* bsd-kvm.c, bsd-kvm.h: New files.

* i386fbsd-nat.c: Include <sys/types.h>, <machine/pcb.h> and
"bsd-kvm.h".
(i386fbsd_supply_pcb): New function.
* Makefile.in (ALLDEPFILES): Add bsd-kvm.c.
(i386fbsd-nat.o): Update dependencies.
(bsd_kvm_h): New variable.
(bsd-kvm.o): New dependency.
* config/i386/fbsd.mh (NATDEPFILES): Add bsd-kvm.o.
(LOADLIBES): New variable.

1 files changed, 43 insertions, 3 deletions

diff --git a/gdb/i386fbsd-nat.c b/gdb/i386fbsd-nat.c
index efc61b6..ed07711 100644
--- a/gdb/i386fbsd-nat.c
+++ b/gdb/i386fbsd-nat.c
@@ -29,9 +29,6 @@
 
 #include "i386-tdep.h"
 
-/* Prevent warning from -Wmissing-prototypes.  */
-void _initialize_i386fbsd_nat (void);
-
 /* Resume execution of the inferior process.
    If STEP is nonzero, single-step it.
    If SIGNAL is nonzero, give it that signal.  */
@@ -79,6 +76,46 @@ child_resume (ptid_t ptid, int step, enum target_signal signal)
     perror_with_name ("ptrace");
 }
 
+
+/* Support for debugging kernel virtual memory images.  */
+
+#include <sys/types.h>
+#include <machine/pcb.h>
+
+#include "bsd-kvm.h"
+
+static int
+i386fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
+{
+  /* The following is true for FreeBSD 4.7:
+
+     The pcb contains %eip, %ebx, %esp, %ebp, %esi, %edi and %gs.
+     This accounts for all callee-saved registers specified by the
+     psABI and then some.  Here %esp contains the stack pointer at the
+     point just after the call to cpu_switch().  From this information
+     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;
+
+  pcb->pcb_esp += 4;
+  regcache_raw_supply (regcache, I386_EDI_REGNUM, &pcb->pcb_edi);
+  regcache_raw_supply (regcache, I386_ESI_REGNUM, &pcb->pcb_esi);
+  regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp);
+  regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp);
+  regcache_raw_supply (regcache, I386_EBX_REGNUM, &pcb->pcb_ebx);
+  regcache_raw_supply (regcache, I386_EIP_REGNUM, &pcb->pcb_eip);
+  regcache_raw_supply (regcache, I386_GS_REGNUM, &pcb->pcb_gs);
+
+  return 1;
+}
+
+
+/* Prevent warning from -Wmissing-prototypes.  */
+void _initialize_i386fbsd_nat (void);
+
 void
 _initialize_i386fbsd_nat (void)
 {
@@ -104,4 +141,7 @@ _initialize_i386fbsd_nat (void)
       }
   }
 #endif
+
+  /* Support debugging kernel virtual memory images.  */
+  bsd_kvm_add_target (i386fbsd_supply_pcb);
 }