u-boot/arch/x86/lib/bios.c
Simon Glass 0ca2426bea x86: Add support for running option ROMs natively
On x86 machines we can use an emulator to run option ROMS as with other
architectures. But with some additional effort (mostly due to the 16-bit
nature of option ROMs) we can run them natively. Add support for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
2014-11-25 06:38:57 -07:00

347 lines
8.7 KiB
C

/*
* From Coreboot file device/oprom/realmode/x86.c
*
* Copyright (C) 2007 Advanced Micro Devices, Inc.
* Copyright (C) 2009-2010 coresystems GmbH
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <common.h>
#include <bios_emul.h>
#include <vbe.h>
#include <asm/cache.h>
#include <asm/processor.h>
#include <asm/i8259.h>
#include <asm/io.h>
#include <asm/post.h>
#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 */
X86EMU_sysEnv _X86EMU_env;
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 = &reg_info;
debug("Oops, 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 *)((u32)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);
}
static u8 vbe_get_mode_info(struct vbe_mode_info *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 vbe_mode_info));
mi->valid = true;
return 0;
}
static u8 vbe_set_mode(struct vbe_mode_info *mi)
{
debug("VBE: Setting VESA mode %#04x\n", mi->video_mode);
/* request linear framebuffer mode */
mi->video_mode |= (1 << 14);
/* request clearing of framebuffer */
mi->video_mode &= ~(1 << 15);
realmode_interrupt(0x10, VESA_SET_MODE, mi->video_mode,
0x0000, 0x0000, 0x0000, 0x0000);
return 0;
}
static void vbe_set_graphics(int vesa_mode, struct vbe_mode_info *mode_info)
{
unsigned char *framebuffer;
mode_info->video_mode = (1 << 14) | vesa_mode;
vbe_get_mode_info(mode_info);
framebuffer = (unsigned char *)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;
}
vbe_set_mode(mode_info);
}
void bios_run_on_x86(pci_dev_t pcidev, unsigned long addr, int vesa_mode,
struct vbe_mode_info *mode_info)
{
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();
disable_caches();
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");
if (vesa_mode != -1)
vbe_set_graphics(vesa_mode, mode_info);
}
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;
}