1 files changed, 78 insertions, 0 deletions
diff --git a/grub-core/gdb/i386/idt.c b/grub-core/gdb/i386/idt.c
new file mode 100644
index 0000000..69bfcb0
--- /dev/null
+++ b/grub-core/gdb/i386/idt.c
@@ -0,0 +1,78 @@
+/* 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");
+}