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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2009 coresystems GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <device/pci.h>
#include <string.h>
#ifdef CONFIG_COREBOOT_V2
#include <arch/io.h>
#include <arch/registers.h>
#include <console/console.h>
#define printk(x...) do_printk(x)
#else
#include <console.h>
#endif
#define REALMODE_BASE ((void *)0x500)
struct realmode_idt {
u16 offset, cs;
};
void x86_exception(struct eregs *info);
extern unsigned char __idt_handler, __idt_handler_size;
extern unsigned char __realmode_code, __realmode_code_size;
extern unsigned char __run_optionrom, __run_interrupt;
void (*run_optionrom)(u32 devfn) = (void *)&__run_optionrom;
void (*vga_enable_console)(void) = (void *)&__run_interrupt;
int (*intXX_handler[256])(struct eregs *regs) = { NULL };
static int intXX_exception_handler(struct eregs *regs)
{
printk(BIOS_INFO, "Oops, exception %d while executing option rom\n",
regs->vector);
x86_exception(regs); // Call coreboot exception handler
return 0; // Never returns?
}
static int intXX_unknown_handler(struct eregs *regs)
{
printk(BIOS_INFO, "Unsupported software interrupt #0x%x\n",
regs->vector);
return -1;
}
int int12_handler(struct eregs *regs);
int int15_handler(struct eregs *regs);
int int1a_handler(struct eregs *regs);
static void setup_interrupt_handlers(void)
{
int i;
/* The first 16 intXX functions are not BIOS services,
* but the CPU-generated exceptions ("hardware interrupts")
*/
for (i = 0; i < 0x10; i++)
intXX_handler[i] = &intXX_exception_handler;
/* Mark all other intXX calls as unknown first */
for (i = 0x10; i < 0x100; i++)
intXX_handler[i] = &intXX_unknown_handler;
/* Now set the default functions that are actually
* needed to initialize the option roms. This is very
* slick, as it allows us to implement mainboard specific
* interrupt handlers, such as the int15
*/
intXX_handler[0x12] = &int12_handler;
intXX_handler[0x15] = &int15_handler;
intXX_handler[0x1a] = &int1a_handler;
}
static void write_idt_stub(void *target, u8 intnum)
{
unsigned char *codeptr;
codeptr = (unsigned char *) target;
memcpy(codeptr, &__idt_handler, (size_t)&__idt_handler_size);
codeptr[3] = intnum; /* modify int# in the code stub. */
}
static void setup_realmode_idt(void)
{
struct realmode_idt *idts = (struct realmode_idt *) 0;
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 * (u32)&__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.
* Only need int10 so far.
*/
/* int42 is the relocated int10 */
write_idt_stub((void *)0xff065, 0x42);
}
void run_bios(struct device *dev, unsigned long addr)
{
int i;
/* clear vga bios data area */
for (i = 0x400; i < 0x500; i++) {
*(unsigned char *) i = 0;
}
/* Set up C interrupt handlers */
setup_interrupt_handlers();
/* Setting up realmode IDT */
setup_realmode_idt();
memcpy(REALMODE_BASE, &__realmode_code, (size_t)&__realmode_code_size);
printk(BIOS_SPEW, "Real mode stub @%p: %d bytes\n", REALMODE_BASE,
(u32)&__realmode_code_size);
printk(BIOS_DEBUG, "Calling Option ROM...\n");
run_optionrom((dev->bus->secondary << 8) | dev->path.pci.devfn);
printk(BIOS_DEBUG, "... Option ROM returned.\n");
}
int __attribute__((regparm(0))) 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 = -1;
struct eregs reg_info;
ip = cs_ip & 0xffff;
cs = cs_ip >> 16;
flags = stackflags;
printk(BIOS_DEBUG, "oprom: INT# 0x%x\n", intnumber);
printk(BIOS_DEBUG, "oprom: eax: %08x ebx: %08x ecx: %08x edx: %08x\n",
eax, ebx, ecx, edx);
printk(BIOS_DEBUG, "oprom: ebp: %08x esp: %08x edi: %08x esi: %08x\n",
ebp, esp, edi, esi);
printk(BIOS_DEBUG, "oprom: ip: %04x cs: %04x flags: %08x\n",
ip, cs, flags);
// Fetch arguments from the stack and put them into
// a structure that we want to pass on to our sub interrupt
// handlers.
reg_info = (struct eregs) {
.eax=eax,
.ecx=ecx,
.edx=edx,
.ebx=ebx,
.esp=esp,
.ebp=ebp,
.esi=esi,
.edi=edi,
.vector=intnumber,
.error_code=0, // ??
.eip=ip,
.cs=cs,
.eflags=flags // ??
};
// Call the interrupt handler for this int#
ret = intXX_handler[intnumber](®_info);
// Put registers back on the stack. The assembler code
// will later pop them.
// What happens here is that we force (volatile!) changing
// the values of the parameters of this function. We do this
// because we know that they stay alive on the stack after
// we leave this function. Don't say this is bollocks.
*(volatile u32 *)&eax = reg_info.eax;
*(volatile u32 *)&ecx = reg_info.ecx;
*(volatile u32 *)&edx = reg_info.edx;
*(volatile u32 *)&ebx = reg_info.ebx;
*(volatile u32 *)&esi = reg_info.esi;
*(volatile u32 *)&edi = reg_info.edi;
flags = reg_info.eflags;
/* Pass errors back to our caller via the CARRY flag */
if (ret) {
printk(BIOS_DEBUG,"error!\n");
flags |= 1; // error: set carry
}else{
flags &= ~1; // no error: clear carry
}
*(volatile u16 *)&stackflags = flags;
return ret;
}
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