New branch with firmware dir from USRP2P branch.

9 files changed, 814 insertions, 0 deletions

diff --git a/firmware/microblaze/usrp2p/bootloader/.gitignore b/firmware/microblaze/usrp2p/bootloader/.gitignore
new file mode 100644
index 000000000..17b0f82f3
--- /dev/null
+++ b/firmware/microblaze/usrp2p/bootloader/.gitignore
@@ -0,0 +1,11 @@
+/*.ihx
+/*.rmi
+/*_rom
+/*.elf
+/*.bin
+/*.dump
+/*.log
+/*.rom
+/*.map
+/Makefile
+/Makefile.in
diff --git a/firmware/microblaze/usrp2p/bootloader/Makefile.am b/firmware/microblaze/usrp2p/bootloader/Makefile.am
new file mode 100644
index 000000000..1fc5daf9c
--- /dev/null
+++ b/firmware/microblaze/usrp2p/bootloader/Makefile.am
@@ -0,0 +1,39 @@
+#
+# Copyright 2007,2008,2009 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/>.
+#
+
+include $(top_srcdir)/Makefile.common
+
+ROM_LINKER_SCRIPT = u2p2-rom.ld
+
+# loads into 8K boot ram located at 0x0000_0000
+AM_CFLAGS = $(COMMON_CFLAGS) -I$(top_srcdir)/usrp2p
+AM_LDFLAGS = -Wl,-T,$(ROM_LINKER_SCRIPT) $(COMMON_LFLAGS) -Wl,-defsym -Wl,_STACK_SIZE=1024
+
+EXTRA_DIST = $(ROM_LINKER_SCRIPT)
+
+LDADD = $(top_srcdir)/usrp2p/libusrp2p.a
+
+noinst_PROGRAMS = \
+	init_bootloader.elf
+
+init_bootloader_elf_SOURCES = init_bootloader.c
+
+.bin.rmi:
+	$(top_srcdir)/bin/bin_to_ram_macro_init.py $< $@
+
+_generated_from_elf += \
+	$(noinst_PROGRAMS:.elf=.rmi)
diff --git a/firmware/microblaze/usrp2p/bootloader/fpga_bootloader.c b/firmware/microblaze/usrp2p/bootloader/fpga_bootloader.c
new file mode 100644
index 000000000..9feff6ecd
--- /dev/null
+++ b/firmware/microblaze/usrp2p/bootloader/fpga_bootloader.c
@@ -0,0 +1,202 @@
+/* -*- c -*- */
+/*
+ * Copyright 2009 Ettus Research LLC
+ *
+ * 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/>.
+ */
+
+/*
+ * This code is bootloader f/w for the slot 0 fpga image.  It's job is
+ * to figure out which fpga image should be loaded, and then to load
+ * that image from the SPI flash.  (FIXME handle retries, errors,
+ * etc.)
+ *
+ * If the center button is down during boot, it loads firwmare
+ * from 0:0 instead of its normal action.
+ */
+
+#include <stdlib.h>
+#include <hal_io.h>
+#include <nonstdio.h>
+#include <mdelay.h>
+#include <quadradio/flashdir.h>
+#include <xilinx_v5_icap.h>
+#include <bootconfig.h>
+#include <bootconfig_private.h>
+#include <spi_flash.h>
+#include <string.h>
+#include <bootloader_utils.h>
+#include <hal_interrupts.h>
+
+#define VERBOSE 1
+
+#define	OUR_FPGA_IMAGE_NUMBER	0	// this code only runs in slot 0
+
+void hal_uart_init(void);
+void spif_init(void);
+void i2c_init(void);
+void bootconfig_init(void);
+
+void pic_interrupt_handler() __attribute__ ((interrupt_handler));
+
+void pic_interrupt_handler()
+{
+  // nop stub
+}
+
+static int
+flash_addr_of_fpga_slot(unsigned int fpga_slot)
+{
+  const struct flashdir *fd = get_flashdir();
+  return fd->slot[fpga_slot + fd->fpga_slot0].start << spi_flash_log2_sector_size();
+}
+
+
+/*
+ * If the first 256 bytes of the image contain the string of bytes,
+ * ff ff ff ff aa 99 55 66, we consider it a likely bitstream.
