Quality RTOS & Embedded Software

 Real time embedded FreeRTOS RSS feed 
Quick Start Supported MCUs PDF Books Trace Tools Ecosystem TCP & FAT




Loading

commit id 1825: Heap_x functions

Posted by Friedrich Lobenstock on February 15, 2013
commit id 1825: Heap_x functions now automatically align the start
of the heap without using the portDOUBLE union member.



/* A few bytes might be lost to byte aligning the heap start address. */
#define configADJUSTED_HEAP_SIZE( configTOTAL_HEAP_SIZE - portBYTE_ALIGNMENT )


Can't we taken into account if the heap was already aligned before
instead of always sacrificing portBYTE_ALIGNMENT bytes?

Couldn't this be accomplished by updating e.g. xFreeBytesRemaining
in prvHeapInit() accordingly?

Just my 2 euro cents.

Regards
Friedl

RE: commit id 1825: Heap_x functions

Posted by Richard on February 17, 2013
I answered this some time ago, but it seems my reply has not turned up in the forum. The reply went something like this:

The first time I implemented the change I did something like:

if( heap already aligned then )
{
basically do nothing
}
else
{
align
}

but that required (in some of the heap_x implementations) a new variable because the adjusted heap size became variable rather than constant. Therefore the RAM saving was halved, so with that in mind, plus the fact the solution was ugly (coding standard required a *lot* of casting to an from pointers), I decided just to go for the simplest solution.

Regards.


[ Back to the top ]    [ About FreeRTOS ]    [ Sitemap ]    [ ]




Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.

Latest News

FreeRTOS kernel V10 is available for immediate download. Now MIT licensed.


FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

IAR Partner

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers

STMicro RTOS partner supporting ARM7, ARM Cortex-M3, ARM Cortex-M4 and ARM Cortex-M0

Texas Instruments MCU Developer Network RTOS partner for ARM and MSP430 microcontrollers

OpenRTOS and SafeRTOS