On Tue, Oct 02, 2012 at 08:36:41PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote: > On 18:50 Tue 02 Oct , Sascha Hauer wrote: > > On Tue, Oct 02, 2012 at 04:30:11PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote: > > > On 15:06 Tue 02 Oct , Sascha Hauer wrote: > > > > Here are two updates for the MMU code in the decompressor. The first > > > > one may come in handy when a JTAG debugger is connected. The second > > > > one is more important. It actually makes turning on the MMU in the > > > > decompressor useful by making map_cachable work. It turned out that > > > > this didn't work leaving the whole mapping uncached. > > > > Note that the code in current master should work, but slow. Since > > > > it actually does work I do not want to put this into the upcoming > > > > release. > > > As I report the current code does not work on at91sam9g45 > > > I suspect as we boot from the second ram controler on this SoC > > > > > > So please hold the release that I can try those patch on sam9g45 if they fix > > > the PBL they will be mandatory for it > > > > I think they won't fix it. map_cachable currently is a noop, but this > > should be fine as now we have a complete 1:1 uncached mapping. I don't > > see why this shouldn't work. I hope you find out. > > > > What we can do for now is to add an additional Kconfig option to make > > enabling the MMU in the pbl optional. Then at least it should work on > > your boards. > Was thinking about this too Ok, I'll prepare a patch. > > > > BTW I hunted down a strange problem with the MMU on a KaRO Tx53 board. > > It turned out that the image header (which basically is a poke table > > to initialize the SDRAM) indeed initialized the SDRAM. The problem was > > that this SDRAM setup depends on some other lowlevel setup which is done > > later. The SDRAM setup was good enough to load with MMU disabled, but > > once the MMU is enabled the SDRAM does burst accesses and the board goes > > to nirvana. > > Maybe your problem is related somehow. > yeah It may solve my issue with the MMU and nand boot > > I was thinking to add a initcall support to the pbl and enable the MMU at the > right momment. This will allow to simplify the adding of generic SPL framework I don't think this is a good idea. I don't want to grow a second bootloader in the pbl. It should stay simple. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