+ */
+static bool
+looks_like_a_bitstream(unsigned int fpga_slot)
+{
+  unsigned char buf[256];
+  static const unsigned char pattern[] = {
+    0xff, 0xff, 0xff, 0xff, 0xaa, 0x99, 0x55, 0x66
+  };
+
+  // Read the first 256 bytes of the bitstream
+  spi_flash_read(flash_addr_of_fpga_slot(fpga_slot), sizeof(buf), buf);
+
+  for (int i = 0; i <= sizeof(buf) - sizeof(pattern); i++)
+    if (memcmp(pattern, &buf[i], sizeof(pattern)) == 0)
+      return true;
+
+  return false;
+}
+
+static bool
+plausible_bootconfig(bootconfig_t bc)
+{
+  // Are the fields in range?
+  if (!validate_bootconfig(bc))
+    return false;
+
+  if (!looks_like_a_bitstream(map_fpga_image_number_to_fpga_slot(bc.fpga_image_number)))
+    return false;
+
+  return true;
+}
+
+// Attempt to boot the fpga image specified in next_boot
+static void
+initial_boot_attempt(eeprom_boot_info_t *ee)
+{
+  if (ee->next_boot.fpga_image_number == OUR_FPGA_IMAGE_NUMBER){
+    load_firmware();
+    return;
+  }
+
+  ee->nattempts = 1;
+  _bc_write_eeprom_shadow();
+
+  unsigned int target_slot =
+    map_fpga_image_number_to_fpga_slot(ee->next_boot.fpga_image_number);
+  int flash_addr = flash_addr_of_fpga_slot(target_slot);
+
+  putstr("fpga_bootloader: chaining to ");
+  puthex4(ee->next_boot.fpga_image_number);
+  putchar(':');
+  puthex4(ee->next_boot.firmware_image_number);
+  newline();
+  mdelay(100);
+
+  while (1){
+    icap_reload_fpga(flash_addr);
+  }
+}
+
+int
+main(int argc, char **argv)
+{
+  hal_disable_ints();	// In case we got here via jmp 0x0
+  hal_uart_init();
+  i2c_init();
+  bootconfig_init();	// Must come after i2c_init.
+  spif_init();		// Needed for get_flashdir.
+
+  sr_leds->leds =  0xAAAA;
+
+  putstr("\n\n>>> fpga_bootloader <<<\n");
+
+  putstr("\nBOOTSTS ");
+  int bootsts = icap_read_config_reg(rBOOTSTS);
+  puthex32_nl(bootsts);
+  putstr("STAT    ");
+  int stat = icap_read_config_reg(rSTAT);
+  puthex32_nl(stat);
+
+  bool fallback =
+    ((bootsts & (BOOTSTS_VALID_0 | BOOTSTS_FALLBACK_0))
+     == (BOOTSTS_VALID_0 | BOOTSTS_FALLBACK_0));
+
+  if (fallback){
+    puts("FALLBACK_0 is set");
+    // FIXME handle fallback condition.
+  }
+
+  const struct flashdir *fd = get_flashdir();
+  if (fd == 0)
+    abort();
+
+  eeprom_boot_info_t *ee = _bc_get_eeprom_shadow();
+
+  if (VERBOSE){
+    putstr("nattempts: ");
+    puthex8_nl(ee->nattempts);
+  }
+
+  mdelay(500);	// wait for low-pass on switches
+  putstr("switches: "); puthex32_nl(readback->switches);
+
+  bool center_btn_down = (readback->switches & BTN_CENTER) != 0;
+  if (center_btn_down){
+    putstr("Center button is down!\n");
+    // Force boot of image 0:0
+    ee->next_boot = make_bootconfig(0, 0);
+  }
+
+  // if next_boot is valid, try it
+  if (plausible_bootconfig(ee->next_boot))
+    initial_boot_attempt(ee);	// no return
+
+  // if default_boot is valid, try it
+  if (plausible_bootconfig(ee->default_boot)){
+    ee->next_boot = ee->default_boot;
+    initial_boot_attempt(ee);	// no return
+  }
+
+  // If we're here, we're in trouble.  Try all of them...
