FreeRTOS Support Archive
The FreeRTOS support forum is used to obtain active support directly from Real
Time Engineers Ltd. In return for using our top quality software and services for
free, we request you play fair and do your bit to help others too! Sign up
to receive notifications of new support topics then help where you can.
This is a read only archive of threads posted to the FreeRTOS support forum.
The archive is updated every week, so will not always contain the very latest posts.
Use these archive pages to search previous posts. Use the Live FreeRTOS Forum
link to reply to a post, or start a new support thread.
[FreeRTOS Home] [Live FreeRTOS Forum] [FAQ] [Archive Top] [July 2005 Threads] Bug in MPLAB C18 portPosted by Dewey on July 28, 2005 Hi,
I have discovered a bug in the MPLAB C18 port that affects things stored in program memory (using the rom qualifier). Things stored in program memory require table operations to retrieve, which makes use of the 21 bit TBLPTR register (which uses 24 bits). Unfortunately, the C18 compiler generated assembly only sets bits 0-16 of the TBLPTR register anytime it needs to set up an address to access program memory. The port.c file sets TBLPTRU to 0x77 when initializing the task context. When that value is restored to the 17-24 bits of TBLPTR, it never gets overwritten by compiler generated code, thus, all program memory operations do not behave correctly. The fix is to set the TBLPTRU to 0x00 when initializing the task context in the pxPortInitialiseStack function of port.c.
RE: Bug in MPLAB C18 portPosted by Richard on July 28, 2005 Good info - thanks. I will add this to the 'known issues' list on the downloads page.
Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.
|