]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/kdp/kdp_udp.c
xnu-2422.1.72.tar.gz
[apple/xnu.git] / osfmk / kdp / kdp_udp.c
index c62dc4ed20721f28c4930212143ec2ba2b18fe7a..e51c482860309f16dd0bdde6f81c9cb2d268bab3 100644 (file)
@@ -1,16 +1,19 @@
 /*
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
  *
  *
- * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
@@ -20,8 +23,9 @@
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
  */
+
 /*
  * Copyright (c) 1982, 1986, 1993
  *      The Regents of the University of California.  All rights reserved.
 /*
  * Copyright (c) 1982, 1986, 1993
  *      The Regents of the University of California.  All rights reserved.
  * Kernel Debugging Protocol UDP implementation.
  */
 
  * Kernel Debugging Protocol UDP implementation.
  */
 
-#include <mach_kdb.h>
 #include <mach/boolean.h>
 #include <mach/boolean.h>
-#include <mach/exception_types.h>
 #include <mach/mach_types.h>
 #include <mach/mach_types.h>
+#include <mach/exception_types.h>
 #include <kern/cpu_data.h>
 #include <kern/debug.h>
 #include <kern/cpu_data.h>
 #include <kern/debug.h>
+#include <kern/clock.h>
 
 
+#include <kdp/kdp_core.h>
 #include <kdp/kdp_internal.h>
 #include <kdp/kdp_en_debugger.h>
 #include <kdp/kdp_internal.h>
 #include <kdp/kdp_en_debugger.h>
+#include <kdp/kdp_callout.h>
 #include <kdp/kdp_udp.h>
 #include <kdp/kdp_udp.h>
+#if CONFIG_SERIAL_KDP
+#include <kdp/kdp_serial.h>
+#endif
+
+#include <vm/vm_map.h>
+#include <vm/vm_protos.h>
+#include <vm/vm_kern.h> /* kernel_map */
+
+#include <mach/memory_object_types.h>
+#include <machine/pal_routines.h>
 
 
-#define DO_ALIGN       1       /* align all packet data accesses */
+#include <sys/msgbuf.h>
+
+/* we just want the link status flags, so undef KERNEL_PRIVATE for this
+ * header file. */
+#undef KERNEL_PRIVATE
+#include <net/if_media.h> 
+#define KERNEL_PRIVATE
+
+#include <string.h>
+
+#include <IOKit/IOPlatformExpert.h>
+#include <libkern/version.h>
+
+extern int      inet_aton(const char *, struct kdp_in_addr *); /* in libkern */
+extern char    *inet_ntoa_r(struct kdp_in_addr ina, char *buf,
+    size_t buflen); /* in libkern */
+
+#define DO_ALIGN       1             /* align all packet data accesses */
+#define KDP_SERIAL_IPADDR  0xABADBABE /* IP address used for serial KDP */
+#define LINK_UP_STATUS     (IFM_AVALID | IFM_ACTIVE)
 
 extern int kdp_getc(void);
 extern int reattach_wait;
 
 
 extern int kdp_getc(void);
 extern int reattach_wait;
 
+/* only used by IONetworkingFamily */
+typedef uint32_t (*kdp_link_t)(void);
+typedef boolean_t (*kdp_mode_t)(boolean_t);
+void   kdp_register_link(kdp_link_t link, kdp_mode_t mode);
+void   kdp_unregister_link(kdp_link_t link, kdp_mode_t mode);
+
 static u_short ip_id;                          /* ip packet ctr, for ids */
 
 /*     @(#)udp_usrreq.c        2.2 88/05/23 4.0NFSSRC SMI;     from UCB 7.1 6/5/86     */
 static u_short ip_id;                          /* ip packet ctr, for ids */
 
 /*     @(#)udp_usrreq.c        2.2 88/05/23 4.0NFSSRC SMI;     from UCB 7.1 6/5/86     */
@@ -56,27 +97,144 @@ static u_short ip_id;                          /* ip packet ctr, for ids */
  * Per RFC 768, August, 1980.
  */
 #define UDP_TTL        60 /* deflt time to live for UDP packets */
  * Per RFC 768, August, 1980.
  */
 #define UDP_TTL        60 /* deflt time to live for UDP packets */
-int            udp_ttl=UDP_TTL;
+static int udp_ttl = UDP_TTL;
 static unsigned char   exception_seq;
 
 static unsigned char   exception_seq;
 
+struct kdp_ipovly {
+        uint32_t ih_next, ih_prev;     /* for protocol sequence q's */
+        u_char  ih_x1;                 /* (unused) */
+        u_char  ih_pr;                 /* protocol */
+        short   ih_len;                        /* protocol length */
+        struct  kdp_in_addr ih_src;    /* source internet address */
+        struct  kdp_in_addr ih_dst;    /* destination internet address */
+};
+
+struct kdp_udphdr {
+       u_short uh_sport;               /* source port */
+       u_short uh_dport;               /* destination port */
+       short   uh_ulen;                /* udp length */
+       u_short uh_sum;                 /* udp checksum */
+};
+
+struct  kdp_udpiphdr {
+        struct  kdp_ipovly ui_i;       /* overlaid ip structure */
+        struct  kdp_udphdr ui_u;       /* udp header */
+};
+#define        ui_next         ui_i.ih_next
+#define        ui_prev         ui_i.ih_prev
+#define        ui_x1           ui_i.ih_x1
+#define        ui_pr           ui_i.ih_pr
+#define        ui_len          ui_i.ih_len
+#define        ui_src          ui_i.ih_src
+#define        ui_dst          ui_i.ih_dst
+#define        ui_sport        ui_u.uh_sport
+#define        ui_dport        ui_u.uh_dport
+#define        ui_ulen         ui_u.uh_ulen
+#define        ui_sum          ui_u.uh_sum
+
+struct kdp_ip {
+       union {
+               uint32_t ip_w;
+               struct {
+                       unsigned int
+#ifdef __LITTLE_ENDIAN__
+                       ip_xhl:4,       /* header length */
+                       ip_xv:4,        /* version */
+                       ip_xtos:8,      /* type of service */
+                       ip_xlen:16;     /* total length */
+#endif
+#ifdef __BIG_ENDIAN__
+                       ip_xv:4,        /* version */
+                       ip_xhl:4,       /* header length */
+                       ip_xtos:8,      /* type of service */
+                       ip_xlen:16;     /* total length */
+#endif
+               } ip_x;
+       } ip_vhltl;
+        u_short ip_id;                 /* identification */
+        short   ip_off;                        /* fragment offset field */
+#define        IP_DF 0x4000                    /* dont fragment flag */
+#define        IP_MF 0x2000                    /* more fragments flag */
+#define        IP_OFFMASK 0x1fff               /* mask for fragmenting bits */
+        u_char  ip_ttl;                        /* time to live */
+        u_char  ip_p;                  /* protocol */
+        u_short ip_sum;                        /* checksum */
+        struct  kdp_in_addr ip_src,ip_dst;  /* source and dest address */
+};
+#define        ip_v            ip_vhltl.ip_x.ip_xv
+#define        ip_hl           ip_vhltl.ip_x.ip_xhl
+#define        ip_tos          ip_vhltl.ip_x.ip_xtos
+#define        ip_len          ip_vhltl.ip_x.ip_xlen
+
+#define        IPPROTO_UDP     17
+#define        IPVERSION       4
+
+#define        ETHERTYPE_IP    0x0800  /* IP protocol */
+
+/*
+ * Ethernet Address Resolution Protocol.
+ *
+ * See RFC 826 for protocol description.  Structure below is adapted
+ * to resolving internet addresses.  Field names used correspond to
+ * RFC 826.
+ */
+
+#define        ETHERTYPE_ARP   0x0806  /* Addr. resolution protocol */
+
+struct  kdp_arphdr {
+       u_short ar_hrd;         /* format of hardware address */
+#define        ARPHRD_ETHER    1       /* ethernet hardware format */
+#define        ARPHRD_FRELAY   15      /* frame relay hardware format */
+       u_short ar_pro;         /* format of protocol address */
+       u_char  ar_hln;         /* length of hardware address */
+       u_char  ar_pln;         /* length of protocol address */
+       u_short ar_op;          /* one of: */
+#define        ARPOP_REQUEST   1       /* request to resolve address */
+#define        ARPOP_REPLY     2       /* response to previous request */
+#define        ARPOP_REVREQUEST 3      /* request protocol address given hardware */
+#define        ARPOP_REVREPLY  4       /* response giving protocol address */
+#define        ARPOP_INVREQUEST 8      /* request to identify peer */
+#define        ARPOP_INVREPLY  9       /* response identifying peer */
+};
+
+struct  kdp_ether_arp {
+       struct  kdp_arphdr ea_hdr;              /* fixed-size header */
+       u_char  arp_sha[ETHER_ADDR_LEN];        /* sender hardware address */
+       u_char  arp_spa[4];                     /* sender protocol address */
+       u_char  arp_tha[ETHER_ADDR_LEN];        /* target hardware address */
+       u_char  arp_tpa[4];                     /* target protocol address */
+};
+#define        arp_hrd ea_hdr.ar_hrd
+#define        arp_pro ea_hdr.ar_pro
+#define        arp_hln ea_hdr.ar_hln
+#define        arp_pln ea_hdr.ar_pln
+#define        arp_op  ea_hdr.ar_op
+
+#define        ETHERMTU        1500
+#define        ETHERHDRSIZE    14
+#define        ETHERCRC        4
+#define        KDP_MAXPACKET   (ETHERHDRSIZE + ETHERMTU + ETHERCRC)
+
 static struct {
     unsigned char      data[KDP_MAXPACKET];
     unsigned int       off, len;
     boolean_t          input;
 } pkt, saved_reply;
 
 static struct {
     unsigned char      data[KDP_MAXPACKET];
     unsigned int       off, len;
     boolean_t          input;
 } pkt, saved_reply;
 
+struct kdp_manual_pkt manual_pkt;
+
 struct {
     struct {
 struct {
     struct {
-       struct in_addr          in;
-       struct ether_addr       ea;
+       struct kdp_in_addr      in;
+       struct kdp_ether_addr   ea;
     } loc;
     struct {
     } loc;
     struct {
-       struct in_addr          in;
-       struct ether_addr       ea;
+       struct kdp_in_addr      in;
+       struct kdp_ether_addr   ea;
     } rmt;
 } adr;
 
     } rmt;
 } adr;
 
-static char
+static const char
 *exception_message[] = {
     "Unknown",
     "Memory access",           /* EXC_BAD_ACCESS */
 *exception_message[] = {
     "Unknown",
     "Memory access",           /* EXC_BAD_ACCESS */
@@ -87,36 +245,243 @@ static char
     "Breakpoint"               /* EXC_BREAKPOINT */
 };
 
     "Breakpoint"               /* EXC_BREAKPOINT */
 };
 
-int kdp_flag = 0;
+volatile int kdp_flag = 0;
+
+static kdp_send_t    kdp_en_send_pkt;
+static kdp_receive_t kdp_en_recv_pkt;
+static kdp_link_t    kdp_en_linkstatus;
+static kdp_mode_t    kdp_en_setmode;
+
+#if CONFIG_SERIAL_KDP
+static void kdp_serial_send(void *rpkt, unsigned int rpkt_len);
+#define KDP_SERIAL_ENABLED()  (kdp_en_send_pkt == kdp_serial_send)
+#else
+#define KDP_SERIAL_ENABLED()  (0)
+#endif
+
+static uint32_t kdp_current_ip_address = 0;
+static struct kdp_ether_addr kdp_current_mac_address = {{0, 0, 0, 0, 0, 0}};
+static void *kdp_current_ifp;
+
+static void kdp_handler( void *);
+
+static uint32_t panic_server_ip = 0; 
+static uint32_t parsed_router_ip = 0;
+static uint32_t router_ip = 0;
+static uint32_t target_ip = 0;
+
+static boolean_t save_ip_in_nvram = FALSE;
+
+static volatile boolean_t panicd_specified = FALSE;
+static boolean_t router_specified = FALSE;
+static boolean_t corename_specified = FALSE;
+static unsigned int panicd_port = CORE_REMOTE_PORT;
+
+static struct kdp_ether_addr etherbroadcastaddr = {{0xff, 0xff, 0xff, 0xff, 0xff, 0xff}};
+
+static struct kdp_ether_addr router_mac = {{0, 0, 0 , 0, 0, 0}};
+static struct kdp_ether_addr destination_mac = {{0, 0, 0 , 0, 0, 0}};
+static struct kdp_ether_addr temp_mac = {{0, 0, 0 , 0, 0, 0}};
+static struct kdp_ether_addr current_resolved_MAC = {{0, 0, 0 , 0, 0, 0}};
+
+static boolean_t flag_panic_dump_in_progress = FALSE;
+static boolean_t flag_router_mac_initialized = FALSE;
+static boolean_t flag_dont_abort_panic_dump  = FALSE;
+
+static boolean_t flag_arp_resolved = FALSE;
 
