Merge branch 'elflink-pxe-fixes-for-mfleming-2' of git://github.com/geneC/syslinux into firmware

Pull various network stack fixes from Gene Cumm and adapt to the 6.xx
core_udp_* API,

* 'elflink-pxe-fixes-for-mfleming-2' of git://github.com/geneC/syslinux:
  PXE ISR: Force polling on select hardware WORKAROUND
  core/lwip: Fix NULL pointer check
  PXE: use ddprintf macro
  com32: Define ddprintf() macro
  PXELINUX: specify PXE/lwIP
  undiif: show thread of execution on UNDIIF_ID_DEBUG
  core: dprintf() the banner.
  PXELINUX: Use sendto() instead of connect()/send()/disconnect()
  core: make mbox_post()/__sem_down_slow() check if valid
  core: mbox/semaphore NULL checks
  core/lwip/undi: Improve UNDIIF_ID_DEBUG messages

Conflicts:
	core/fs/pxe/pxe.c
	core/fs/pxe/tftp.c
	core/init.c

18 files changed, 292 insertions, 69 deletions

diff --git a/com32/include/dprintf.h b/com32/include/dprintf.h
index ef23282b..b3f1b46b 100644
--- a/com32/include/dprintf.h
+++ b/com32/include/dprintf.h
@@ -18,9 +18,11 @@
 # ifdef DEBUG_STDIO
 #  define dprintf  printf
 #  define vdprintf vprintf
+#  define ddprintf dprintf
 # else
 void dprintf(const char *, ...);
 void vdprintf(const char *, va_list);
+#  define ddprintf(...)	{ printf(__VA_ARGS__); dprintf(__VA_ARGS__); }
 # endif
 
 #else
@@ -31,6 +33,7 @@ void vdprintf(const char *, va_list);
 #define vdprintf(fmt, ap) \
     if (syslinux_debug_enabled) \
         vprintf(fmt, ap)
+#define ddprintf	printf
 
 #endif /* CORE_DEBUG */
 
diff --git a/core/bios.c b/core/bios.c
index 9e911947..25e857b9 100644
--- a/core/bios.c
+++ b/core/bios.c
@@ -642,6 +642,8 @@ void bios_init(void)
 	syslinux_memscan_add(&bios_memscan);
 	mem_init();
 
+	dprintf("%s%s", syslinux_banner, copyright_str);
+
 	/* CPU-dependent initialization and related checks. */
 	check_escapes();
 
diff --git a/core/fs/pxe/bios.c b/core/fs/pxe/bios.c
index c16b7c08..e3d9adc8 100644
--- a/core/fs/pxe/bios.c
+++ b/core/fs/pxe/bios.c
@@ -179,13 +179,13 @@ int pxe_init(bool quiet)
 
     /* Found nothing at all !! */
     if (!quiet)
-	printf("No !PXE or PXENV+ API found; we're dead...\n");
+	ddprintf("No !PXE or PXENV+ API found; we're dead...\n");
     return -1;
 
  have_pxenv:
     APIVer = pxenv->version;
     if (!quiet)
-	printf("Found PXENV+ structure\nPXE API version is %04x\n", APIVer);
+	ddprintf("Found PXENV+ structure\nPXE API version is %04x\n", APIVer);
 
     /* if the API version number is 0x0201 or higher, use the !PXE structure */
     if (APIVer >= 0x201) {
@@ -223,10 +223,10 @@ int pxe_init(bool quiet)
 
  have_entrypoint:
     if (!quiet) {
-	printf("%s entry point found (we hope) at %04X:%04X via plan %c\n",
+	ddprintf("%s entry point found (we hope) at %04X:%04X via plan %c\n",
 	       type, PXEEntry.seg, PXEEntry.offs, plan);
-	printf("UNDI code segment at %04X len %04X\n", code_seg, code_len);
-	printf("UNDI data segment at %04X len %04X\n", data_seg, data_len);
+	ddprintf("UNDI code segment at %04X len %04X\n", code_seg, code_len);
+	ddprintf("UNDI data segment at %04X len %04X\n", data_seg, data_len);
     }
 
     syslinux_memscan_new(pxelinux_scan_memory);
@@ -273,7 +273,7 @@ static int pxe_get_cached_info(int type, void *buf, size_t bufsiz)
 {
     int err;
     static __lowmem struct s_PXENV_GET_CACHED_INFO get_cached_info;
-    printf(" %02x", type);
+    ddprintf(" %02x", type);
 
     memset(&get_cached_info, 0, sizeof get_cached_info);
     get_cached_info.PacketType  = type;
@@ -281,7 +281,7 @@ static int pxe_get_cached_info(int type, void *buf, size_t bufsiz)
     get_cached_info.Buffer      = FAR_PTR(buf);
     err = pxe_call(PXENV_GET_CACHED_INFO, &get_cached_info);
     if (err) {
-        printf("PXE API call failed, error  %04x\n", err);
+        ddprintf("PXE API call failed, error  %04x\n", err);
 	kaboom();
     }
 
