Copied a snapshot of the usrp2 firmware into the microblaze firmware directory in the uhd repo.

Added erllc copyrights to the files created and modified at erllc.

3 files changed, 786 insertions, 0 deletions

diff --git a/firmware/microblaze/apps/bitrot/tx_drop.c b/firmware/microblaze/apps/bitrot/tx_drop.c
new file mode 100644
index 000000000..3a336e938
--- /dev/null
+++ b/firmware/microblaze/apps/bitrot/tx_drop.c
@@ -0,0 +1,261 @@
+/*
+ * Copyright 2007,2008 Free Software Foundation, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "u2_init.h"
+#include "memory_map.h"
+#include "spi.h"
+#include "hal_io.h"
+#include "buffer_pool.h"
+#include "pic.h"
+#include <stdbool.h>
+#include "ethernet.h"
+#include "nonstdio.h"
+#include "usrp2_eth_packet.h"
+#include "dbsm.h"
+#include "app_common.h"
+#include "print_rmon_regs.h"
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/*
+ * Like tx_only.c, but we discard data packets instead of sending them to the
+ * DSP TX pipeline.
+ */
+
+int total_rx_pkts = 0;
+int total_rx_bytes = 0;
+
+
+static int timer_delta = MASTER_CLK_RATE/1000;	// tick at 1kHz
+
+/*
+ * This program can respond to queries from the host
+ * and stream rx samples.
+ *
+ * Buffer 1 is used by the cpu to send frames to the host.
+ * Buffers 2 and 3 are used to double-buffer the DSP Rx to eth flow
+ * Buffers 4 and 5 are used to double-buffer the eth to DSP Tx  eth flow
+ */
+//#define CPU_RX_BUF	0	// eth -> cpu
+//#define CPU_TX_BUF 	1	// cpu -> eth
+
+#define	DSP_RX_BUF_0	2	// dsp rx -> eth (double buffer)
+#define	DSP_RX_BUF_1	3	// dsp rx -> eth
+#define	DSP_TX_BUF_0	4	// eth -> dsp tx (double buffer)
+#define	DSP_TX_BUF_1	5	// eth -> dsp tx
+
+
+/*
+ * ================================================================
+ *      configure DSP TX double buffering state machine
+ * ================================================================
+ */
+
+// 4 lines of ethernet hdr + 2 lines (word0 + timestamp)
+// DSP Tx reads word0 (flags) + timestamp followed by samples
+
+#define DSP_TX_FIRST_LINE		  4
+#define DSP_TX_SAMPLES_PER_FRAME	250	// not used except w/ debugging
+#define	DSP_TX_EXTRA_LINES		  2	// reads word0 + timestamp
+
+// Receive from ethernet
+buf_cmd_args_t dsp_tx_recv_args = {
+  PORT_ETH,
+  0,
+  BP_LAST_LINE
+};
+
+// send to DSP Tx
+buf_cmd_args_t dsp_tx_send_args = {
+  PORT_DSP,
+  DSP_TX_FIRST_LINE,	// starts just past ethernet header
+  0			// filled in from last_line register
+};
+
+dbsm_t dsp_tx_sm;	// the state machine
+
+
+// ----------------------------------------------------------------
+
+
+// The mac address of the host we're sending to.