 
-static kdp_send_t kdp_en_send_pkt = 0;
-static kdp_receive_t kdp_en_recv_pkt = 0;
+static unsigned int panic_timeout = 100000;
+static unsigned int last_panic_port = CORE_REMOTE_PORT;
 
 
+#define KDP_THROTTLE_VALUE       (10ULL * NSEC_PER_SEC)
 
 
-static unsigned int kdp_current_ip_address = 0;
-static struct ether_addr kdp_current_mac_address = {{0, 0, 0, 0, 0, 0}};
-static char kdp_arp_init = 0;
+uint32_t kdp_crashdump_pkt_size = 512;
+#define KDP_LARGE_CRASHDUMP_PKT_SIZE (1440 - 6 - sizeof(struct kdp_udpiphdr))
+static char panicd_ip_str[20];
+static char router_ip_str[20];
+static char corename_str[50];
 
 
-static void kdp_handler( void  *);
+static unsigned int panic_block = 0;
+volatile unsigned int kdp_trigger_core_dump = 0;
+__private_extern__ volatile unsigned int flag_kdp_trigger_reboot = 0;
+
+extern unsigned int not_in_kdp;
+
+extern unsigned int disableConsoleOutput;
+
+extern void            kdp_call(void);
+extern boolean_t       kdp_call_kdb(void);
+extern int             kern_dump(void);
+
+void * kdp_get_interface(void);
+void    kdp_set_gateway_mac(void *gatewaymac);
+void   kdp_set_ip_and_mac_addresses(struct kdp_in_addr *ipaddr, struct kdp_ether_addr *);
+void   kdp_set_interface(void *interface, const struct kdp_ether_addr *macaddr);
+
+void                   kdp_disable_arp(void);
+static void            kdp_arp_reply(struct kdp_ether_arp *);
+static void            kdp_process_arp_reply(struct kdp_ether_arp *);
+static boolean_t       kdp_arp_resolve(uint32_t, struct kdp_ether_addr *);
+
+static volatile unsigned       kdp_reentry_deadline;
+
+static uint32_t kdp_crashdump_feature_mask = KDP_FEATURE_LARGE_CRASHDUMPS | KDP_FEATURE_LARGE_PKT_SIZE;
+uint32_t kdp_feature_large_crashdumps, kdp_feature_large_pkt_size;
+
+char kdp_kernelversion_string[256];
+
+static boolean_t       gKDPDebug = FALSE;
+#define KDP_DEBUG(...) if (gKDPDebug) printf(__VA_ARGS__);
+
+int kdp_snapshot = 0;
+static int stack_snapshot_ret = 0;
+static unsigned stack_snapshot_bytes_traced = 0;
+
+static void *stack_snapshot_buf;
+static uint32_t stack_snapshot_bufsize;
+static int stack_snapshot_pid;
+static uint32_t stack_snapshot_flags;
+static uint32_t stack_snapshot_dispatch_offset;
+
+static unsigned int old_debugger;
+
+#define SBLOCKSZ (2048)
+uint64_t kdp_dump_start_time = 0;
+uint64_t kdp_min_superblock_dump_time = ~1ULL;
+uint64_t kdp_max_superblock_dump_time = 0;
+uint64_t kdp_superblock_dump_time = 0;
+uint64_t kdp_superblock_dump_start_time = 0;
+
+void
+kdp_snapshot_preflight(int pid, void * tracebuf, uint32_t tracebuf_size,
+    uint32_t flags, uint32_t dispatch_offset);
+
+void
+kdp_snapshot_postflight(void);
+
+extern int
+kdp_stackshot(int pid, void *tracebuf, uint32_t tracebuf_size,
+    uint32_t flags, uint32_t dispatch_offset, uint32_t *pbytesTraced);
+
+int
+kdp_stack_snapshot_geterror(void);
+
+int
+kdp_stack_snapshot_bytes_traced(void);
+
+static thread_call_t
+kdp_timer_call;
+
+static void
+kdp_ml_enter_debugger_wrapper(__unused void *param0, __unused void *param1) {
+       kdp_ml_enter_debugger();
+}
+
+static void
+kdp_timer_callout_init(void) {
+       kdp_timer_call = thread_call_allocate(kdp_ml_enter_debugger_wrapper, NULL);
+}
+
+
+/* only send/receive data if the link is up */
+inline static void wait_for_link(void)
+{
+    static int first = 0;
+
+    if (!kdp_en_linkstatus)
+        return;
+
+    while (((*kdp_en_linkstatus)() & LINK_UP_STATUS) != LINK_UP_STATUS) {
+        if (first)
+            continue;
+
+        first = 1;
+        printf("Waiting for link to become available.\n");
+        kprintf("Waiting for link to become available.\n");
+    }
+}
+
+
+inline static void kdp_send_data(void *packet, unsigned int len)
+{
+    wait_for_link();
+    (*kdp_en_send_pkt)(packet, len);
+}
+
+
+inline static void kdp_receive_data(void *packet, unsigned int *len,
+                                    unsigned int timeout)
+{
+    wait_for_link();
+    (*kdp_en_recv_pkt)(packet, len, timeout);
+}
+
+
+void kdp_register_link(kdp_link_t link, kdp_mode_t mode)
+{
+        kdp_en_linkstatus = link;
+        kdp_en_setmode    = mode;
+}
+
+void kdp_unregister_link(__unused kdp_link_t link, __unused kdp_mode_t mode)
+{
+        kdp_en_linkstatus = NULL;
+        kdp_en_setmode    = NULL;
+}
 
 void
 kdp_register_send_receive(
 
 void
 kdp_register_send_receive(
-       kdp_send_t              send, 
+       kdp_send_t      send, 
        kdp_receive_t   receive)
 {
        kdp_receive_t   receive)
 {
-       unsigned int    debug;
+       unsigned int    debug = 0;
+
+       PE_parse_boot_argn("debug", &debug, sizeof (debug));
+
+
+       if (!debug)
+               return;
+
+       kdp_en_send_pkt   = send;
+       kdp_en_recv_pkt   = receive;
 
 
-       kdp_en_send_pkt = send;
-       kdp_en_recv_pkt = receive;
-       debug_log_init();
-       PE_parse_boot_arg("debug", &debug);
        if (debug & DB_KDP_BP_DIS)
                kdp_flag |= KDP_BP_DIS;   
        if (debug & DB_KDP_BP_DIS)
                kdp_flag |= KDP_BP_DIS;   
+       if (debug & DB_KDP_GETC_ENA)
+               kdp_flag |= KDP_GETC_ENA;   
+       if (debug & DB_ARP)
+               kdp_flag |= KDP_ARP;
+
+       if (debug & DB_KERN_DUMP_ON_PANIC)
+               kdp_flag |= KDP_PANIC_DUMP_ENABLED;
+       if (debug & DB_KERN_DUMP_ON_NMI)
+               kdp_flag |= PANIC_CORE_ON_NMI;
+
+       if (debug & DB_DBG_POST_CORE)
+               kdp_flag |= DBG_POST_CORE;
+
+       if (debug & DB_PANICLOG_DUMP)
+               kdp_flag |= PANIC_LOG_DUMP;
+
+       if (PE_parse_boot_argn("_panicd_ip", panicd_ip_str, sizeof (panicd_ip_str)))
+               panicd_specified = TRUE;
+
+       if ((debug & DB_REBOOT_POST_CORE) && (panicd_specified == TRUE))
+               kdp_flag |= REBOOT_POST_CORE;
+
+       if (PE_parse_boot_argn("_router_ip", router_ip_str, sizeof (router_ip_str)))
+               router_specified = TRUE;
+
+       if (!PE_parse_boot_argn("panicd_port", &panicd_port, sizeof (panicd_port)))
+               panicd_port = CORE_REMOTE_PORT;
+
+       if (PE_parse_boot_argn("_panicd_corename", &corename_str, sizeof (corename_str)))
+               corename_specified = TRUE;
 
        kdp_flag |= KDP_READY;
        if (current_debugger == NO_CUR_DB)
                current_debugger = KDP_CUR_DB;
 
        kdp_flag |= KDP_READY;
        if (current_debugger == NO_CUR_DB)
                current_debugger = KDP_CUR_DB;
-       if (halt_in_debugger) {
+       if ((kdp_current_ip_address != 0) && halt_in_debugger) {
                kdp_call(); 
                halt_in_debugger=0;
        }
                kdp_call(); 
                halt_in_debugger=0;
        }
@@ -124,14 +489,62 @@ kdp_register_send_receive(
 
 void
 kdp_unregister_send_receive(
 
 void
 kdp_unregister_send_receive(
-       kdp_send_t              send, 
-       kdp_receive_t   receive)
+       __unused kdp_send_t     send, 
+       __unused kdp_receive_t  receive)
 {
        if (current_debugger == KDP_CUR_DB)
                current_debugger = NO_CUR_DB;
        kdp_flag &= ~KDP_READY;
 {
        if (current_debugger == KDP_CUR_DB)
                current_debugger = NO_CUR_DB;
        kdp_flag &= ~KDP_READY;
-       kdp_en_send_pkt = NULL;
-       kdp_en_recv_pkt = NULL;
+       kdp_en_send_pkt   = NULL;
+       kdp_en_recv_pkt   = NULL;
+}
+
+/* Cache stack snapshot parameters in preparation for a trace */
+void
+kdp_snapshot_preflight(int pid, void * tracebuf, uint32_t tracebuf_size, uint32_t flags, uint32_t dispatch_offset)
+{
+       stack_snapshot_pid = pid;
+       stack_snapshot_buf = tracebuf;
+       stack_snapshot_bufsize = tracebuf_size;
+       stack_snapshot_flags = flags;
+       stack_snapshot_dispatch_offset = dispatch_offset;
+       kdp_snapshot++;
+       /* Mark this debugger as active, since the polled mode driver that 
+        * ordinarily does this may not be enabled (yet), or since KDB may be
+        * the primary debugger.
+        */
+       old_debugger = current_debugger;
+       if (old_debugger != KDP_CUR_DB) {
+               current_debugger = KDP_CUR_DB;
+       }
+}
+
+void
+kdp_snapshot_postflight(void)
+{
+       kdp_snapshot--;
+       if ((kdp_en_send_pkt == NULL) || (old_debugger == KDB_CUR_DB))
+               current_debugger = old_debugger;
+}
+
+int
+kdp_stack_snapshot_geterror(void)
+{
+       return stack_snapshot_ret;
+}
+
+int
+kdp_stack_snapshot_bytes_traced(void)
+{
+       return stack_snapshot_bytes_traced;
+}
+
+static void
+kdp_schedule_debugger_reentry(unsigned interval) {
+       uint64_t deadline;;
+
+       clock_interval_to_deadline(interval, 1000 * 1000, &deadline);
+       thread_call_enter_delayed(kdp_timer_call, deadline);
 }
 
 static void
 }
 
 static void
@@ -140,100 +553,103 @@ enaddr_copy(
        void    *dst
 )
 {
        void    *dst
 )
 {
-       bcopy((char *)src, (char *)dst, sizeof (struct ether_addr));
+       bcopy((char *)src, (char *)dst, sizeof (struct kdp_ether_addr));
 }
 
 static unsigned short
 ip_sum(
        unsigned char   *c,
        unsigned int    hlen
 }
 
 static unsigned short
 ip_sum(
        unsigned char   *c,
        unsigned int    hlen
-)
+       )
 {
 {
-    unsigned int       high, low, sum;
+       unsigned int    high, low, sum;
     
     
-    high = low = 0;
-    while (hlen-- > 0) {
-       low += c[1] + c[3];
-       high += c[0] + c[2];
+       high = low = 0;
+       while (hlen-- > 0) {
+               low += c[1] + c[3];
+               high += c[0] + c[2];
        
        
-       c += sizeof (int);
-    }
+               c += sizeof (int);
+       }
     
     
-    sum = (high << 8) + low;
-    sum = (sum >> 16) + (sum & 65535);
+       sum = (high << 8) + low;
+       sum = (sum >> 16) + (sum & 65535);
     
     
-    return (sum > 65535 ? sum - 65535 : sum);
+       return (sum > 65535 ? sum - 65535 : sum);
 }
 
 static void
 kdp_reply(
 }
 
 static void
 kdp_reply(
-       unsigned short          reply_port
-)
+          unsigned short               reply_port,
+          const boolean_t         sideband
+          )
 {
 {
-    struct udpiphdr            aligned_ui, *ui = &aligned_ui;
-    struct ip                  aligned_ip, *ip = &aligned_ip;
-    struct in_addr             tmp_ipaddr;
-    struct ether_addr          tmp_enaddr;
-    struct ether_header                *eh;
+       struct kdp_udpiphdr     aligned_ui, *ui = &aligned_ui;
+       struct kdp_ip           aligned_ip, *ip = &aligned_ip;
+       struct kdp_in_addr      tmp_ipaddr;
+       struct kdp_ether_addr   tmp_enaddr;
+       struct kdp_ether_header *eh = NULL;
     