@@ -339,7 +339,7 @@ __export void unload_pxe(uint16_t flags)
 	memset(&unload_call, 0, sizeof unload_call);
 	err = pxe_call(api, &unload_call);
 	if (err || unload_call.Status != PXENV_STATUS_SUCCESS) {
-	    printf("PXE unload API call %04x failed: 0x%x\n",
+	    ddprintf("PXE unload API call %04x failed: 0x%x\n",
 		   api, unload_call.Status);
 	    goto cant_free;
 	}
@@ -367,7 +367,7 @@ __export void unload_pxe(uint16_t flags)
 	    *(uint32_t *)(4 * 0x1a), int_addr);
 
 cant_free:
-    printf("Failed to free base memory error %04x-%08x (%d/%dK)\n",
+    ddprintf("Failed to free base memory error %04x-%08x (%d/%dK)\n",
 	   api, *(uint32_t *)(4 * 0x1a), bios_fbm(), real_base_mem);
     return;
 }
@@ -380,7 +380,7 @@ void net_parse_dhcp(void)
 
     bp = lmalloc(dhcp_max_packet);
     if (!bp) {
-	printf("Out of low memory\n");
+	ddprintf("Out of low memory\n");
 	kaboom();
     }
 
@@ -389,7 +389,7 @@ void net_parse_dhcp(void)
     /*
      * Get the DHCP client identifiers (query info 1)
      */
-    printf("Getting cached packet ");
+    ddprintf("Getting cached packet ");
     pkt_len = pxe_get_cached_info(1, bp, dhcp_max_packet);
     parse_dhcp(bp, pkt_len);
     /*
@@ -424,7 +424,7 @@ void net_parse_dhcp(void)
      */
     pkt_len = pxe_get_cached_info(3, bp, dhcp_max_packet);
     parse_dhcp(bp, pkt_len);
-    printf("\n");
+    ddprintf("\n");
 
     lfree(bp);
 }
diff --git a/core/fs/pxe/core.c b/core/fs/pxe/core.c
index e6bbee9b..a43ac465 100644
--- a/core/fs/pxe/core.c
+++ b/core/fs/pxe/core.c
@@ -6,6 +6,8 @@
 #include <net.h>
 #include "pxe.h"
 
+#include <dprintf.h>
+
 const struct url_scheme url_schemes[] = {
     { "tftp", tftp_open, 0 },
     { "http", http_open, O_DIRECTORY },
@@ -32,7 +34,7 @@ int core_udp_open(struct pxe_pvt_inode *socket)
     priv->conn->recv_timeout = 15; /* A 15 ms recv timeout... */
     err = netconn_bind(priv->conn, NULL, 0);
     if (err) {
-	printf("netconn_bind error %d\n", err);
+	ddprintf("netconn_bind error %d\n", err);
 	return -1;
     }
 
@@ -67,6 +69,7 @@ void core_udp_connect(struct pxe_pvt_inode *socket, uint32_t ip,
     struct net_private_lwip *priv = &socket->net.lwip;
     struct ip_addr addr;
 
+    dprintf("net_core_connect: %08X %04X\n", ntohl(ip), port);
     addr.addr = ip;
     netconn_connect(priv->conn, &addr, port);
 }
@@ -138,13 +141,13 @@ void core_udp_send(struct pxe_pvt_inode *socket, const void *data, size_t len)
 
     nbuf = netbuf_new();
     if (!nbuf) {
-	printf("netbuf allocation error\n");
+	ddprintf("netbuf allocation error\n");
 	return;
     }
 
     pbuf = netbuf_alloc(nbuf, len);
     if (!pbuf) {
-	printf("pbuf allocation error\n");
+	ddprintf("pbuf allocation error\n");
 	goto out;
     }
 
