view Small_CPU/CPU2-RTE.ld @ 250:822416168585 bm-2

Buelmann: new implementation for ceiling Since my first functional fix in the ceiling computation in commit ceecabfddb57, I noticed that the computation used a linear search, that became rather computational expensive after that commit. The simple question is: why not a binary search? So, this commit implements the binary search. But there is a long story attached to this. Comparing ceiling results from hwOS and this OSTC4 code were very different. Basically, the original OSTC4 algorithm computed the ceiling using the same GFlow to GFhigh slope, in such a way, that the ceiling was in sync with the presented deco stops, where the hwOS code presents a GFhigh based ceiling. This said, it is more logical when the OSTC4 and hwOS code give similar results. This new recursive algorithm gives very similar results for the ceiling compared to hwOS. To be complete here, the Buelmann ceiling is the depth to which you can ascend, so that the leading tissue reaches GFhigh. This also explains why the deepest deco stop is normally deeper than the ceiling (unless one dives with GF like 80/80). The code implemented here is rather straightforward recursion. Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
author Jan Mulder <jlmulder@xs4all.nl>
date Thu, 11 Apr 2019 17:48:48 +0200
parents 321df89d5710
children aa286a4926c2
line wrap: on
line source

/* ---------------------------------------------------------------------------- */
/*                  Em::Blocks embedded development Support                     */
/* ---------------------------------------------------------------------------- */
/* Copyright (c) 2014, EmBlocks                                                 */
/*                                                                              */
/* All rights reserved.                                                         */
/*                                                                              */
/* Redistribution and use in source and binary forms, with or without           */
/* modification, are permitted provided that the following condition is met:    */
/*                                                                              */
/* - Redistributions of source code must retain the above copyright notice,     */
/* this list of conditions and the disclaimer below.                            */
/*                                                                              */
/* EmBlocks's name may not be used to endorse or promote products derived from  */
/* this software without specific prior written permission.                     */
/*                                                                              */
/* DISCLAIMER:  THIS SOFTWARE IS PROVIDED BY EBLOCKS "AS IS" AND ANY EXPRESS OR */
/* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE   */
/* DISCLAIMED. IN NO EVENT SHALL EMBLOCKS BE LIABLE FOR ANY DIRECT, INDIRECT,   */
/* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT */
/* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,  */
/* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF    */
/* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING         */
/* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, */
/* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                           */
/* ---------------------------------------------------------------------------- */

/*------------------------------------------------------------------------------
 *      Linker script for running in internal FLASH on the STM32F401RE
 *----------------------------------------------------------------------------*/

/* Entry Point */
ENTRY(Reset_Handler)

OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
OUTPUT_ARCH(arm)
SEARCH_DIR(.)

/* Memory Spaces Definitions */
MEMORY
{
    ROM  (rx) : ORIGIN = 0x08000000, LENGTH = 512K /* 80000 */
    RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 96K
}
/* Linker script to place sections and symbol values. Should be used together
 * with other linker script that defines memory regions FLASH and RAM.
 * It references following symbols, which must be defined in code:
 *   Reset_Handler : Entry of reset handler
 * 
 * It defines following symbols, which code can use without definition:
 *   __exidx_start
 *   __exidx_end
 *   __etext
 *   __data_start__
 *   __preinit_array_start
 *   __preinit_array_end
 *   __init_array_start
 *   __init_array_end
 *   __fini_array_start
 *   __fini_array_end
 *   __data_end__
 *   __bss_start__
 *   __bss_end__
 *   __end__
 *   end
 *   __HeapLimit
 *   __StackLimit
 *   __StackTop
 *   __stack
 */


SECTIONS
{
  .isr_vector 0x08000000 :
  {
  . = ALIGN(4);
    KEEP( *(.isr_vector) ) 
    KEEP(*(.init))
    KEEP(*(.fini))
  } >ROM
  
	/* Place FirmwareData at absolute address */
	.firmware_data 0x08005000:
	{
		cpu2_FirmwareData = 0; 
		KEEP( *(.firmware_data) )
	} > ROM

	.text 0x08005100 :
	{	
		. = ALIGN(4);
		*(.text)           /* .text sections (code) */
		*(.text*)
		*(.eh_frame*)
        . = ALIGN(4); 
  
	} > ROM

/********************** Constant data into ROM memory *********************/
  .rodata :
  {
    . = ALIGN(4);
    *(.rodata)         /* .rodata sections (constants, strings, etc.) */
    *(.rodata*)        /* .rodata* sections (constants, strings, etc.) */
    . = ALIGN(4);
  } >ROM
  
	.ARM.extab :
	{
		*(.ARM.extab* .gnu.linkonce.armextab.*)
	} > ROM

	__exidx_start = .;
	.ARM.exidx :
	{
		*(.ARM.exidx* .gnu.linkonce.armexidx.*)
	} > ROM
	__exidx_end = .;

  .preinit_array     :
  {
    . = ALIGN(4);
    PROVIDE_HIDDEN( __preinit_array_start = . );
    KEEP( *(.preinit_array*) )
    PROVIDE_HIDDEN( __preinit_array_end = . );
    . = ALIGN(4);
  } >ROM
  
  .init_array :
  {
    . = ALIGN(4);
    PROVIDE_HIDDEN( __init_array_start = . );
    KEEP( *(SORT(.init_array.*)) )
    KEEP( *(.init_array*) )
    PROVIDE_HIDDEN( __init_array_end = . );
    . = ALIGN(4);
  } >ROM
  
  .fini_array :
  {
    . = ALIGN(4);
    PROVIDE_HIDDEN( __fini_array_start = . );
    KEEP( *(SORT(.fini_array.*)) )
    KEEP( *(.fini_array*) )
    PROVIDE_HIDDEN( __fini_array_end = . );
    . = ALIGN(4);
    
    __etext = .;        /* define a global symbols at end of code */
  } >ROM

 /* Used by the startup to initialize data */
 	_sidata = LOADADDR(.data);

	.data : 
	{
		. = ALIGN(4);
		__data_start__ = .;
		_sdata = .;        /* create a global symbol at data start */
    	*(.data)           /* .data sections */
		*(.data*)
		*(vtable)
		. = ALIGN(4);
		/* All data end */
		__data_end__ = .;
	} >RAM AT>ROM

	.bss :
	{
		__bss_start__ = .;
		*(.bss*)
		*(COMMON)
		__bss_end__ = .;
	} >RAM
	
	.heap :
	{
		__end__ = .;
		end = __end__;
		*(.heap*)
		__HeapLimit = .;
	} > RAM

	/* .stack_dummy section doesn't contains any symbols. It is only
	 * used for linker to calculate size of stack sections, and assign
	 * values to stack symbols later */
	.stack_dummy :
	{
		*(.stack)
	} > RAM

	/* Set stack top to end of RAM, and stack limit move down by
	 * size of stack_dummy section */
	__StackTop = ORIGIN(RAM) + LENGTH(RAM);
	__StackLimit = __StackTop - SIZEOF(.stack_dummy);
	PROVIDE(__stack = __StackTop);
	
	/* Check if data + heap + stack exceeds RAM limit */
	ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack")
}