     
-    if (!pkt.input)
-       kdp_panic("kdp_reply");
+       if (!pkt.input)
+               kdp_panic("kdp_reply");
        
        
-    pkt.off -= sizeof (struct udpiphdr);
+       pkt.off -= (unsigned int)sizeof (struct kdp_udpiphdr);
 
 #if DO_ALIGN    
 
 #if DO_ALIGN    
-    bcopy((char *)&pkt.data[pkt.off], (char *)ui, sizeof(*ui));
+       bcopy((char *)&pkt.data[pkt.off], (char *)ui, sizeof(*ui));
 #else
 #else
-    ui = (struct udpiphdr *)&pkt.data[pkt.off];
+       ui = (struct kdp_udpiphdr *)&pkt.data[pkt.off];
 #endif
 #endif
-    ui->ui_next = ui->ui_prev = 0;
-    ui->ui_x1 = 0;
-    ui->ui_pr = IPPROTO_UDP;
-    ui->ui_len = htons((u_short)pkt.len + sizeof (struct udphdr));
-    tmp_ipaddr = ui->ui_src;
-    ui->ui_src = ui->ui_dst;
-    ui->ui_dst = tmp_ipaddr;
-    ui->ui_sport = htons(KDP_REMOTE_PORT);
-    ui->ui_dport = reply_port;
-    ui->ui_ulen = ui->ui_len;
-    ui->ui_sum = 0;
+       ui->ui_next = ui->ui_prev = 0;
+       ui->ui_x1 = 0;
+       ui->ui_pr = IPPROTO_UDP;
+       ui->ui_len = htons((u_short)pkt.len + sizeof (struct kdp_udphdr));
+       tmp_ipaddr = ui->ui_src;
+       ui->ui_src = ui->ui_dst;
+       ui->ui_dst = tmp_ipaddr;
+       ui->ui_sport = htons(KDP_REMOTE_PORT);
+       ui->ui_dport = reply_port;
+       ui->ui_ulen = ui->ui_len;
+       ui->ui_sum = 0;
 #if DO_ALIGN
 #if DO_ALIGN
-    bcopy((char *)ui, (char *)&pkt.data[pkt.off], sizeof(*ui));
-    
-    bcopy((char *)&pkt.data[pkt.off], (char *)ip, sizeof(*ip));
+       bcopy((char *)ui, (char *)&pkt.data[pkt.off], sizeof(*ui));
+       bcopy((char *)&pkt.data[pkt.off], (char *)ip, sizeof(*ip));
 #else
 #else
-    ip = (struct ip *)&pkt.data[pkt.off];
+       ip = (struct kdp_ip *)&pkt.data[pkt.off];
 #endif
 #endif
-    ip->ip_len = htons(sizeof (struct udpiphdr) + pkt.len);
-    ip->ip_v = IPVERSION;
-    ip->ip_id = htons(ip_id++);
-    ip->ip_hl = sizeof (struct ip) >> 2;
-    ip->ip_ttl = udp_ttl;
-    ip->ip_sum = 0;
-    ip->ip_sum = htons(~ip_sum((unsigned char *)ip, ip->ip_hl));
+       ip->ip_len = htons(sizeof (struct kdp_udpiphdr) + pkt.len);
+       ip->ip_v = IPVERSION;
+       ip->ip_id = htons(ip_id++);
+       ip->ip_hl = sizeof (struct kdp_ip) >> 2;
+       ip->ip_ttl = udp_ttl;
+       ip->ip_sum = 0;
+       ip->ip_sum = htons(~ip_sum((unsigned char *)ip, ip->ip_hl));
 #if DO_ALIGN
 #if DO_ALIGN
-    bcopy((char *)ip, (char *)&pkt.data[pkt.off], sizeof(*ip));
+       bcopy((char *)ip, (char *)&pkt.data[pkt.off], sizeof(*ip));
 #endif
     
 #endif
     
-    pkt.len += sizeof (struct udpiphdr);
+       pkt.len += (unsigned int)sizeof (struct kdp_udpiphdr);
     
     
-    pkt.off -= sizeof (struct ether_header);
+       pkt.off -= (unsigned int)sizeof (struct kdp_ether_header);
     
     
-    eh = (struct ether_header *)&pkt.data[pkt.off];
-    enaddr_copy(eh->ether_shost, &tmp_enaddr);
-    enaddr_copy(eh->ether_dhost, eh->ether_shost);
-    enaddr_copy(&tmp_enaddr, eh->ether_dhost);
-    eh->ether_type = htons(ETHERTYPE_IP);
+       eh = (struct kdp_ether_header *)&pkt.data[pkt.off];
+       enaddr_copy(eh->ether_shost, &tmp_enaddr);
+       enaddr_copy(eh->ether_dhost, eh->ether_shost);
+       enaddr_copy(&tmp_enaddr, eh->ether_dhost);
+       eh->ether_type = htons(ETHERTYPE_IP);
     
     
-    pkt.len += sizeof (struct ether_header);
+       pkt.len += (unsigned int)sizeof (struct kdp_ether_header);
     
     
-    // save reply for possible retransmission
-    bcopy((char *)&pkt, (char *)&saved_reply, sizeof(pkt));
+       // save reply for possible retransmission
+       assert(pkt.len <= KDP_MAXPACKET);
+       if (!sideband)
+               bcopy((char *)&pkt, (char *)&saved_reply, sizeof(saved_reply));
 
 
-    (*kdp_en_send_pkt)(&pkt.data[pkt.off], pkt.len);
+       kdp_send_data(&pkt.data[pkt.off], pkt.len);
 
 
-    // increment expected sequence number
-    exception_seq++;
+       // increment expected sequence number
+       if (!sideband) 
+               exception_seq++;
 }
 
 static void
 }
 
 static void
@@ -241,24 +657,24 @@ kdp_send(
     unsigned short             remote_port
 )
 {
     unsigned short             remote_port
 )
 {
-    struct udpiphdr            aligned_ui, *ui = &aligned_ui;
-    struct ip                  aligned_ip, *ip = &aligned_ip;
-    struct ether_header                *eh;
+    struct kdp_udpiphdr                aligned_ui, *ui = &aligned_ui;
+    struct kdp_ip              aligned_ip, *ip = &aligned_ip;
+    struct kdp_ether_header    *eh;
     
     if (pkt.input)
        kdp_panic("kdp_send");
 
     
     if (pkt.input)
        kdp_panic("kdp_send");
 
-    pkt.off -= sizeof (struct udpiphdr);
+    pkt.off -= (unsigned int)sizeof (struct kdp_udpiphdr);
 
 #if DO_ALIGN
     bcopy((char *)&pkt.data[pkt.off], (char *)ui, sizeof(*ui));
 #else
 
 #if DO_ALIGN
     bcopy((char *)&pkt.data[pkt.off], (char *)ui, sizeof(*ui));
 #else
-    ui = (struct udpiphdr *)&pkt.data[pkt.off];
+    ui = (struct kdp_udpiphdr *)&pkt.data[pkt.off];
 #endif
     ui->ui_next = ui->ui_prev = 0;
     ui->ui_x1 = 0;
     ui->ui_pr = IPPROTO_UDP;
 #endif
     ui->ui_next = ui->ui_prev = 0;
     ui->ui_x1 = 0;
     ui->ui_pr = IPPROTO_UDP;
-    ui->ui_len = htons((u_short)pkt.len + sizeof (struct udphdr));
+    ui->ui_len = htons((u_short)pkt.len + sizeof (struct kdp_udphdr));
     ui->ui_src = adr.loc.in;
     ui->ui_dst = adr.rmt.in;
     ui->ui_sport = htons(KDP_REMOTE_PORT);
     ui->ui_src = adr.loc.in;
     ui->ui_dst = adr.rmt.in;
     ui->ui_sport = htons(KDP_REMOTE_PORT);
@@ -269,12 +685,12 @@ kdp_send(
     bcopy((char *)ui, (char *)&pkt.data[pkt.off], sizeof(*ui));
     bcopy((char *)&pkt.data[pkt.off], (char *)ip, sizeof(*ip));
 #else
     bcopy((char *)ui, (char *)&pkt.data[pkt.off], sizeof(*ui));
     bcopy((char *)&pkt.data[pkt.off], (char *)ip, sizeof(*ip));
 #else
-    ip = (struct ip *)&pkt.data[pkt.off];
+    ip = (struct kdp_ip *)&pkt.data[pkt.off];
 #endif
 #endif
-    ip->ip_len = htons(sizeof (struct udpiphdr) + pkt.len);
+    ip->ip_len = htons(sizeof (struct kdp_udpiphdr) + pkt.len);
     ip->ip_v = IPVERSION;
     ip->ip_id = htons(ip_id++);
     ip->ip_v = IPVERSION;
     ip->ip_id = htons(ip_id++);
-    ip->ip_hl = sizeof (struct ip) >> 2;
+    ip->ip_hl = sizeof (struct kdp_ip) >> 2;
     ip->ip_ttl = udp_ttl;
     ip->ip_sum = 0;
     ip->ip_sum = htons(~ip_sum((unsigned char *)ip, ip->ip_hl));
     ip->ip_ttl = udp_ttl;
     ip->ip_sum = 0;
     ip->ip_sum = htons(~ip_sum((unsigned char *)ip, ip->ip_hl));
@@ -282,40 +698,134 @@ kdp_send(
     bcopy((char *)ip, (char *)&pkt.data[pkt.off], sizeof(*ip));
 #endif
     
     bcopy((char *)ip, (char *)&pkt.data[pkt.off], sizeof(*ip));
 #endif
     
-    pkt.len += sizeof (struct udpiphdr);
+    pkt.len += (unsigned int)sizeof (struct kdp_udpiphdr);
     
     
-    pkt.off -= sizeof (struct ether_header);
+    pkt.off -= (unsigned int)sizeof (struct kdp_ether_header);
     
     
-    eh = (struct ether_header *)&pkt.data[pkt.off];
+    eh = (struct kdp_ether_header *)&pkt.data[pkt.off];
     enaddr_copy(&adr.loc.ea, eh->ether_shost);
     enaddr_copy(&adr.rmt.ea, eh->ether_dhost);
     eh->ether_type = htons(ETHERTYPE_IP);
     
     enaddr_copy(&adr.loc.ea, eh->ether_shost);
     enaddr_copy(&adr.rmt.ea, eh->ether_dhost);
     eh->ether_type = htons(ETHERTYPE_IP);
     
-    pkt.len += sizeof (struct ether_header);
-    (*kdp_en_send_pkt)(&pkt.data[pkt.off], pkt.len);
+    pkt.len += (unsigned int)sizeof (struct kdp_ether_header);
+    kdp_send_data(&pkt.data[pkt.off], pkt.len);
 }
 
 
 }
 
 
-void 
-kdp_set_ip_and_mac_addresses(
-       struct in_addr          *ipaddr, 
-       struct ether_addr       *macaddr)
+inline static void debugger_if_necessary(void)
 {
 {
-       unsigned int debug = 0;
+    if ((current_debugger == KDP_CUR_DB) && halt_in_debugger) {
+        kdp_call();
+        halt_in_debugger=0;
+    }
+}
 
 
-       kdp_current_ip_address = ipaddr->s_addr;
-       kdp_current_mac_address = *macaddr;
 
 
-       /* Get the debug boot-arg to decide if ARP replies are allowed */
-       if (kdp_arp_init == 0) {
-               PE_parse_boot_arg("debug", &debug);
-               if (debug & DB_ARP)
-                       kdp_flag |= KDP_ARP;
-               kdp_arp_init = 1;
-       }
+/* We don't interpret this pointer, we just give it to the bsd stack
+   so it can decide when to set the MAC and IP info. We'll
+   early initialize the MAC/IP info if we can so that we can use
+   KDP early in boot. These values may subsequently get over-written
+   when the interface gets initialized for real.
+*/
+void
+kdp_set_interface(void *ifp, const struct kdp_ether_addr *macaddr)
+{
+       char kdpstr[80];
+        struct kdp_in_addr addr = { 0 };
+        unsigned int len;
+        
+       kdp_current_ifp = ifp;
+
+        if (PE_parse_boot_argn("kdp_ip_addr", kdpstr, sizeof(kdpstr))) {
+            /* look for a static ip address */
+            if (inet_aton(kdpstr, &addr) == FALSE)
+                goto done;
+
+            goto config_network;
+        }
+
+        /* use saved ip address */
+        save_ip_in_nvram = TRUE;
+
+        len = sizeof(kdpstr);
+        if (PEReadNVRAMProperty("_kdp_ipstr", kdpstr, &len) == FALSE)
+            goto done;
+
+        kdpstr[len < sizeof(kdpstr) ? len : sizeof(kdpstr) - 1] = '\0';
+        if (inet_aton(kdpstr, &addr) == FALSE)
+            goto done;
+
+config_network:
+        kdp_current_ip_address = addr.s_addr;
+        if (macaddr)
+            kdp_current_mac_address = *macaddr;
+
+        /* we can't drop into the debugger at this point because the
+           link will likely not be up. when getDebuggerLinkStatus() support gets
+           added to the appropriate network drivers, adding the
+           following will enable this capability:
+           debugger_if_necessary();
+        */
+done:
+        return;
+}
+
+void *
+kdp_get_interface(void)
+{
+       return kdp_current_ifp;
 }
 
