Hi all. I need to have a very critical interrupt. So, i decided to use FIQ. In port.c and port macro.h (for IAR compiler) i changed calls to enable_interrupt and disable_interrupt (with calls to other similar assembler functions, which doesn’t disable FIQ flag in cpsr). I have some questions: 1. when fiq occurs, it can interrupts both application routines and RTOS critical routines. can be a problem??? (i don’t use rtos api inside fiq routine) 2. for licensing: have i to provide my changes in port with our emebedded device? i’m thinking to add in our website two links, one for freertos download page for official version, and one for a zip file which will have modified files. Is it right? Bye Piero  

> 1. when fiq occurs, it can interrupts both application routines and > RTOS critical routines. can be a problem??? (i don’t use rtos api > inside fiq routine) No problem – so long as you don’t use the API from the FIQ (as you say).  This is effectively implementing the configKERNEL_INTERRUPT_PRIORITY feature for the ARM7 -> http://www.freertos.org/a00110.html >2. for licensing: have i to provide my changes in port with our emebedded >device? i’m thinking to add in our website two links, one for freertos >download page for official version, That’s good. >and one for a zip file which will >have modified files. Is it right? This is quite a common change, which I already have on file should others want to use it, so in this case I don’t think it is necessary to have the .zip file as a download from your site.  The code is already "in the community" – but you definitely do the right thing by asking. Regards.