@@ -152,7 +155,52 @@ void core_udp_send(struct pxe_pvt_inode *socket, const void *data, size_t len)
 
     err = netconn_send(conn, nbuf);
     if (err) {
-	printf("netconn_send error %d\n", err);
+	ddprintf("netconn_send error %d\n", err);
+	goto out;
+    }
+
+out:
+    netbuf_delete(nbuf);
+}
+
+ /**
+ * Send a UDP packet to a destination
+ *
+ * @param:socket, the open socket
+ * @param:data, data buffer to send
+ * @param:len, size of data bufer
+ * @param:ip, the ip address
+ * @param:port, the port number, host-byte order
+ */
+void core_udp_sendto(struct pxe_pvt_inode *socket, const void *data,
+		     size_t len, uint32_t ip, uint16_t port)
+{
+    struct netconn *conn = socket->net.lwip.conn;
+    struct ip_addr addr;
+    struct netbuf *nbuf;
+    void *pbuf;
+    int err;
+
+    nbuf = netbuf_new();
+    if (!nbuf) {
+	ddprintf("netbuf allocation error\n");
+	return;
+    }
+
+    pbuf = netbuf_alloc(nbuf, len);
+    if (!pbuf) {
+	ddprintf("pbuf allocation error\n");
+	goto out;
+    }
+
+    memcpy(pbuf, data, len);
+
+    dprintf("core_udp_sendto: %08X %04X\n", ntohl(ip), port);
+    addr.addr = ip;
+
+    err = netconn_sendto(conn, nbuf, &addr, port);
+    if (err) {
+	ddprintf("netconn_sendto error %d\n", err);
 	goto out;
     }
 
@@ -176,7 +224,7 @@ void net_core_init(void)
     /* Start up the undi driver for lwip */
     err = undiif_start(IPInfo.myip, IPInfo.netmask, IPInfo.gateway);
     if (err) {
-       printf("undiif driver failed to start: %d\n", err);
+       ddprintf("undiif driver failed to start: %d\n", err);
        kaboom();
     }
 
@@ -192,7 +240,7 @@ void probe_undi(void)
     pxe_call(PXENV_UNDI_GET_INFORMATION, &pxe_undi_info);
     pxe_call(PXENV_UNDI_GET_IFACE_INFO,  &pxe_undi_iface);
 
-    printf("UNDI: baseio %04x int %d MTU %d type %d \"%s\" flags 0x%x\n",
+    ddprintf("UNDI: baseio %04x int %d MTU %d type %d \"%s\" flags 0x%x\n",
 	   pxe_undi_info.BaseIo, pxe_undi_info.IntNumber,
 	   pxe_undi_info.MaxTranUnit, pxe_undi_info.HwType,
 	   pxe_undi_iface.IfaceType, pxe_undi_iface.ServiceFlags);
diff --git a/core/fs/pxe/isr.c b/core/fs/pxe/isr.c
index 069fefd5..d0a0bf90 100644
--- a/core/fs/pxe/isr.c
+++ b/core/fs/pxe/isr.c
@@ -18,6 +18,14 @@ static DECLARE_INIT_SEMAPHORE(pxe_receive_thread_sem, 0);
 static DECLARE_INIT_SEMAPHORE(pxe_poll_thread_sem, 0);
 static struct thread *pxe_thread, *poll_thread;
 
+#ifndef PXE_POLL_FORCE
+#  define PXE_POLL_FORCE 0
+#endif
+
+#ifndef PXE_POLL_BY_MODEL
+#  define PXE_POLL_BY_MODEL 1
+#endif
+
 /*
  * Note: this *must* be called with interrupts enabled.
  */
@@ -73,7 +81,7 @@ static bool install_irq_vector(uint8_t irq, void (*isr)(void), far_ptr_t *old)
     if (!ok)
 	*entry = *old;		/* Restore the old vector */
 
-    printf("UNDI: IRQ %d(0x%02x): %04x:%04x -> %04x:%04x\n", irq, vec,
+    ddprintf("UNDI: IRQ %d(0x%02x): %04x:%04x -> %04x:%04x\n", irq, vec,
 	   old->seg, old->offs, entry->seg, entry->offs);
 
     return ok;
@@ -251,8 +259,20 @@ void pxe_start_isr(void)
     poll_thread = start_thread("pxe poll", 4096, POLL_THREAD_PRIORITY,
 			       pxe_poll_thread, NULL);
 
-    if (!irq ||	!(pxe_undi_iface.ServiceFlags & PXE_UNDI_IFACE_FLAG_IRQ))
+    if (!irq ||	!(pxe_undi_iface.ServiceFlags & PXE_UNDI_IFACE_FLAG_IRQ)) {
 	asm volatile("orb $1,%0" : "+m" (pxe_need_poll));
+	dprintf("pxe_start_isr: forcing pxe_need_poll\n");
+    } else if (PXE_POLL_BY_MODEL) {
+	dprintf("pxe_start_isr: trying poll by model\n");
+	int hwad = ((int)MAC[0] << 16) + ((int)MAC[1] << 8) + MAC[2];
+	dprintf("pxe_start_isr: got %06x %04x\n", hwad, pxe_undi_iface.ServiceFlags);
+	if (hwad == 0x000023ae) {
+	    if (pxe_undi_iface.ServiceFlags == 0xdc1b) {
+		asm volatile("orb $1,%0" : "+m" (pxe_need_poll));
+		dprintf("pxe_start_isr: forcing pxe_need_poll by model\n");
+	    }
+	}
+    }
 }
 
 int reset_pxe(void)
diff --git a/core/fs/pxe/pxe.c b/core/fs/pxe/pxe.c
index 4591edc9..4de4dbfb 100644
--- a/core/fs/pxe/pxe.c
+++ b/core/fs/pxe/pxe.c
@@ -371,7 +371,7 @@ static void get_prefix(void)
 	*(p + 2) = 0;                /* Zero-terminate after delimiter */
     }
 