 }
 
-struct ether_addr 
+void 
+kdp_set_ip_and_mac_addresses(
+       struct kdp_in_addr              *ipaddr, 
+       struct kdp_ether_addr   *macaddr)
+{
+        static uint64_t last_time    = (uint64_t) -1;
+        static uint64_t throttle_val = 0;
+        uint64_t cur_time;
+        char addr[16];
+
+        if (kdp_current_ip_address == ipaddr->s_addr) 
+            goto done;
+
+        /* don't replace if serial debugging is configured */
+        if (!KDP_SERIAL_ENABLED() ||
+            (kdp_current_ip_address != KDP_SERIAL_IPADDR)) {
+            kdp_current_mac_address = *macaddr;
+            kdp_current_ip_address  = ipaddr->s_addr;
+        }
+
+        if (save_ip_in_nvram == FALSE)
+            goto done;
+
+        if (inet_ntoa_r(*ipaddr, addr, sizeof(addr)) == NULL)
+            goto done;
+
+        /* throttle writes if needed */
+        if (!throttle_val)
+            nanoseconds_to_absolutetime(KDP_THROTTLE_VALUE, &throttle_val);
+
+        cur_time = mach_absolute_time();
+        if (last_time == (uint64_t) -1 ||
+            ((cur_time - last_time) > throttle_val)) {
+            PEWriteNVRAMProperty("_kdp_ipstr", addr, 
+                                 (const unsigned int) strlen(addr));
+        }
+        last_time = cur_time;
+
+done:
+        debugger_if_necessary();
+}
+
+void
+kdp_set_gateway_mac(void *gatewaymac)
+{
+    router_mac = *(struct kdp_ether_addr *)gatewaymac;
+    flag_router_mac_initialized = TRUE;
+} 
+
+struct kdp_ether_addr 
 kdp_get_mac_addr(void)
 {
   return kdp_current_mac_address;
 kdp_get_mac_addr(void)
 {
   return kdp_current_mac_address;
@@ -324,41 +834,87 @@ kdp_get_mac_addr(void)
 unsigned int 
 kdp_get_ip_address(void)
 {
 unsigned int 
 kdp_get_ip_address(void)
 {
-  return kdp_current_ip_address;
+  return (unsigned int)kdp_current_ip_address;
+}
+
+void
+kdp_disable_arp(void)
+{
+       kdp_flag &= ~(DB_ARP);
+}
+
+static void
+kdp_arp_dispatch(void)
+{
+       struct kdp_ether_arp    aligned_ea, *ea = &aligned_ea;
+       unsigned                arp_header_offset;
+
+       arp_header_offset = (unsigned)sizeof(struct kdp_ether_header) + pkt.off;
+       memcpy((void *)ea, (void *)&pkt.data[arp_header_offset], sizeof(*ea));
+
+       switch(ntohs(ea->arp_op)) {
+       case ARPOP_REQUEST:
+               kdp_arp_reply(ea);
+               break;
+       case ARPOP_REPLY:
+               kdp_process_arp_reply(ea);
+               break;
+       default:
+               return;
+       }
+}
+
+static void
+kdp_process_arp_reply(struct kdp_ether_arp *ea)
+{
+       /* Are we interested in ARP replies? */
+       if (flag_arp_resolved == TRUE)
+               return;
+
+       /* Did we receive a reply from the right source? */
+       if (((struct kdp_in_addr *)(ea->arp_spa))->s_addr != target_ip)
+         return;
+
+       flag_arp_resolved = TRUE;
+       current_resolved_MAC = *(struct kdp_ether_addr *) (ea->arp_sha);
+
+       return;
 }
 
 /* ARP responses are enabled when the DB_ARP bit of the debug boot arg
 }
 
 /* ARP responses are enabled when the DB_ARP bit of the debug boot arg
-   is set. A workaround if you don't want to reboot is to set 
-   kdpDEBUGFlag &= DB_ARP when connected (but that certainly isn't a published
-   interface!)
-*/
+ * is set.
+ */
 
 static void 
 
 static void 
-kdp_arp_reply(void)
+kdp_arp_reply(struct kdp_ether_arp *ea)
 {
 {
-       struct ether_header     *eh;
-       struct ether_arp                aligned_ea, *ea = &aligned_ea;
+       struct kdp_ether_header *eh;
 
 
-       struct in_addr          isaddr, itaddr, myaddr;
-       struct ether_addr               my_enaddr;
+       struct kdp_in_addr              isaddr, itaddr, myaddr;
+       struct kdp_ether_addr   my_enaddr;
 
 
-       eh = (struct ether_header *)&pkt.data[pkt.off];
-       pkt.off += sizeof(struct ether_header);
+       eh = (struct kdp_ether_header *)&pkt.data[pkt.off];
+       pkt.off += (unsigned int)sizeof(struct kdp_ether_header);
 
 
-        memcpy((void *)ea, (void *)&pkt.data[pkt.off],sizeof(*ea));
-  
-        if(ntohs(ea->arp_op) != ARPOP_REQUEST)
-               return;
+       if(ntohs(ea->arp_op) != ARPOP_REQUEST)
+         return;
 
        myaddr.s_addr = kdp_get_ip_address();
        my_enaddr = kdp_get_mac_addr();
 
 
        myaddr.s_addr = kdp_get_ip_address();
        my_enaddr = kdp_get_mac_addr();
 
-       if (!(myaddr.s_addr) || !(my_enaddr.ether_addr_octet[1]))
+       if ((ntohl(myaddr.s_addr) == 0) ||
+           ((my_enaddr.ether_addr_octet[0] & 0xff) == 0
+                && (my_enaddr.ether_addr_octet[1] & 0xff) == 0
+                && (my_enaddr.ether_addr_octet[2] & 0xff) == 0
+                && (my_enaddr.ether_addr_octet[3] & 0xff) == 0
+                && (my_enaddr.ether_addr_octet[4] & 0xff) == 0
+                && (my_enaddr.ether_addr_octet[5] & 0xff) == 0
+                ))
                return;
 
        (void)memcpy((void *)&isaddr, (void *)ea->arp_spa, sizeof (isaddr));
        (void)memcpy((void *)&itaddr, (void *)ea->arp_tpa, sizeof (itaddr));
                return;
 
        (void)memcpy((void *)&isaddr, (void *)ea->arp_spa, sizeof (isaddr));
        (void)memcpy((void *)&itaddr, (void *)ea->arp_tpa, sizeof (itaddr));
-  
+
        if (itaddr.s_addr == myaddr.s_addr) {
                (void)memcpy((void *)ea->arp_tha, (void *)ea->arp_sha, sizeof(ea->arp_sha));
                (void)memcpy((void *)ea->arp_sha, (void *)&my_enaddr, sizeof(ea->arp_sha));
        if (itaddr.s_addr == myaddr.s_addr) {
                (void)memcpy((void *)ea->arp_tha, (void *)ea->arp_sha, sizeof(ea->arp_sha));
                (void)memcpy((void *)ea->arp_sha, (void *)&my_enaddr, sizeof(ea->arp_sha));
@@ -372,95 +928,196 @@ kdp_arp_reply(void)
                (void)memcpy(eh->ether_shost, &my_enaddr, sizeof(eh->ether_shost));
                eh->ether_type = htons(ETHERTYPE_ARP);
                (void)memcpy(&pkt.data[pkt.off], ea, sizeof(*ea));
                (void)memcpy(eh->ether_shost, &my_enaddr, sizeof(eh->ether_shost));
                eh->ether_type = htons(ETHERTYPE_ARP);
                (void)memcpy(&pkt.data[pkt.off], ea, sizeof(*ea));
-               pkt.off -= sizeof (struct ether_header);
+               pkt.off -= (unsigned int)sizeof (struct kdp_ether_header);
                /* pkt.len is still the length we want, ether_header+ether_arp */
                /* pkt.len is still the length we want, ether_header+ether_arp */
-               (*kdp_en_send_pkt)(&pkt.data[pkt.off], pkt.len);
+               kdp_send_data(&pkt.data[pkt.off], pkt.len);
        }
 }
 
 static void
 kdp_poll(void)
 {
        }
 }
 
 static void
 kdp_poll(void)
 {
-  struct ether_header  *eh;
-  struct udpiphdr              aligned_ui, *ui = &aligned_ui;
-  struct ip                            aligned_ip, *ip = &aligned_ip;
-  static int                   msg_printed;
+       struct kdp_ether_header *eh = NULL;
+       struct kdp_udpiphdr     aligned_ui, *ui = &aligned_ui;
+       struct kdp_ip           aligned_ip, *ip = &aligned_ip;
+       static int              msg_printed;
 
 
-
-    if (pkt.input)
-       kdp_panic("kdp_poll");
+       if (pkt.input)
+               kdp_panic("kdp_poll");
  
  
-    if (!kdp_en_recv_pkt || !kdp_en_send_pkt) {
-       if( msg_printed == 0) {
-           msg_printed = 1;
-            printf("kdp_poll: no debugger device\n");
+       if (!kdp_en_recv_pkt || !kdp_en_send_pkt) {
+               if( msg_printed == 0) {
+                       msg_printed = 1;
+                       printf("kdp_poll: no debugger device\n");
+               }
+               return;
        }
        }
-       return;
-    }
 
 
-    pkt.off = pkt.len = 0;
-    (*kdp_en_recv_pkt)(pkt.data, &pkt.len, 3/* ms */);
-  
-    if (pkt.len == 0)
-       return;
+       pkt.off = pkt.len = 0;
+       kdp_receive_data(pkt.data, &pkt.len, 3/* ms */);
 
 
-    if (pkt.len >= sizeof(struct ether_header))
-      {
-       eh = (struct ether_header *)&pkt.data[pkt.off];  
-       
-       if (kdp_flag & KDP_ARP)
-         {
-           if (ntohs(eh->ether_type) == ETHERTYPE_ARP)
-             {
-               kdp_arp_reply();
+       if (pkt.len == 0)
                return;
                return;
-             }
-         }
-      }
 
 
-    if (pkt.len < (sizeof (struct ether_header) + sizeof (struct udpiphdr)))
-       return;
+       if (pkt.len >= sizeof(struct kdp_ether_header))
+       {
+               eh = (struct kdp_ether_header *)&pkt.data[pkt.off];  
+       
+               if (kdp_flag & KDP_ARP)
+               {
+                       if (ntohs(eh->ether_type) == ETHERTYPE_ARP)
+                       {
+                               kdp_arp_dispatch();
+                               return;
+                       }
+               }
+       }
 
 
-    pkt.off += sizeof (struct ether_header);
-    if (ntohs(eh->ether_type) != ETHERTYPE_IP) {
-       return;
-    }
+       if (pkt.len < (sizeof (struct kdp_ether_header) + sizeof (struct kdp_udpiphdr)))
+               return;
+
+       pkt.off += (unsigned int)sizeof (struct kdp_ether_header);
+       if (ntohs(eh->ether_type) != ETHERTYPE_IP) {
+               return;
+       }
 
 #if DO_ALIGN
 
 #if DO_ALIGN
-    bcopy((char *)&pkt.data[pkt.off], (char *)ui, sizeof(*ui));
-    bcopy((char *)&pkt.data[pkt.off], (char *)ip, sizeof(*ip));
+       bcopy((char *)&pkt.data[pkt.off], (char *)ui, sizeof(*ui));
+       bcopy((char *)&pkt.data[pkt.off], (char *)ip, sizeof(*ip));
 #else
 #else
-    ui = (struct udpiphdr *)&pkt.data[pkt.off];
-    ip = (struct ip *)&pkt.data[pkt.off];
+       ui = (struct kdp_udpiphdr *)&pkt.data[pkt.off];
+       ip = (struct kdp_ip *)&pkt.data[pkt.off];
 #endif
 
 #endif
 
-    pkt.off += sizeof (struct udpiphdr);
-    if (ui->ui_pr != IPPROTO_UDP) {
-       return;
-    }
+       pkt.off += (unsigned int)sizeof (struct kdp_udpiphdr);
+       if (ui->ui_pr != IPPROTO_UDP) {
+               return;
+       }
  
  
-    if (ip->ip_hl > (sizeof (struct ip) >> 2)) {
-       return;
-    }
+       if (ip->ip_hl > (sizeof (struct kdp_ip) >> 2)) {
+               return;
+       }
 
