_info_t *vbe_mode_info(void)
 219 {
 220         if (!mode_info_valid || !mode_info.vesa.phys_base_ptr)
 221                 return NULL;
 222         return &mode_info;
 223 }
 224
 225 static int vbe_check_for_failure(int ah);
 226
 227 static u8 vbe_get_ctrl_info(vbe_info_block *info)
 228 {
 229         char *buffer = PTR_TO_REAL_MODE(__realmode_buffer);
 230         u16 buffer_seg = (((unsigned long)buffer) >> 4) & 0xff00;
 231         u16 buffer_adr = ((unsigned long)buffer) & 0xffff;
 232         X86_EAX = realmode_interrupt(0x10, VESA_GET_INFO, 0x0000, 0x0000,
 233                         0x0000, buffer_seg, buffer_adr);
 234         /* If the VBE function completed successfully, 0x0 is returned in AH */
 235         if (X86_AH) {
 236                 printk(BIOS_WARNING, "Error from VGA BIOS in %s\n", __func__);
 237                 return 1;
 238         }
 239         memcpy(info, buffer, sizeof(vbe_info_block));
 240         return 0;
 241 }
 242
 243 static void vbe_oprom_list_supported_mode(uint16_t *video_mode_ptr)
 244 {
 245         uint16_t mode;
 246         printk(BIOS_DEBUG, "Supported Video Mode list for OpRom:\n");
 247         do {
 248                 mode = *video_mode_ptr++;
 249                 if (mode != 0xffff)
 250                         printk(BIOS_DEBUG, "%x\n", mode);
 251         } while (mode != 0xffff);
 252 }
 253
 254 static u8 vbe_oprom_supported_mode_list(void)
 255 {
 256         uint16_t segment, offset;
 257         vbe_info_block info;
 258
 259         if (vbe_get_ctrl_info(&info))
 260                 return 1;
 261
 262         offset = info.video_mode_ptr;
 263         segment = info.video_mode_ptr >> 16;
 264
 265         vbe_oprom_list_supported_mode((uint16_t *)((segment << 4) + offset));
 266         return 0;
 267 }
 268 /*
 269  * EAX register is used to indicate the completion status upon return from
 270  * VBE function in real mode.
 271  *
 272  * If the VBE function completed successfully then 0x0 is returned in the AH
 273  * register. Otherwise the AH register is set with the nature of the failure:
 274  *
 275  * AH == 0x00: Function call successful
 276  * AH == 0x01: Function call failed
 277  * AH == 0x02: Function is not supported in the current HW configuration
 278  * AH == 0x03: Function call invalid in current video mode
 279  *
 280  * Return 0 on success else -1 for failure
 281  */
 282 static int vbe_check_for_failure(int ah)
 283 {
 284         int status;
 285
 286         switch (ah) {
 287         case 0x0:
 288                 status = 0;
 289                 break;
 290         case 1:
 291                 printk(BIOS_DEBUG, "VBE: Function call failed!\n");
 292                 status = -1;
 293                 break;
 294         case 2:
 295                 printk(BIOS_DEBUG, "VBE: Function is not supported!\n");
 296                 status = -1;
 297                 break;
 298         case 3:
 299         default:
 300                 printk(BIOS_DEBUG, "VBE: Unsupported video mode %x!\n",
 301                         CONFIG_FRAMEBUFFER_VESA_MODE);
 302                 if (vbe_oprom_supported_mode_list())
 303                         printk(BIOS_WARNING, "VBE Warning: Could not get VBE mode list.\n");
 304                 status = -1;
 305                 break;
 306         }
 307
 308         return status;
 309 }
 310 static u8 vbe_get_mode_info(vbe_mode_info_t * mi)
 311 {
 312         printk(BIOS_DEBUG, "VBE: Getting information about VESA mode %04x\n",
 313                 mi->video_mode);
 314         char *buffer = PTR_TO_REAL_MODE(__realmode_buffer);
 315         u16 buffer_seg = (((unsigned long)buffer) >> 4) & 0xff00;
 316         u16 buffer_adr = ((unsigned long)buffer) & 0xffff;
 317         X86_EAX = realmode_interrupt(0x10, VESA_GET_MODE_INFO, 0x0000,
 318                         mi->video_mode, 0x0000, buffer_seg, buffer_adr);
 319         if (vbe_check_for_failure(X86_AH)) {
 320                 printk(BIOS_WARNING, "VBE Warning: Error from VGA BIOS in %s\n", __func__);
 321                 return 1;
 322         }
 323         memcpy(mi->mode_info_block, buffer, sizeof(mi->mode_info_block));
 324         mode_info_valid = 1;
 325         return 0;
 326 }
 327
 328 static u8 vbe_set_mode(vbe_mode_info_t * mi)
 329 {
 330         printk(BIOS_DEBUG, "VBE: Setting VESA mode %04x\n", mi->video_mode);
 331         // request linear framebuffer mode
 332         mi->video_mode |= (1 << 14);
 333         // request clearing of framebuffer
 334         mi->video_mode &= ~(1 << 15);
 335         X86_EAX = realmode_interrupt(0x10, VESA_SET_MODE, mi->video_mode,
 336                         0x0000, 0x0000, 0x0000, 0x0000);
 337         if (vbe_check_for_failure(X86_AH)) {
 338                 printk(BIOS_WARNING, "VBE Warning: Error from VGA BIOS in %s\n", __func__);
 339                 return 1;
 340         }
 341         return 0;
 342 }
 343
 344 /* These two functions could probably even be generic between
 345  * yabel and x86 native. TBD later.