-    printf("TFTP prefix: %s\n", path_prefix);
+    ddprintf("TFTP prefix: %s\n", path_prefix);
 
     if (url_type(path_prefix) == URL_SUFFIX) {
 	/*
@@ -476,7 +476,7 @@ static int pxe_open_config(struct com32_filedata *filedata)
     if (open_file(ConfigName, O_RDONLY, filedata) >= 0)
         return 0;
 
-    printf("%-68s\n", "Unable to locate configuration file");
+    ddprintf("%-68s\n", "Unable to locate configuration file");
     kaboom();
 }
 
@@ -532,7 +532,7 @@ static void ip_init(void)
     gendotquad(dot_quad_buf, ip);
 
     ip = ntohl(ip);
-    printf("My IP address seems to be %08X %s\n", ip, dot_quad_buf);
+    ddprintf("My IP address seems to be %08X %s\n", ip, dot_quad_buf);
 }
 
 /*
diff --git a/core/fs/pxe/tftp.c b/core/fs/pxe/tftp.c
index b5dc72e4..1f374a3f 100644
--- a/core/fs/pxe/tftp.c
+++ b/core/fs/pxe/tftp.c
@@ -255,18 +255,15 @@ void tftp_open(struct url_info *url, int flags, struct inode *inode,
 
     timeout_ptr = TimeoutTable;   /* Reset timeout */
 sendreq:
-    core_udp_disconnect(socket);
     timeout = *timeout_ptr++;
     if (!timeout)
 	return;			/* No file available... */
     oldtime = jiffies();
 
-    core_udp_connect(socket, url->ip, url->port);
-    core_udp_send(socket, rrq_packet_buf, rrq_len);
+    core_udp_sendto(socket, rrq_packet_buf, rrq_len, url->ip, url->port);
 
     /* If the WRITE call fails, we let the timeout take care of it... */
 wait_pkt:
-    core_udp_disconnect(socket);
     for (;;) {
 	buf_len = sizeof(reply_packet_buf);
 
@@ -277,8 +274,10 @@ wait_pkt:
 	    if (now - oldtime >= timeout)
 		 goto sendreq;
 	} else {
-	    /* Make sure the packet actually came from the server */
-	    if (src_ip == url->ip)
+	    /* Make sure the packet actually came from the server and
+	       is long enough for a TFTP opcode */
+	    dprintf("tftp_open: got packet buflen=%d\n", buf_len);
+	    if ((src_ip == url->ip) && (buf_len >= 2))
 		break;
 	}
     }
@@ -290,8 +289,6 @@ wait_pkt:
     inode->size = -1;
     socket->tftp_blksize = TFTP_BLOCKSIZE;
     buffersize = buf_len - 2;	  /* bytes after opcode */
-    if (buffersize < 0)
-        goto wait_pkt;                     /* Garbled reply */
 
     /*
      * Get the opcode type, and parse it
diff --git a/core/include/mbox.h b/core/include/mbox.h
index 3c35ce4e..6fec267c 100644
--- a/core/include/mbox.h
+++ b/core/include/mbox.h
@@ -45,7 +45,8 @@ mstime_t mbox_fetch(struct mailbox *mbox, void **msg, mstime_t timeout);
  */
 static inline void mbox_set_invalid(struct mailbox *mbox)
 {
-    sem_set_invalid(&mbox->prod_sem);
+    if (!!mbox)
+	sem_set_invalid(&mbox->prod_sem);
 }
 
 /*
@@ -53,7 +54,7 @@ static inline void mbox_set_invalid(struct mailbox *mbox)
  */
 static inline bool mbox_is_valid(struct mailbox *mbox)
 {
-    return sem_is_valid(&mbox->prod_sem);
+    return ((!!mbox) && sem_is_valid(&mbox->prod_sem));
 }
 
 #endif /* _MBOX_H */
diff --git a/core/include/net.h b/core/include/net.h
index a5dcd724..c64191d8 100644
--- a/core/include/net.h
+++ b/core/include/net.h
@@ -23,6 +23,9 @@ int core_udp_recv(struct pxe_pvt_inode *socket, void *buf, uint16_t *buf_len,
 void core_udp_send(struct pxe_pvt_inode *socket,
 		   const void *data, size_t len);
 