+eth_mac_addr_t host_mac_addr;
+
+
+void
+timer_irq_handler(unsigned irq)
+{
+  hal_set_timeout(timer_delta);	// schedule next timeout
+}
+
+// Tx DSP underrun
+void
+underrun_irq_handler(unsigned irq)
+{
+  putchar('U');
+
+  dbsm_stop(&dsp_tx_sm);
+  dsp_tx_regs->clear_state = 1;
+  dbsm_start(&dsp_tx_sm);  // restart sm so we're listening to ethernet again
+
+  // putstr("\nirq: underrun\n");
+}
+
+
+void
+start_rx_cmd(const eth_mac_addr_t *host, op_start_rx_t *p)
+{
+}
+
+void
+stop_rx_cmd(void)
+{
+}
+
+static void
+setup_tx()
+{
+  dsp_tx_regs->clear_state = 1;
+  bp_clear_buf(DSP_TX_BUF_0);
+  bp_clear_buf(DSP_TX_BUF_1);
+
+  int tx_scale = 256;
+  int interp = 32;
+
+  op_config_tx_t def_config;
+  memset(&def_config, 0, sizeof(def_config));
+  def_config.phase_inc  = 408021893;			// 9.5 MHz [2**32 * fc/fsample]
+  def_config.scale_iq = (tx_scale << 16) | tx_scale;
+  def_config.interp = interp;
+
+  // setup Tx DSP regs
+  config_tx_cmd(&def_config);
+}
+
+
+inline static void
+buffer_irq_handler(unsigned irq)
+{
+  uint32_t  status = buffer_pool_status->status;
+
+  if (status & BPS_ERROR_ALL){
+    // FIXME rare path, handle error conditions
+    putstr("Errors! status = ");
+    puthex32_nl(status);
+
+    printf("total_rx_pkts  = %d\n", total_rx_pkts);
+    printf("total_rx_bytes = %d\n", total_rx_bytes);
+
+    print_rmon_regs();
+
+    if (status & (BPS_ERROR(DSP_TX_BUF_0) | BPS_ERROR(DSP_TX_BUF_1))){
+      dbsm_stop(&dsp_tx_sm);		
+      dsp_tx_regs->clear_state = 1; // try to restart
+      dbsm_start(&dsp_tx_sm);
+      return;
+    }
+  }
+
+  dbsm_process_status(&dsp_tx_sm, status);
+
+  if (status & BPS_DONE(CPU_TX_BUF)){
+    bp_clear_buf(CPU_TX_BUF);
+  }
+}
+
+
+/*
+ * Called when an ethernet packet is received.
+ *
+ * Claim that we handled all the packets,
+ * dropping those destined for the TX DSP chain
+ * on the ground.
+ */
+bool
+nop_eth_pkt_inspector(dbsm_t *sm, int bufno)
+{
+  hal_toggle_leds(0x1);
+
+  u2_eth_packet_t *pkt = (u2_eth_packet_t *) buffer_ram(bufno);
+  size_t byte_len = (buffer_pool_status->last_line[bufno] - 1) * 4;
+
+  total_rx_pkts++;
+  total_rx_bytes += byte_len;
+
+  // inspect rcvd frame and figure out what do do.
+
+  if (pkt->ehdr.ethertype != U2_ETHERTYPE)
+    return true;	// ignore, probably bogus PAUSE frame from MAC
+
+  int chan = u2p_chan(&pkt->fixed);
+
+  switch (chan){
+  case CONTROL_CHAN:
+    handle_control_chan_frame(pkt, byte_len);
+    return true;	// we handled the packet
+    break;
+
+  case 0:
+  default:
+    return true;	// We handled the data by dropping it :)
+    break;
+  }
+}
+
+
+int
+main(void)
+{
+  u2_init();
+
+  // setup tx gpio bits for GPIOM_FPGA_1 -- fpga debug output
+  hal_gpio_set_tx_mode(15, 0, GPIOM_FPGA_1);
+  hal_gpio_set_rx_mode(15, 0, GPIOM_FPGA_1);
+
+  putstr("\ntx_drop\n");
+  
+  // Control LEDs
+  hal_set_leds(0x0, 0x3);
+
+  pic_register_handler(IRQ_UNDERRUN, underrun_irq_handler);
+
+  ethernet_register_link_changed_callback(link_changed_callback);
+  ethernet_init();
+
+  // initialize double buffering state machine for ethernet -> DSP Tx
+
+  dbsm_init(&dsp_tx_sm, DSP_TX_BUF_0,
+	    &dsp_tx_recv_args, &dsp_tx_send_args,
+	    nop_eth_pkt_inspector);
+
+  // program tx registers
+  setup_tx();
+
+  // kick off the state machine
+  dbsm_start(&dsp_tx_sm);
+
+  while(1){
+    buffer_irq_handler(0);
+  }
+}
+
diff --git a/firmware/microblaze/apps/bitrot/tx_drop2.c b/firmware/microblaze/apps/bitrot/tx_drop2.c
new file mode 100644
index 000000000..3afd722e6
--- /dev/null
+++ b/firmware/microblaze/apps/bitrot/tx_drop2.c
@@ -0,0 +1,292 @@
+/*
+ * Copyright 2007,2008 Free Software Foundation, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "u2_init.h"
+#include "memory_map.h"
+#include "spi.h"
+#include "hal_io.h"
+#include "buffer_pool.h"
+#include "pic.h"
+#include <stdbool.h>
+#include "ethernet.h"
+#include "nonstdio.h"
+#include "usrp2_eth_packet.h"
+#include "dbsm.h"
+#include "app_common.h"
+#include "print_rmon_regs.h"
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/*
+ * Like tx_only.c, but we discard data packets instead of sending them to the
+ * DSP TX pipeline.