 
-    if (ntohs(ui->ui_dport) != KDP_REMOTE_PORT) {
-       return;
-    }
-       
-    if (!kdp.is_conn) {
-       enaddr_copy(eh->ether_dhost, &adr.loc.ea);
-       adr.loc.in = ui->ui_dst;
+       if (ntohs(ui->ui_dport) != KDP_REMOTE_PORT) {
+               if (panicd_port == (ntohs(ui->ui_dport)) && 
+                   flag_panic_dump_in_progress) {
+                       last_panic_port = ui->ui_sport;
+               }
+               else
+                       return;
+       }
+       /* If we receive a kernel debugging packet whilst a 
+        * core dump is in progress, abort the transfer and 
+        * enter the debugger if not told otherwise. 
+        */
+       else
+               if (flag_panic_dump_in_progress)
+               {
+                       if (!flag_dont_abort_panic_dump) {
+                               abort_panic_transfer();
+                       }
+                       return;
+               }
+
+       if (!kdp.is_conn && !flag_panic_dump_in_progress) {
+               enaddr_copy(eh->ether_dhost, &adr.loc.ea);
+               adr.loc.in = ui->ui_dst;
+
+               enaddr_copy(eh->ether_shost, &adr.rmt.ea);
+               adr.rmt.in = ui->ui_src;
+       }
 
 
-       enaddr_copy(eh->ether_shost, &adr.rmt.ea);
-       adr.rmt.in = ui->ui_src;
-    }
+       /*
+        * Calculate kdp packet length.
+        */
+       pkt.len = ntohs((u_short)ui->ui_ulen) - (unsigned int)sizeof (struct kdp_udphdr);
+       pkt.input = TRUE;
+}
 
 
-    /*
-     * Calculate kdp packet length.
-     */
-    pkt.len = ntohs((u_short)ui->ui_ulen) - sizeof (struct udphdr);
-    pkt.input = TRUE;
+/* Create and transmit an ARP resolution request for the target IP address.
+ * This is modeled on ether_inet_arp()/RFC 826.
+ */
+
+static void
+transmit_ARP_request(uint32_t ip_addr)
+{
+       struct kdp_ether_header *eh = (struct kdp_ether_header *) &pkt.data[0];
+       struct kdp_ether_arp    *ea = (struct kdp_ether_arp *) &pkt.data[sizeof(struct kdp_ether_header)];
+
+       KDP_DEBUG("Transmitting ARP request\n");
+       /* Populate the ether_header */
+       eh->ether_type = htons(ETHERTYPE_ARP);
+       enaddr_copy(&kdp_current_mac_address, eh->ether_shost);
+       enaddr_copy(&etherbroadcastaddr, eh->ether_dhost);
+
+       /* Populate the ARP header */
+       ea->arp_pro = htons(ETHERTYPE_IP);
+       ea->arp_hln = sizeof(ea->arp_sha);
+       ea->arp_pln = sizeof(ea->arp_spa);
+       ea->arp_hrd = htons(ARPHRD_ETHER);
+       ea->arp_op = htons(ARPOP_REQUEST);
+
+       /* Target fields */
+       enaddr_copy(&etherbroadcastaddr, ea->arp_tha);
+       memcpy(ea->arp_tpa, (void *) &ip_addr, sizeof(ip_addr));
+
+       /* Source fields */
+       enaddr_copy(&kdp_current_mac_address, ea->arp_sha);
+       memcpy(ea->arp_spa, (void *) &kdp_current_ip_address, sizeof(kdp_current_ip_address));
+
+       pkt.off = 0;
+       pkt.len = sizeof(struct kdp_ether_header) + sizeof(struct kdp_ether_arp);
+       /* Transmit */
+       kdp_send_data(&pkt.data[pkt.off], pkt.len);
+}
+
+static boolean_t
+kdp_arp_resolve(uint32_t arp_target_ip, struct kdp_ether_addr *resolved_MAC)
+{
+       int poll_count = 256; /* ~770 ms modulo broadcast/delayed traffic? */
+       char tretries = 0;
+
+#define NUM_ARP_TX_RETRIES 5
+
+       target_ip = arp_target_ip;
+       flag_arp_resolved = FALSE;
+
+TRANSMIT_RETRY:
+       pkt.off = pkt.len = 0;
+
+       tretries++;
+
+       if (tretries >= NUM_ARP_TX_RETRIES) {
+               return FALSE;
+       }
+
+       KDP_DEBUG("ARP TX attempt #%d \n", tretries);
+
+       transmit_ARP_request(arp_target_ip);
 
 
+       while (!pkt.input && !flag_arp_resolved && flag_panic_dump_in_progress && --poll_count) {
+               kdp_poll();
+       }
+
+       if (flag_arp_resolved) {
+               *resolved_MAC = current_resolved_MAC;
+               return TRUE;
+       }
+       
+       if (!flag_panic_dump_in_progress || pkt.input) /* we received a debugging packet, bail*/
+       {
+               printf("Received a debugger packet,transferring control to debugger\n");
+               /* Indicate that we should wait in the debugger when we return */
+               kdp_flag |= DBG_POST_CORE;
+               pkt.input = FALSE;
+               return FALSE;
+       }
+       else /* We timed out */
+               if (0 == poll_count) {
+                       poll_count = 256;
+                       goto TRANSMIT_RETRY;
+               }
+       return FALSE;
 }
 
 static void
 }
 
 static void
@@ -471,7 +1128,6 @@ kdp_handler(
     unsigned short             reply_port;
     kdp_hdr_t                  aligned_hdr, *hdr = &aligned_hdr;
 
     unsigned short             reply_port;
     kdp_hdr_t                  aligned_hdr, *hdr = &aligned_hdr;
 
-
     kdp.saved_state = saved_state;  // see comment in kdp_raise_exception
 
     do {
     kdp.saved_state = saved_state;  // see comment in kdp_raise_exception
 
     do {
@@ -495,19 +1151,54 @@ kdp_handler(
        // check for retransmitted request
        if (hdr->seq == (exception_seq - 1)) {
            /* retransmit last reply */
        // check for retransmitted request
        if (hdr->seq == (exception_seq - 1)) {
            /* retransmit last reply */
-           (*kdp_en_send_pkt)(&saved_reply.data[saved_reply.off],
-                           saved_reply.len);
+           kdp_send_data(&saved_reply.data[saved_reply.off],
+                          saved_reply.len);
            goto again;
            goto again;
-       } else if (hdr->seq != exception_seq) {
+       } else if ((hdr->seq != exception_seq) &&
+                   (hdr->request != KDP_CONNECT)) {
            printf("kdp: bad sequence %d (want %d)\n",
                        hdr->seq, exception_seq);
            goto again;
        }
        
            printf("kdp: bad sequence %d (want %d)\n",
                        hdr->seq, exception_seq);
            goto again;
        }
        
+       /* This is a manual side-channel to the main KDP protocol.
+        * A client like GDB/kgmacros can manually construct 
+        * a request, set the input flag, issue a dummy KDP request,
+        * and then manually collect the result
+        */
+       if (manual_pkt.input) {
+         kdp_hdr_t *manual_hdr = (kdp_hdr_t *)&manual_pkt.data;
+         unsigned short manual_port_unused = 0;
+         if (!manual_hdr->is_reply) {
+           /* process */
+           kdp_packet((unsigned char *)&manual_pkt.data,
+                      (int *)&manual_pkt.len,
+                      &manual_port_unused);
+         }
+         manual_pkt.input = 0;
+       }
+
        if (kdp_packet((unsigned char*)&pkt.data[pkt.off], 
                        (int *)&pkt.len, 
                        (unsigned short *)&reply_port)) {
        if (kdp_packet((unsigned char*)&pkt.data[pkt.off], 
                        (int *)&pkt.len, 
                        (unsigned short *)&reply_port)) {
-           kdp_reply(reply_port);
+            boolean_t sideband = FALSE;
+
+            /* if it's an already connected error message, 
+             * send a sideband reply for that. for successful connects,
+             * make sure the sequence number is correct. */
+            if (hdr->request == KDP_CONNECT) {
+                kdp_connect_reply_t *rp = 
+                       (kdp_connect_reply_t *) &pkt.data[pkt.off];
+                kdp_error_t err = rp->error;
+
+                if (err == KDPERR_NO_ERROR) {
+                    exception_seq = hdr->seq;
+                } else if (err == KDPERR_ALREADY_CONNECTED) {
+                    sideband = TRUE;
+                }
+            } 
+
+           kdp_reply(reply_port, sideband);
        }
 
 again:
        }
 
 again:
@@ -518,104 +1209,115 @@ again:
 static void
 kdp_connection_wait(void)
 {
 static void
 kdp_connection_wait(void)
 {
-    unsigned short     reply_port;
-    boolean_t kdp_call_kdb();
-    struct ether_addr  kdp_mac_addr = kdp_get_mac_addr();
-    unsigned int ip_addr = kdp_get_ip_address();
-
-       printf( "ethernet MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n",
-            kdp_mac_addr.ether_addr_octet[0] & 0xff,
-            kdp_mac_addr.ether_addr_octet[1] & 0xff,
-            kdp_mac_addr.ether_addr_octet[2] & 0xff,
-            kdp_mac_addr.ether_addr_octet[3] & 0xff,
-            kdp_mac_addr.ether_addr_octet[4] & 0xff,
-            kdp_mac_addr.ether_addr_octet[5] & 0xff);
+       unsigned short          reply_port;
+       struct kdp_ether_addr   kdp_mac_addr = kdp_get_mac_addr();
+       unsigned int            ip_addr = ntohl(kdp_get_ip_address());
+
+       /*
+        * Do both a printf() and a kprintf() of the MAC and IP so that
+        * they will print out on headless machines but not be added to
+        * the panic.log
+        */
+
+        if (KDP_SERIAL_ENABLED()) {
+            printf("Using serial KDP.\n");
+            kprintf("Using serial KDP.\n");
+        } else {
+            printf( "ethernet MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n",
+                    kdp_mac_addr.ether_addr_octet[0] & 0xff,
+                    kdp_mac_addr.ether_addr_octet[1] & 0xff,
+                    kdp_mac_addr.ether_addr_octet[2] & 0xff,
+                    kdp_mac_addr.ether_addr_octet[3] & 0xff,
+                    kdp_mac_addr.ether_addr_octet[4] & 0xff,
+                    kdp_mac_addr.ether_addr_octet[5] & 0xff);
                
                
-       printf( "ip address: %d.%d.%d.%d\n",
-            (ip_addr & 0xff000000) >> 24,
-            (ip_addr & 0xff0000) >> 16,
-            (ip_addr & 0xff00) >> 8,
-            (ip_addr & 0xff));
+            kprintf( "ethernet MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n",
+                     kdp_mac_addr.ether_addr_octet[0] & 0xff,
+                     kdp_mac_addr.ether_addr_octet[1] & 0xff,
+                     kdp_mac_addr.ether_addr_octet[2] & 0xff,
+                     kdp_mac_addr.ether_addr_octet[3] & 0xff,
+                     kdp_mac_addr.ether_addr_octet[4] & 0xff,
+                     kdp_mac_addr.ether_addr_octet[5] & 0xff);
+               
+            printf( "ip address: %d.%d.%d.%d\n",
+                    (ip_addr & 0xff000000) >> 24,
+                    (ip_addr & 0xff0000) >> 16,
+                    (ip_addr & 0xff00) >> 8,
+                    (ip_addr & 0xff));
             
             
-    printf("\nWaiting for remote debugger connection.\n");
-
-    if (reattach_wait == 0)
-      {
-#ifdef MACH_PE
-       if( 0 != kdp_getc())
-#endif
-         {
-           printf("Options.....    Type\n");
-           printf("------------    ----\n");
-           printf("continue....    'c'\n");
-           printf("reboot......    'r'\n");
-#if MACH_KDB
-           printf("enter kdb...    'k'\n");
-#endif
-         }
-      }
-    else
-      reattach_wait = 0;
+            kprintf( "ip address: %d.%d.%d.%d\n",
+                     (ip_addr & 0xff000000) >> 24,
+                     (ip_addr & 0xff0000) >> 16,
+                     (ip_addr & 0xff00) >> 8,
+                     (ip_addr & 0xff));
+        }
+            
+       printf("\nWaiting for remote debugger connection.\n");
+       kprintf("\nWaiting for remote debugger connection.\n");
+
+
+       if (reattach_wait == 0) {
+               if((kdp_flag & KDP_GETC_ENA) && (0 != kdp_getc()))
+               {
+                       printf("Options.....    Type\n");
+                       printf("------------    ----\n");
+                       printf("continue....    'c'\n");
+                       printf("reboot......    'r'\n");
+               }
+       } else
+               reattach_wait = 0;
     
     
-    exception_seq = 0;
-    do {
-       kdp_hdr_t aligned_hdr, *hdr = &aligned_hdr;
+       exception_seq = 0;
+
+       do {
+               kdp_hdr_t aligned_hdr, *hdr = &aligned_hdr;
        
