diff options
Diffstat (limited to 'util/x86emu/x86.c')
| -rw-r--r-- | util/x86emu/x86.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/util/x86emu/x86.c b/util/x86emu/x86.c new file mode 100644 index 000000000000..8f7204d45805 --- /dev/null +++ b/util/x86emu/x86.c @@ -0,0 +1,228 @@ +/* + * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + */ + +#include <device/pci.h> +#include <string.h> + +#ifdef COREBOOT_V2 +#include <arch/io.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; +}; + +struct eregs { + uint32_t eax, ecx, edx, ebx, esp, ebp, esi, edi; + uint32_t vector; + uint32_t error_code; + uint32_t eip; + uint32_t cs; + uint32_t eflags; +}; + +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); +} + +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; +} + |