1// SPDX-License-Identifier: GPL-2.0 2/* 3 * From Coreboot file device/oprom/realmode/x86.c 4 * 5 * Copyright (C) 2007 Advanced Micro Devices, Inc. 6 * Copyright (C) 2009-2010 coresystems GmbH 7 */ 8#include <common.h> 9#include <compiler.h> 10#include <bios_emul.h> 11#include <irq_func.h> 12#include <log.h> 13#include <vesa.h> 14#include <linux/linkage.h> 15#include <asm/cache.h> 16#include <asm/processor.h> 17#include <asm/i8259.h> 18#include <asm/io.h> 19#include <asm/post.h> 20#include "bios.h" 21 22/* Interrupt handlers for each interrupt the ROM can call */ 23static int (*int_handler[256])(void); 24 25/* to have a common register file for interrupt handlers */ 26#if !CONFIG_IS_ENABLED(BIOSEMU) 27X86EMU_sysEnv _X86EMU_env; 28#endif 29 30asmlinkage void (*realmode_call)(u32 addr, u32 eax, u32 ebx, u32 ecx, u32 edx, 31 u32 esi, u32 edi); 32 33asmlinkage void (*realmode_interrupt)(u32 intno, u32 eax, u32 ebx, u32 ecx, 34 u32 edx, u32 esi, u32 edi); 35 36static void setup_realmode_code(void) 37{ 38 memcpy((void *)REALMODE_BASE, &asm_realmode_code, 39 asm_realmode_code_size); 40 41 /* Ensure the global pointers are relocated properly. */ 42 realmode_call = PTR_TO_REAL_MODE(asm_realmode_call); 43 realmode_interrupt = PTR_TO_REAL_MODE(__realmode_interrupt); 44 45 debug("Real mode stub @%x: %d bytes\n", REALMODE_BASE, 46 asm_realmode_code_size); 47} 48 49static void setup_rombios(void) 50{ 51 const char date[] = "06/11/99"; 52 memcpy((void *)0xffff5, &date, 8); 53 54 const char ident[] = "PCI_ISA"; 55 memcpy((void *)0xfffd9, &ident, 7); 56 57 /* system model: IBM-AT */ 58 writeb(0xfc, 0xffffe); 59} 60 61static int int_exception_handler(void) 62{ 63 /* compatibility shim */ 64 struct eregs reg_info = { 65 .eax = M.x86.R_EAX, 66 .ecx = M.x86.R_ECX, 67 .edx = M.x86.R_EDX, 68 .ebx = M.x86.R_EBX, 69 .esp = M.x86.R_ESP, 70 .ebp = M.x86.R_EBP, 71 .esi = M.x86.R_ESI, 72 .edi = M.x86.R_EDI, 73 .vector = M.x86.intno, 74 .error_code = 0, 75 .eip = M.x86.R_EIP, 76 .cs = M.x86.R_CS, 77 .eflags = M.x86.R_EFLG 78 }; 79 struct eregs *regs = ®_info; 80 81 log_err("Exception %d while executing option rom\n", regs->vector); 82 cpu_hlt(); 83 84 return 0; 85} 86 87static int int_unknown_handler(void) 88{ 89 debug("Unsupported software interrupt #0x%x eax 0x%x\n", 90 M.x86.intno, M.x86.R_EAX); 91 92 return -1; 93} 94 95/* setup interrupt handlers for mainboard */ 96void bios_set_interrupt_handler(int intnum, int (*int_func)(void)) 97{ 98 int_handler[intnum] = int_func; 99} 100 101static void setup_interrupt_handlers(void) 102{ 103 int i; 104 105 /* 106 * The first 16 int_handler functions are not BIOS services, 107 * but the CPU-generated exceptions ("hardware interrupts") 108 */ 109 for (i = 0; i < 0x10; i++) 110 int_handler[i] = &int_exception_handler; 111 112 /* Mark all other int_handler calls as unknown first */ 113 for (i = 0x10; i < 0x100; i++) { 114 /* Skip if bios_set_interrupt_handler() isn't called first */ 115 if (int_handler[i]) 116 continue; 117 118 /* 119 * Now set the default functions that are actually needed 120 * to initialize the option roms. The board may override 121 * these with bios_set_interrupt_handler() 122 */ 123 switch (i) { 124 case 0x10: 125 int_handler[0x10] = &int10_handler; 126 break; 127 case 0x12: 128 int_handler[0x12] = &int12_handler; 129 break; 130 case 0x16: 