+ */
+
+int total_rx_pkts = 0;
+int total_rx_bytes = 0;
+
+
+static int timer_delta = MASTER_CLK_RATE/1000;	// tick at 1kHz
+
+/*
+ * This program can respond to queries from the host
+ * and stream rx samples.
+ *
+ * Buffer 1 is used by the cpu to send frames to the host.
+ * Buffers 2 and 3 are used to double-buffer the DSP Rx to eth flow
+ * Buffers 4 and 5 are used to double-buffer the eth to DSP Tx  eth flow
+ */
+//#define CPU_RX_BUF	0	// eth -> cpu
+//#define CPU_TX_BUF 	1	// cpu -> eth
+
+#define	DSP_RX_BUF_0	2	// dsp rx -> eth (double buffer)
+#define	DSP_RX_BUF_1	3	// dsp rx -> eth
+#define	DSP_TX_BUF_0	4	// eth -> dsp tx (double buffer)
+#define	DSP_TX_BUF_1	5	// eth -> dsp tx
+
+
+/*
+ * ================================================================
+ *      configure DSP RX double buffering state machine
+ * ================================================================
+ */
+
+// 4 lines of ethernet hdr + 1 line (word0)
+// DSP Rx writes timestamp followed by nlines_per_frame of samples
+#define DSP_RX_FIRST_LINE		  5
+#define DSP_RX_SAMPLES_PER_FRAME	128
+#define	DSP_RX_EXTRA_LINES		  1	// writes timestamp
+
+// Receive from DSP Rx
+buf_cmd_args_t dsp_rx_recv_args = {
+  PORT_DSP,
+  DSP_RX_FIRST_LINE,
+  BP_LAST_LINE
+};
+
+// send to ethernet
+buf_cmd_args_t dsp_rx_send_args = {
+  PORT_ETH,
+  0,		// starts with ethernet header in line 0
+  0,		// filled in from last_line register
+};
+
+dbsm_t dsp_rx_sm;	// the state machine
+
+/*
+ * ================================================================
+ *      configure DSP TX double buffering state machine
+ * ================================================================
+ */
+
+// 4 lines of ethernet hdr + 2 lines (word0 + timestamp)
+// DSP Tx reads word0 (flags) + timestamp followed by samples
+
+#define DSP_TX_FIRST_LINE		  4
+#define DSP_TX_SAMPLES_PER_FRAME	250	// not used except w/ debugging
+#define	DSP_TX_EXTRA_LINES		  2	// reads word0 + timestamp
+
+// Receive from ethernet
+buf_cmd_args_t dsp_tx_recv_args = {
+  PORT_ETH,
+  0,
+  BP_LAST_LINE
+};
+
+// send to DSP Tx
+buf_cmd_args_t dsp_tx_send_args = {
+  PORT_DSP,
+  DSP_TX_FIRST_LINE,	// starts just past ethernet header
+  0			// filled in from last_line register
+};
+
+dbsm_t dsp_tx_sm;	// the state machine
+
+
+// ----------------------------------------------------------------
+
+
+// The mac address of the host we're sending to.