+void core_udp_sendto(struct pxe_pvt_inode *socket, const void *data, size_t len,
+		     uint32_t ip, uint16_t port);
+
 void probe_undi(void);
 void pxe_init_isr(void);
 
diff --git a/core/include/thread.h b/core/include/thread.h
index 6bfdfaa7..8ec4a267 100644
--- a/core/include/thread.h
+++ b/core/include/thread.h
@@ -93,7 +93,8 @@ void sem_init(struct semaphore *, int);
  */
 static inline void sem_set_invalid(struct semaphore *sem)
 {
-    sem->list.next = NULL;
+    if (!!sem)
+	sem->list.next = NULL;
 }
 
 /*
@@ -101,7 +102,7 @@ static inline void sem_set_invalid(struct semaphore *sem)
  */
 static inline bool sem_is_valid(struct semaphore *sem)
 {
-    return !!sem->list.next;
+    return ((!!sem) && (!!sem->list.next));
 }
 
 struct thread *start_thread(const char *name, size_t stack_size, int prio,
diff --git a/core/legacynet/core.c b/core/legacynet/core.c
index 3ebc8f97..eacb4927 100644
--- a/core/legacynet/core.c
+++ b/core/legacynet/core.c
@@ -147,6 +147,43 @@ void core_udp_send(struct pxe_pvt_inode *socket, const void *data, size_t len)
 }
 
 /**
+ * Send a UDP packet to a destination
+ *
+ * @param:socket, the open socket
+ * @param:data, data buffer to send
+ * @param:len, size of data bufer
+ * @param:ip, the ip address
+ * @param:port, the port number, host-byte order
+ */
+void core_udp_sendto(struct pxe_pvt_inode *socket, const void *data, size_t len,
+		     uint32_t ip, uint16_t port)
+{
+    static __lowmem struct s_PXENV_UDP_WRITE udp_write;
+    struct net_private_tftp *priv = &socket->net.tftp;
+    void *lbuf;
+    uint16_t tid;
+
+    lbuf = lmalloc(len);
+    if (!lbuf)
+	return;
+
+    memcpy(lbuf, data, len);
+
+    tid = priv->localport;   /* TID(local port No) */
+    udp_write.buffer    = FAR_PTR(lbuf);
+    udp_write.ip        = ip;
+    udp_write.gw        = gateway(udp_write.ip);
+    udp_write.src_port  = tid;
+    udp_write.dst_port  = htons(port);
+    udp_write.buffer_size = len;
+
+    pxe_call(PXENV_UDP_WRITE, &udp_write);
+
+    lfree(lbuf);
+}
+
+
+/**
  * Network stack-specific initialization
  *
  * Initialize UDP stack
diff --git a/core/lwip/src/arch/sys_arch.c b/core/lwip/src/arch/sys_arch.c
index 894f6ada..4081d01e 100644
--- a/core/lwip/src/arch/sys_arch.c
+++ b/core/lwip/src/arch/sys_arch.c
@@ -48,7 +48,7 @@ u32_t sys_arch_sem_wait(sys_sem_t *sem, u32_t timeout)
 {
     mstime_t rv;
 
-    if (!!sem)
+    if (!sem || !*sem)
 	return SYS_ARCH_TIMEOUT;
     rv = sem_down(*sem, timeout);
     if (rv == (mstime_t)-1)
@@ -71,8 +71,11 @@ err_t sys_mbox_new(sys_mbox_t *mbox, int size)
 
 void sys_mbox_free(sys_mbox_t *mbox)
 {
-    if (!!mbox && !!*mbox)
+    if (!!mbox && !!*mbox) {
+	sys_mbox_set_invalid(mbox);
 	free(*mbox);
+	*mbox = NULL;
+    }
 }
 
 void sys_mbox_post(sys_mbox_t *mbox, void *msg)
diff --git a/core/lwip/src/netif/undiif.c b/core/lwip/src/netif/undiif.c
index 0dee67a2..e62a984d 100644
--- a/core/lwip/src/netif/undiif.c
+++ b/core/lwip/src/netif/undiif.c
@@ -174,7 +174,7 @@ static u8_t undiarp_cached_entry;
 #define UNDIARP_TRY_HARD 1
 #define UNDIARP_FIND_ONLY  2
 