131 int_handler[0x16] = &int16_handler; 132 break; 133 case 0x1a: 134 int_handler[0x1a] = &int1a_handler; 135 break; 136 default: 137 int_handler[i] = &int_unknown_handler; 138 break; 139 } 140 } 141} 142 143static void write_idt_stub(void *target, u8 intnum) 144{ 145 unsigned char *codeptr; 146 147 codeptr = (unsigned char *)target; 148 memcpy(codeptr, &__idt_handler, __idt_handler_size); 149 codeptr[3] = intnum; /* modify int# in the code stub. */ 150} 151 152static void setup_realmode_idt(void) 153{ 154 struct realmode_idt *idts = NULL; 155 int i; 156 157 /* 158 * Copy IDT stub code for each interrupt. This might seem wasteful 159 * but it is really simple 160 */ 161 for (i = 0; i < 256; i++) { 162 idts[i].cs = 0; 163 idts[i].offset = 0x1000 + (i * __idt_handler_size); 164 write_idt_stub((void *)((ulong)idts[i].offset), i); 165 } 166 167 /* 168 * Many option ROMs use the hard coded interrupt entry points in the 169 * system bios. So install them at the known locations. 170 */ 171 172 /* int42 is the relocated int10 */ 173 write_idt_stub((void *)0xff065, 0x42); 174 /* BIOS Int 11 Handler F000:F84D */ 175 write_idt_stub((void *)0xff84d, 0x11); 176 /* BIOS Int 12 Handler F000:F841 */ 177 write_idt_stub((void *)0xff841, 0x12); 178 /* BIOS Int 13 Handler F000:EC59 */ 179 write_idt_stub((void *)0xfec59, 0x13); 180 /* BIOS Int 14 Handler F000:E739 */ 181 write_idt_stub((void *)0xfe739, 0x14); 182 /* BIOS Int 15 Handler F000:F859 */ 183 write_idt_stub((void *)0xff859, 0x15); 184 /* BIOS Int 16 Handler F000:E82E */ 185 write_idt_stub((void *)0xfe82e, 0x16); 186 /* BIOS Int 17 Handler F000:EFD2 */ 187 write_idt_stub((void *)0xfefd2, 0x17); 188 /* ROM BIOS Int 1A Handler F000:FE6E */ 189 write_idt_stub((void *)0xffe6e, 0x1a); 190} 191 192#ifdef CONFIG_FRAMEBUFFER_SET_VESA_MODE 193static u8 vbe_get_mode_info(struct vesa_state *mi) 194{ 195 u16 buffer_seg; 196 u16 buffer_adr; 197 char *buffer; 198 199 debug("VBE: Getting information about VESA mode %04x\n", 200 mi->video_mode); 201 buffer = PTR_TO_REAL_MODE(asm_realmode_buffer); 202 buffer_seg = (((unsigned long)buffer) >> 4) & 0xff00; 203 buffer_adr = ((unsigned long)buffer) & 0xffff; 204 205 realmode_interrupt(0x10, VESA_GET_MODE_INFO, 0x0000, mi->video_mode, 206 0x0000, buffer_seg, buffer_adr); 207 memcpy(mi->mode_info_block, buffer, sizeof(struct vesa_mode_info)); 208 mi->valid = true; 209 210 return 0; 211} 212 213static u8 vbe_set_mode(struct vesa_state *mi) 214{ 215 int video_mode = mi->video_mode; 216 217 debug("VBE: Setting VESA mode %#04x\n", video_mode); 218 /* request linear framebuffer mode */ 219 video_mode |= (1 << 14); 220 /* don't clear the framebuffer, we do that later */ 221 video_mode |= (1 << 15); 222 realmode_interrupt(0x10, VESA_SET_MODE, video_mode, 223 0x0000, 0x0000, 0x0000, 0x0000); 224 225 return 0; 226} 227 228static void vbe_set_graphics(int vesa_mode, struct vesa_state *mode_info) 229{ 230 unsigned char *framebuffer; 231 232 mode_info->video_mode = (1 << 14) | vesa_mode; 233 vbe_get_mode_info(mode_info); 234 235 framebuffer = (unsigned char *)(ulong)mode_info->vesa.phys_base_ptr; 236 debug("VBE: resolution: %dx%d@%d\n", 237 le16_to_cpu(mode_info->vesa.x_resolution), 238 le16_to_cpu(mode_info->vesa.y_resolution), 239 mode_info->vesa.bits_per_pixel); 240 debug("VBE: framebuffer: %p\n", framebuffer); 241 if (!framebuffer) { 242 debug("VBE: Mode does not support linear framebuffer\n"); 243 return; 244 } 245 246 mode_info->video_mode &= 0x3ff; 247 vbe_set_mode(mode_info); 248} 249#endif /* CONFIG_FRAMEBUFFER_SET_VESA_MODE */ 250 251void bios_run_on_x86(struct udevice *dev, unsigned long addr, int vesa_mode, 252 struct vesa_state *mode_info) 253{ 254 pci_dev_t pcidev = dm_pci_get_bdf(dev); 255 u32 num_dev; 256 257 num_dev = PCI_BUS(pcidev) << 8 | PCI_DEV(pcidev) << 3 | 258 PCI_FUNC(pcidev); 259 260 /* Needed to avoid exceptions in some ROMs */ 261 interrupt_init(); 262 263 /* Set up some legacy information in the F segment */ 264 setup_rombios(); 265 266 /* Set up C interrupt handlers */ 267 setup_interrupt_handlers(); 268 269 /* Set up real-mode IDT */ 270 setup_realmode_idt(); 271 272 /* Make sure the code is placed. */ 273 setup_realmode_code(); 274 275 debug("Calling Option ROM at %lx, pci device %#x...", addr, num_dev); 276 277 /* Option ROM entry point is at OPROM start + 3 */ 278 realmode_call(addr + 0x0003, num_dev, 0xffff, 0x0000, 0xffff, 0x0, 279 0x0); 280 debug("done\n"); 281 282#ifdef CONFIG_FRAMEBUFFER_SET_VESA_MODE 283 if (vesa_mode != -1) 284 vbe_set_graphics(vesa_mode, mode_info); 285#endif 286} 287 288asmlinkage int interrupt_handler(u32 intnumber, u32 gsfs, u32 dses, 289 u32 edi, u32 esi, u32 ebp, u32 esp, 290 u32 ebx, u32 edx, u32 ecx, u32 eax, 291 u32 cs_ip, u16 stackflags) 292{ 293 u32 ip; 294 u32 cs; 295 u32 flags; 296 int ret = 0; 297 298 ip = cs_ip & 0xffff; 299 cs = cs_ip >> 16; 300 flags = stackflags; 301 302#ifdef CONFIG_REALMODE_DEBUG 303 debug("oprom: INT# 0x%x\n", intnumber); 304 debug("oprom: eax: %08x ebx: %08x ecx: %08x edx: %08x\n", 305 eax, ebx, ecx, edx); 306 debug("oprom: ebp: %08x esp: %08x edi: %08x esi: %08x\n", 307 ebp, esp, edi, esi); 308 debug("oprom: ip: %04x cs: %04x flags: %08x\n", 309 ip, cs, flags); 310 debug("oprom: stackflags = %04x\n", stackflags); 311#endif 312 313 /* 314 * Fetch arguments from the stack and put them to a place 315 * suitable for the interrupt handlers 316 */ 317 M.x86.R_EAX = eax; 318 M.x86.R_ECX = ecx; 319 M.x86.R_EDX = edx; 320 M.x86.R_EBX = ebx; 321 M.x86.R_ESP = esp; 322 M.x86.R_EBP = ebp; 323 M.x86.R_ESI = esi; 324 M.x86.R_EDI = edi; 325 M.x86.intno = intnumber; 326 M.x86.R_EIP = ip; 327 M.x86.R_CS = cs; 328 M.x86.R_EFLG = flags; 329 330 /* Call the interrupt handler for this interrupt number */ 331 ret = int_handler[intnumber](); 332 333 /* 334 * This code is quite strange... 335 * 336 * Put registers back on the stack. The assembler code will pop them 337 * later. We force (volatile!) changing the values of the parameters 338 * of this function. We know that they stay alive on the stack after 339 * we leave this function. 340 */ 341 *(volatile u32 *)&eax = M.x86.R_EAX; 342 *(volatile u32 *)&ecx = M.x86.R_ECX; 343 *(volatile u32 *)&edx = M.x86.R_EDX; 344 *(volatile u32 *)&ebx = M.x86.R_EBX; 345 *(volatile u32 *)&esi = M.x86.R_ESI; 346 *(volatile u32 *)&edi = M.x86.R_EDI; 347 flags = M.x86.R_EFLG; 348 349 /* Pass success or error back to our caller via the CARRY flag */ 350 if (ret) { 351 flags &= ~1; /* no error: clear carry */ 352 } else { 353 debug("int%02x call returned error\n", intnumber); 354 flags |= 1; /* error: set carry */ 355 } 356 *(volatile u16 *)&stackflags = flags; 357 358 return ret; 359} 360