// SPDX-License-Identifier: GPL-2.0 /* * From Coreboot file device/oprom/realmode/x86.c * * Copyright (C) 2007 Advanced Micro Devices, Inc. * Copyright (C) 2009-2010 coresystems GmbH */ #include #include #include #include #include #include #include #include #include #include #include #include #include "bios.h" /* Interrupt handlers for each interrupt the ROM can call */ static int (*int_handler[256])(void); /* to have a common register file for interrupt handlers */ #if !CONFIG_IS_ENABLED(BIOSEMU) X86EMU_sysEnv _X86EMU_env; #endif asmlinkage void (*realmode_call)(u32 addr, u32 eax, u32 ebx, u32 ecx, u32 edx, u32 esi, u32 edi); asmlinkage void (*realmode_interrupt)(u32 intno, u32 eax, u32 ebx, u32 ecx, u32 edx, u32 esi, u32 edi); static void setup_realmode_code(void) { memcpy((void *)REALMODE_BASE, &asm_realmode_code, asm_realmode_code_size); /* Ensure the global pointers are relocated properly. */ realmode_call = PTR_TO_REAL_MODE(asm_realmode_call); realmode_interrupt = PTR_TO_REAL_MODE(__realmode_interrupt); debug("Real mode stub @%x: %d bytes\n", REALMODE_BASE, asm_realmode_code_size); } static void setup_rombios(void) { const char date[] = "06/11/99"; memcpy((void *)0xffff5, &date, 8); const char ident[] = "PCI_ISA"; memcpy((void *)0xfffd9, &ident, 7); /* system model: IBM-AT */ writeb(0xfc, 0xffffe); } static int int_exception_handler(void) { /* compatibility shim */ struct eregs reg_info = { .eax = M.x86.R_EAX, .ecx = M.x86.R_ECX, .edx = M.x86.R_EDX, .ebx = M.x86.R_EBX, .esp = M.x86.R_ESP, .ebp = M.x86.R_EBP, .esi = M.x86.R_ESI, .edi = M.x86.R_EDI, .vector = M.x86.intno, .error_code = 0, .eip = M.x86.R_EIP, .cs = M.x86.R_CS, .eflags = M.x86.R_EFLG }; struct eregs *regs = ®_info; log_err("Exception %d while executing option rom\n", regs->vector); cpu_hlt(); return 0; } static int int_unknown_handler(void) { debug("Unsupported software interrupt #0x%x eax 0x%x\n", M.x86.intno, M.x86.R_EAX); return -1; } /* setup interrupt handlers for mainboard */ void bios_set_interrupt_handler(int intnum, int (*int_func)(void)) { int_handler[intnum] = int_func; } static void setup_interrupt_handlers(void) { int i; /* * The first 16 int_handler functions are not BIOS services, * but the CPU-generated exceptions ("hardware interrupts") */ for (i = 0; i < 0x10; i++) int_handler[i] = &int_exception_handler; /* Mark all other int_handler calls as unknown first */ for (i = 0x10; i < 0x100; i++) { /* Skip if bios_set_interrupt_handler() isn't called first */ if (int_handler[i]) continue; /* * Now set the default functions that are actually needed * to initialize the option roms. The board may override * these with bios_set_interrupt_handler() */ switch (i) { case 0x10: int_handler[0x10] = &int10_handler; break; case 0x12: int_handler[0x12] = &int12_handler; break; case 0x16: int_handler[0x16] = &int16_handler; break; case 0x1a: int_handler[0x1a] = &int1a_handler; break; default: int_handler[i] = &int_unknown_handler; break; } } } static void write_idt_stub(void *target, u8 intnum) { unsigned char *codeptr; codeptr = (unsigned char *)target; memcpy(codeptr, &__idt_handler, __idt_handler_size); codeptr[3] = intnum; /* modify int# in the code stub. */ } static void setup_realmode_idt(void) { struct realmode_idt *idts = NULL; int i; /* * Copy IDT stub code for each interrupt. This might seem wasteful * but it is really simple */ for (i = 0; i < 256; i++) { idts[i].cs = 0; idts[i].offset = 0x1000 + (i * __idt_handler_size); write_idt_stub((void *)((ulong)idts[i].offset), i); } /* * Many option ROMs use the hard coded interrupt entry points in the * system bios. So install them at the known locations. */ /* int42 is the relocated int10 */ write_idt_stub((void *)0xff065, 0x42); /* BIOS Int 11 Handler F000:F84D */ write_idt_stub((void *)0xff84d, 0x11); /* BIOS Int 12 Handler F000:F841 */ write_idt_stub((void *)0xff841, 0x12); /* BIOS Int 13 Handler F000:EC59 */ write_idt_stub((void *)0xfec59, 0x13); /* BIOS Int 14 Handler F000:E739 */ write_idt_stub((void *)0xfe739, 0x14); /* BIOS Int 15 Handler F000:F859 */ write_idt_stub((void *)0xff859, 0x15); /* BIOS Int 16 Handler F000:E82E */ write_idt_stub((void *)0xfe82e, 0x16); /* BIOS Int 17 Handler F000:EFD2 */ write_idt_stub((void *)0xfefd2, 0x17); /* ROM BIOS Int 1A Handler F000:FE6E */ write_idt_stub((void *)0xffe6e, 0x1a); } #ifdef CONFIG_FRAMEBUFFER_SET_VESA_MODE static u8 vbe_get_mode_info(struct vesa_state *mi) { u16 buffer_seg; u16 buffer_adr; char *buffer; debug("VBE: Getting information about VESA mode %04x\n", mi->video_mode); buffer = PTR_TO_REAL_MODE(asm_realmode_buffer); buffer_seg = (((unsigned long)buffer) >> 4) & 0xff00; buffer_adr = ((unsigned long)buffer) & 0xffff; realmode_interrupt(0x10, VESA_GET_MODE_INFO, 0x0000, mi->video_mode, 0x0000, buffer_seg, buffer_adr); memcpy(mi->mode_info_block, buffer, sizeof(struct vesa_mode_info)); mi->valid = true; return 0; } static u8 vbe_set_mode(struct vesa_state *mi) { int video_mode = mi->video_mode; debug("VBE: Setting VESA mode %#04x\n", video_mode); /* request linear framebuffer mode */ video_mode |= (1 << 14); /* don't clear the framebuffer, we do that later */ video_mode |= (1 << 15); realmode_interrupt(0x10, VESA_SET_MODE, video_mode, 0x0000, 0x0000, 0x0000, 0x0000); return 0; } static void vbe_set_graphics(int vesa_mode, struct vesa_state *mode_info) { unsigned char *framebuffer; mode_info->video_mode = (1 << 14) | vesa_mode; vbe_get_mode_info(mode_info); framebuffer = (unsigned char *)(ulong)mode_info->vesa.phys_base_ptr; debug("VBE: resolution: %dx%d@%d\n", le16_to_cpu(mode_info->vesa.x_resolution), le16_to_cpu(mode_info->vesa.y_resolution), mode_info->vesa.bits_per_pixel); debug("VBE: framebuffer: %p\n", framebuffer); if (!framebuffer) { debug("VBE: Mode does not support linear framebuffer\n"); return; } mode_info->video_mode &= 0x3ff; vbe_set_mode(mode_info); } #endif /* CONFIG_FRAMEBUFFER_SET_VESA_MODE */ void bios_run_on_x86(struct udevice *dev, unsigned long addr, int vesa_mode, struct vesa_state *mode_info) { pci_dev_t pcidev = dm_pci_get_bdf(dev); u32 num_dev; num_dev = PCI_BUS(pcidev) << 8 | PCI_DEV(pcidev) << 3 | PCI_FUNC(pcidev); /* Needed to avoid exceptions in some ROMs */ interrupt_init(); /* Set up some legacy information in the F segment */ setup_rombios(); /* Set up C interrupt handlers */ setup_interrupt_handlers(); /* Set up real-mode IDT */ setup_realmode_idt(); /* Make sure the code is placed. */ setup_realmode_code(); debug("Calling Option ROM at %lx, pci device %#x...", addr, num_dev); /* Option ROM entry point is at OPROM start + 3 */ realmode_call(addr + 0x0003, num_dev, 0xffff, 0x0000, 0xffff, 0x0, 0x0); debug("done\n"); #ifdef CONFIG_FRAMEBUFFER_SET_VESA_MODE if (vesa_mode != -1) vbe_set_graphics(vesa_mode, mode_info); #endif } asmlinkage int interrupt_handler(u32 intnumber, u32 gsfs, u32 dses, u32 edi, u32 esi, u32 ebp, u32 esp, u32 ebx, u32 edx, u32 ecx, u32 eax, u32 cs_ip, u16 stackflags) { u32 ip; u32 cs; u32 flags; int ret = 0; ip = cs_ip & 0xffff; cs = cs_ip >> 16; flags = stackflags; #ifdef CONFIG_REALMODE_DEBUG debug("oprom: INT# 0x%x\n", intnumber); debug("oprom: eax: %08x ebx: %08x ecx: %08x edx: %08x\n", eax, ebx, ecx, edx); debug("oprom: ebp: %08x esp: %08x edi: %08x esi: %08x\n", ebp, esp, edi, esi); debug("oprom: ip: %04x cs: %04x flags: %08x\n", ip, cs, flags); debug("oprom: stackflags = %04x\n", stackflags); #endif /* * Fetch arguments from the stack and put them to a place * suitable for the interrupt handlers */ M.x86.R_EAX = eax; M.x86.R_ECX = ecx; M.x86.R_EDX = edx; M.x86.R_EBX = ebx; M.x86.R_ESP = esp; M.x86.R_EBP = ebp; M.x86.R_ESI = esi; M.x86.R_EDI = edi; M.x86.intno = intnumber; M.x86.R_EIP = ip; M.x86.R_CS = cs; M.x86.R_EFLG = flags; /* Call the interrupt handler for this interrupt number */ ret = int_handler[intnumber](); /* * This code is quite strange... * * Put registers back on the stack. The assembler code will pop them * later. We force (volatile!) changing the values of the parameters * of this function. We know that they stay alive on the stack after * we leave this function. */ *(volatile u32 *)&eax = M.x86.R_EAX; *(volatile u32 *)&ecx = M.x86.R_ECX; *(volatile u32 *)&edx = M.x86.R_EDX; *(volatile u32 *)&ebx = M.x86.R_EBX; *(volatile u32 *)&esi = M.x86.R_ESI; *(volatile u32 *)&edi = M.x86.R_EDI; flags = M.x86.R_EFLG; /* Pass success or error back to our caller via the CARRY flag */ if (ret) { flags &= ~1; /* no error: clear carry */ } else { debug("int%02x call returned error\n", intnumber); flags |= 1; /* error: set carry */ } *(volatile u16 *)&stackflags = flags; return ret; }