+  for (int i = 0; i < 4; i++){
+    bootconfig_t bc = make_bootconfig(i, 0);
+    if (plausible_bootconfig(bc)){
+      ee->next_boot = bc;
+      initial_boot_attempt(ee);	// no return
+    }
+  }
+
+  // FIXME, try to find something we can load
+  puts("\n!!! Failed to find a valid FPGA bitstream!\n\n");
+
+  return 0;
+}
diff --git a/firmware/microblaze/usrp2p/bootloader/fw_bootloader.c b/firmware/microblaze/usrp2p/bootloader/fw_bootloader.c
new file mode 100644
index 000000000..a2c32bf8e
--- /dev/null
+++ b/firmware/microblaze/usrp2p/bootloader/fw_bootloader.c
@@ -0,0 +1,50 @@
+/* -*- c -*- */
+/*
+ * Copyright 2009 Ettus Research LLC
+ *
+ * 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/>.
+ */
+
+#include <memory_map.h>
+#include <nonstdio.h>
+#include <stdlib.h>
+#include <bootconfig.h>
+#include <bootconfig_private.h>
+#include <bootloader_utils.h>
+#include <hal_interrupts.h>
+
+
+void hal_uart_init(void);
+void spif_init(void);
+void i2c_init(void);
+void bootconfig_init(void);
+
+void pic_interrupt_handler() __attribute__ ((interrupt_handler));
+
+void pic_interrupt_handler()
+{
+  // nop stub
+}
+
+int
+main(int argc, char **argv)
+{
+  hal_disable_ints();	// In case we got here via jmp 0x0
+  hal_uart_init();
+  i2c_init();
+  bootconfig_init();	// Must come after i2c_init.
+  spif_init();		// Needed for get_flashdir.
+
+  load_firmware();
+}
diff --git a/firmware/microblaze/usrp2p/bootloader/icap_test.c b/firmware/microblaze/usrp2p/bootloader/icap_test.c
new file mode 100644
index 000000000..5feb9d014
--- /dev/null
+++ b/firmware/microblaze/usrp2p/bootloader/icap_test.c
@@ -0,0 +1,31 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2010 Ettus Research LLC
+ *
+ */
+
+#include <memory_map.h>
+#include <hal_io.h>
+#include <xilinx_s3_icap.h>
+#include <nonstdio.h>
+
+void delay(uint32_t t) {
+	while(t-- != 0) asm("NOP");
+}
+
+
+int main(int argc, char *argv[]) {
+	pic_init();
+	hal_uart_init();
+	puts("\nStarting delay...\n");
+
+	output_regs->leds = 0xFF;
+	delay(4000000);
+	output_regs->leds = 0x00;
+	delay(4000000);
+
+	puts("Rebooting FPGA to 0x00000000\n");
+	icap_reload_fpga((uint32_t)0x00000000);
+
+	return 0;
+}
diff --git a/firmware/microblaze/usrp2p/bootloader/init_bootloader.c b/firmware/microblaze/usrp2p/bootloader/init_bootloader.c
new file mode 100644
index 000000000..15d719d73
--- /dev/null
+++ b/firmware/microblaze/usrp2p/bootloader/init_bootloader.c
@@ -0,0 +1,108 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2010 Ettus Research LLC
+ *
+ */
+
+#include <memory_map.h>
+#include <nonstdio.h>
+#include <hal_io.h>
+#include <xilinx_s3_icap.h>
+#include <spi_flash.h>
+#include <spi_flash_private.h>
+//#include <clocks.h>
+#include <ihex.h>
+#include <bootloader_utils.h>
+#include <string.h>
+#include <hal_uart.h>
+
+void pic_interrupt_handler() __attribute__ ((interrupt_handler));
+
+void pic_interrupt_handler()
+{
+  // nop stub
+}
+
+void load_ihex(void) { //simple IHEX parser to load proper records into RAM. loads program when it receives end of record.