+eth_mac_addr_t host_mac_addr;
+
+
+void
+timer_irq_handler(unsigned irq)
+{
+  hal_set_timeout(timer_delta);	// schedule next timeout
+}
+
+// Tx DSP underrun
+void
+underrun_irq_handler(unsigned irq)
+{
+  putchar('U');
+
+  dbsm_stop(&dsp_tx_sm);
+  dsp_tx_regs->clear_state = 1;
+  dbsm_start(&dsp_tx_sm);  // restart sm so we're listening to ethernet again
+
+  // putstr("\nirq: underrun\n");
+}
+
+
+void
+start_rx_cmd(const eth_mac_addr_t *host, op_start_rx_t *p)
+{
+}
+
+void
+stop_rx_cmd(void)
+{
+}
+
+static void
+setup_tx()
+{
+  dsp_tx_regs->clear_state = 1;
+  bp_clear_buf(DSP_TX_BUF_0);
+  bp_clear_buf(DSP_TX_BUF_1);
+
+#if 1
+  int tx_scale = 256;
+  int interp = 32;
+
+  op_config_tx_t def_config;
+  memset(&def_config, 0, sizeof(def_config));
+  def_config.phase_inc  = 408021893;			// 9.5 MHz [2**32 * fc/fsample]
+  def_config.scale_iq = (tx_scale << 16) | tx_scale;
+  def_config.interp = interp;
+
+  // setup Tx DSP regs
+  config_tx_cmd(&def_config);
+#endif
+}
+
+
+inline static void
+buffer_irq_handler(unsigned irq)
+{
+  uint32_t  status = buffer_pool_status->status;
+
+  if (status & BPS_ERROR_ALL){
+    // FIXME rare path, handle error conditions
+    putstr("Errors! status = ");
+    puthex32_nl(status);
+
+    printf("total_rx_pkts  = %d\n", total_rx_pkts);
+    printf("total_rx_bytes = %d\n", total_rx_bytes);
+
+    print_rmon_regs();
+
+    if (status & (BPS_ERROR(DSP_TX_BUF_0) | BPS_ERROR(DSP_TX_BUF_1))){
+      dbsm_stop(&dsp_tx_sm);		
+      dsp_tx_regs->clear_state = 1; // try to restart
+      dbsm_start(&dsp_tx_sm);
+      return;
+    }
+  }
+
+  dbsm_process_status(&dsp_tx_sm, status);
+
+  if (status & BPS_DONE(CPU_TX_BUF)){
+    bp_clear_buf(CPU_TX_BUF);
+  }
+}
+
+/*
+ * Called when an ethernet packet is received.
+ * Return true if we handled it here (always!)
+ */
+bool
+nop_eth_pkt_inspector(dbsm_t *sm, int bufno)
+{
+  hal_toggle_leds(0x1);
+
+  u2_eth_packet_t *pkt = (u2_eth_packet_t *) buffer_ram(bufno);
+  size_t byte_len = (buffer_pool_status->last_line[bufno] - 1) * 4;
+
+  total_rx_pkts++;
+  total_rx_bytes += byte_len;
+
+  // inspect rcvd frame and figure out what do do.
+
+  if (pkt->ehdr.ethertype != U2_ETHERTYPE)
+    return true;	// ignore, probably bogus PAUSE frame from MAC
+
+  int chan = u2p_chan(&pkt->fixed);
+
+  switch (chan){
+  case CONTROL_CHAN:
+    handle_control_chan_frame(pkt, byte_len);
+    return true;	// we handled the packet
+    break;
+
+  case 0:
+  default:
+    return true;	// say we handled it
+    break;
+  }
+}
+
+
+int
+main(void)
+{
+  u2_init();
+
+  // setup tx gpio bits for GPIOM_FPGA_1 -- fpga debug output
+  hal_gpio_set_tx_mode(15, 0, GPIOM_FPGA_1);
+  hal_gpio_set_rx_mode(15, 0, GPIOM_FPGA_1);	// no printing...
