Hi Andreas, Le 15/05/2013 09:44, Andreas Bießmann a écrit : > Dear Maxime Ripard, > > (CCing Board Maintainer) > > On 05/14/2013 04:25 PM, Maxime Ripard wrote: >> Hi, >> >> I'm currently testing u-boot 2013.04 with SPL on a Devkit8000 with 256MB >> of RAM. >> >> Trouble is, it only detects 128MB of RAM. The x-loader found on the NAND >> detects 256MB and works perfectly with it. >> >> I obviously tried to change the mcfg field of the timings structure to >> be at MICRON_V_MCFG_165(256 << 20), however, while it obviously detects >> 256MB of RAM, it then crashes quite badly when booting to a userspace >> (and actually using that much RAM I guess). It works perfectly fine >> though with only 128MB of RAM, so I think the timings are ok. > > I guess this is linux related. We have the same problem with tricorder > board here. Please have a look at linux kernel > a/a/mach-omap2/board-devkit8000.c and check the following line: > > ---8<--- > omap_sdrc_init(mt46h32m32lf6_sdrc_params, > mt46h32m32lf6_sdrc_params); > --->8--- > > The mt64h32m32 is a 1Gb device which is 128MiB. I think is an leftover > from the very beginning of these bords in linux. Maybe in former days > the boot-loader did not initialize SDRAM correctly so it was required to > re-write the timing registers in linux. Nowadays this should be removed.
Ouch, yes, I didn't think to look in Linux to see if it was doing some timings configurations. Thanks for the pointer. Now, both by changing the mentioned line in U-boot and by removing these settings, and it seems to be working fine now. >> Any ideas on how to solve this? > > Patch u-boot to detect whether it needs to initialize 256MiB or 128MiB. > Initialize timings correctly and remove the mentioned kernel re-timing. > Patches are welcome (I havn't fixed the tricorder issue til now ... ;). I'm not familiar enough yet with this board and the OMAP so that I know how to do this right know, but I'll figure out. Thanks, Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