        
-       while (!pkt.input) {
-           int c;
-           c = kdp_getc();
-           switch(c) {
-               case 'c':
-                   printf("Continuing...\n");
-                   return;
-               case 'r':
-                   printf("Rebooting...\n");
-                   kdp_reboot();
-                   break;
-#if MACH_KDB
-               case 'k':
-                   printf("calling kdb...\n");
-                   if (kdp_call_kdb())
-                       return;
-                   else
-                       printf("not implemented...\n");
-#endif
-               default:
-                   break;
-           }
-           kdp_poll();
-       }
+               while (!pkt.input) {
+                       if (kdp_flag & KDP_GETC_ENA) {
+                               switch(kdp_getc()) {
+                               case 'c':
+                                       printf("Continuing...\n");
+                                       return;
+                               case 'r':
+                                       printf("Rebooting...\n");
+                                       kdp_machine_reboot();
+                                       break;
+                               default:
+                                       break;
+                               }
+                       }
+                       kdp_poll();
+               }
 
 
-       // check for sequence number of 0
 #if DO_ALIGN
 #if DO_ALIGN
-       bcopy((char *)&pkt.data[pkt.off], (char *)hdr, sizeof(*hdr));
+               bcopy((char *)&pkt.data[pkt.off], (char *)hdr, sizeof(*hdr));
 #else
 #else
-       hdr = (kdp_hdr_t *)&pkt.data[pkt.off];
+               hdr = (kdp_hdr_t *)&pkt.data[pkt.off];
 #endif
 #endif
-       if (hdr->request == KDP_HOSTREBOOT) {
-               kdp_reboot();
-               /* should not return! */
-       }
-       if (((hdr->request == KDP_CONNECT) || (hdr->request == KDP_REATTACH)) &&
-               !hdr->is_reply && (hdr->seq == exception_seq)) {
-           if (kdp_packet((unsigned char *)&pkt.data[pkt.off], 
-                       (int *)&pkt.len, 
-                       (unsigned short *)&reply_port))
-               kdp_reply(reply_port);
-           if (hdr->request == KDP_REATTACH)
-             {
-               reattach_wait = 0;
-               hdr->request=KDP_DISCONNECT;
-               exception_seq = 0;
-             }
-         }
-           
-       pkt.input = FALSE;
-    } while (!kdp.is_conn);
+               if (hdr->request == KDP_HOSTREBOOT) {
+                       kdp_machine_reboot();
+                       /* should not return! */
+               }
+               if (((hdr->request == KDP_CONNECT) || (hdr->request == KDP_REATTACH)) &&
+                       !hdr->is_reply && (hdr->seq == exception_seq)) {
+                   if (kdp_packet((unsigned char *)&pkt.data[pkt.off], 
+                               (int *)&pkt.len, 
+                               (unsigned short *)&reply_port))
+                           kdp_reply(reply_port, FALSE);
+                   if (hdr->request == KDP_REATTACH) {
+                               reattach_wait = 0;
+                               hdr->request=KDP_DISCONNECT;
+                               exception_seq = 0;
+                       }
+               }
+
+               pkt.input = FALSE;
+       } while (!kdp.is_conn);
     
     
-    if (current_debugger == KDP_CUR_DB)
-       active_debugger=1;
-    printf("Connected to remote debugger.\n");
+       if (current_debugger == KDP_CUR_DB)
+               active_debugger=1;
+       printf("Connected to remote debugger.\n");
+       kprintf("Connected to remote debugger.\n");
 }
 
 static void
 }
 
 static void
@@ -630,7 +1332,7 @@ kdp_send_exception(
     unsigned int                poll_timeout;
 
     do {
     unsigned int                poll_timeout;
 
     do {
-       pkt.off = sizeof (struct ether_header) + sizeof (struct udpiphdr);
+       pkt.off = sizeof (struct kdp_ether_header) + sizeof (struct kdp_udpiphdr);
        kdp_exception((unsigned char *)&pkt.data[pkt.off], 
                        (int *)&pkt.len, 
                        (unsigned short *)&remote_port,
        kdp_exception((unsigned char *)&pkt.data[pkt.off], 
                        (int *)&pkt.len, 
                        (unsigned short *)&remote_port,
@@ -678,6 +1380,18 @@ kdp_raise_exception(
 )
 {
     int                        index;
 )
 {
     int                        index;
+    unsigned int       initial_not_in_kdp = not_in_kdp;
+
+    not_in_kdp = 0;
+    /* Was a system trace requested ? */
+    if (kdp_snapshot && (!panic_active()) && (panic_caller == 0)) {
+           stack_snapshot_ret = kdp_stackshot(stack_snapshot_pid,
+           stack_snapshot_buf, stack_snapshot_bufsize,
+           stack_snapshot_flags, stack_snapshot_dispatch_offset, 
+               &stack_snapshot_bytes_traced);
+           not_in_kdp = initial_not_in_kdp;
+           return;
+    }
 
     disable_preemption();
 
 
     disable_preemption();
 
@@ -700,17 +1414,38 @@ kdp_raise_exception(
      * do this. I think the client and the host can get out of sync.
      */
     kdp.saved_state = saved_state;
      * do this. I think the client and the host can get out of sync.
      */
     kdp.saved_state = saved_state;
+    kdp.kdp_cpu = cpu_number();
+    kdp.kdp_thread = current_thread();
+
+    if (kdp_en_setmode)  
+        (*kdp_en_setmode)(TRUE); /* enabling link mode */
 
     if (pkt.input)
        kdp_panic("kdp_raise_exception");
 
     if (pkt.input)
        kdp_panic("kdp_raise_exception");
+
+    if (((kdp_flag & KDP_PANIC_DUMP_ENABLED) || (kdp_flag & PANIC_LOG_DUMP))
+       && (panicstr != (char *) 0)) {
+           kdp_panic_dump();
+           if (kdp_flag & REBOOT_POST_CORE)
+                   kdp_machine_reboot();
+      }
+    else
+      if ((kdp_flag & PANIC_CORE_ON_NMI) && (panicstr == (char *) 0) &&
+         !kdp.is_conn) {
+
+       disable_debug_output = disableConsoleOutput = FALSE;
+       kdp_panic_dump();
+
+       if (!(kdp_flag & DBG_POST_CORE))
+         goto exit_raise_exception;
+      }
+
  again:
     if (!kdp.is_conn)
        kdp_connection_wait();
  again:
     if (!kdp.is_conn)
        kdp_connection_wait();
-    else
-      {
+    else {
        kdp_send_exception(exception, code, subcode);
        kdp_send_exception(exception, code, subcode);
-       if (kdp.exception_ack_needed)
-         {
+       if (kdp.exception_ack_needed) {
            kdp.exception_ack_needed = FALSE;
            kdp_remove_all_breakpoints();
            printf("Remote debugger disconnected.\n");
            kdp.exception_ack_needed = FALSE;
            kdp_remove_all_breakpoints();
            printf("Remote debugger disconnected.\n");
@@ -726,12 +1461,47 @@ kdp_raise_exception(
            printf("Remote debugger disconnected.\n");
          }
     }
            printf("Remote debugger disconnected.\n");
          }
     }
+    /* Allow triggering a panic core dump when connected to the machine
+     * Continuing after setting kdp_trigger_core_dump should do the
+     * trick.
+     */
+
+    if (1 == kdp_trigger_core_dump) {
+       kdp_flag |= KDP_PANIC_DUMP_ENABLED;
+       kdp_panic_dump();
+       if (kdp_flag & REBOOT_POST_CORE)
+               kdp_machine_reboot();
+       kdp_trigger_core_dump = 0;
+      }
+
+/* Trigger a reboot if the user has set this flag through the
+ * debugger.Ideally, this would be done through the HOSTREBOOT packet
+ * in the protocol,but that will need gdb support,and when it's
+ * available, it should work automatically.
+ */
+    if (1 == flag_kdp_trigger_reboot) {
+           kdp_machine_reboot();
+           /* If we're still around, reset the flag */
+           flag_kdp_trigger_reboot = 0;
+    }
+
+    if (kdp_reentry_deadline) {
+           kdp_schedule_debugger_reentry(kdp_reentry_deadline);
+           printf("Debugger re-entry scheduled in %d milliseconds\n", kdp_reentry_deadline);
+           kdp_reentry_deadline = 0;
+    }
 
     kdp_sync_cache();
 
     if (reattach_wait == 1)
       goto again;
 
 
     kdp_sync_cache();
 
     if (reattach_wait == 1)
       goto again;
 
+exit_raise_exception:
+    if (kdp_en_setmode)  
+        (*kdp_en_setmode)(FALSE); /* link cleanup */
+
+    not_in_kdp = initial_not_in_kdp;
+
     enable_preemption();
 }
 