 346  */
 347 void vbe_set_graphics(void)
 348 {
 349         mode_info.video_mode = (1 << 14) | CONFIG_FRAMEBUFFER_VESA_MODE;
 350         if (vbe_get_mode_info(&mode_info)) {
 351                 printk(BIOS_WARNING, "VBE Warning: Could not get VBE graphics mode info.\n");
 352                 return;
 353         }
 354         unsigned char *framebuffer =
 355                 (unsigned char *)mode_info.vesa.phys_base_ptr;
 356         printk(BIOS_DEBUG, "VBE: resolution:  %dx%d@%d\n",
 357                 le16_to_cpu(mode_info.vesa.x_resolution),
 358                 le16_to_cpu(mode_info.vesa.y_resolution),
 359                 mode_info.vesa.bits_per_pixel);
 360
 361         printk(BIOS_DEBUG, "VBE: framebuffer: %p\n", framebuffer);
 362         if (!framebuffer) {
 363                 printk(BIOS_DEBUG, "VBE: Mode does not support linear "
 364                         "framebuffer\n");
 365                 return;
 366         }
 367
 368         if (vbe_set_mode(&mode_info)) {
 369                 printk(BIOS_WARNING, "VBE Warning: Could not set VBE graphics mode.\n");
 370                 return;
 371         }
 372         const struct lb_framebuffer fb = {
 373                 .physical_address    = mode_info.vesa.phys_base_ptr,
 374                 .x_resolution        = le16_to_cpu(mode_info.vesa.x_resolution),
 375                 .y_resolution        = le16_to_cpu(mode_info.vesa.y_resolution),
 376                 .bytes_per_line      = le16_to_cpu(mode_info.vesa.bytes_per_scanline),
 377                 .bits_per_pixel      = mode_info.vesa.bits_per_pixel,
 378                 .red_mask_pos        = mode_info.vesa.red_mask_pos,
 379                 .red_mask_size       = mode_info.vesa.red_mask_size,
 380                 .green_mask_pos      = mode_info.vesa.green_mask_pos,
 381                 .green_mask_size     = mode_info.vesa.green_mask_size,
 382                 .blue_mask_pos       = mode_info.vesa.blue_mask_pos,
 383                 .blue_mask_size      = mode_info.vesa.blue_mask_size,
 384                 .reserved_mask_pos   = mode_info.vesa.reserved_mask_pos,
 385                 .reserved_mask_size  = mode_info.vesa.reserved_mask_size,
 386                 .orientation         = LB_FB_ORIENTATION_NORMAL,
 387         };
 388
 389         fb_add_framebuffer_info_ex(&fb);
 390 }
 391
 392 void vbe_textmode_console(void)
 393 {
 394         u8 retval = 1;
 395         if (mode_info.vesa.phys_base_ptr) {
 396                 delay(2);
 397                 X86_EAX = realmode_interrupt(0x10, 0x0003, 0x0000, 0x0000,
 398                                         0x0000, 0x0000, 0x0000);
 399                 if (!vbe_check_for_failure(X86_AH))
 400                         retval = 0;
 401         }
 402
 403         if (retval)
 404                 printk(BIOS_WARNING, "VBE Warning: Could not set VBE text mode.\n");
 405 }
 406
 407 #endif
 408
 409 void run_bios(struct device *dev, unsigned long addr)
 410 {
 411         u32 num_dev = (dev->bus->secondary << 8) | dev->path.pci.devfn;
 412
 413         /* Setting up required hardware.
 414          * Removing this will cause random illegal instruction exceptions
 415          * in some option roms.