+	char buf[128]; //input data buffer
+	uint8_t ihx[32]; //ihex data buffer
+
+	ihex_record_t ihex_record;
+	ihex_record.data = ihx;
+
+	while(1) {
+		gets(buf);
+
+		if(!ihex_parse(buf, &ihex_record)) { //RAM data record is valid
+			if(ihex_record.addr >= RAM_BASE) { //it's expecting to see FULLY RELOCATED IHX RECORDS. every address referenced to 0x8000, including vectors.
+				memcpy((void *) (ihex_record.addr), ihex_record.data, ihex_record.length);
+				puts("OK");
+			} else if(ihex_record.type == 1) { //end of record
+				puts("OK");
+				//load main firmware
+				start_program(RAM_BASE);
+				puts("ERROR: main image returned! Back in IHEX load mode.");
+			} else puts("NOK"); //RAM loads do not support extended segment address records (04) -- upper 16 bits are always "0".
+		} else puts("NOK");
+	}
+}
+
+void delay(uint32_t t) {
+	while(t-- != 0) asm("NOP");
+}
+
+//let's clean up this logic. state machine? no, you only have to go through it once.
+
+//don't need else cases since all these are terminal cases
+
+int main(int argc, char *argv[]) {
+  hal_disable_ints();	// In case we got here via jmp 0x0
+	output_regs->leds = 0xFF;
+	delay(500000);
+	output_regs->leds = 0x00;
+  hal_uart_init();
+	spif_init();
+//	i2c_init(); //for EEPROM
+	puts("USRP2+ bootloader\n");
+
+	if(BUTTON_PUSHED) { //see memory_map.h
+		puts("Starting USRP2+ in safe mode.");
+		if(is_valid_fw_image(SAFE_FW_IMAGE_LOCATION_ADDR)) {
+				spi_flash_read(SAFE_FW_IMAGE_LOCATION_ADDR, FW_IMAGE_SIZE_BYTES, (void *)RAM_BASE);
+				start_program(RAM_BASE);
+				puts("ERROR: return from main program! This should never happen!");
+				//icap_reload_fpga(SAFE_FPGA_IMAGE_LOCATION_ADDR);
+			} else {
+				puts("ERROR: no safe firmware image available. I am a brick. Feel free to load IHEX to RAM.");
+				load_ihex();
+			}
+	}
+
+	puts("Checking for valid production FPGA image...");
+	if(is_valid_fpga_image(PROD_FPGA_IMAGE_LOCATION_ADDR)) {
+		puts("Valid production FPGA image found. Attempting to boot.");
+		//icap_reload_fpga(PROD_FPGA_IMAGE_LOCATION_ADDR);
+	}
+	puts("No valid production FPGA image found.\nAttempting to load production firmware...");
+	if(is_valid_fw_image(PROD_FW_IMAGE_LOCATION_ADDR)) {
+		puts("Valid production firmware found. Loading...");
+		spi_flash_read(PROD_FW_IMAGE_LOCATION_ADDR, FW_IMAGE_SIZE_BYTES, (void *)RAM_BASE);
+		start_program(RAM_BASE);
+		puts("ERROR: Return from main program! This should never happen!");
+		//if this happens, though, the safest thing to do is reboot the whole FPGA and start over.
+		//icap_reload_fpga(SAFE_FPGA_IMAGE_LOCATION_ADDR);
+		return 1;
+	}
+	puts("No valid production firmware found. Trying safe firmware...");
+	if(is_valid_fw_image(SAFE_FW_IMAGE_LOCATION_ADDR)) {
+		spi_flash_read(SAFE_FW_IMAGE_LOCATION_ADDR, FW_IMAGE_SIZE_BYTES, (void *)RAM_BASE);
+		start_program(RAM_BASE);
+		puts("ERROR: return from main program! This should never happen!");
+		//icap_reload_fpga(SAFE_FPGA_IMAGE_LOCATION_ADDR);
+		return 1; //_exit will trap in loop
+	}
+	puts("ERROR: no safe firmware image available. I am a brick. Feel free to load IHEX to RAM.");
+	load_ihex();
+
+	return 0;
+}
diff --git a/firmware/microblaze/usrp2p/bootloader/serial_loader_burner.c b/firmware/microblaze/usrp2p/bootloader/serial_loader_burner.c
new file mode 100644
index 000000000..4ac4df454
--- /dev/null
+++ b/firmware/microblaze/usrp2p/bootloader/serial_loader_burner.c
@@ -0,0 +1,49 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2009 Ettus Research LLC
+ *
+ * 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/>.
