The first draft of the design specification for 20-bit support in mspgcc has been added to the wiki at:
https://sourceforge.net/apps/mediawiki/mspgcc/index.php?title=Gcc47:20-Bit_Design Interested parties are invited to read the document on the wiki, and comment on this mailing list. The specification focuses on the atomic capabilities which combine to form what's normally called a "memory model". They are highly orthogonal, although some combinations are likely to result in unexpected (i.e., buggy) behavior. I specifically invite comment on exactly what memory models should be supported by roll-up options that enable/disable the individual features described on that page, and what compiler option will identify them. (It'd be something like "-mmodel=large", but what exactly should "large" mean?) Preferably the naming and semantics of these models should tie back to existing practice in other MSP430 toolchains or other GCC back-ends. At this time, I believe what's described is technically possible, but the management of the namespaces, correct specification of pointer types based on code and options, and exactly how to get the linker to assign data and function objects into the split address space are yet to be implemented, and some showstopper issue might arise. (As far as I can tell nobody's ever made binutils support a split address space before. Getting 20-bit integers to work produced five bug reports against upstream gcc so far, all of which have been fixed in mspgcc with at least one already fixed upstream as well.) Peter ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Mspgcc-users mailing list Mspgcc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mspgcc-users