-#define UNIDIF_ID_STRLEN 244
+#define UNIDIF_ID_STRLEN 300
 
 
 static inline bool undi_is_ethernet(struct netif *netif)
@@ -248,7 +248,7 @@ int snprintf_eth_hdr(char *str, size_t size, char head[],
   return snprintf(str, size,
 		"%s: d:%02x:%02x:%02x:%02x:%02x:%02x"
 		" s:%02x:%02x:%02x:%02x:%02x:%02x"
-		" t:%4hx %c%c %s\n", head,
+		" t:%4hx %c%c%s\n", head,
 		d[0], d[1], d[2], d[3], d[4], d[5],
 		s[0], s[1], s[2], s[3], s[4], s[5],
 		(unsigned)htons(ethhdr->type),
@@ -273,7 +273,7 @@ int snprintf_arp_hdr(char *str, size_t size, char head[],
 		" %3d.%3d.%3d.%3d"
 		" %02x:%02x:%02x:%02x:%02x:%02x"
 		" %3d.%3d.%3d.%3d"
-		" %c%c %s\n", head,
+		" %c%c%s\n", head,
 		s[0], s[1], s[2], s[3], s[4], s[5],
 		ip4_addr1(sip), ip4_addr2(sip),
 		ip4_addr3(sip), ip4_addr4(sip),
@@ -296,7 +296,7 @@ int snprintf_ip_hdr(char *str, size_t size, char head[],
     return snprintf(str, size,
 		 "%s: s:%3d.%3d.%3d.%3d %3d.%3d.%3d.%3d l:%5d"
 		 " i:%04x p:%04x c:%04x hl:%3d"
-		 " %c%c %s\n", head,
+		 " %c%c%s\n", head,
 		  ip4_addr1(&iphdr->src), ip4_addr2(&iphdr->src),
 		  ip4_addr3(&iphdr->src), ip4_addr4(&iphdr->src),
 		  ip4_addr1(&iphdr->dest), ip4_addr2(&iphdr->dest),
@@ -323,7 +323,7 @@ int snprintf_icmp_hdr(char *str, size_t size, char head[],
       return snprintf(str, size,
 		 "%s: t:%02x c:%02x k:%04x"
 		   " i:%04x s:%04x "
-		   " %c%c %s\n", head,
+		   " %c%c%s\n", head,
 		   icmphdr->type, icmphdr->code, ntohs(icmphdr->chksum),
 		   ntohs(icmphdr->id), ntohs(icmphdr->seqno),
 		    dir, status, tail);
@@ -345,12 +345,13 @@ int snprintf_tcp_hdr(char *str, size_t size, char head[],
     iphdr = (struct ip_hdr *)((void *)ethhdr + 14);
     if (IPH_PROTO(iphdr) == IP_PROTO_TCP) {
       tcphdr = (struct tcp_hdr *)((void *)iphdr + (IPH_HL(iphdr) << 2));
+      u16_t lenfl = ntohs(tcphdr->_hdrlen_rsvd_flags);
       return snprintf(str, size,
-		 "%s: s:%5d %5d q:%08x a:%08x k:%04x"
-		   " %c%c %s\n", head,
+		 "%s: s:%5d %5d q:%08x a:%08x lf:%04x k:%04x"
+		   " %c%c%s\n", head,
 		    ntohs(tcphdr->src), ntohs(tcphdr->dest),
 		    ntohl(tcphdr->seqno), ntohl(tcphdr->ackno),
-		    ntohs(tcphdr->chksum),
+		    lenfl, ntohs(tcphdr->chksum),
 		    dir, status, tail);
     } else {
       return 0;
@@ -372,7 +373,7 @@ int snprintf_udp_hdr(char *str, size_t size, char head[],
       udphdr = (struct udp_hdr *)((void *)iphdr + (IPH_HL(iphdr) << 2));
       return snprintf(str, size,
 		 "%s: s:%5d %5d l:%d c:%04x"
-		   " %c%c %s\n", head,
+		   " %c%c%s\n", head,
 		    ntohs(udphdr->src), ntohs(udphdr->dest),
 		    ntohs(udphdr->len), ntohs(udphdr->chksum),
 		    dir, status, tail);
@@ -480,7 +481,9 @@ undi_transmit(struct netif *netif, struct pbuf *pbuf,
   struct eth_hdr *ethhdr = pbuf->payload;
 
 
-  strpos = snprintf_eth_hdr(str + strpos, UNIDIF_ID_STRLEN - strpos,
+  strpos += snprintf(str + strpos, UNIDIF_ID_STRLEN - strpos,
+		     "undi xmit thd '%s'\n", current()->name);
+  strpos += snprintf_eth_hdr(str + strpos, UNIDIF_ID_STRLEN - strpos,
 			      "undi", ethhdr, 'x', '0', "");
   strpos += snprintf_arp_hdr(str + strpos, UNIDIF_ID_STRLEN - strpos,
 			      "  arp", ethhdr, 'x', '0', "");
@@ -1464,7 +1467,9 @@ void undiif_input(t_PXENV_UNDI_ISR *isr)
     char *str = malloc(UNIDIF_ID_STRLEN);
     int strpos = 0;
 
