78 lines
2.3 KiB
C
78 lines
2.3 KiB
C
/* idt.c - routines for constructing IDT fot the GDB stub */
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/*
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* Copyright (C) 2006 Lubomir Kundrak
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <grub/machine/memory.h>
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#include <grub/misc.h>
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#include <grub/cpu/gdb.h>
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#include <grub/gdb.h>
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static struct grub_cpu_interrupt_gate grub_gdb_idt[GRUB_GDB_LAST_TRAP + 1]
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__attribute__ ((aligned(16)));
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/* Sets up a gate descriptor in the IDT table. */
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static void
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grub_idt_gate (struct grub_cpu_interrupt_gate *gate, void (*offset) (void),
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grub_uint16_t selector, grub_uint8_t type, grub_uint8_t dpl)
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{
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gate->offset_lo = (int) offset & 0xffff;
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gate->selector = selector & 0xffff;
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gate->unused = 0;
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gate->gate = (type & 0x1f) | ((dpl & 0x3) << 5) | 0x80;
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gate->offset_hi = ((int) offset >> 16) & 0xffff;
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}
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static struct grub_cpu_idt_descriptor grub_gdb_orig_idt_desc
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__attribute__ ((aligned(16)));
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static struct grub_cpu_idt_descriptor grub_gdb_idt_desc
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__attribute__ ((aligned(16)));
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/* Set up interrupt and trap handler descriptors in IDT. */
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void
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grub_gdb_idtinit (void)
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{
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int i;
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grub_uint16_t seg;
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asm volatile ("xorl %%eax, %%eax\n"
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"mov %%cs, %%ax\n" :"=a" (seg));
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for (i = 0; i <= GRUB_GDB_LAST_TRAP; i++)
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{
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grub_idt_gate (&grub_gdb_idt[i],
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grub_gdb_trapvec[i], seg,
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GRUB_CPU_TRAP_GATE, 0);
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}
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grub_gdb_idt_desc.base = (grub_addr_t) grub_gdb_idt;
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grub_gdb_idt_desc.limit = sizeof (grub_gdb_idt) - 1;
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asm volatile ("sidt %0" : : "m" (grub_gdb_orig_idt_desc));
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asm volatile ("lidt %0" : : "m" (grub_gdb_idt_desc));
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}
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void
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grub_gdb_idtrestore (void)
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{
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asm volatile ("lidt %0" : : "m" (grub_gdb_orig_idt_desc));
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}
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void
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grub_gdb_breakpoint (void)
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{
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asm volatile ("int $3");
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}
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