+
+  putstr("\ntx_drop2\n");
+  
+  // Control LEDs
+  hal_set_leds(0x0, 0x3);
+
+  // pic_register_handler(IRQ_OVERRUN,  overrun_irq_handler);
+  pic_register_handler(IRQ_UNDERRUN, underrun_irq_handler);
+
+  //pic_register_handler(IRQ_TIMER, timer_irq_handler);
+  //hal_set_timeout(timer_delta);
+
+  ethernet_register_link_changed_callback(link_changed_callback);
+
+  ethernet_init();
+
+  // initialize double buffering state machine for ethernet -> DSP Tx
+
+  dbsm_init(&dsp_tx_sm, DSP_TX_BUF_0,
+	    &dsp_tx_recv_args, &dsp_tx_send_args,
+	    nop_eth_pkt_inspector);
+
+  // program tx registers
+  setup_tx();
+
+  // kick off the state machine
+  dbsm_start(&dsp_tx_sm);
+
+  while(1){
+    buffer_irq_handler(0);
+  }
+}
+
diff --git a/firmware/microblaze/apps/bitrot/tx_drop_rate_limited.c b/firmware/microblaze/apps/bitrot/tx_drop_rate_limited.c
new file mode 100644
index 000000000..2b8db7f7d
--- /dev/null
+++ b/firmware/microblaze/apps/bitrot/tx_drop_rate_limited.c
@@ -0,0 +1,233 @@
+/*
+ * Copyright 2007,2008 Free Software Foundation, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "u2_init.h"
+#include "memory_map.h"
+#include "spi.h"
+#include "hal_io.h"
+#include "buffer_pool.h"
+#include "pic.h"
+#include <stdbool.h>
+#include "ethernet.h"
+#include "nonstdio.h"
+#include "usrp2_eth_packet.h"
+#include "dbsm.h"
+#include "app_common.h"
+#include "print_rmon_regs.h"
+#include "eth_mac.h"
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/*
+ * receive packets from ethernet at a fixed rate and discard them
+ */
+
+int total_rx_pkts = 0;
+int total_rx_bytes = 0;
+
+
+static int timer_delta = (int)(MASTER_CLK_RATE * 10e-6); // 10us / tick
+
+
+/*
+ * This program can respond to queries from the host
+ * and stream rx samples.
+ *
+ * Buffer 1 is used by the cpu to send frames to the host.
+ * Buffers 2 and 3 are used to double-buffer the DSP Rx to eth flow
+ * Buffers 4 and 5 are used to double-buffer the eth to DSP Tx  eth flow
+ */
+//#define CPU_RX_BUF	0	// eth -> cpu
+//#define CPU_TX_BUF 	1	// cpu -> eth
+
+#define	DSP_RX_BUF_0	2	// dsp rx -> eth (double buffer)
+#define	DSP_RX_BUF_1	3	// dsp rx -> eth
+#define	DSP_TX_BUF_0	4	// eth -> dsp tx (double buffer)
+#define	DSP_TX_BUF_1	5	// eth -> dsp tx
+
+
+
+// ----------------------------------------------------------------
+
+
+// The mac address of the host we're sending to.
+eth_mac_addr_t host_mac_addr;
+
+
+static volatile bool receive_packet_now = false;
+
+void
+timer_irq_handler(unsigned irq)
+{
+  hal_set_timeout(timer_delta);	// schedule next timeout
+  receive_packet_now = true;
+}
+
+
+// Tx DSP underrun
+void
+underrun_irq_handler(unsigned irq)
+{
+  putchar('U');
+}
+
+
+void
+start_rx_cmd(const eth_mac_addr_t *host, op_start_rx_t *p)
+{
+}
+
+void
+stop_rx_cmd(void)
+{
+}
+
+static void
+setup_tx()
+{
+  dsp_tx_regs->clear_state = 1;
+  bp_clear_buf(DSP_TX_BUF_0);
+  bp_clear_buf(DSP_TX_BUF_1);
+
+  int tx_scale = 256;
+  int interp = 32;
+
+  op_config_tx_t def_config;
+  memset(&def_config, 0, sizeof(def_config));
+  def_config.phase_inc  = 408021893;			// 9.5 MHz [2**32 * fc/fsample]
+  def_config.scale_iq = (tx_scale << 16) | tx_scale;
+  def_config.interp = interp;
+
+  // setup Tx DSP regs
+  config_tx_cmd(&def_config);
+}
+
+
+/*
+ * Called when an ethernet packet is received.