+ */
+
+#include <hal_io.h>
+#include <nonstdio.h>
+#include <mdelay.h>
+#include <gdbstub2.h>
+
+void hal_uart_init(void);
+void spif_init(void);
+
+void pic_interrupt_handler() __attribute__ ((interrupt_handler));
+
+void pic_interrupt_handler()
+{
+  // nop stub
+}
+
+int
+main(int argc, char **argv)
+{
+  hal_uart_init();
+  spif_init();
+
+  sr_leds->leds =  0;
+  mdelay(100);
+  sr_leds->leds = ~0;
+  mdelay(100);
+  sr_leds->leds =  0;
+
+  puts("\n\n>>> stage1: serial_loader_burner <<<");
+
+  gdbstub2_main_loop();
+}
diff --git a/firmware/microblaze/usrp2p/bootloader/spi_bootloader.c b/firmware/microblaze/usrp2p/bootloader/spi_bootloader.c
new file mode 100644
index 000000000..678e66cf7
--- /dev/null
+++ b/firmware/microblaze/usrp2p/bootloader/spi_bootloader.c
@@ -0,0 +1,134 @@
+/* -*- c -*- */
+/*
+ * Copyright 2009 Ettus Research LLC
+ *
+ * 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/>.
+ */
+
+#include <hal_io.h>
+#include <nonstdio.h>
+#include <mdelay.h>
+#include <spi_flash.h>
+#include <quadradio/flashdir.h>
+#include <quadradio/simple_binary_format.h>
+#include <stdlib.h>
+
+
+void hal_uart_init(void);
+void spif_init(void);
+
+void pic_interrupt_handler() __attribute__ ((interrupt_handler));
+
+void pic_interrupt_handler()
+{
+  // nop stub
+}
+
+static void
+error(int e)
+{
+  putstr("ERR");
+  puthex8(e);
+  newline();
+}
+
+static void
+load(uint32_t flash_addr, uint32_t ram_addr, uint32_t size)
+{
+  spi_flash_read(flash_addr, size, (void *) ram_addr);
+}
+
+static bool
+load_from_slot(const struct flashdir *fd, int fw_slot)
+{
+    putstr("Loading f/w image ");
+    putchar('0' + fw_slot);
+    putstr("... ");
+
+    if (fw_slot >= fd->fw_nslots){
+      error(1);
+      return false;
+    }
+
+    int slot = fw_slot + fd->fw_slot0;
+    if (fd->slot[slot].start == 0 || fd->slot[slot].start == 0xffff
+	|| fd->slot[slot].len == 0 || fd->slot[slot].len == 0xffff){
+      error(2);
+      return false;
+    }
+    
+    uint32_t sbf_base = fd->slot[slot].start << spi_flash_log2_sector_size();
+    uint32_t sbf_len  = fd->slot[slot].len << spi_flash_log2_sector_size();
+    uint32_t sbf_offset = 0;
+
+    struct sbf_header sbf;
+    spi_flash_read(sbf_base, sizeof(struct sbf_header), &sbf);
+    if (sbf.magic != SBF_MAGIC || sbf.nsections > SBF_MAX_SECTIONS){
+      error(3);
+      return false;
+    }
+    sbf_offset += sizeof(struct sbf_header);
+
+    unsigned int i;
+    for (i = 0; i < sbf.nsections; i++){
+      if (sbf_offset + sbf.sec_desc[i].length > sbf_len){
+	error(4);
+	return false;
+      }
+      load(sbf_offset + sbf_base,
+	   sbf.sec_desc[i].target_addr,
+	   sbf.sec_desc[i].length);
+      sbf_offset += sbf.sec_desc[i].length;
+    }
