URL:
<http://savannah.nongnu.org/bugs/?40206>
Summary: SP initialization in startup code for xmegas is
inconsistent with compiler generated initialization in function prologue
Project: AVR C Runtime Library
Submitted by: saaadhu
Submitted on: Tue 08 Oct 2013 12:24:16 PM GMT
Category: Library
Severity: 3 - Normal
Priority: 5 - Normal
Item Group: Startup code
Status: None
Percent Complete: 0%
Assigned to: None
Originator Email:
Open/Closed: Open
Discussion Lock: Any
Release: 1.8.0
Fixed Release: None
_______________________________________________________
Details:
gcrt1.S writes SPH before SPL for all devices. For xmegas, the compiler,
however, writes SPL before SPH. This is to avoid occurence of interrupts after
the writing of SPH but before the writing of SPL; the hardware disables
interrupts for four instructions after the write to SPL.
Also, things like writing to the CCP first up in main fail silently because of
the reversed order of writing to the SP (when there are less than 4
instructions separating the write to SPL and the write to CCP).
The attached patch (patch #1) makes the startup code write to SPL and then SPH
for xmegas, making it consistent with what the compiler does for function
prologues.
_______________________________________________________
File Attachments:
-------------------------------------------------------
Date: Tue 08 Oct 2013 12:24:16 PM GMT Name: fix_sp_write_xmega.patch Size:
707B By: saaadhu
<http://savannah.nongnu.org/bugs/download.php?file_id=29326>
_______________________________________________________
Reply to this item at:
<http://savannah.nongnu.org/bugs/?40206>
_______________________________________________
Message sent via/by Savannah
http://savannah.nongnu.org/
_______________________________________________
AVR-libc-dev mailing list
AVR-libc-dev@nongnu.org
https://lists.nongnu.org/mailman/listinfo/avr-libc-dev
