| /* idt.c - routines for constructing IDT fot the GDB stub */ |
| /* |
| * Copyright (C) 2006 Lubomir Kundrak |
| * |
| * 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; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * 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., 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #include <grub/machine/memory.h> |
| #include <grub/misc.h> |
| #include <grub/cpu/gdb.h> |
| #include <grub/gdb.h> |
| |
| static struct grub_cpu_interrupt_gate grub_gdb_idt[GRUB_GDB_LAST_TRAP + 1] |
| __attribute__ ((aligned(16))); |
| |
| /* Sets up a gate descriptor in the IDT table. */ |
| static void |
| grub_idt_gate (struct grub_cpu_interrupt_gate *gate, void (*offset) (void), |
| grub_uint16_t selector, grub_uint8_t type, grub_uint8_t dpl) |
| { |
| gate->offset_lo = (int) offset & 0xffff; |
| gate->selector = selector & 0xffff; |
| gate->unused = 0; |
| gate->gate = (type & 0x1f) | ((dpl & 0x3) << 5) | 0x80; |
| gate->offset_hi = ((int) offset >> 16) & 0xffff; |
| } |
| |
| static struct grub_cpu_idt_descriptor grub_gdb_orig_idt_desc |
| __attribute__ ((aligned(16))); |
| static struct grub_cpu_idt_descriptor grub_gdb_idt_desc |
| __attribute__ ((aligned(16))); |
| |
| /* Set up interrupt and trap handler descriptors in IDT. */ |
| void |
| grub_gdb_idtinit (void) |
| { |
| int i; |
| grub_uint16_t seg; |
| |
| asm volatile ("xorl %%eax, %%eax\n" |
| "mov %%cs, %%ax\n" :"=a" (seg)); |
| |
| for (i = 0; i <= GRUB_GDB_LAST_TRAP; i++) |
| { |
| grub_idt_gate (&grub_gdb_idt[i], |
| grub_gdb_trapvec[i], seg, |
| GRUB_CPU_TRAP_GATE, 0); |
| } |
| |
| grub_gdb_idt_desc.base = (grub_addr_t) grub_gdb_idt; |
| grub_gdb_idt_desc.limit = sizeof (grub_gdb_idt) - 1; |
| asm volatile ("sidt %0" : : "m" (grub_gdb_orig_idt_desc)); |
| asm volatile ("lidt %0" : : "m" (grub_gdb_idt_desc)); |
| } |
| |
| void |
| grub_gdb_idtrestore (void) |
| { |
| asm volatile ("lidt %0" : : "m" (grub_gdb_orig_idt_desc)); |
| } |
| |
| void |
| grub_gdb_breakpoint (void) |
| { |
| asm volatile ("int $3"); |
| } |