grub/grub-core/lib/i386/relocator.c
Vladimir 'phcoder' Serbinenko b28fd807eb freedos support
2010-12-26 00:38:20 +01:00

272 lines
7.5 KiB
C

/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB 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, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/types.h>
#include <grub/err.h>
#include <grub/term.h>
#include <grub/i386/relocator.h>
#include <grub/relocator_private.h>
extern grub_uint8_t grub_relocator_forward_start;
extern grub_uint8_t grub_relocator_forward_end;
extern grub_uint8_t grub_relocator_backward_start;
extern grub_uint8_t grub_relocator_backward_end;
extern void *grub_relocator_backward_dest;
extern void *grub_relocator_backward_src;
extern grub_size_t grub_relocator_backward_chunk_size;
extern void *grub_relocator_forward_dest;
extern void *grub_relocator_forward_src;
extern grub_size_t grub_relocator_forward_chunk_size;
extern grub_uint8_t grub_relocator16_start;
extern grub_uint8_t grub_relocator16_end;
extern grub_uint16_t grub_relocator16_cs;
extern grub_uint16_t grub_relocator16_ip;
extern grub_uint16_t grub_relocator16_ds;
extern grub_uint16_t grub_relocator16_es;
extern grub_uint16_t grub_relocator16_fs;
extern grub_uint16_t grub_relocator16_gs;
extern grub_uint16_t grub_relocator16_ss;
extern grub_uint16_t grub_relocator16_sp;
extern grub_uint32_t grub_relocator16_edx;
extern grub_uint32_t grub_relocator16_ebx;
extern grub_uint8_t grub_relocator32_start;
extern grub_uint8_t grub_relocator32_end;
extern grub_uint32_t grub_relocator32_eax;
extern grub_uint32_t grub_relocator32_ebx;
extern grub_uint32_t grub_relocator32_ecx;
extern grub_uint32_t grub_relocator32_edx;
extern grub_uint32_t grub_relocator32_eip;
extern grub_uint32_t grub_relocator32_esp;
extern grub_uint32_t grub_relocator32_ebp;
extern grub_uint32_t grub_relocator32_esi;
extern grub_uint32_t grub_relocator32_edi;
extern grub_uint8_t grub_relocator64_start;
extern grub_uint8_t grub_relocator64_end;
extern grub_uint64_t grub_relocator64_rax;
extern grub_uint64_t grub_relocator64_rbx;
extern grub_uint64_t grub_relocator64_rcx;
extern grub_uint64_t grub_relocator64_rdx;
extern grub_uint64_t grub_relocator64_rip;
extern grub_uint64_t grub_relocator64_rip_addr;
extern grub_uint64_t grub_relocator64_rsp;
extern grub_uint64_t grub_relocator64_rsi;
extern grub_addr_t grub_relocator64_cr3;
#define RELOCATOR_SIZEOF(x) (&grub_relocator##x##_end - &grub_relocator##x##_start)
grub_size_t grub_relocator_align = 1;
grub_size_t grub_relocator_forward_size;
grub_size_t grub_relocator_backward_size;
#ifdef __x86_64__
grub_size_t grub_relocator_jumper_size = 12;
#else
grub_size_t grub_relocator_jumper_size = 7;
#endif
void
grub_cpu_relocator_init (void)
{
grub_relocator_forward_size = RELOCATOR_SIZEOF(_forward);
grub_relocator_backward_size = RELOCATOR_SIZEOF(_backward);
}
void
grub_cpu_relocator_jumper (void *rels, grub_addr_t addr)
{
grub_uint8_t *ptr;
ptr = rels;
#ifdef __x86_64__
/* movq imm64, %rax (for relocator) */
*(grub_uint8_t *) ptr = 0x48;
ptr++;
*(grub_uint8_t *) ptr = 0xb8;
ptr++;
*(grub_uint64_t *) ptr = addr;
ptr += sizeof (grub_uint64_t);
#else
/* movl imm32, %eax (for relocator) */
*(grub_uint8_t *) ptr = 0xb8;
ptr++;
*(grub_uint32_t *) ptr = addr;
ptr += sizeof (grub_uint32_t);
#endif
/* jmp $eax/$rax */
*(grub_uint8_t *) ptr = 0xff;
ptr++;
*(grub_uint8_t *) ptr = 0xe0;
ptr++;
}
void
