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/* Native-dependent code for NetBSD/i386.
Copyright 2004 Free Software Foundation, Inc.
This file is part of GDB.
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., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "gdbcore.h"
#include "regcache.h"
#include "target.h"
#include "i386-tdep.h"
#include "i386bsd-nat.h"
/* Support for debugging kernel virtual memory images. */
#include <sys/types.h>
#include <machine/frame.h>
#include <machine/pcb.h>
#include "bsd-kvm.h"
static int
i386nbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
{
struct switchframe sf;
/* The following is true for NetBSD 1.6.2:
The pcb contains %esp and %ebp at the point of the context switch
in cpu_switch(). At that point we have a stack frame as
described by `struct switchframe', which for NetBSD 1.6.2 has the
following layout:
interrupt level
%edi
%esi
%ebx
%eip
we reconstruct the register state as it would look when we just
returned from cpu_switch(). */
/* The stack pointer shouldn't be zero. */
if (pcb->pcb_esp == 0)
return 0;
/* Read the stack frame, and check its validity. We do this by
checking if the saved interrupt priority level in the stack frame
looks reasonable.. */
read_memory (pcb->pcb_esp, (char *) &sf, sizeof sf);
if ((unsigned int) sf.sf_ppl < 0x100 && (sf.sf_ppl & 0xf) == 0)
{
/* Yes, we have a frame that matches cpu_switch(). */
pcb->pcb_esp += sizeof (struct switchframe);
regcache_raw_supply (regcache, I386_EDI_REGNUM, &sf.sf_edi);
regcache_raw_supply (regcache, I386_ESI_REGNUM, &sf.sf_esi);
regcache_raw_supply (regcache, I386_EBX_REGNUM, &sf.sf_ebx);
regcache_raw_supply (regcache, I386_EIP_REGNUM, &sf.sf_eip);
}
else
{
/* No, the pcb must have been last updated by savectx(). */
pcb->pcb_esp += 4;
regcache_raw_supply (regcache, I386_EIP_REGNUM, &sf);
}
regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp);
regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp);
return 1;
}
/* Provide a prototype to silence -Wmissing-prototypes. */
void _initialize_i386nbsd_nat (void);
void
_initialize_i386nbsd_nat (void)
{
/* We've got nothing to add to the common *BSD/i386 target. */
add_target (i386bsd_target ());
/* Support debugging kernel virtual memory images. */
bsd_kvm_add_target (i386nbsd_supply_pcb);
}
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