+    putstr("Done!");
+
+    typedef void (*fptr_t)(void);
+    (*(fptr_t) sbf.entry)();		// almost certainly no return
+
+    return true;
+}
+
+int
+main(int argc, char **argv)
+{
+  hal_uart_init();
+  spif_init();
+
+  sr_leds->leds =  0;
+  mdelay(100);
+  sr_leds->leds = ~0;
+  mdelay(100);
+  sr_leds->leds =  0;
+
+  putstr("\n>>> spi_bootloader <<<\n");
+
+  const struct flashdir *fd = get_flashdir();
+  if (fd == 0)
+    abort();
+
+  while(1){
+    int sw;
+    int fw_slot;
+    
+    sw = readback->switches;
+    fw_slot = sw & 0x7;
+
+    if (!load_from_slot(fd, fw_slot)){
+      if (fw_slot != 0){
+	putstr("Falling back to slot 0\n");
+	load_from_slot(fd, 0);
+      }
+    }
+  }
+}
diff --git a/firmware/microblaze/usrp2p/bootloader/u2p2-rom.ld b/firmware/microblaze/usrp2p/bootloader/u2p2-rom.ld
new file mode 100644
index 000000000..4c9eaa8e5
--- /dev/null
+++ b/firmware/microblaze/usrp2p/bootloader/u2p2-rom.ld
@@ -0,0 +1,190 @@
+/*
+ * Same as default, but with bss and stack moved to top 2K of main ram
+ * Copied from qr-rom.ld
+ */
+
+/* Default linker script, for normal executables */
+OUTPUT_FORMAT("elf32-microblaze", "", "")
+/*SEARCH_DIR("/home/eb/build/Xilinx_EDK_GNU_10.1i/mb/release/lin/mb/microblaze-xilinx-elf/lib");*/
+
+
+ENTRY(_start)
+_TEXT_START_ADDR = DEFINED(_TEXT_START_ADDR) ? _TEXT_START_ADDR : 0x50;
+_HEAP_SIZE = DEFINED(_HEAP_SIZE) ? _HEAP_SIZE : 0x0;
+_STACK_SIZE = DEFINED(_STACK_SIZE) ? _STACK_SIZE : 0x400;
+_BSS_START_ADDR = DEFINED(_BSS_START_ADDR) ? _BSS_START_ADDR : 0xF800;
+SECTIONS
+{
+  .vectors.reset 0x0 : { KEEP (*(.vectors.reset)) } = 0
+  .vectors.sw_exception 0x8 : { KEEP (*(.vectors.sw_exception)) } = 0
+  .vectors.interrupt 0x10 : { KEEP (*(.vectors.interrupt)) } = 0
+  .vectors.debug_sw_break 0x18 : { KEEP (*(.vectors.debug_sw_break)) } = 0
+  .vectors.hw_exception 0x20 : { KEEP (*(.vectors.hw_exception)) } = 0
+  . = _TEXT_START_ADDR;
+   _ftext  =  .;
+  .text : {
+    *(.text)
+    *(.text.*)
+    *(.gnu.linkonce.t.*)
+  }
+   _etext  =  .;
+  .init : { KEEP (*(.init))	} =0
+  .fini : { KEEP (*(.fini))	} =0
+  PROVIDE (__CTOR_LIST__ = .);
+  PROVIDE (___CTOR_LIST__ = .);
+  .ctors   :
+  {
+    /* gcc uses crtbegin.o to find the start of
+       the constructors, so we make sure it is
+       first.  Because this is a wildcard, it
+       doesn't matter if the user does not
+       actually link against crtbegin.o; the
+       linker won't look for a file to match a
+       wildcard.  The wildcard also means that it
+       doesn't matter which directory crtbegin.o
+       is in.  */
+    KEEP (*crtbegin.o(.ctors))
+    /* We don't want to include the .ctor section from
+       from the crtend.o file until after the sorted ctors.