-    strpos = snprintf_eth_hdr(str + strpos, UNIDIF_ID_STRLEN - strpos,
+    strpos += snprintf(str + strpos, UNIDIF_ID_STRLEN - strpos,
+		       "undi recv thd '%s'\n", current()->name);
+    strpos += snprintf_eth_hdr(str + strpos, UNIDIF_ID_STRLEN - strpos,
 			        "undi", ethhdr, 'r', '0', "");
     strpos += snprintf_arp_hdr(str + strpos, UNIDIF_ID_STRLEN - strpos,
 			        "  arp", ethhdr, 'r', '0', "");
diff --git a/core/macros.inc b/core/macros.inc
index e3aedca1..c8fbe8de 100644
--- a/core/macros.inc
+++ b/core/macros.inc
@@ -31,6 +31,11 @@
 %endif
 %ifdef IS_PXELINUX
  %define MY_NAME 'PXELINUX'
+ %if IS_LPXELINUX > 0
+  %define MY_TYPE 'lwIP'
+ %else
+  %define MY_TYPE 'PXE'
+ %endif
 %else
  %define IS_PXELINUX 0
 %endif
diff --git a/core/pxelinux.asm b/core/pxelinux.asm
index 6b8c9e4c..64194d38 100644
--- a/core/pxelinux.asm
+++ b/core/pxelinux.asm
@@ -561,13 +561,14 @@ pxe_file_exit_hook:
 		section .data16
 
 		global copyright_str, syslinux_banner
-copyright_str   db ' Copyright (C) 1994-'
+copyright_str   db 'Copyright (C) 1994-'
 		asciidec YEAR
 		db ' H. Peter Anvin et al', CR, LF, 0
 err_bootfailed	db CR, LF, 'Boot failed: press a key to retry, or wait for reset...', CR, LF, 0
 bailmsg		equ err_bootfailed
 localboot_msg	db 'Booting from local disk...', CR, LF, 0
-syslinux_banner	db CR, LF, MY_NAME, ' ', VERSION_STR, ' ', DATE_STR, ' ', 0
+syslinux_banner	db CR, LF, MY_NAME, ' ', VERSION_STR, ' ', MY_TYPE, ' '
+		db DATE_STR, ' ', 0
 
 ;
 ; Misc initialized (data) variables
diff --git a/core/thread/mbox.c b/core/thread/mbox.c
index c518eeba..d1c640a9 100644
--- a/core/thread/mbox.c
+++ b/core/thread/mbox.c
@@ -10,18 +10,22 @@
 
 void mbox_init(struct mailbox *mbox, size_t size)
 {
-    sem_init(&mbox->prod_sem, size); /* All slots empty */
-    sem_init(&mbox->cons_sem, 0);    /* No slots full */
-    sem_init(&mbox->head_sem, 1);    /* Head mutex */
-    sem_init(&mbox->tail_sem, 1);    /* Tail mutex */
-
-    mbox->wrap = &mbox->data[size];
-    mbox->head = &mbox->data[0];
-    mbox->tail = &mbox->data[0];
+    if (!!mbox) {
+	sem_init(&mbox->prod_sem, size); /* All slots empty */
+	sem_init(&mbox->cons_sem, 0);    /* No slots full */
+	sem_init(&mbox->head_sem, 1);    /* Head mutex */
+	sem_init(&mbox->tail_sem, 1);    /* Tail mutex */
+
+	mbox->wrap = &mbox->data[size];
+	mbox->head = &mbox->data[0];
+	mbox->tail = &mbox->data[0];
+    }
 };
 
 int mbox_post(struct mailbox *mbox, void *msg, mstime_t timeout)
 {
+    if (!mbox_is_valid(mbox))
+	return ENOMEM;
     if (sem_down(&mbox->prod_sem, timeout) == (mstime_t)-1)
 	return ENOMEM;
     sem_down(&mbox->head_sem, 0);
@@ -40,6 +44,8 @@ mstime_t mbox_fetch(struct mailbox *mbox, void **msg, mstime_t timeout)
 {
     mstime_t t;
 
+    if (!mbox)
+	return -1;
     t = sem_down(&mbox->cons_sem, timeout);
     if (t == (mstime_t)-1)
 	return -1;
diff --git a/core/thread/semaphore.c b/core/thread/semaphore.c
index 6a2e4c13..c99af9c5 100644
--- a/core/thread/semaphore.c
+++ b/core/thread/semaphore.c
@@ -3,8 +3,10 @@
 
 void sem_init(struct semaphore *sem, int count)
 {
-    sem->list.next = sem->list.prev = &sem->list;
-    sem->count = count;
+    if (!!sem) {
+	sem->list.next = sem->list.prev = &sem->list;
+	sem->count = count;
+    }
 }
 
 mstime_t __sem_down_slow(struct semaphore *sem, mstime_t timeout)
@@ -14,7 +16,9 @@ mstime_t __sem_down_slow(struct semaphore *sem, mstime_t timeout)
 
     irq = irq_save();
 