     enable_preemption();
 }
 
@@ -741,5 +1511,743 @@ kdp_reset(void)
        kdp.reply_port = kdp.exception_port = 0;
        kdp.is_halted = kdp.is_conn = FALSE;
        kdp.exception_seq = kdp.conn_seq = 0;
        kdp.reply_port = kdp.exception_port = 0;
        kdp.is_halted = kdp.is_conn = FALSE;
        kdp.exception_seq = kdp.conn_seq = 0;
+       kdp.session_key = 0;
+       pkt.input = manual_pkt.input = FALSE;
+       pkt.len = pkt.off = manual_pkt.len = 0;
+}
+
+struct corehdr *
+create_panic_header(unsigned int request, const char *corename, 
+    unsigned length, unsigned int block)
+{
+       struct kdp_udpiphdr     aligned_ui, *ui = &aligned_ui;
+       struct kdp_ip           aligned_ip, *ip = &aligned_ip;
+       struct kdp_ether_header *eh;
+       struct corehdr          *coreh;
+       const char              *mode = "octet";
+       char                    modelen  = strlen(mode) + 1;
+
+       size_t                  fmask_size = sizeof(KDP_FEATURE_MASK_STRING) + sizeof(kdp_crashdump_feature_mask);
+
+       pkt.off = sizeof (struct kdp_ether_header);
+       pkt.len = (unsigned int)(length + ((request == KDP_WRQ) ? modelen + fmask_size : 0) + 
+       (corename ? (strlen(corename) + 1 ): 0) + sizeof(struct corehdr));
+
+#if DO_ALIGN
+       bcopy((char *)&pkt.data[pkt.off], (char *)ui, sizeof(*ui));
+#else
+       ui = (struct kdp_udpiphdr *)&pkt.data[pkt.off];
+#endif
+       ui->ui_next = ui->ui_prev = 0;
+       ui->ui_x1 = 0;
+       ui->ui_pr = IPPROTO_UDP;
+       ui->ui_len = htons((u_short)pkt.len + sizeof (struct kdp_udphdr));
+       ui->ui_src.s_addr = (uint32_t)kdp_current_ip_address;
+       /* Already in network byte order via inet_aton() */
+       ui->ui_dst.s_addr = panic_server_ip;
+       ui->ui_sport = htons(panicd_port);
+       ui->ui_dport = ((request == KDP_WRQ) ? htons(panicd_port) : last_panic_port);
+       ui->ui_ulen = ui->ui_len;
+       ui->ui_sum = 0;
+#if DO_ALIGN
+       bcopy((char *)ui, (char *)&pkt.data[pkt.off], sizeof(*ui));
+       bcopy((char *)&pkt.data[pkt.off], (char *)ip, sizeof(*ip));
+#else
+       ip = (struct kdp_ip *)&pkt.data[pkt.off];
+#endif
+       ip->ip_len = htons(sizeof (struct kdp_udpiphdr) + pkt.len);
+       ip->ip_v = IPVERSION;
+       ip->ip_id = htons(ip_id++);
+       ip->ip_hl = sizeof (struct kdp_ip) >> 2;
+       ip->ip_ttl = udp_ttl;
+       ip->ip_sum = 0;
+       ip->ip_sum = htons(~ip_sum((unsigned char *)ip, ip->ip_hl));
+#if DO_ALIGN
+       bcopy((char *)ip, (char *)&pkt.data[pkt.off], sizeof(*ip));
+#endif
+    
+       pkt.len += (unsigned int)sizeof (struct kdp_udpiphdr);
+
+       pkt.off += (unsigned int)sizeof (struct kdp_udpiphdr);
+  
+       coreh = (struct corehdr *) &pkt.data[pkt.off];
+       coreh->th_opcode = htons((u_short)request);
+  
+       if (request == KDP_WRQ)
+       {
+               char *cp;
+
+               cp = coreh->th_u.tu_rpl;
+               cp += strlcpy (cp, corename, KDP_MAXPACKET);
+               *cp++ = '\0';
+               cp += strlcpy (cp, mode, KDP_MAXPACKET - strlen(corename));
+               *cp++ = '\0';
+               cp += strlcpy(cp, KDP_FEATURE_MASK_STRING, sizeof(KDP_FEATURE_MASK_STRING));
+               *cp++ = '\0'; /* Redundant */
+               bcopy(&kdp_crashdump_feature_mask, cp, sizeof(kdp_crashdump_feature_mask));
+               kdp_crashdump_pkt_size = KDP_LARGE_CRASHDUMP_PKT_SIZE;
+               PE_parse_boot_argn("kdp_crashdump_pkt_size", &kdp_crashdump_pkt_size, sizeof(kdp_crashdump_pkt_size));
+               cp += sizeof(kdp_crashdump_feature_mask);
+               *(uint32_t *)cp = htonl(kdp_crashdump_pkt_size);
+       }
+       else
+       {
+               coreh->th_block = htonl((unsigned int) block);
+       }
+
+       pkt.off -= (unsigned int)sizeof (struct kdp_udpiphdr);
+       pkt.off -= (unsigned int)sizeof (struct kdp_ether_header);
+
+       eh = (struct kdp_ether_header *)&pkt.data[pkt.off];
+       enaddr_copy(&kdp_current_mac_address, eh->ether_shost);
+       enaddr_copy(&destination_mac, eh->ether_dhost);
+       eh->ether_type = htons(ETHERTYPE_IP);
+    
+       pkt.len += (unsigned int)sizeof (struct kdp_ether_header);
+       return coreh;
+}
+
+static int kdp_send_crashdump_seek(char *corename, uint64_t seek_off)
+{
+       int panic_error;
+
+       if (kdp_feature_large_crashdumps) {
+               panic_error = kdp_send_crashdump_pkt(KDP_SEEK, corename, 
+                                                    sizeof(seek_off),
+                                                    &seek_off);
+       } else {
+               uint32_t off = (uint32_t) seek_off;
+               panic_error = kdp_send_crashdump_pkt(KDP_SEEK, corename, 
+                                                    sizeof(off), &off);
+       }
+
+       if (panic_error < 0) {
+               printf ("kdp_send_crashdump_pkt failed with error %d\n",
+                       panic_error);
+               return panic_error;
+       }
+
+       return 0;
+}
+
+int kdp_send_crashdump_data(unsigned int request, char *corename,
+    int64_t length, caddr_t txstart)
+{
+       int panic_error = 0;
+
+       while (length > 0) {
+               uint64_t chunk = MIN(kdp_crashdump_pkt_size, length);
+
+               panic_error = kdp_send_crashdump_pkt(request, corename, chunk,
+                                                       txstart);
+               if (panic_error < 0) {
+                       printf ("kdp_send_crashdump_pkt failed with error %d\n", panic_error);
+                       return panic_error;
+               }
+
+               txstart += chunk;
+               length  -= chunk;
+       }
+       return 0;
+}
+
+uint32_t kdp_crashdump_short_pkt;
+
+int
+kdp_send_crashdump_pkt(unsigned int request, char *corename, 
+    uint64_t length, void *panic_data)
+{
+       int poll_count;
+       struct corehdr *th = NULL;
+       char rretries, tretries;
+
+       if (kdp_dump_start_time == 0) {
+               kdp_dump_start_time = mach_absolute_time();
+               kdp_superblock_dump_start_time = kdp_dump_start_time;
+       }
+
+       tretries = rretries = 0;
+       poll_count = KDP_CRASHDUMP_POLL_COUNT;
+       pkt.off = pkt.len = 0;
+       if (request == KDP_WRQ) /* longer timeout for initial request */
+               poll_count += 1000;
+
+TRANSMIT_RETRY:
+       tretries++;
+
+       if (tretries >=15) {
+/* The crashdump server is unreachable for some reason. This could be a network
+ * issue or, if we've been especially unfortunate, we've hit Radar 2760413,
+ * which is a long standing problem with the IOKit polled mode network driver
+ * shim which can prevent transmits/receives completely.
+ */
+               printf ("Cannot contact panic server, timing out.\n");
+               return (-3);
+       }
+
+       if (tretries > 2)
+               printf("TX retry #%d ", tretries );
+  
+       th = create_panic_header(request, corename, (unsigned)length, panic_block);
+
+       if (request == KDP_DATA) {
+               /* as all packets are kdp_crashdump_pkt_size in length, the last packet
+                * may end up with trailing bits. make sure that those
+                * bits aren't confusing. */
+               if (length < kdp_crashdump_pkt_size) {
+                       kdp_crashdump_short_pkt++;
+                       memset(th->th_data + length, 'Y', 
+                               kdp_crashdump_pkt_size - (uint32_t) length);
+               }
+
+               if (!kdp_machine_vm_read((mach_vm_address_t)(uintptr_t)panic_data, (caddr_t) th->th_data, length)) {
+                       uintptr_t next_page = round_page((uintptr_t)panic_data);
+                       memset((caddr_t) th->th_data, 'X', (size_t)length);
+                       if ((next_page - ((uintptr_t) panic_data)) < length) {
+                               uint64_t resid = length - (next_page - (intptr_t) panic_data);
+                               if (!kdp_machine_vm_read((mach_vm_address_t)(uintptr_t)next_page, (caddr_t) th->th_data + (length - resid), resid)) {
+                                       memset((caddr_t) th->th_data + (length - resid), 'X', (size_t)resid);
+                               }
+                       }
+               }
+       }
+       else if (request == KDP_SEEK) {
+               if (kdp_feature_large_crashdumps)
+                       *(uint64_t *) th->th_data = OSSwapHostToBigInt64((*(uint64_t *) panic_data));
+               else
+                       *(unsigned int *) th->th_data = htonl(*(unsigned int *) panic_data);
+       }
+
+       kdp_send_data(&pkt.data[pkt.off], pkt.len);
+
+       /* Listen for the ACK */
+RECEIVE_RETRY:
+       while (!pkt.input && flag_panic_dump_in_progress && poll_count) {
+               kdp_poll();
+               poll_count--;
+       }
+
+       if (pkt.input) {
+    
+               pkt.input = FALSE;
+    
+               th = (struct corehdr *) &pkt.data[pkt.off];
+               if (request == KDP_WRQ) {
+                       uint16_t opcode64 = ntohs(th->th_opcode);
+                       uint16_t features64 = (opcode64 & 0xFF00)>>8;
+                       if ((opcode64 & 0xFF) == KDP_ACK) {
+                               kdp_feature_large_crashdumps = features64 & KDP_FEATURE_LARGE_CRASHDUMPS;
+                               if (features64 & KDP_FEATURE_LARGE_PKT_SIZE) {
+                                       kdp_feature_large_pkt_size = 1;
+                               }
+                               else {
+                                       kdp_feature_large_pkt_size = 0;
+                                       kdp_crashdump_pkt_size = 512;
+                               }
+                               printf("Protocol features: 0x%x\n", (uint32_t) features64);
+                               th->th_opcode = htons(KDP_ACK);
+                       }
+               }
+               if (ntohs(th->th_opcode) == KDP_ACK && ntohl(th->th_block) == panic_block) {
+               }
+               else
+                       if (ntohs(th->th_opcode) == KDP_ERROR) {
+                               printf("Panic server returned error %d, retrying\n", ntohl(th->th_code));
+                               poll_count = 1000;
+                               goto TRANSMIT_RETRY;
+                       }
+                       else 
+                               if (ntohl(th->th_block) == (panic_block - 1)) {
+                                       printf("RX retry ");
+                                       if (++rretries > 1)
+                                               goto TRANSMIT_RETRY;
+                                       else
+                                               goto RECEIVE_RETRY;
+                               }
+       }
+       else
+               if (!flag_panic_dump_in_progress) /* we received a debugging packet, bail*/
+               {
+                       printf("Received a debugger packet,transferring control to debugger\n");
+                       /* Configure that if not set ..*/
+                       kdp_flag |= DBG_POST_CORE;
+                       return (-2);
+               }
+               else /* We timed out */
+                       if (0 == poll_count) {
+                               poll_count = 1000;
+                               kdp_us_spin ((tretries%4) * panic_timeout); /* capped linear backoff */
+                               goto TRANSMIT_RETRY;
+                       }
+
+       if (!(++panic_block % SBLOCKSZ)) {
+               uint64_t ctime;
+               kdb_printf_unbuffered(".");
+               ctime = mach_absolute_time();
+               kdp_superblock_dump_time = ctime - kdp_superblock_dump_start_time;
+               kdp_superblock_dump_start_time = ctime;
+               if (kdp_superblock_dump_time > kdp_max_superblock_dump_time)
+                       kdp_max_superblock_dump_time = kdp_superblock_dump_time;
+               if (kdp_superblock_dump_time < kdp_min_superblock_dump_time)
+                       kdp_min_superblock_dump_time = kdp_superblock_dump_time;
+       }
+
+       if (request == KDP_EOF) {
+               printf("\nTotal number of packets transmitted: %d\n", panic_block);
+               printf("Avg. superblock transfer abstime 0x%llx\n", ((mach_absolute_time() - kdp_dump_start_time) / panic_block) * SBLOCKSZ);
+               printf("Minimum superblock transfer abstime: 0x%llx\n", kdp_min_superblock_dump_time);
+               printf("Maximum superblock transfer abstime: 0x%llx\n", kdp_max_superblock_dump_time);
+       }
+       return 1;
+}
+
+static int 
+isdigit (char c)
+{
+  return ((c > 47) && (c < 58));
 }
 
