Hi, I am not sure to understand fully myself. GPIO IO registers (set reset read) in the recent documentation are also given in the 0x7E2xxx range and not in the 0x20... range. For some reason something (MMU?) remap 7E range to 20 range. I was not yet able to find low level booting code of rapsberry pi, there is probably something in the boot sequence code that define physical to logical addressing. To resume in official documentation GPIO is advertized in 0x7E2nnnnn range this GPIO level output in 0x7E1nnnnn range All code I have seen address GPIO at 0x202nnnnn So something do remap 7E to 20
Cheers On 09/23/2013 01:24 PM, Paul Fertser wrote: > Hi, > > On Mon, Sep 23, 2013 at 01:08:07PM +0200, Nicolas Produit wrote: >> your new code does not make mmap error anymore. >> But it is not correct, from documentation: >> Physical addresses range from 0x20000000 to 0x20FFFFFF for peripherals. >> The bus addresses for peripherals are set up to map onto the peripheral >> bus address range starting at 0x7E000000. > > What exactly does this mean? Those 3 registers, where exactly are they > mapped to? I'm using 0x20000000 for GPIO, and it's doesn't seem to be > mapped anywhere, just the address on the main (and only) address bus, > both in mmap and in the docs I've read. > >> Thus a peripheral advertised here at bus address 0x7Ennnnnn is >> available at physical address 0x20nnnnnn. > > What does 0x7Exxx address mean then? When I was using BCM2835 pdf > partial datasheet all the addresses there were straight, I can't see > where this dichotomy you describe comes from. > > Thanks for your patience. > -- Nicolas Produit ISDC, Data Centre for Astrophysics Phone:+41 22 379 2140 16, Chemin d'Ecogia Fax: +41 22 379 2133 CH-1290 Versoix www: http://isdc.unige.ch/~produit ------------------------------------------------------------------------------ LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13. http://pubads.g.doubleclick.net/gampad/clk?id=58041151&iu=/4140/ostg.clktrk _______________________________________________ OpenOCD-devel mailing list OpenOCD-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openocd-devel
