view Small_CPU/CPU2-RTE.ld @ 238:a9d798e8c11f div-fixes-5

cleanup, bugfix: do not mask I2C_SystemStatus with local variable This commit is partly cleanup, and partly possible bugfix. Masking the global I2C_SystemStatus with a local variable is (very) bad practice, but more importantly, dangerous, as other code uses this I2C_SystemStatus to base decisions on. So, this is definitely non-trivial, as it can possibly change the flow of control. This said, its tested and seems to have no negative effects (but also no positive, as I sort of hoped for), so that is why I mark it cleanup as well. Constructs like this shall be heavily documented in the code, when there is a reason to do things like this. Further, remove a 2nd rather useless construct. There is no reason to & 0x03 the output of I2C_SystemStatus. This is the only location in the entire code base where this is done, so, its not only useless but also inconsistent and confusing the true intentions here. Finally, littered to code with todo's that I will take care of in next commits. Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
author Jan Mulder <jlmulder@xs4all.nl>
date Mon, 08 Apr 2019 10:16:17 +0200
parents 321df89d5710
children aa286a4926c2
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/* ---------------------------------------------------------------------------- */
/*                  Em::Blocks embedded development Support                     */
/* ---------------------------------------------------------------------------- */
/* Copyright (c) 2014, EmBlocks                                                 */
/*                                                                              */
/* All rights reserved.                                                         */
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/* Redistribution and use in source and binary forms, with or without           */
/* modification, are permitted provided that the following condition is met:    */
/*                                                                              */
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/* this list of conditions and the disclaimer below.                            */
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/* this software without specific prior written permission.                     */
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/* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */
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/* DISCLAIMED. IN NO EVENT SHALL EMBLOCKS BE LIABLE FOR ANY DIRECT, INDIRECT,   */
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/* 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")
}