-    if (sem->count >= 0) {
+    if (!sem_is_valid(sem)) {
+	rv = -1;
+    } else if (sem->count >= 0) {
 	/* Something already freed the semaphore on us */
 	rv = 0;
     } else if (timeout == -1) {
@@ -64,17 +68,19 @@ void __sem_up_slow(struct semaphore *sem)
      * we don't have to do anything, since the bailout clause in
      * __sem_down_slow will take care of it.
      */
-    l = sem->list.next;
-    if (l != &sem->list) {
-	struct thread_block *block;
-	block = container_of(l, struct thread_block, list);
+    if (!!sem) {
+	l = sem->list.next;
+	if (l != &sem->list) {
+	    struct thread_block *block;
+	    block = container_of(l, struct thread_block, list);
 
-	sem->list.next = block->list.next;
-	block->list.next->prev = &sem->list;
+	    sem->list.next = block->list.next;
+	    block->list.next->prev = &sem->list;
 
-	block->thread->blocked = NULL;
+	    block->thread->blocked = NULL;
 
-	__schedule();
+	    __schedule();
+	}
     }
 
     irq_restore(irq);
diff --git a/efi/udp.c b/efi/udp.c
index db9bc8f9..59bb4263 100644
--- a/efi/udp.c
+++ b/efi/udp.c
@@ -297,3 +297,88 @@ bail:
     free(txdata);
     free(token);
 }
+
+/**
+ * Send a UDP packet to a destination
+ *
+ * @param:socket, the open socket
+ * @param:data, data buffer to send
+ * @param:len, size of data bufer
+ * @param:ip, the ip address
+ * @param:port, the port number, host-byte order
+ */
+void core_udp_sendto(struct pxe_pvt_inode *socket, const void *data,
+		     size_t len, uint32_t ip, uint16_t port)
+{
+    EFI_UDP4_COMPLETION_TOKEN *token;
+    EFI_UDP4_TRANSMIT_DATA *txdata;
+    EFI_UDP4_FRAGMENT_DATA *frag;
+    EFI_UDP4_CONFIG_DATA udata;
+    EFI_STATUS status;
+    struct efi_binding *b;
+    EFI_UDP4 *udp;
+
+    (void)socket;
+
+    b = efi_create_binding(&Udp4ServiceBindingProtocol, &Udp4Protocol);
+    if (!b)
+	return;
+
+    udp = (EFI_UDP4 *)b->this;
+
+    token = zalloc(sizeof(*token));
+    if (!token)
+	goto out;
+
+    txdata = zalloc(sizeof(*txdata));
+    if (!txdata)
+	goto bail;
+
+    memset(&udata, 0, sizeof(udata));
+
+    memcpy(&udata.StationAddress, &IPInfo.myip, sizeof(IPInfo.myip));
+    memcpy(&udata.SubnetMask, &IPInfo.netmask, sizeof(IPInfo.netmask));
+    memcpy(&udata.RemoteAddress, &ip, sizeof(ip));
+    udata.RemotePort = port;
+    udata.AcceptPromiscuous = TRUE;
+    udata.TimeToLive = 64;
+
+    status = uefi_call_wrapper(udp->Configure, 2, udp, &udata);
+    if (status != EFI_SUCCESS)
+	goto bail;
+
+    status = efi_setup_event(&token->Event, (EFI_EVENT_NOTIFY)udp4_cb,
+			     token);
+    if (status != EFI_SUCCESS)
+	goto bail;
+
+    txdata->UdpSessionData = NULL;
+    txdata->GatewayAddress = NULL;
+    txdata->DataLength = len;
+    txdata->FragmentCount = 1;
+    frag = &txdata->FragmentTable[0];
+
+    frag->FragmentLength = len;
+    frag->FragmentBuffer = (void *)data;
+
+    token->Packet.TxData = txdata;
+
+    status = uefi_call_wrapper(udp->Transmit, 2, udp, token);
+    if (status != EFI_SUCCESS)
+	goto close;
+
+    while (cb_status == -1)
+	uefi_call_wrapper(udp->Poll, 1, udp);
+
+    /* Reset */
+    cb_status = -1;
+
+close:
+    uefi_call_wrapper(BS->CloseEvent, 1, token->Event);
+
+bail:
+    free(txdata);
+    free(token);
+out:
+    efi_destroy_binding(b, &Udp4ServiceBindingProtocol);
+}