>Von: "Matthias Welwarsky" <[email protected]> >An: [email protected] >Cc: "Xen Mann" <[email protected]> >Betreff: Re: [OpenOCD-devel] adding new interface(TAP): need to shift 36 bit >to read 8 bit, how to handle Buffer? > >On Montag, 21. Januar 2019 16:36:10 CET Xen Mann wrote: >> I' m implementing a new TAP-Interface. >> The dr-regiter of the TAP is 36bit wide. >> [35:32] status/opcode etc >> [31:0] data (32/16/8 bit) >> >> The read/write wrapper for the target has a buffer which has only the length >> for the exact number of bytes. target_type.read_memory() / ... > >Hm. If you're implementing a new TAP interface, why do you bother with >target_type? Just curious ... > >BR, >Matthias
Hey Matthias, to add a new interface for OpenOCD I used the arm7_9 files as a sample. This and all other implementations of interfaces are based on the structure "struct target_type". So to make this interface usable at least a minimal subset of those have to be implemented. To archive JTAG-Transactions I need functions provided in <jtag/jtag.h>. So those both are my entry and exit points into openOCD when implementing a new TAP-Interace. This is my innocent point of view, which took me some time to figure out.^^ But if there is an other possibilety to design a new interface, please let me know =). As I've said, I'm new to open source projects and such huge codebases. Does this answer your question? The idea was that ARM uses in it's arm7/9 implementatiion a 32 bit dr-register and sends it output dirctly to the provided buffer from the upper level functions if I'm correct. This does not work for me, because I clock out 36 bit. So thats why I ask if there's a solution out there without allocating additional memory. Something like an intermediate step done on the fly. Greatings Xense =) _______________________________________________ OpenOCD-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/openocd-devel