grub_cpu_relocator_backward (void *ptr, void *src, void *dest,
grub_size_t size)
{
grub_relocator_backward_dest = dest;
grub_relocator_backward_src = src;
grub_relocator_backward_chunk_size = size;
grub_memmove (ptr,
&grub_relocator_backward_start,
RELOCATOR_SIZEOF (_backward));
}
void
grub_cpu_relocator_forward (void *ptr, void *src, void *dest,
grub_size_t size)
{
grub_relocator_forward_dest = dest;
grub_relocator_forward_src = src;
grub_relocator_forward_chunk_size = size;
grub_memmove (ptr,
&grub_relocator_forward_start,
RELOCATOR_SIZEOF (_forward));
}
grub_err_t
grub_relocator32_boot (struct grub_relocator *rel,
struct grub_relocator32_state state)
{
grub_err_t err;
void *relst;
grub_relocator_chunk_t ch;
err = grub_relocator_alloc_chunk_align (rel, &ch, 0,
(0xffffffff - RELOCATOR_SIZEOF (32))
+ 1, RELOCATOR_SIZEOF (32), 16,
GRUB_RELOCATOR_PREFERENCE_NONE);
if (err)
return err;
grub_relocator32_eax = state.eax;
grub_relocator32_ebx = state.ebx;
grub_relocator32_ecx = state.ecx;
grub_relocator32_edx = state.edx;
grub_relocator32_eip = state.eip;
grub_relocator32_esp = state.esp;
grub_relocator32_ebp = state.ebp;
grub_relocator32_esi = state.esi;
grub_relocator32_edi = state.edi;
grub_memmove (get_virtual_current_address (ch), &grub_relocator32_start,
RELOCATOR_SIZEOF (32));
err = grub_relocator_prepare_relocs (rel, get_physical_target_address (ch),
&relst, NULL);
if (err)
return err;
asm volatile ("cli");
((void (*) (void)) relst) ();
/* Not reached. */
return GRUB_ERR_NONE;
}
grub_err_t
grub_relocator16_boot (struct grub_relocator *rel,
struct grub_relocator16_state state)
{
grub_err_t err;
void *relst;
grub_relocator_chunk_t ch;
err = grub_relocator_alloc_chunk_align (rel, &ch, 0,
0xa0000 - RELOCATOR_SIZEOF (16),
RELOCATOR_SIZEOF (16), 16,
GRUB_RELOCATOR_PREFERENCE_NONE);
if (err)
return err;
grub_relocator16_cs = state.cs;
grub_relocator16_ip = state.ip;
grub_relocator16_ds = state.ds;
grub_relocator16_es = state.es;
grub_relocator16_fs = state.fs;
grub_relocator16_gs = state.gs;
grub_relocator16_ss = state.ss;
grub_relocator16_sp = state.sp;
grub_relocator16_ebx = state.ebx;
grub_relocator16_edx = state.edx;
grub_memmove (get_virtual_current_address (ch), &grub_relocator16_start,
RELOCATOR_SIZEOF (16));
err = grub_relocator_prepare_relocs (rel, get_physical_target_address (ch),
&relst, NULL);
if (err)
return err;
asm volatile ("cli");
((void (*) (void)) relst) ();
/* Not reached. */
return GRUB_ERR_NONE;
}
grub_err_t
grub_relocator64_boot (struct grub_relocator *rel,
struct grub_relocator64_state state,
grub_addr_t min_addr, grub_addr_t max_addr)
{
grub_err_t err;
void *relst;
grub_relocator_chunk_t ch;
err = grub_relocator_alloc_chunk_align (rel, &ch, min_addr,
max_addr - RELOCATOR_SIZEOF (64),
RELOCATOR_SIZEOF (64), 16,
GRUB_RELOCATOR_PREFERENCE_NONE);
if (err)
return err;
grub_relocator64_rax = state.rax;
grub_relocator64_rbx = state.rbx;
grub_relocator64_rcx = state.rcx;
grub_relocator64_rdx = state.rdx;
grub_relocator64_rip = state.rip;
grub_relocator64_rsp = state.rsp;
grub_relocator64_rsi = state.rsi;
grub_relocator64_cr3 = state.cr3;
grub_memmove (get_virtual_current_address (ch), &grub_relocator64_start,
RELOCATOR_SIZEOF (64));
err = grub_relocator_prepare_relocs (rel, get_physical_target_address (ch),
&relst, NULL);
if (err)
return err;
asm volatile ("cli");
((void (*) (void)) relst) ();
/* Not reached. */
return GRUB_ERR_NONE;
}