Quality RTOS & Embedded Software

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




Loading

ARM execution from System or Supervisor mode

Posted by William Deninger on September 2, 2009
I've recently completed an ARM9 build (LH7A404) and have a question regarding the processor modes using FreeRTOS. The RTOS is configured in a FIQ preemptive mode.

Because the User and System mode share a cpsr, I find it necessary when executing FreeRTOS in the System mode to add enable_fiq's at the end of the FIQ ISR, but find it not necessary if FreeROTS is executed in the supervisor mode.

Does FreeRTOS expect (among other places within it's code) that one execute the kernel in System or Supervisor mode?

And does FreeRTOS expect all the tasks to run in System mode as opposed to User mode?

-W

RE: ARM execution from System or Supervisor mode

Posted by William Deninger on September 2, 2009
I guess to answer my own question, it appears that for the uIP Embedded WEB Server Demo, the vTaskStartScheduler is required to be run from Supervisor mode (http://www.freertos.org/portsam7xiar.html/) Lucky me. That is how I had chosen.

-W


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




Copyright (C) 2004-2010 Richard Barry. Copyright (C) 2010-2016 Real Time Engineers Ltd.
Any and all data, files, source code, html content and documentation included in the FreeRTOSTM distribution or available on this site are the exclusive property of Real Time Engineers Ltd.. See the files license.txt (included in the distribution) and this copyright notice for more information. FreeRTOSTM and FreeRTOS.orgTM are trade marks of Real Time Engineers Ltd.

Latest News:

FreeRTOS V9.0.0 is now available for download.


Free TCP/IP and file system demos for the RTOS


Sponsored Links

⇓ Now With No Code Size Limit! ⇓
⇑ Free Download Without Registering ⇑


FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

Renesas Electronics Gold Alliance RTOS Partner.jpg

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers

Atmel RTOS partner supporting ARM Cortex-M3 and AVR32 microcontrollers

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

Xilinx Microblaze and Zynq partner

Silicon Labs low power RTOS partner

Altera RTOS partner for Nios II and Cortex-A9 SoC

Freescale Alliance RTOS Member supporting ARM and ColdFire microcontrollers

Infineon ARM Cortex-M microcontrollers

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

Cypress RTOS partner supporting ARM Cortex-M3

Fujitsu RTOS partner supporting ARM Cortex-M3 and FM3

Microsemi (previously Actel) RTOS partner supporting ARM Cortex-M3

Atollic Partner

IAR Partner

Keil ARM Partner

Embedded Artists