 }
 
+/* Horrid hack to extract xnu version if possible - a much cleaner approach
+ * would be to have the integrator run a script which would copy the
+ * xnu version into a string or an int somewhere at project submission
+ * time - makes assumptions about sizeof(version), but will not fail if
+ * it changes, but may be incorrect.
+ */
+/* 2006: Incorporated a change from Darwin user P. Lovell to extract
+ * the minor kernel version numbers from the version string.
+ */
+static int 
+kdp_get_xnu_version(char *versionbuf)
+{
+       char *versionpos;
+       char vstr[20];
+       int retval = -1;
+       char *vptr;
+
+       strlcpy(vstr, "custom", 10);
+       if (kdp_machine_vm_read((mach_vm_address_t)(uintptr_t)version, versionbuf, 128)) {
+               versionbuf[127] = '\0';
+               versionpos = strnstr(versionbuf, "xnu-", 115);
+               if (versionpos) {
+                       strncpy(vstr, versionpos, sizeof(vstr));
+                       vstr[sizeof(vstr)-1] = '\0';
+                       vptr = vstr + 4; /* Begin after "xnu-" */
+                       while (*vptr && (isdigit(*vptr) || *vptr == '.'))
+                               vptr++;
+                       *vptr = '\0';
+                       /* Remove trailing period, if any */
+                       if (*(--vptr) == '.')
+                               *vptr = '\0';
+                       retval = 0;
+               }
+       }
+       strlcpy(versionbuf, vstr, KDP_MAXPACKET);
+       return retval;
+}
+
+void
+kdp_set_dump_info(const uint32_t flags, const char *filename, 
+                  const char *destipstr, const char *routeripstr,
+                  const uint32_t port)
+{
+       uint32_t cmd;
+
+       if (destipstr && (destipstr[0] != '\0')) {
+               strlcpy(panicd_ip_str, destipstr, sizeof(panicd_ip_str));
+               panicd_specified = 1;
+       }
+
+       if (routeripstr && (routeripstr[0] != '\0')) {
+               strlcpy(router_ip_str, routeripstr, sizeof(router_ip_str));
+               router_specified = 1;
+       }
+
+       if (filename && (filename[0] != '\0')) {
+               strlcpy(corename_str, filename, sizeof(corename_str));
+               corename_specified = TRUE;
+       } else {
+               corename_specified = FALSE;
+       }
+
+       if (port) 
+               panicd_port = port;
+
+        /* on a disconnect, should we stay in KDP or not? */
+        noresume_on_disconnect = (flags & KDP_DUMPINFO_NORESUME) ? 1 : 0;
+
+       if ((flags & KDP_DUMPINFO_DUMP) == 0)
+               return;
+
+       /* the rest of the commands can modify kdp_flags */
+       cmd = flags & KDP_DUMPINFO_MASK;
+        if (cmd == KDP_DUMPINFO_DISABLE) {
+               kdp_flag &= ~KDP_PANIC_DUMP_ENABLED;
+               panicd_specified       = 0;
+               kdp_trigger_core_dump  = 0;
+               return;
+        }
+
+       kdp_flag &= ~REBOOT_POST_CORE;
+       if (flags & KDP_DUMPINFO_REBOOT)
+            kdp_flag |= REBOOT_POST_CORE;
+
+       kdp_flag &= ~PANIC_LOG_DUMP;
+       if (cmd == KDP_DUMPINFO_PANICLOG)
+            kdp_flag |= PANIC_LOG_DUMP;
+       
+       kdp_flag &= ~SYSTEM_LOG_DUMP;
+       if (cmd == KDP_DUMPINFO_SYSTEMLOG)
+            kdp_flag |= SYSTEM_LOG_DUMP;
+
+       /* trigger a dump */
+       kdp_flag |= DBG_POST_CORE;
+
+       flag_dont_abort_panic_dump = (flags & KDP_DUMPINFO_NOINTR) ? 
+               TRUE : FALSE;
+
+       reattach_wait          = 1;
+       logPanicDataToScreen   = 1;
+       disableConsoleOutput   = 0;
+       disable_debug_output   = 0;
+       kdp_trigger_core_dump  = 1;
+}
+
+void
+kdp_get_dump_info(uint32_t *flags, char *filename, char *destipstr, 
+                  char *routeripstr, uint32_t *port)
+{
+       if (destipstr) {
+               if (panicd_specified)
+                       strlcpy(destipstr, panicd_ip_str, 
+                                sizeof(panicd_ip_str));
+               else 
+                       destipstr[0] = '\0';
+       }
+
+       if (routeripstr) {
+               if (router_specified)
+                       strlcpy(routeripstr, router_ip_str,
+                                sizeof(router_ip_str));
+               else
+                       routeripstr[0] = '\0';
+       }
+
+       if (filename) {
+               if (corename_specified)
+                       strlcpy(filename, corename_str, 
+                                sizeof(corename_str));
+               else 
+                       filename[0] = '\0';
+
+       }
+
+       if (port) 
+               *port = panicd_port;
+
+       if (flags) {
+               *flags = 0;
+                if (!panicd_specified) 
+                       *flags |= KDP_DUMPINFO_DISABLE;
+                else if (kdp_flag & PANIC_LOG_DUMP)
+                       *flags |= KDP_DUMPINFO_PANICLOG;
+               else
+                       *flags |= KDP_DUMPINFO_CORE;
+
+               if (noresume_on_disconnect)
+                       *flags |= KDP_DUMPINFO_NORESUME;
+       }
+}
+
+
+/* Primary dispatch routine for the system dump */
+void 
+kdp_panic_dump(void)
+{
+       char coreprefix[10];
+       int panic_error;
+
+       uint64_t        abstime;
+       uint32_t        current_ip = ntohl((uint32_t)kdp_current_ip_address);
+
+       if (flag_panic_dump_in_progress) {
+               kdb_printf("System dump aborted.\n");
+               goto panic_dump_exit;
+       }
+               
+       printf("Entering system dump routine\n");
+
+       if (!kdp_en_recv_pkt || !kdp_en_send_pkt) {
+                       kdb_printf("Error: No transport device registered for kernel crashdump\n");
+                       return;
+       }
+
+       if (!panicd_specified) {
+               kdb_printf("A dump server was not specified in the boot-args, terminating kernel core dump.\n");
+               goto panic_dump_exit;
+       }
+
+       flag_panic_dump_in_progress = TRUE;
+
+       if (pkt.input)
+               kdp_panic("kdp_panic_dump: unexpected pending input packet");
+
+       kdp_get_xnu_version((char *) &pkt.data[0]);
+
+        if (!corename_specified) {
+            /* Panic log bit takes precedence over core dump bit */
+            if ((panicstr != (char *) 0) && (kdp_flag & PANIC_LOG_DUMP))
+               strlcpy(coreprefix, "paniclog", sizeof(coreprefix));
+            else if (kdp_flag & SYSTEM_LOG_DUMP) 
+               strlcpy(coreprefix, "systemlog", sizeof(coreprefix));
+           else
+               strlcpy(coreprefix, "core", sizeof(coreprefix));
+  
+            abstime = mach_absolute_time();
+           pkt.data[20] = '\0';
+           snprintf (corename_str, sizeof(corename_str), "%s-%s-%d.%d.%d.%d-%x", 
+                     coreprefix, &pkt.data[0],
+                     (current_ip & 0xff000000) >> 24,
+                     (current_ip & 0xff0000) >> 16,
+                     (current_ip & 0xff00) >> 8,
+                     (current_ip & 0xff),
+                     (unsigned int) (abstime & 0xffffffff));
+        }
+
+       if (0 == inet_aton(panicd_ip_str, (struct kdp_in_addr *) &panic_server_ip)) {
+               kdb_printf("inet_aton() failed interpreting %s as a panic server IP\n", panicd_ip_str);
+       }
+       else
+               kdb_printf("Attempting connection to panic server configured at IP %s, port %d\n", panicd_ip_str, panicd_port);
+
+       destination_mac = router_mac;
+
+       if (kdp_arp_resolve(panic_server_ip, &temp_mac)) {
+               kdb_printf("Resolved %s's (or proxy's) link level address\n", panicd_ip_str);
+               destination_mac = temp_mac;
+       }
+       else {
+               if (!flag_panic_dump_in_progress) goto panic_dump_exit;
+               if (router_specified) {
+                       if (0 == inet_aton(router_ip_str, (struct kdp_in_addr *) &parsed_router_ip))
+                               kdb_printf("inet_aton() failed interpreting %s as an IP\n", router_ip_str);
+                       else {
+                               router_ip = parsed_router_ip;
+                               if (kdp_arp_resolve(router_ip, &temp_mac)) {
+                                       destination_mac = temp_mac;
+                                       kdb_printf("Routing through specified router IP %s (%d)\n", router_ip_str, router_ip);
+                               }
+                       }
+               }
+       }
+
+       if (!flag_panic_dump_in_progress) goto panic_dump_exit;
+
+       kdb_printf("Transmitting packets to link level address: %02x:%02x:%02x:%02x:%02x:%02x\n",
+           destination_mac.ether_addr_octet[0] & 0xff,
+           destination_mac.ether_addr_octet[1] & 0xff,
+           destination_mac.ether_addr_octet[2] & 0xff,
+           destination_mac.ether_addr_octet[3] & 0xff,
+           destination_mac.ether_addr_octet[4] & 0xff,
+           destination_mac.ether_addr_octet[5] & 0xff);
+
+       kdb_printf("Kernel map size is %llu\n", (unsigned long long) get_vmmap_size(kernel_map));
+       kdb_printf("Sending write request for %s\n", corename_str);  
+
+       if ((panic_error = kdp_send_crashdump_pkt(KDP_WRQ, corename_str, 0 , NULL)) < 0) {
+               kdb_printf ("kdp_send_crashdump_pkt failed with error %d\n", panic_error);
+               goto panic_dump_exit;
+       }
+
+       /* Just the panic log requested */
+       if ((panicstr != (char *) 0) && (kdp_flag & PANIC_LOG_DUMP)) {
+               kdb_printf_unbuffered("Transmitting panic log, please wait: ");
+               kdp_send_crashdump_data(KDP_DATA, corename_str, 
+                                       debug_buf_ptr - debug_buf,
+                                       debug_buf);
+               kdp_send_crashdump_pkt (KDP_EOF, NULL, 0, ((void *) 0));
+               printf("Please file a bug report on this panic, if possible.\n");
+               goto panic_dump_exit;
+       }
+  
+       /* maybe we wanted the systemlog */
+        if (kdp_flag & SYSTEM_LOG_DUMP) {
+               long start_off = msgbufp->msg_bufx;
+                long len;
+
+               kdb_printf_unbuffered("Transmitting system log, please wait: ");
+               if (start_off >= msgbufp->msg_bufr) {
+                       len = msgbufp->msg_size - start_off;
+                       kdp_send_crashdump_data(KDP_DATA, corename_str, len, 
+                                               msgbufp->msg_bufc + start_off);
+                       /* seek to remove trailing bytes */
+                       kdp_send_crashdump_seek(corename_str, len);
+                       start_off  = 0;
+               }
+
+               if (start_off != msgbufp->msg_bufr) {
+                       len = msgbufp->msg_bufr - start_off;
+                       kdp_send_crashdump_data(KDP_DATA, corename_str, len,
+                                               msgbufp->msg_bufc + start_off);
+               }
+
+               kdp_send_crashdump_pkt (KDP_EOF, NULL, 0, ((void *) 0));
+               goto panic_dump_exit;
+        }
+
+       /* We want a core dump if we're here */
+       kern_dump();
+
+panic_dump_exit:
+       abort_panic_transfer();
+       kdp_reset();
+       return;
+}
+
+void 
+abort_panic_transfer(void)
+{
+       flag_panic_dump_in_progress = FALSE;
+       flag_dont_abort_panic_dump  = FALSE;
+       panic_block = 0;
+}
+
+#if CONFIG_SERIAL_KDP
+
+static boolean_t needs_serial_init = TRUE;
+
+static void
+kdp_serial_send(void *rpkt, unsigned int rpkt_len)
+{
+       //      printf("tx\n");
+       kdp_serialize_packet((unsigned char *)rpkt, rpkt_len, pal_serial_putc);
+}
+
+static void 
+kdp_serial_receive(void *rpkt, unsigned int *rpkt_len, unsigned int timeout)
+{
+       int readkar;
+       uint64_t now, deadline;
+       
+       clock_interval_to_deadline(timeout, 1000 * 1000 /* milliseconds */, &deadline);
+
+//     printf("rx\n");
+       for(clock_get_uptime(&now); now < deadline; clock_get_uptime(&now))
+       {
+               readkar = pal_serial_getc();
+               if(readkar >= 0)
+               {
+                       unsigned char *packet;
+                       //                      printf("got char %02x\n", readkar);
+                       if((packet = kdp_unserialize_packet(readkar,rpkt_len)))
+                       {
+                               memcpy(rpkt, packet, *rpkt_len);
+                               return;
+                       }
+               }
+       }
+       *rpkt_len = 0;
+}
+
+static boolean_t
+kdp_serial_setmode(boolean_t active)
+{
+        if (active == FALSE) /* leaving KDP */
+            return TRUE;
+
+       if (!needs_serial_init)
+            return TRUE;
+
+        pal_serial_init();
+        needs_serial_init = FALSE;
+        return TRUE;
+}
+
+
+static void kdp_serial_callout(__unused void *arg, kdp_event_t event)
+{
+    /* When we stop KDP, set the bit to re-initialize the console serial port
+     * the next time we send/receive a KDP packet.  We don't do it on
+     * KDP_EVENT_ENTER directly because it also gets called when we trap to KDP
+     * for non-external debugging, i.e., stackshot or core dumps.
+     *
+     * Set needs_serial_init on exit (and initialization, see above) and not
+     * enter because enter is sent multiple times and causes excess reinitialization.
+     */
+       
+    switch (event)
+    {
+               case KDP_EVENT_PANICLOG:
+               case KDP_EVENT_ENTER:
+                       break;
+               case KDP_EVENT_EXIT:
+                       needs_serial_init = TRUE;
+                       break;
+    }
+}
+
+#endif /* CONFIG_SERIAL_KDP */
+
+void
+kdp_init(void)
+{
+       strlcpy(kdp_kernelversion_string, version, sizeof(kdp_kernelversion_string));
+
+       /* Relies on platform layer calling panic_init() before kdp_init() */
+       if (kernel_uuid_string[0] != '\0') {
+               /*
+                * Update kdp_kernelversion_string with our UUID
+                * generated at link time.
+                */
+
+               strlcat(kdp_kernelversion_string, "; UUID=", sizeof(kdp_kernelversion_string));
+               strlcat(kdp_kernelversion_string, kernel_uuid_string, sizeof(kdp_kernelversion_string));
+       }
+
+       debug_log_init();
+
+#if defined(__x86_64__) || defined(__arm__)
+       if (vm_kernel_slide) {
+               char    KASLR_stext[19];
+               strlcat(kdp_kernelversion_string, "; stext=", sizeof(kdp_kernelversion_string));
+               snprintf(KASLR_stext, sizeof(KASLR_stext), "%p", (void *) vm_kernel_stext);
+               strlcat(kdp_kernelversion_string, KASLR_stext, sizeof(kdp_kernelversion_string));
+       }
+#endif
+
+       if (debug_boot_arg & DB_REBOOT_POST_CORE)
+               kdp_flag |= REBOOT_POST_CORE;
+#if    defined(__x86_64__)     
+       kdp_machine_init();
+#endif
+
+       kdp_timer_callout_init();
+       kdp_crashdump_feature_mask = htonl(kdp_crashdump_feature_mask);
+
+#if CONFIG_SERIAL_KDP
+       char kdpname[80];
+       struct kdp_in_addr ipaddr;
+       struct kdp_ether_addr macaddr;
+
+
+       // serial must be explicitly requested
+       if(!PE_parse_boot_argn("kdp_match_name", kdpname, sizeof(kdpname)) || strncmp(kdpname, "serial", sizeof(kdpname)) != 0)
+               return;
+       
+       kprintf("Initializing serial KDP\n");
+
+       kdp_register_callout(kdp_serial_callout, NULL);
+        kdp_register_link(NULL, kdp_serial_setmode);
+       kdp_register_send_receive(kdp_serial_send, kdp_serial_receive);
+       
+       /* fake up an ip and mac for early serial debugging */
+       macaddr.ether_addr_octet[0] = 's';
+       macaddr.ether_addr_octet[1] = 'e';
+       macaddr.ether_addr_octet[2] = 'r';
+       macaddr.ether_addr_octet[3] = 'i';
+       macaddr.ether_addr_octet[4] = 'a';
+       macaddr.ether_addr_octet[5] = 'l';
+       ipaddr.s_addr = KDP_SERIAL_IPADDR;
+       kdp_set_ip_and_mac_addresses(&ipaddr, &macaddr);
+        
+#endif /* CONFIG_SERIAL_KDP */
+}