 416          */
 417         setup_i8259();
 418         setup_i8254();
 419
 420         /* Set up some legacy information in the F segment */
 421         setup_rombios();
 422
 423         /* Set up C interrupt handlers */
 424         setup_interrupt_handlers();
 425
 426         /* Set up real-mode IDT */
 427         setup_realmode_idt();
 428
 429         /* Make sure the code is placed. */
 430         setup_realmode_code();
 431
 432         printk(BIOS_DEBUG, "Calling Option ROM...\n");
 433         /* TODO ES:DI Pointer to System BIOS PnP Installation Check Structure */
 434         /* Option ROM entry point is at OPROM start + 3 */
 435         realmode_call(addr + 0x0003, num_dev, 0xffff, 0x0000, 0xffff, 0x0, 0x0);
 436         printk(BIOS_DEBUG, "... Option ROM returned.\n");
 437
 438 #if CONFIG(FRAMEBUFFER_SET_VESA_MODE)
 439         if ((dev->class >> 8)== PCI_CLASS_DISPLAY_VGA)
 440                 vbe_set_graphics();
 441 #endif
 442 }
 443
 444 /* interrupt_handler() is called from assembler code only,
 445  * so there is no use in putting the prototype into a header file.
 446  */
 447 int asmlinkage interrupt_handler(u32 intnumber,
 448             u32 gsfs, u32 dses,
 449             u32 edi, u32 esi,
 450             u32 ebp, u32 esp,
 451             u32 ebx, u32 edx,
 452             u32 ecx, u32 eax,
 453             u32 cs_ip, u16 stackflags);
 454
 455 int asmlinkage interrupt_handler(u32 intnumber,
 456             u32 gsfs, u32 dses,
 457             u32 edi, u32 esi,
 458             u32 ebp, u32 esp,
 459             u32 ebx, u32 edx,
 460             u32 ecx, u32 eax,
 461             u32 cs_ip, u16 stackflags)
 462 {
 463         u32 ip;
 464         u32 cs;
 465         u32 flags;
 466         int ret = 0;
 467
 468         ip = cs_ip & 0xffff;
 469         cs = cs_ip >> 16;
 470         flags = stackflags;
 471
 472 #if CONFIG(REALMODE_DEBUG)
 473         printk(BIOS_DEBUG, "oprom: INT# 0x%x\n", intnumber);
 474         printk(BIOS_DEBUG, "oprom: eax: %08x ebx: %08x ecx: %08x edx: %08x\n",
 475                       eax, ebx, ecx, edx);
 476         printk(BIOS_DEBUG, "oprom: ebp: %08x esp: %08x edi: %08x esi: %08x\n",
 477                      ebp, esp, edi, esi);
 478         printk(BIOS_DEBUG, "oprom:  ip: %04x      cs: %04x   flags: %08x\n",
 479                      ip, cs, flags);
 480 #endif
 481
 482         // Fetch arguments from the stack and put them to a place
 483         // suitable for the interrupt handlers
 484         X86_EAX = eax;
 485         X86_ECX = ecx;
 486         X86_EDX = edx;
 487         X86_EBX = ebx;
 488         X86_ESP = esp;
 489         X86_EBP = ebp;
 490         X86_ESI = esi;
 491         X86_EDI = edi;
 492         M.x86.intno = intnumber;
 493         /* TODO: error_code must be stored somewhere */
 494         X86_EIP = ip;
 495         X86_CS = cs;
 496         X86_EFLAGS = flags;
 497
 498         // Call the interrupt handler for this int#
 499         ret = intXX_handler[intnumber]();
 500
 501         // Put registers back on the stack. The assembler code
 502         // will later pop them.
 503         // What happens here is that we force (volatile!) changing
 504         // the values of the parameters of this function. We do this
 505         // because we know that they stay alive on the stack after
 506         // we leave this function. Don't say this is bollocks.
 507         *(volatile u32 *)&eax = X86_EAX;
 508         *(volatile u32 *)&ecx = X86_ECX;
 509         *(volatile u32 *)&edx = X86_EDX;
 510         *(volatile u32 *)&ebx = X86_EBX;
 511         *(volatile u32 *)&esi = X86_ESI;
 512         *(volatile u32 *)&edi = X86_EDI;
 513         flags = X86_EFLAGS;
 514
 515         /* Pass success or error back to our caller via the CARRY flag */
 516         if (ret) {
 517                 flags &= ~1; // no error: clear carry
 518         }else{
 519                 printk(BIOS_DEBUG,"int%02x call returned error.\n", intnumber);
 520                 flags |= 1;  // error: set carry
 521         }
 522         *(volatile u16 *)&stackflags = flags;
 523
 524         /* The assembler code doesn't actually care for the return value,
 525          * but keep it around so its expectations are met */
 526         return ret;
 527 }