+       The .ctor section from the crtend file contains the
+       end of ctors marker and it must be last */
+    KEEP (*(EXCLUDE_FILE (*crtend.o) .ctors))
+    KEEP (*(SORT(.ctors.*)))
+    KEEP (*(.ctors))
+  }
+  PROVIDE (__CTOR_END__ = .);
+  PROVIDE (___CTOR_END__ = .);
+  PROVIDE (__DTOR_LIST__ = .);
+  PROVIDE (___DTOR_LIST__ = .);
+   .dtors         :
+  {
+    KEEP (*crtbegin.o(.dtors))
+    KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
+    KEEP (*(SORT(.dtors.*)))
+    KEEP (*(.dtors))
+  }
+  PROVIDE (__DTOR_END__ = .);
+  PROVIDE (___DTOR_END__ = .);
+   . = ALIGN(4);
+    _frodata = . ;
+  .rodata : {
+    *(.rodata)
+    *(.rodata.*)
+    *(.gnu.linkonce.r.*)
+    CONSTRUCTORS; /* Is this needed? */
+  }
+   _erodata = .;
+  /* Alignments by 8 to ensure that _SDA2_BASE_ on a word boundary */
+  /* Note that .sdata2 and .sbss2 must be contiguous */
+  . = ALIGN(8);
+   _ssrw = .;
+  .sdata2 : {
+    *(.sdata2)
+    *(.sdata2.*)
+    *(.gnu.linkonce.s2.*)
+  }
+  . = ALIGN(4);
+  .sbss2 : {
+    PROVIDE (__sbss2_start = .);
+    *(.sbss2)
+    *(.sbss2.*)
+    *(.gnu.linkonce.sb2.*)
+    PROVIDE (__sbss2_end = .);
+  }
+  . = ALIGN(8);
+   _essrw = .;
+   _ssrw_size = _essrw - _ssrw;
+   PROVIDE (_SDA2_BASE_ = _ssrw + (_ssrw_size / 2 ));
+   . = ALIGN(4);
+   _fdata = .;
+  .data : {
+    *(.data)
+    *(.gnu.linkonce.d.*)
+    CONSTRUCTORS; /* Is this needed? */
+  }
+   _edata = . ;
+   /* Added to handle pic code */
+  .got : {
+    *(.got)
+  }
+  .got1 : {
+    *(.got1)
+  }
+  .got2 : {
+    *(.got2)
+  }
+  /* Added by Sathya to handle C++ exceptions */
+  .eh_frame : {
+    *(.eh_frame)
+  }
+  .jcr : {
+    *(.jcr)
+  }
+  .gcc_except_table : {
+    *(.gcc_except_table)
+  }
+  /* Alignments by 8 to ensure that _SDA_BASE_ on a word boundary */
+  /* Note that .sdata and .sbss must be contiguous */
+  . = ALIGN(8);
+   _ssro = .;
+  .sdata : {
+    *(.sdata)
+    *(.sdata.*)
+    *(.gnu.linkonce.s.*)
+  }
+  . = ALIGN(4);
+  .sbss : {
+    PROVIDE (__sbss_start = .);
+    *(.sbss)
+    *(.sbss.*)
+    *(.gnu.linkonce.sb.*)
+    PROVIDE (__sbss_end = .);
+  }
+  . = ALIGN(8);
+   _essro = .;
+   _ssro_size = _essro - _ssro;
+  PROVIDE (_SDA_BASE_ = _ssro + (_ssro_size / 2 ));
+   . = _BSS_START_ADDR;
+   . = ALIGN(4);
+   _fbss = .;
+  .bss : {
+    PROVIDE (__bss_start = .);
+    *(.bss)
+    *(.bss.*)
+    *(.gnu.linkonce.b.*)
+    *(COMMON)
+    . = ALIGN(4);
+    PROVIDE (__bss_end = .);
+  }
+   . = ALIGN(4);
+  .heap : {
+     _heap = .;
+     _heap_start = .;
+     . += _HEAP_SIZE;
+     _heap_end = .;
+  }
+  _end = .;
+   . = ALIGN(4);
+   . = 0xFFF0;
+  .stack : {
+  /*
+     _stack_end = .;
+     . += _STACK_SIZE;
+     . = ALIGN(8);
+     _stack = .;
+     _end = .;
+   */
+   _stack_end = .;
+   _stack = .;
+  }
+  .tdata : {
+    *(.tdata)
+    *(.tdata.*)
+    *(.gnu.linkonce.td.*)
+  }
+  .tbss : {
+    *(.tbss)
+    *(.tbss.*)
+    *(.gnu.linkonce.tb.*)
+  }
+}