+ *
+ * Claim that we handled all the packets,
+ * dropping those destined for the TX DSP chain
+ * on the ground.
+ */
+bool
+nop_eth_pkt_inspector(dbsm_t *sm, int bufno)
+{
+  hal_toggle_leds(0x1);
+
+  u2_eth_packet_t *pkt = (u2_eth_packet_t *) buffer_ram(bufno);
+  size_t byte_len = (buffer_pool_status->last_line[bufno] - 1) * 4;
+
+  total_rx_pkts++;
+  total_rx_bytes += byte_len;
+
+  // inspect rcvd frame and figure out what do do.
+
+  if (pkt->ehdr.ethertype != U2_ETHERTYPE)
+    return true;	// ignore, probably bogus PAUSE frame from MAC
+
+  int chan = u2p_chan(&pkt->fixed);
+
+  switch (chan){
+  case CONTROL_CHAN:
+    handle_control_chan_frame(pkt, byte_len);
+    return true;	// we handled the packet
+    break;
+
+  case 0:
+  default:
+    return true;	// We handled the data by dropping it :)
+    break;
+  }
+}
+
+
+inline static void
+buffer_irq_handler(unsigned irq)
+{
+  uint32_t  status = buffer_pool_status->status;
+
+  if (status & (BPS_DONE(CPU_TX_BUF) | BPS_ERROR(CPU_TX_BUF)))
+    bp_clear_buf(CPU_TX_BUF);
+
+  if (status & (BPS_DONE(DSP_TX_BUF_0) | BPS_ERROR(DSP_TX_BUF_0))){
+    bp_clear_buf(DSP_TX_BUF_0);
+
+    if (status & BPS_ERROR(DSP_TX_BUF_0)){
+      int crc = eth_mac_read_rmon(0x05);
+      int fifo_full = eth_mac_read_rmon(0x06);
+      int too_short_too_long = eth_mac_read_rmon(0x07);
+      putstr("Errors! status = ");
+      puthex32_nl(status);
+
+      printf("crc_err\t\t= %d\n", crc);
+      printf("fifo_full\t\t= %d\n", fifo_full);
+      printf("too_short_too_long\t= %d\n", too_short_too_long);
+
+      printf("total_rx_pkts  = %d\n", total_rx_pkts);
+      printf("total_rx_bytes = %d\n", total_rx_bytes);
+    }
+    else
+      nop_eth_pkt_inspector(0, DSP_TX_BUF_0);
+  }
+
+  if (receive_packet_now && (status & BPS_IDLE(DSP_TX_BUF_0))){
+    receive_packet_now = false;
+    bp_receive_to_buf(DSP_TX_BUF_0, PORT_ETH, 1, 0, BP_LAST_LINE);
+  }
+}
+
+
+int
+main(void)
+{
+  u2_init();
+
+  // setup tx gpio bits for GPIOM_FPGA_1 -- fpga debug output
+  hal_gpio_set_tx_mode(15, 0, GPIOM_FPGA_1);
+  hal_gpio_set_rx_mode(15, 0, GPIOM_FPGA_1);
+
+  putstr("\ntx_drop_rate_limited\n");
+  
+  // Control LEDs
+  hal_set_leds(0x0, 0x3);
+
+  pic_register_handler(IRQ_UNDERRUN, underrun_irq_handler);
+
+  pic_register_handler(IRQ_TIMER, timer_irq_handler);
+  hal_set_timeout(timer_delta);
+
+  ethernet_register_link_changed_callback(link_changed_callback);
+  ethernet_init();
+
+  // program tx registers
+  setup_tx();
+
+  // start a receive from ethernet
+  bp_receive_to_buf(DSP_TX_BUF_0, PORT_ETH, 1, 0, BP_LAST_LINE);
+
+  while(1){
+    buffer_irq_handler(0);
+  }
+}
+